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Ministry of high Education and Scientific Research Foundation of Technical Education

Institute of Medical Technology / Al-Mansour.

Training package in Theoretical lecture

Histology and anatomy

For

Students of first class Pathology analysis Medical laboratory quality control

By

Enaam Aziz Jasim Asistant lecturer , abdul karim Asistant lecturer and Mohammed khamas lecturer Dep.Pathology analysis Medical laboratory Techniques and Quality

control Jun.2010

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a –Target population -:

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For students of first class Institute of medical technology department of pathology analysis medical laboratory Techniques and quality control.

b –RationaleHistology is very important subject to be studied in order to have a full knowledge about meaning thereby the study of tissues .It is study of the fundamental tissues of the body, I have designed this modular unit for this knowledge to be understood . c – Central idea

general purpose :- To know the general anatomy of human body to see instrument, organs

systems and studying all histological tissue under the microscope. Special purpose:-

Of graduate technician while able to know the structure, morphology as situation of every organ from all organs of the body.

In this case the graduate technician could know the skull when they taken the specimen from all organ of the body.

To differentiate between the different tissue of the body and know the microscope structure for helping the student to studying the all abnormal tissue incase of disease.

d –Instructions:- 1. Study over view thoroughly.

2. Identify the goal of this modular unit. 3. Do the pre test and if you:-

a- get true answers not need to proceed. b- get false answers you have to study this modular unit well . 4. After studying the text of this modular unit, do the post test, and if you:-

a- get true answers, so go on studying modular unit three. b- get false answers , go back and study the second modular unit ; or

any part of it ; again and then do the post test again .

weeksTheoretical lecturePage.No

1Microscope7

2Shape of cell11

4

3Epithelial tissue – simple epith. T.18

4Epithelial tissue – stratified epith. T.24

5Epithelial tissue – stratified epith. T.24

6Connective tissue – loose co. T.30

7Connective tissue – dense co. T.34

8Connective tissue – the blood37

9Connective tissue – cartilage44

10Connective tissue – compact bone48

11Connective tissue – spongy bone48

12Muscular tissue (cardiac muscle, skeletal muscle, smooth muscle )

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13+14Examination for mid year

15+16Holiday for mid year

17External feature of frog digestive system

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18Urino genital system of male&female frog

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19Types of papillae62

20liver66

21spleen67

22Lymph node69

23Circulatory system (Artery)72

24Circulatory system (Vein)74

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25Nervous system77

26Hairy skin82

27Examination for second term

28Non hairy skin82

29kidney87

30Examination of final theoretical lecture

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1

RationaleMicroscope is very important instrument which is used for examination of fine structure of objects . to be studied in order to have a full knowledge about it and how to use it.

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Pre text Define the microscope.

Note Check your answers in key answer page 90.

The text

MicroscopeThe microscope is an instrument which is used for examination of fine structure of objects .

Micro = small

Scope = to view

It enlarges of the images of the objects which then can be seen by the eye .

Types :

Simple microscope : It is made of single or combination of lenses which act as single position convex lens .

Compound microscope : Itś made up of 2 lenses which are fitted in a brass tube , one of the tubes can be slided into the other so that the distance between lenses can be changed and adjusted.

Parts of microscope 1. Stand : consist of base & arm2. Body tube3. Focussing adjustment : coarse & fine adjustment which moves the

tube or stage depending upon the make of microscope .4. Nose piese – Where the objective is fitted .5. Stage- where slide is kept with the help of clips, stage may be

stationary or movable .6. Substage- where lighting arrangement is fitted.

Some generl pointes :

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1. It is not always necessary to use high power/ oil immersion.2. Try to focus with the smallest magnification scaning objective

(4x) first 3. Oil immersion lens is to be use for cytological study.4. Make sure the cover slip is clean .

Use and care1.Take care of cleanliness and safety of microslides .2. Microscope is sensitive instrument , try not to make it dirtry , avoid dust and moisture .3. After every use of immersion oil , clean the lens with xylene or pure petrol with lens paper .4. Avoid putting oil on other objectives .

Post text List the types of microscope List the parts of microscope

Note

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Check your answers in key answer page 90 .

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2RationaleShapes of cell is very important object to be studied in order to have a full knowledge about shapes of different cells under microscope.Pre text

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Define the cell. List animal cell organelles.

Note Check your answers in key answer page 90 .

The text

Shapes of cell

Introduction and the cell

Histology :

Histology meaning the study of the tissue, itś the study of the fundamental tissues of the body.The term histology is derived from two Greek words:

Histos = Tissue

Logos = Science

Tissue word was introduced by Bichat in the late 18th century .

Micro-anatomy :

Is the study of minute structure of tissue in different regions .The term Histology & Microantomy are symbolically different , Histology deals with the study of minute structure of tissue in general whereas the micro-anatomy deals with the fine structure of all the tissue present in particular organ. Histology also be differentiated from cytology , Cytology deals with the detailed study of individual cell and it is internal components .

Cell :

Cell is the unit of structure and function in animals and plants. It was first named as cell by Robert Hooke in 1665 after texture of cork , the cell is a membrane bound unit containing discreet organelles , protoplasm and nucleus

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, the organelles are organized forms of biological molecules which play an important role in the function of cell , example Mitochondria for providing energy , endoplasmic reticulum for producing secretions like enzymes and hormones .

Cell membrane :Each cell is limited by semi-permeable membrane called cell membrane (plasmalemma) in which cell protoplasm is limited, cell membrane is made of double layers of phospholipids and protein molecules .

Function of cell membrane :

1. Itś giving cell shape .2. Diffusion inside and outside the cell .3. Generate bioelectrical potential.4. They are sites for intracellular granules .5. They are sites for intercellular contacts.

Animal cell organelles :1. Mitochondria .2. Endoplasmic reticulum .3. Ribosomes : are the sites of protein synthesis .4. Golgi apparatus (dictyosome) .5. Lysosome.6. Microtubles and filaments.7. Centrioles.8. Nucleus.

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Animal cell

Nucleus:

Its, a spherical shape or oval membrane –bound body, 4-10μm in diameter, nuclear envelope is flattened sac , nucleus is bounded by two layers, the outer membrane is apart of endoplasmic reticulum, nucleus contain:

1. Chromatin net work

2. Nucleoli

3. Some intranuclear vesicles , crystals and filaments are present.

Function of nucleus

1. Protein synthesis.2. Cell division .3. Cell motility .

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Post text answer the following by true or false

1. The example of spherical shape of cell is blood frog.2. Polyhedral shape having basal nucleus.

Write the functions of the nucleus

Note Check your answers in key answer page 90 .

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3

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RationaleEpithelial tissue- simple epith. T.is very important object to be studied in order to have a full knowledge about epithelial tissue under microscope.

Pre text Define the tissue. Define epithelial tissue.

Note Check your answers in key answer page 91.

The text

Epithelial tissue- simple epith. T.

Primary tissue of the body

Tissue: Is a group of similar cells specialised in common direction and set apart for performance of a common function .

Classification of tissue :

Tissues are classified into four primary tissues according to structure and function :

1.Epithelial tissue

It is a layer or layers of cells which cover the body surface, and line the body tubes and membranes, they also form gland.

2. Connective tissue

It has supportive and connective function .

3. Muscular tissue

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It is specialized for producing movement because it posses the property of contraction .

4. Nervous tissue

It is specialized for conduction, integration and relay of impulses .

Epithelial tissue

It is a cellular layer which lines the body surface , skin , mucous membranes and glands. Cells may be arranged in a single or multiple layers, the cells rest on abasement membrane which is made of non-cellular amorphous substances mainly mucopolysaccharides.

Classification of epithelium:On the basis of arrangement of cell layers:

1.Simple: one cell thick layer.

2.Stratified: more than one cell thick layers.

3.Pseudostratified: one cell thick layer but the height of cells varies so as to give a false appearance of multiple layers, because the nuclei are seen in more than one row.

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See pic.1

Pic.1 simple columnar epithelium tissue

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Post text Classify the epithelium tissue.

Note Check your answers in key answer page 91 .

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4+5

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RationaleEpithelial tissue- stratified epith. T. is important object to be studied in order to have a full knowledge about the different between simple and stratified epith. T. under microscope.

Pre text

List the types of stratified squamous epithelium.

Note

Check your answers in key answer page 91.

The text

Epithelium tissue- Stratified epithelium tissue

1. Stratified squamous epithelium :

It consists of several layers of cells, the deepest layer consist of columnar cells arranged on basement membrane, middle layer or layers contain polyhedral cells and superficial are squamous cells (flattened cells). This tissue is specialized for resistance friction.There are 2 types of stratified squamous epithelium :

a. Kertinized :

As in epidermis (palm of hand) , where the superficial squamous cells are hardened due to a protein keratin pic. 2.

Pic.2.Human skin(Kertinized)

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b.Non-keratinised :

Pic.3 Skin frog (Non-keratinised)

Example : cornea, oesophagus,skin frog pic.3.

2. Sratified columnar and cuboidal epithelium:

It consists of fusiform cells as in the membranous urethra, stratified cuboidal epithelium found in the ducts of salivary glands & pancreatic duct.

3- Pseudostratified epithelium:

Asingle layer of cells set on a basement membrane but the height of the cells varies; all cells donť reach the surface, the nuclei too are present at different levels pic.4.

Example : lining of epithelium of nasal cavity .

Pic.4 psudostratified epithelium tissue

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4- Transitional epithelium :

Itś appearance varies with the state of distension or contraction of the wall , itś characteristic of urinary bladder and part of urethra.

In the relaxd condition it has 5 to 6 layers , the basal cells are polyhedral, the middle ones are pear shaped with their conical ends touching the basement membrane cells, the superficial cells are dome shaped (umbrella) with the basal surface touching the rounded end of pear shaped cells of second layer.

In distended condition the cells of superficial layer get more flattened & those of middle layers get sandwiched between deeper cells pic.5.

Pic.5 Transitional epithelium

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Transitional epithelium

Function of epithelial tissue :

1.Selective diffution. 2.Protection . 3. Transport : mucous & particulate material is transported along the

epithelial surface. 4. Secretion : in glandular epithelium. 5. Excretion : urine, sweat & co2 are diffused across the epithelial

surfaces, they filter from blood the waste product of metabolism. 6. Absorption : as in intestinal epithelium. 7, Sensory reception : some epithelium cells are specialized for

impulse transmission , e.g: taste bud. 8. Lubrication : mucous secreted by epithelial cells act as lubricant.

9.Transitional epithelium has two important functions, itś capable of distension and provide a waterproof surface impermeable to urine .

Post text Draw and label transitional epithelium.

Note Check your answers in key answer page 91.

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6+7+8

Rationale

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Loose connective tissue is very important object to be studied in order to have a full knowledge about the mesh work of collagen and elastic fibers interlacing in all directions, and all types of connective tissue cells under microscope.Connective tissue- dense co.t. is important object to be studied components of connective tissue and to know the different between loose and dense connective tissue under microscope.

Pre text a. answer the following by true or false

Loose connective tissue contains of mesh work of collagen and elastic fibers interlacing in one directions.

Adipose tissue consists of fat cells embedded in areolar tissue . Loose connective tissue contains all types of connective tissue cells.

b. List the connective tissue cells. c. Write the types of blood cells

Note Check your answers in key answer page 92.

The text

Loose connective tissue

Loose areolar tissue :

Itś extensively distributed in the body, itś chief function is to bind the parts together and at the same time to permit free movements between them. It occurs as subcutaneous tissue, submucous coats of digestive tube and between the muscles, nerves and vessels.

It contains loose mesh work of collagen and elastic fibers interlacing in all directions, with large meshes containing semi fluid matrix, it contains all types of connective tissue cells except reticular cells pic.6.

Example : under the skin

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Pic.6 Loose areolar connective tissue

( contain all types of connective tissue cells)

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C. Dense irregular connective tissue :

Fibroblasts, macrophages, and other cells of connective tissue are present, collagen fiber, elastic fiber and reticular fiber are present.

Example : dermis of skin.

Adipose tissue :

Consists of fat cells embedded in areolar tissue pic.7 . It serves as a store of fat and also mechanical cushion, conserve body heat.

Pic.7 adipose tissue

Example : tongue

Reticular tissue :

Itś composed of reticular fibers and reticular cells, the ground substance may be fluid. It forms the internal network of many organs like lymph nodes, spleen, liver……..etc pic.8.

Pic.8 reticular connective tissue

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Function of connective tissue :

1. Protect and support other cells by forming capsule.2. They protect the tissue against foreign invasion.3. They carry blood to the cells.4. The ground substance prevents spread harmful substances during

inflammation.

Epithelial tissue Connective tissue

1.Cover and line the body tubes.

2. Epithelial cells attach on basement membrane.

3. Classify according to arrangement of cell layers or shape of cell.

4. No fibers .

5. Free of nerves and blood vessels.

6. Haven`t or few intercellular spaces.

1. Binds and support tissues.

2. not attach.

3. Classify according to ground substance and type of fibers.

4.Posses 3 types of fibers.

5. Have nerves and blood vessels.

6. Intercellular spaces are present.

Connective tissue - dense co. t.Connective tissue binds & supports the other functionally active tissue, itś responsible for mechanical support and defence (phagocytic and immunological function) mechanism.

Itś derived from embryonic mesoderm or mesenchyme which provide different connective tissue cells embedded in their matrix.

Components of connective tissue:

A- cells : there are many types:1. Fibroblasts and fibrocytes2. Macrophages3. Mast cells

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4. Plasma cells5. Fat cells 6. Pigment cells7. Reticular cells

B- Matrix : it consists of :

a.Collagen fibers.

b. Elastic fibers

c.Reticular fibers

Connective tissue cells :1. Fibrobalsts:

They are irregular, flattened cells with numerous branching processes, fibroblast are the stem cells of fibers , the mature (old) fibroblast are called fibrocyte.

2. Macrophages (histiocytes) : They are present in small groups or singly, they are capable of amoeboid movements , are large irregular cells with branched processes, they are phagocytic in action and have lysosome bodies in the cytoplasm for hydrolysis of the ingested particles, macrophages are involved in immunological defence mechanism .

3. Plasma cells:They are modified large lymphocytes, commonly present in submucous and mucous coats of gut. They are round or oval cells having a granular cytoplasm with eccentric nucleus, plasma cells are concerned with the production of antibodies and are modified B lymphocytes.

4. Mast cells :Found in loose connective tissue and around blood vessels. They are oval or round cells with small central nucleus, cytoplasm is metachromatic and has numerous large closely packed granules, they are produce : a- heparin ; b- histamine ; c- serotonin .

And are concerned with anticoagulant property of blood & defence against foreign allergens and toxin.

5. Fat cells :They are oval, spherical or some times polygonal , almost whole cell is occupied by a fat globule moving the cytoplasm to the

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periphery with eccentric flattened nucleus giving a single ring appearance, they are meant for fat storage.

6. Pigment cells (chromatophores) : Found in dermis of skin iris and choroids of eye. They are stellate cells with long processes and numerous brown to black melanin granules in the cytoplasm.

7. Reticular cells :They occur in the reticular tissue amongst the reticular mesh-work , they are like fibroblasts and form reticulum fibers.

Ground substance : Amorphous substance, occupying space between cells and fibers,it contains mucopolysaccharides, glycoproteins, electrolytes and water. The mucopolysaccharides are sulphated (chondroitin sulphate) or non-sulphated

( chcondroitin and hyaluoronic acid).

Function of ground substance :1. It protects and binds the connective tissue element.2. Provide medium for movement of cells and diffusion of

metabolites .

Classification of connective tissue :1. Embryonic connective tissue

a.Mesenchymeb. Mucoid connective tissue, as in umbilical cord.

2. Regular or ordinary connective tissue a. Loose connective Tissue or aereolar tissue.

b. Dense connective tissue : I. Regularly arranged as tendons, ligments.

II. irregularly arranged as dermis, perichondrium. c. Reticular tissue d. Adipose tissue g. Pigment tissue 3. Special connective tissue a. Bone

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blood smear

Post text Write the functions of the connective tissue. Write the matrix component. Write the types of blood cells.Note

Check your answers in key answer page 92.

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Rationalecartilage is very important object to be studied in order to have a full knowledge about the special type of adult connective tissue and how to classify cartilage according to the nature of fibers.

Pre text Define the cartilage.

Note Check your answers in key answer page 93 .

The text cartilage

Itś special type of adult connective tissue, like all other connective tissues, it has cells and matrix ( matrix is solid and elastic), matrix containing fibers and ground substance.

Cartilage is non vascular and forms the supporting frame of certain organs( articulating surfaces and greater part of fetal skeleton), although most of that will be replaced by bone.

Cartilage cells:

Cartilage cells or called chondrocytes are large cells contained in the spaces in the matrix called lacunae, the walls of lacunae are thickened to form the capsule. Younger cells are called chondroblasts which rapidly divide to form mature chondrocytes.

In single lacunae usually two cells are present, with large clear nucleus and two or more nucleoli , the multiple cells in lacuna are infact the daughter cells of single parent(ابوي) chondroblast.

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Classification of cartilage:

The cartilage classify according to the nature of fibers to:

1. Hyaline cartilage

The ward hyaline means glass like, itś bluish white in colour and translucent in fresh condition, the chondrocytes are situated in smooth walled lacunae in the matrix, they are large cells with large spherical nuclei having one or more nucleoli. The multinucleated cells may be seen, in the living the cells completely fill their lacuna, but in acid fixed preparation they shrink and become separated by space from lacunar wall. Matrix is occupy by anetwork of collagen fibrils which are not visible and responsible of hyaline appearance, except for articular cartilage, all types of hyaline cartilages are surrounded by perichondrium. Hyaline cartilage found in cartilage of nose, trachea, ….etc.

Function of hyaline cartilage

1. Provides supports by itś resilience and rigidity.2. Withstand compression in joints.3. Allows frictionless movement.

2. Fibro-cartilage

Itś found in few places, example Eustachian tube, intervertebral discs……etc. It differ from hyaline cartilage and elastic cartilage, it has no

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perichondrium, chondrocytes are smaller and arranged in longitudinal rows, matrix contain large number of thick type I collagen fiber bundles between rows of chondrocytes .

Function of fibro-cartilage:

Fibro-cartilage play an important role against external forces.

3. Elastic cartilage

This type possesses perichondrium, cells are similar to hyaline cartilage, matrix contain dark elastic fibers in addition to collagen fibers, example : external ear, epiglottis…..etc. Elastic cartilage is specialized for flexibility.

Post text Write the Function of hyaline cartilage

Note Check your answers in key answer page 93 .

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10+11

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RationaleBone is very important object to be studied in order to have a full knowledge about bone develops. Pre text

Define the bone.

Note Check your answers in key answer page 93 .

The textBONE

Bone is a special type of connective tissue. It is complex tissue, composed of:

1. Cells 2. Matrix:- a. Fiber b.Ground substance containing of minerals salts.

Bone develops either by the-: 1 .Direct transformation of mesenchyme (membrane bone).

2 .Indirect where in first stage mesenchyme from cartilage model which later on is transformed into bone.

Types of bone -:

Examination of bone in cross section shows two types-:

1 .Compact bone.2 .Spongy bone (cancellous bone) or (trabecular bone).

COMPACT BONEThis type of bone placed outward, is dense.In it solid matter is abundant and spaces smaller.

SPONGY BONE

This type is placed inward, consist of mesh work of trabeculae with action spaces(canaliculi).

Differences between the types of bones are the amount of solid matter, size and number of spaces in each-:

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Spongy boneCompact bone

1-Solid matter is little and spaces larger than compact.

2-This type placed inward.

1-Solid matter is aboundant and spaces are smaller.

2-This type placed outward.

The bone is lined by-:

1.Periosteum.

2.Endosteum.

Periosteum consist of-:

1.White fibrous tissue.

2.Elastic fibrous.

3.Soft osteogenic tissue.

Endosteom :- is mean bone cavity filled with bone marrow , this cavity lined by vascular areolar tissue.

Bone tissue:-

Compact bone consist of a number of irregular cylinderical units called (Haversian system) or secondary osteons , each system consist of (lamella) of bone tissue surrounding of central (Haversian canal) , spaces between lamella are called (lacunae) which are connected with each other and with central haversian canal by fine radiating canals called (canaliculi).

Lacunai contain bone cells or osteocytes and the canaliculi contain their process.The (interstitial lamellae)lie in the interval between secondary osteons.Lamella are thin plates of bone tissue.

Haversian canals-:

In transverse section haversain canal appear round or oval shape.Each canal contain artery , vein and some loose areolar tissue.

Haversain canals connect with medullary cavity by Volkman`s canal and also with surface of the bone

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Each lamella consist of matrix which comprises of ground substance and fibers.Lamella also have (lacunae) containing osteocytes arranged in aring formalong them.

Many lamella are concetrically aranged around a Haversian canal forming a Haversian system or secondary osteon which is a cylindrical pieces of bone tissue.

Bone cells :-

1-Osteoblasts :- these are the bone forming cells (osteogenic). These are cuboidal or trapezoid in shape with the nuclei lyning at one or the other. They have many processes. The cytoplasm is rich with RNA.

2-Osteocytes :- they flattened , ovoid shaped lying in the lacunae and each consists of darkly staining nucleus with small amount of cytoplasm and numerous branching processes. The processes of an osteocytes joined with the other osteocyte (adjacent cells) , there function generater osteoblasts when the bone has been laid down.

3-Osteoclasts :- these are large cells found on the surface bone where resorption are takin place. They are multinucleated with a vacuolated cytoplasm. They have important role in remodeling of bone.

BONE MARROWIt is present in the cavity of compact and spongy bone , consist of reticular connective tissue , fibers ,RBC , fat cells and blood vessels and reticular cells.

They are two types of bone marrow-:

1 .Red bone marrow.

2.Yellow bone marrow.

The reticular cells connected with capillary blood vessels by reticular fibers and formed blood

1.RBC.

2.WBC.

3.Megakarycytes(large cells formed from process of platlet cytoplasm).

Red bone marrow produce blood cells , but yellow bone marrow cannot, the cytoplasm of reticular cells filled with fat droplet. The yellow color is due to lipocrom stain which found inside.

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Bone function :-

1. Support other organs.2. Protection.3. Mineral storage and haemopoises.Matrix :-

Matrix contain water , organic matter and inorganic matter. The main organic component is collagen

(90%-95%), collagen fibers also in the matrix.The bone salt includes the ion of calcium , chloride , fluoride , magnesium phosphates.The lacunae are situated in matrix along the margin of lamella and contain bone cells.

Post text List the types of bone cells

Note Check your answers in key answer page 93 .

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RationaleMuscular Tissue is very important object to be studied in order to have a full knowledge about the fiber with property of contractility.

Pre text Write function of Muscular Cells .

Note Check your answers in key answer page 93,94.

The textMuscular Tissue

Muscular tissue is composed of fiber with property of contractility All muscle tissue is composed the group muscle fiber held together and surrounded by C.T. sheath called Epimysium. A number of muscles fibers constitute as muscle bundle which surrounded by a C.T. sheath called Perimysium. Individual fibers are unsheathed in fibrous, sheath called endomysium. Connective tissue frame work of muscle consist mainly:

Function of Muscular Cells : 1. Protection of bone 2. Permits independent movement of muscular bundle and individual

fibers .3. Helps in transmission of force of contraction of muscle .

Classification of muscles

1. Voluntary skeletal muscle or striped. 2. In voluntary smooth muscle or un striped .3. Cardiac muscle striped in voluntary . ex: Heart .

1. Skeletal Muscle ( striped ) : Muscle cell (fiber). Muscle cell is an elongated structure, it is multinucleated Cell, surrounded by plasma membrane called (Sarcolemma).Cytoplasm called ( Saecoplasm ) containing myofibrilis , sarcoplasm also contain glycogen and globules. Some time branch e.g. in tongue . The myofibrils appear fine

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longitudinal section and transverse section of alternating dark bands and light bands . Hundreds of nuclei which is lie in sarcolemma.

2. Smooth Muscle : 1. Unstriped or plain or involuntary muscle, found in the wall of the

hollow viscera , walls of ducts , urinary bladder . 2. Smooth muscle cell is uninuclear & elongated spindle shaped cell

collected into bundles and held together by areolar C.T.3. Nucleus is oval shaped, centric lies along the fiber.4. Cell wall is elastic surrounded the cell called sarcolemma . 5. Cytoplasm of living all appears homogenous, myofibrils (fine

longitudinal section) embedded in the cytoplasm.6. Also the cytoplasm contains mitochondria, golgi bodies and

ribosome`s.

3. Involuntary striped cardiac muscle : Striped muscle structure, develops from mesoderm of pericardium. Special characteristic is rhythmic activity. It occurs only in heart and in great vessels entering the heart. The cell fibers are parallel to each other. Each cell contains single or two oval nuclei. Myofibrils are embedded in the sarcoplasm and appear fine

longitudinal and transverse striped of alternating dark bands and light bands. Numerous complex mitochondria arranged between the myofibrils. Heart muscles are branched. Muscles fiber appear to be united having a cytoplasmic continuity

with each other, these fibers are separated from each other by intercellular contracts called inter calated disk.

Inter calated disk:

Junction between the cardiac muscles cells are marked by cytoplasm transverse bands called intercalated disk. The function on intercalated disk transmit the impulse from one cell to the other.

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Smooth Muscle Tissue Skeletal Muscle Tissue Cardiac Muscle Tissue

Compare between Skeletal m. and cardiac m.

Skeletal Muscle Cardiac Muscle

Nucleus at side. Nucleus at center.

Myofibrils is found. Myofibrils is Also.

No-branched. Branched.

Thick Sarcolemma. Thin.

Striped.Also.

Voluntary. Non-Voluntary.

No-intercalated disk. Yes – present .

In tongue. In Heart .

Post text Write the Compare between Skeletal m. and cardiac m. Note Check your answers in key answer page 93,94.

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17+18

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RationaleThe anatomy of frog is very similar to anatomy of man. Both man and the frog have the same kinds of organs and system of organs.The frog`s anatomy is however is much simpler.

Pre text

Write the external feature of the frog.

Note Check your answers in key answer page 94 .

The textExternal feature of frog digestive system

The external feature :-

General body color adaptive coloration , absence of neck and tail , longer hind than for limbs , eyes are bluing , buccal cavity , to distinguish the sexes by the color of dorsal surface being black in the male , which in the female , body surface roughened presence of small warts . The skin also sticks due to the presence of mucous secretion which keeps the body moist.

The head :-

Which is triangular , it is dorsa-ventrally compressed , the external nares which are two small opening , lying near the anterior tip of the head , the eyes are guarded each semi-transparent movable lower eyelid , the ear drum is more or less circular area found posterior to each eye.

The trunk :-

The trunk is compact and divided in to thorax and abdomen.The limbs are two pairs :1. The fore limbs hands has four digits with horny pads on ventral surface.2. The hind limbs consist of femur , crus and pes , the pes with six digits connected together by web, pic.14.

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Pic.14 parts of the frog

Anatomy of FrogThe anatomy of frog is very similar to anatomy of man. Both man and the frog have the same kinds of organs and system of organs. The frog`s anatomy is however is much simpler.The urogenital system of the frog consist of organs that function are reproduction and excretion.You will need to look at other frog groups in order to complete the dissection.Check the box when you have located the structure. The description of their location and appearance will help you lable the diagram.Frog digestive system The digestive system beginning by mouth opening and ending by cloacal opening. The mouth opening leads to the buccal cavity which is without teeth and indistinct from pharyngeal cavity, both forming buccopharyngeal cavity and this lead to the esophagus which is cylindrical, short and opens in to the stomach . esophagus located under the lung and liver.The stomach is a muscular curved sac which lies in the left side of abdominal cavity.The stomach have two ends :

1.Cardiac opening.2.Pyloric opening.The intestine is long and differentiated to :1.Small intestine.2.Large intestine.

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The small intestine consist of duodenum (forms with stomach a U shaped loop around the pancreas) and the ileum in to several loop bound by mesenteries.The large intestine is short, straight and consist of only the rectum, this is wider than the ileum and extends backwards to open into the cloaca.

The accessory glands connected with digestive system:-1.The liver: it is large, dark red in color and consist of two lobes connected by isthmus.2.The gall bladder lies between the two lobes, posterior to the isthmus, the hepatics and cystic duct, as they collect from the liver and gall bladder to form the common bile duct.3.The pancreatic duct open in the duodenum by a very short common hepato-pancreatic duct near to the pyloric of the stomach.4.The pancreas which lies between the stomach and duodenum, it`s much smaller than liver, pale yellowish cream in color.

Male frog -:1- Locate they kidneys. They are reddish brown organs located to the back of frog.2- Find the vessels attached to the kidneys. These are renal vessels (it may be difficult to determine) which is an artery and which is a vein.3- The orangish-yellow hair like structures attached to the top of the kidney are the fat bodies.4- Locate the testes which are light colored spherical objects at the top of the kidney.5- Small tube like structures to the side of the kidney are vestigial oviducts. In the male frog they have no function.6-The tubes that extend from the kidney and enter the cloaca are the ureters they carry urine.7-The flap like structure is the bladder , it is empty in a preserved frogs.Female frog :-1+2+3 are same male frog.4-The tube like structures to the side of the kidney are oviducts. They may not be visible if your frog has eggs. Eggs can be seen as black speckled masses in the frog body`s cavity.5- At the top of the oviduct is the ostium. This is where the eggs in the body cavity enter the oviducts tube excreted. You may not able to find it on your frog.6-The oviducts lead to the cloaca , eggs and urine will exit the body through the cloaca.7-The flap like structure is the bladder , it is empty in a preserved frogs.8-The tube extends from the kidney to the cloaca is the ureters – it carry urine - from kidneys.

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Post text Write the accessory glands connected with digestive system. Note Check your answers in key answer page 94 .

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19

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RationaleThe Types of papillae is important object to be studied in order to have a

full knowledge the papillae.There are four types of papillae present in the human tongue.

Pre text Write the location of Taste buds and function.Note

Check your answers in key answer page 95.

The text

The Types of papillae

Taste buds.

Are small structures on the upper surface of the tongue, soft palate, upper esophagus and epiglottis that provide information about the taste of food being eaten. These structures are involved in detecting the five (known) elements of taste perception: salty, sour, bitter, sweet, and umami (or savory). Via small openings in the tongue epithelium, called taste pores, parts of the food dissolved in saliva come into contact with taste receptors. These are located on top of the taste receptor cells that constitute the taste buds. The taste receptor cells send information detected by clusters of various receptors and ion channels to the gustatory areas of the brain via the seventh, ninth and tenth cranial nerves, pic. 12.

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Pic.12. the types of papillae, taste bud

The Types of papillae

majority of taste buds on the tongue sit on raised protrusions of the tongue surface called papillae, pic.12. There are four types of papillae present in the human tongue:

Fungiform papillae - as the name suggests, these are slightly mushroom-shaped if looked at in longitudinal section. These are present mostly at the apex (tip) of the tongue, as well as at the sides. Innervated by facial nerve.

Filiform papillae - these are thin, long papillae "V"-shaped cones that don't contain taste buds but are the most numerous. These papillae are mechanical and not involved in gustation. Characterized increased keratinization.

Foliate papillae - these are ridges and grooves towards the posterior part of the tongue found on lateral margins. Innervated by facial nerve (anterior papillae) and glossopharyngeal nerve (posterior papillae).

Circumvallate papillae - there are only about 3-14 of these papillae on most people, and they are present at the back of the oral part of the tongue. They are arranged in a circular-shaped row just in front of the

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sulcus terminalis of the tongue. They are associated with ducts of Von Ebner's glands. Innervated by the glossopharyngeal nerve.

Structure of taste buds

Each taste bud is flask-like in shape, its broad base resting on the corium, and its neck opening, the gustatory pore, between the cells of the epithelium.

The bud is formed by two kinds of cells: supporting cells and gustatory cells.

The supporting (sustentacular) cells are mostly arranged like the staves of a cask, and form an outer envelope for the bud. Some, however, are found in the interior of the bud between the gustatory cells.

The gustatory (taste) cells, a chemoreceptor, occupy the central portion of the bud; they are spindle-shaped, and each possesses a large spherical nucleus near the middle of the cell.

The peripheral end of the cell terminates at the gustatory pore in a fine hair filament, the gustatory hair. The central process passes toward the deep extremity of the bud, and there ends in single or bifurcated varicosities.The nerve fibrils after losing their medullary sheaths enter the taste bud, and end in fine extremities between the gustatory cells; other nerve fibrils ramify between the supporting cells and terminate in fine extremities; these, however, are believed to be nerves of ordinary sensation and not gustatory.

Post text Write the types of papillae.

Note Check your answers in key answer page 95 .

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22+21+20

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RationaleThe is Spleen, liver and lymph node important object to be studied in order to have a full knowledge the lymphoid tissue in the body, their structure and functions.

Pre text answer the following by true or false

It is the largest lymphoid tissue collection in the body. The liver shows cells arranged in a number of polyhedral hepatic

lobules having the central artery as its axis. Lymph node function is protection from foreign noxious particles by

phagocytosis by macrophages only.

Note Check your answers in key answer page 95 .

The textSpleen

It is the largest lymphoid tissue collection in the body .it is invested by two coats : an external serous coat of visceral peritoneum and another inner fibroelastic coat or proper capsule .

The framework or reticulum

From the capsule, the trabeculae approach the interior and branch to provide a framework to spleen . The capsule and the trabeculae are made of collagen fibers, elastic fibers, few scattered smooth muscle cells and reticular fibers. The reticular fibers predominate towards the interior.

The pulp

The spaces or interices of reticulum are occupied by splenic pulp which is of two kinds: red pulp and white pulp.

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The red pulp is invaded by numerous cords of branching reticulum, to them many macrophages are attached. These are called the cords of Billroth.the cords contain many lymphocytes also, derived from white pulp. Brisk phagocytosis occurs in the cords by the macrophages. Amongst the cords, venous sinusoids are present containing varieties of blood cells.

The endothelial cells of venous sinusoids are called stave cells since they resemble the long wooden bars or shafts surrounding a barrel or cask used for containing liquour. When the sinusoids are engorged with blood, gaps appear between the stave cells, permitting the blood to pass out in the splenic cords.

The ultrastructure of the endothelial stave cells reveals numerous pinocytic vesicles and an array of filaments arranged both longitudinal and transversely. The plasma membrane has many microvill like projections towards the lumen of sinusoids. They are supposed to be midly phagocytic also.

Functions of spleen

1. Phagocytosis : phagocytosis of antigens (microbes included) and removal of dead blood cells is carried out by macrophages present in the cords of billroth, at the marginal zone of white pulp and in the ellipsoids. Stave cells are also midly phagocytic.

2. Lymphocytic immunological functions:B and T lymphocytes present in the white follicles execute their immunological functions as in lymph nodes.

3. Cytopoisis:spleen functions as asite of haemopoisis in foetus after 16th

week.production of lymphocytes (lymphopoiesis) and mononuclear cells of blood as well as connective tissues occurs in the white pulp throughout the life.

4. Storage of red cells:in tims of need, the stored red cells are thrown into circulation by strong recoil of the elastic fibers of splenic reticulum.in some other animals, the reticulum and capsule have smooth muscle fibres which contract to squeeze the blood in circulction.

Liver The liver is invested with peritoneum, deep to which lies a thin connective tissue capsule called glisson`s capsule. In histological sections, the liver shows cells arranged in a number of polyhedral hepatic lobules having the central vein as its axis pic.13.

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Pic.13, liver, hepatic lobules

Each lobule has six or more sides. It is about 1mm in diameter and is surrounded at its angles by groups of three tubes termed as portal triad.

portal triad : consisting of

1. Branch of portal vein.2. Hepatic artery.3. Interlobular bile ductile.

Each triad is enclosed by a connective tissue perivascular fibrous capsule.The portal lobule, which is triangular in shape, can be marked out by joining the three central veins of adjacent hepatic lobules.The liver cells or hepatocytes are arranged in a hepatic lobule as cords, radiating from the central vein.Each cord consists of two rows of liver cells between which lie the bile canaliculi. The adjacent cord of liver cells are separated by the liver sinusoids. So the bile canaliculi are separated from the liver sinusoids by thickness of a single cord of hepatocytes.Structure of hepatocyte.The liver cell or hepatocyte is polyhedral having 5 to 12 sides and is from 15 to 25 microns across. Nucleus is spherical and open faced. The cytoplasm contains glycogen granules, fat vacuoles, ferritin and heamosiderin pigments.

Function of hepatocytes1. Glycogen and lipid storage;2. Synthesis o plasma proteins and fibrin;3. Deamination of amino acids in the urea cycle;4. Detoxication;5. Metabolism of bilirubin;6. Synthesis of bile salts which help in lipid digestion.

Storage of iron as ferritin.

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Lymph nodesThese are encaosulaed lymphatic organs located in the course of lymphtic vessels. They are ovoid or bean shapes having a hilum where blood vessels enter or leave. The efferent lymphatic vessels leave node at the hilum only, whereas the afferent vessels enter the capsule at different points. The lymph node has outer cortex and an inner medulla which are indistinctly separatedfrom each other.

A lymph node consists essentially of a fibrous framework which includes a capsule, the trabeculae, reticular tissue framework in which cells, mostly lymphocytes and a few macrophages are entangled.

The external connective tissue capsule is composed of mainly collagen fibres and few scattered elastic fibres. It gives off fibrous septa or trabculae into the interior. The trabeculae divide the lymph node into incomplete compartments. It is containous with a fine reticulum in the interior of the organ.the capsule is thicker in the region of the hilum and blood r vessels entering or leaving the hilum follow the trabeculae to reach their site of distribution.

The lymph nodes have a highly cellular outer cortex and medulla. The cortex is absent at hilum where medulla reaches the surface. In the cortex, densely packed lymphocytes are arranged in rounded masses called lymphatic nodules or follicles.

The central part of a nodule is pale and has larger lymphoblast cells which rapidly multiply. This pale central zone is called germinal centre. Around the germinal centre is a marginal zone where newly formed lymphocytes accumulate and later they are sent via the lymphatic sinuses to efferent lymphatics or veins. In the medulla, lymphatocytes are present as cords called medullary cords. The cords lie amongst the reticulum and around the lymphatic sinuses.

Reticulum, lymphatics sinuses and vasculature

The reticulum or supporting framework is a fine fibrocellular meshworkof reticular fibres and cells. In the cortex, it is indistinct due to dense population of cells entangled in the interices. In the medulla, it is much more distinct and looserdue to fewer entangled cells. Reticulin fibres are continuous with the trabeculae. The reticulum allows the passage of lymph and forms the lymph sinuses which are lined by special endothelial or reticular cells.

Three zones of the cells have been described in the lymph node :

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I. Peripheral zone is the peripheral part of lymph nodules. It extends in the medullary cords also and consists of small lymphocytes, macrophages and plasma cells.

II. Middle zone consists of the outer part of noudles and paracortex. Paracortex is the region between the nodules and medulla.

III. Inner zone or the 3rd zone includes the germinal centre of the follicles.

Distribution of T and B lymphocytesT cells are present in the marginal zones and the paracortex. The paracortex therefore, is also called the thymus-dependent zone. immature B cells are present in the interfollicular reticulum. They multiply in the germinal centres. Mature B cellsare seen in the medullary cords. Functions

1. Site of lymphocytic production.2. Protection from foreign noxious particles by:

a- Phagocytosis by macrophages.b- Antibody production(humoral immunity) by B lymphocytes.c- Cellular immunity by T lymphocytes.d- Macrophages containing phagocytosed antigen also react with

lymphocytes and help in bringing about cellular and humoral immunity.

Post text write the Function of hepatocytes

Note Check your answers in key answer page 95 .

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23+24

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RationaleCirculatory system is important object to be studied in order to have a full knowledge about an organ system that passes nutrients (such as amino acids and electrolytes), gases, hormones, blood cells, etc. to and from cells in the body to help fight diseases and help stabilize body temperature and pH to maintain homeostasis.

Pre text Define Tunica intima.Note

Check your answers in key answer page 96 .

The text

Circulation system1- Blood vascular system a- Heart. b- Arteries. c- Veins. 2- Lymph vascular system: a- Conducting channels. b- Lymphatic organs.Heart : a modified blood vessel functioning as a powerfull pump for circulation the blood.Arteries : These are the following types:

1- Large arteries.2- Medium arteries.3- Arterioles.4- Capillaries.5- Sinusoids.Veins: these are the following types:1- Large veins.2- Medium.3- Small veins and veinules.All vessels have a common general plan of 3 layers:- a- Tunica intima. b- Tunica media.

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c- Tunica adventitia.

A- Tunica intima (the thinnest layer):

A single layer of simple squamous endothelial cell, surrounded by a thin layer of sub endothelial connective tissue interlaced with a number of circularly arranged elastic bands called the internal elastic lamina.

B- Tunica media (the thickest layer):

Circularly arranged elastic fibers, connective tissue, the second and third layers are separated by another thick elastic lamina.

The tunica media may (especially in arteries) be rich in vascular smooth muscles, which controls the caliber of the vessel.

C- Tunica adventitia:

It is made up elastic fiber tissue, having a longitudinal or spiral course. Elastic fibers here may be organized to form an external elastic lamina.

Arteries:-

All arteries are supplied by sympathetic nerve fiber.

A- Large arteries (conducting arteries);-

Elastic type, ex:- pulmonary trunk, aorta, and their main branches.They have the following layers from inner to outer side:-1- Tunica intima:-Endothelial cells are squamous. Sub endothelial C.T. is thick and has elastic fibers.2- Tunica media:-Muscular tissue presents a very thin layer of spirally arranged smooth muscle fibers. Elastic tissue and collagen are also present.3- Tunica adventitia:-It is thinner than media, no external elastic membrane is present. Longitudinal or spiral collagen fibers are present on the outer surface.B- Medium arteries (muscular type):-

1- Tunica intima:-Endothelial cells are elongated sub endothelial layer is very thin. Internal elastic membrane is very clear.2- Tunica media (muscular layer):-(30-40) layers of a circularly arranged smooth muscle fibers. Elastic tissue is very scanty.3- Tunica adventitia:-

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As thick as media, fibro-elastic coat and internal elastic membrane is present, surrounded by collagen fibers externally.C- Arterioles and small arteries:-1- Tunica intima:-Endothelial cells are elongated. Sub endothelial layer is not seen. There is an internal elastic membrane having a network of elastic fibers.2- Tunica media:-Muscular tissue presents 1 to 5 layers of muscle fibers. No elastic or collagen fibers are present.

3- Tunica adventitia:-It is thinner than the media. Fibro-elastic coat is thin. No external elastic membrane is present.D- Capillaries:-They are composed of curved, plate like diamond shaped; flattened endothelial cells set on a basement membrane. Pericapillary cells show solitary around the basement membrane. These are fibroblasts histocytes and contractile pericytes. There is no media or adventitia.

E- Sinusoids:

These are special channels present between vessels. They may connect an anteriole with a venule as in spleen and bone marrow.

VEINS:-As compared to arteries, veins have larger lumen but thinner walls as the muscular and elastic, fibers are diminished. Collagen fibers are in preponderance. Media and adventitia are indistinct, veins have several valves formed by reduplication of intima with a fibrous core.

The transverse section of vein is always seen collapsed in contrast to circular outline of arteries. Most veins have one-way flaps called venous valves that prevent blood from flowing back.

A- Large veins:-

1- Tunica intima:-Endothelial cells are polygonal sub endothelial smooth muscle fibers. Internal elastic lamina is delicate.2- Tunica media (very thin):-Muscular fibers are 1-3 layers there is no elastic and collagen fibers.3- Tunica adventitia (thickest of all coats):-Bundles of smooth muscle are present, there is no elastic layer.B- Medium veins:-

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1- Tunica intimaEndothelial cells are short and polygonal. Sub endothelial layer are delicate.2- Tunica mediaMade up of plate like smooth muscle fibers bundles.3- Tunica adventitiaExternal elastic fibers layer and longitudinal smooth muscle layer.C- Venules and small veins:-1- Tunica intima:-The endothelial cells are elongated and are supported on a network of longitudinal elastic fibers.2- Tunica media:- Is muscle tissue 1-3 layers. There is no elastic and collagen fibers.3- Tunica adventitia:-Is thickest part of the wall and is wholly collagenous.Functions of circulation system:-Transport blood throughout the body. The most important vessels in the system are capillaries which enable the actual exchange of water and chemicals between the blood and the tissue.

Post text

Write the differences between the arteries and veins.

Note Check your answers in key answer page 96.

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RationaleThe nervous system is important object to be studied in order to have a full knowledge about it which enables the body to responded to continuous changes in it`s external and internal environment it controls and integrates the functional activities of organ and organ system.

Pre text Define the neurons.

Note Check your answers in key answer page 96 .

The textNervous system

The nervous system enables the body to responded to continuous changes in it`s external and internal environment it controls and integrates the functional activities of organ and organ system.The mammalian nervous system is divided into two major parts :-1. Central nervous system. (CNS)2. Peripheral nervous system.(PNS)

The CNS consist of the brain and spinal cord.The PNS consist of spinal nerves which are located outside the CNS.The nervous system is composed of following types of cells :1.Neurons :- excitable cells (chief active cell).2.Neuroglia.3.Ependyma.4.Schwan cell.The last 3 types are non-excitable cells. (connective tissue cells of nervous system).

1 .Neurons: Are the chief functioning cells of nervous system .They are highly specialized cell capable of reception , integration of information which are coming to them as stimuli. They also react to these stimuli and transmit the information onwords in the form of electro-chemical impulses.

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Neuron part : cell body is large , rounded , pale with prominent one or more nucleoli.

Nissel granules : are prominent basophilic granules in the cell body located , they are absent in neuritis.

Nissel bodies have role in metabolism protein.

A con like projection leading to extension of axon is called axon hillock.

They have 2 types-:

1.Soma or cell body (perikaryon) with large surface area.2.Neurites : branch like extensions , and this divide to-:

a- Dendrites (the receiving processes) .b- Axon (the efferent processes).There is one axon and many dendrites pic.9 .

Pic.9. Neuron part

Axon function: -

Transmit the information from cell body to another neuron or another tissue.

Component of axon:

The plasma membrane of axon is called (axolemma), the cytoplasm of axon is called (axoplasm). Terminal end of axon breaks called (telodendria), and this

can be end in-:

a. Interneuronal junction with other neurons or their dendrites.b. Neuromuscular junction.c. Junction with gland cells.

d. In adipose tissue.

Node of ranvier located between two consecutive Schwann cells. Dendrites function Receiving information from the body to cell body.

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Classification of neurons or dendrites according to the number of neuritis pic.10-: .

Pic.10. A. unipolar; B. Bipolar and C. Multipolar

a. Unipolar neurons : these have a single neurite dividing in to two : a–one dendrite; b–another axonal branch.

b. Bipolar neurons :have neurite at each end of the cell body , it`s shape is oval.c.Multipolar neurons : most of the cells are this type , having multiple neuritis.d.Psedounipolar neurons : are bipolar in origin but assume secondary unipolar shape during development , as two poles due to the folding of the cell body , com near to each other and giving a false unipolar appearance.

2.Neuroglial cells: Nervous system include cells that do not transmit impulses , but support the activities of neurons . They called neuroglial cells.

3.Ependymal cell : lining the cavities of CNS.4.Schwann cells : They are surrounding the peripheral axons forming

nervs.

Types of nerve fibers: 1. myelinated fibers : this type have axons which surrounded by external sheath called (Schwann sheath) and inside there is cell with nucleus which called (Schwann cell).Myelin sheath are not continuous along the axon, rather , they are punctuated by gaps , called (nodes of ranvier). 2. Unmyelinated fibers : this type hav`nt myelin sheath.

Functions of Nerve Tissue

Nervous tissue allows an organism to sense stimuli in both the internal and external environment.

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The stimuli are analysed and integrated to provide appropriate, co-ordinated responses in various organs.

The afferent or sensory neurons conduct nerve impulses from the sense organs and receptors to the central nervous system.

Internuncial or connector neurons supply the connection between the afferent and efferent neurons as well as different parts of the central nervous system.

Efferent or somatic motor neurons transmit the impulse from the central nervous system to a muscle (the effector organ) which then react to the initial stimulus.

Autonomic motor or efferent neurons transmit impulses to the involuntary muscles and glands.

Post text Write the Classify of neurons or dendrites according to the

number of neuritis.Note

Check your answers in key answer page 96 .

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RationaleThe skin is important object to be studied in order to have a full knowledge about it which enables the body to responded to continuous changes in it`s external and internal environment it controls and integrates the functional activities of organ and organ system.

Pre text List the layer of the epidermis.Note

Check your answers in key answer page 96, 97 . The text

The skinIt is the outer covering of the body. It is the largest organ of the integumentary system made up of multiple layers of epithelial tissues, and guards the underlying muscles , bones , ligaments and internal organs.

Skin layers : they composed of three primary layers:

1. Epidermis : which provides waterproofing and serves as a barriers to infection. Epidermis contain no blood vessels and cells in the deepest layers are nourished by diffusion from blood capillaries extending to the upper layers of the dermis pic 11. This layer composed from :

a. Stratum corneum.b. Stratum lucidum.c. Stratum granulosum.d. Stratum spinosum.e. Stratum germinatium, (also called stratum basale).A. Stratum corneum : it composed of many layers of non-nucleated flattened epithelial cells containing soft keratin (protein) in their cytoplasm is contrast to hard keratin (dead cells) of the hair and nails.B. Stratum lucidum : usually found in thick skin, it`s composed of thin layer of flattened eosinophilic non-nucleated, have no clear membrane cells, these cells contain immature keratin.C. Stratum granulosum : it`s composed of flattened polyhedral cells with oval or round nuclei. The cytoplasm is granular due to keratohylain granules.

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D. Stratum spinosum : consist of cuboidal and polyhedral cells with central nucleus with cytoplasm of numerous processes like spine.E. Stratum germinatium : it is the deepest layer of epidermis it composed of one layer of basophilic short columnar or cuboidal cells it is responsible for production of keratinocytes which has responsible for renewal of epidermal cells.

2 -Dermis corium :

Composed of connective tissue containing elastic, reticular and collagen fibers , vessels , nerves and lymphotics.

It is divided into two layers-;

1 .Superficial papillary layer : they are made of fine interlacting collagen, elastic and reticular fiber. This layer has numerous conical dermal papillae and ridges projecting into the epidermis.

2 .Reticular layer : provides main fibroelastic network of coarse and densely interlacting fibers running mostly parallel to surface. Amongst them connective tissue cells are present.

Skin function :

1. Protection : the skin provides protection against ultra violate light (UV), mechanical, thermal and chemical injuries, and prevents dehydration, invasion of microorganisms.2. Sensation : skin has so many (sensory receptors) for pressure, pain and temperature.3.Thermoregulation : skin protects body against heat loss by presence of hair and subcutaineous adipose tissue. Heat-loss by evaporation by sweet glands.4. Metabolic function : vit. D is synthesized in the epidermis under the action of ultra violet radiation of sun light.5. Excretion : sweat contains urea, however it`s low concentration than urine.6. Storage : acts as a storage center for lipids.

Appendages of the skin 1 .Hair.2 .Nails.

3 .Skin glands : a. Sweat glands.b. Sebaceous glands.

1 .Hair :(the skin with hair called hairy skin) the hair have different parts:

Shaft : the free portion over the skin surface. Hair root : the portion embedded in the skin.

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Hair follicle : the hair root enclosed by an outer C.T. sheath derived from the dermis and inner epithelial sheath derived from the epidermis.Hair papillae : the bulbous deep end of the hair root covering a vascular portion of the dermis. The color of the hair depends on pigment concentration in the medulla and cortex. The hair are set at an acute angle with the skin surface at rest, but they stand erect when the arrectore pili muscles contract.Arrectores : are small bands of smooth muscles fibers.

2.Nails : the nail is composed of clear flattened cells with degenerated nuclei. They contain hard keratin.

Nail parts:

A. Unattached distal free edge.B. Nail root.C. The whitish crescent near the root.D.The nail body.

3 .Skin glands:

A. Sweat gland.B.Sebaceous gland.

A. Sweat glands: These are simple coiled tubular glands. They are lined with cuboidal or columnar epithelium against a basement membrane. The ducts are lined by double layer of cubical cells.

B. Sebaceous glands:

These are simple or branched alveolar glands, opening in the hair follicle it is embedded in the dermis. The gross secretory product is the sebum.

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pic.11 cross section in human skin

Post text Write the skin function .

Note Check your answers in key answer page 96,97.

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29

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RationaleThe kidney is important object to be studied in order to have a full knowledge about primarily concerned with the excretion of urine .

Pre text

Write the function of renal tubules.Note

Check your answers in key answer page 97 . The text

KidneyThe kidney is primarily concerned with the excretion of urine. It is large bean – shaped organ, enclosed by a connective tissue capsule composed of collagen fibers and a few elastic fibers pic.15.

Pic.15, the right kidney

Kidney parts : 1- Outer cortex.2- Inner medulla.CortexIt contain many convoluted tubules and numerous rounded bodies known as renal corpuscles, medullary rays, interlobular arteries and veins pic.15.

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Medulla

It contains numerous cone – shape renal pyramids, the round apex of each pyramids extend downward to the renal pelvis to from the renal papillae. Each renal papilla is surrounded by a funnel – shape minor calyx, which collects urine from the papilla.The renal sinus contains :-1- Renal pelvis : the upper expanded portion of the ureters;2- 2 to 3 major calyces;3- About 8 minor calyces;4- Branches of renal artery and vien;5- Nerves and lymphatics;6- Loose connective tissue and fat.Uriniferous tubules :

The functional unit of each kidney is the microscopic uriniferous tubules , which is consists of :1- Nephrons;2- Collecting ducts.Collecting duct into which empty the filtered contents of the nephron. Millions of nephrons are present in each kidney cortex.Nephron subdivided : 1- Renal corpuscle;2- Renal tubules.Function of renal corpuscle : concerned with the filtration of substances from the plasma.

Function of renal tubules :

Concerned with the selective resorption of substances from glomerular filtrate until it reaches the composition of urine.

Renal corpuscles :

They are rounded bodies, about 0.2 mm in diameter, found in the cortex and renal columns. There are one million or more renal corpuscles in each kidney. Each one of them is composed of two parts :- a central glomerulus and glomerar capsule, which is small pouch renal tubule called Bowman`s capsule.

Glomerulus :

It consists of number of capillaries connecting an afferent arteriole. It function filtration of blood.

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Bowman`s capsule :

It consists of an inner layer covering the glomerulus and an outer layer.

Ureters

Ureter has three coats :-1- Fibrous coat;2- Muscular coat;3- Mucous coat.Urinary bladderIt made of three layers :1- Serous coat;2- Muscular coat;3- Mucous coat.Kidney functions ;1- Homeostasis;2- Filtration;3- Re absorption;4- Excretion;5- Produce hormones.Post text

Define the renal corpuscles.

Note Check your answers in key answer page 97 .

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1. key answer :-

Pre text :- The microscope is an instrument which is used for examination of

fine structure of objects. It enlarges of the images of the objects which then can be seen by the eye.

Post text :- Simple Microscope: It is made of single or combination of

lenses which act as single position convex lens . Compound Microscope: Itś made up of 2 lenses which are

fitted in a brass tube, one of the tubes can be slided into the other so that the distance between lenses can be changed and adjusted.

2. key answer :-

Pre text Cell is the unit of structure and function in animals and plants. 1. Mitochondria ;

2. Endoplasmic reticulum ;3. Ribosomes are the sites of protein synthesis;4. Golgi apparatus (dictyosome);5. Lysosome;6. Microtubles and filaments;7. Centrioles;8. Nucleus.

Post textA.1. false.

2. false.B. 1. Protein synthesis.

2.Cell division .

3.Cell motility .

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3. key answer :- pre text

Tissue: Is a group of similar cells specialised in common direction and set apart for performance of a common function.

Epithelial tissue:It is a layer or layers of cells which cover the body surface, and line the body tubes and membranes, they also form gland.Post text1.Simple: one cell thick layer;

2.Stratified: more than one cell thick layers; 3.Pseudostratified: one cell thick layer but the height of cells varies so as to give a false appearance of multiple layers, because the nuclei are seen in more than one row.4+5. key answer :-

pre text

1. Stratified squamous epithelium;

Kertinized Non-keratinised

2. Sratified columnar and cuboidal epithelium;

3. Pseudostratified epithelium;

4- Transitional epithelium. Post text

Transitional epithelium

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6+7+8 key answer :-pre text

a .False. True. False.

B.1. Fibroblasts and fibrocytes;2. Macrophages;3. Mast cells;4. Plasma cells;5. Fat cells;6. Pigment cells;7. Reticular cells.

c. 1. Red blood cell;2. White blood cell;3. Platlate.

Post texta.1. Protect and support other cells by forming capsule;

2.They protect the tissue against foreign invasion;

3.They carry blood to the cells;

4.The ground substance prevents spread harmful substances during inflammation.

b. a. Collagen fibers; b. Elastic fibers; c. Reticular fibers.

c. 1. Red blood cell;4. White blood cell;5. Platlate.

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9 . key answer :- pre text

Cartilage is special type of adult connective tissue, it is non vascular and forms the supporting frame of certain organs( articulating surfaces and greater part of fetal skeleton), although most of that will be replaced by bone.Post text

Function of hyaline cartilage

1. Provides supports by it`s resilience and rigidity.2. Withstand compression in joints.3. Allows frictionless movement.

10 +11. key answer :- pre text

Bone is a special type of connective tissue. It is complex tissue, composed of: 1. Cells 2. Matrix:- a. Fiber b. Ground substance containing of minerals salts.

Post text

1-Osteoblasts 2-Osteocytes 3-Osteoclasts

1 2 . key answer :- pre text

Function of Muscular Cells :

1. Protection of bone 2. Permits independent movement of muscular bundle and individual

fibers.3. Helps in transmission of force of contraction of muscle. Post text

Compare between Skeletal m. and cardiac m.

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Skeletal Muscle Cardiac Muscle

Nucleus at side Nucleus at center

Myofibrils is found Myofibrils is Also

No-branched Branched

Thick sarcolemma Thin

StraidAlso

Voluntary Non-Voluntary

No-intercalated disk Yes – present

In tounqe In Heart

17+18 . key answer :- pre text

The external feature :-

General body color adaptive coloration , absence of neck and tail , longer hind than for limbs, eyes are bluing, buccal cavity, to distinguish the sexes by the color of dorsal surface being black in the male, which in the female, body surface roughened presence of small warts. The skin also sticks due to the presence of mucous secretion which keeps the body moist.

Post text The accessory glands connected with digestive system:-

1. The liver: it is large, dark red in color and consist of two lobes connected by isthmus.2. The gall bladder lies between the two lobes, posterior to the isthmus, the hepatics and cystic duct, as they collect from the liver and gall bladder to form the common bile duct.3. The pancreatic duct open in the duodenum by a very short common hepato-pancreatic duct near to the pyloric of the stomach.4. The pancreas which lies between the stomach and duodenum , it`s much smaller than liver , pale yellowish cream in color.

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19 . key answer :- pre text

Are small structures on the upper surface of the tongue, soft palate, upper esophagus and epiglottis that provide information about the taste of food being eaten. These structures are involved in detecting the five (known) elements of taste perception: salty, sour, bitter, sweet, and umami (or savory).

Post text Fungiform papillae; Filiform papillae; Foliate papillae; Circumvallate papillae.

20+21+22 . key answer :- Pre text

True. False. False.

Post text Function of hepatocytes

1. Glycogen and lipid storage;2. Synthesis o plasma proteins and fibrin;3. Deamination of amino acids in the urea cycle;4. Detoxication;5. Metabolism of bilirubin;6. Synthesis of bile salts which help in lipid digestion;

7.Storage of iron as ferritin.

23+24 . key answer :-

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Pre text Tunica intima (the thinnest layer):

A single layer of simple squamous endothelial cell, surrounded by a thin layer of sub endothelial connective tissue interlaced with a number of circularly arranged elastic bands called the internal elastic lamina.

Post text As compared to arteries, veins have larger lumen but thinner

walls as the muscular and elastic, fibers are diminished.

25 . key answer :- Pre text

Neurons : Are the chief functioning cells of nervous system .They are highly specialized cell capable of reception, integration of information which are coming to them as stimuli. They also react to these stimuli and transmit the information on words in the form of electro-chemical impulses.

Post text a. Unipolar neurons ;

b. Bipolar neurons;c. Multipolar neurons ;d. Psedounipolar neurons .

26+28 . key answer :- Pre text

a. Stratum corneum; b. Stratum lucidum;

c. Stratum granulosum; d. Stratum spinosum;

e. Stratum germinatium,(also called stratum basale).

Post text Skin function

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1. Protection; 2. Sensation ;3. Thermoregulation ;4. Metabolic function; 5. Excretion;6. Storage. 29 . key answer :- Pre text

Function of renal tubules :

Concerned with the selective resorption of substances from glomerular filtrate until it reaches the composition of urine.

Post text Renal corpuscles :

They are rounded bodies, about 0.2 mm in diameter, found in the cortex and renal columns. There are one million or more renal corpuscles in each kidney. Each one of them is composed of two parts :- a central glomerulus and glomerar capsule, which is small pouch renal tubule called Bowman`s capsule.

Reference-: 1.BAJAPI, R. N. M.S. , "Human histology", (1987).

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2. Evelyn pear, Faber and Faber," Anatomy and physiology for nurses (P15)" , 1987.(16thedition), by London. Boston.

3. Clark, W.E.L.G."The tissues of body".

4. Encyclopædia Britannica. 2009. 5.Huang A. L., et al. ""The cells and logic for mammalian sour taste detection"". http://www.nature.com/nature/journal/v442/n7105/abs/nature0508html., Nature, 442. 934 - 938 (2006). 6. Collings, V.B., 1974. Human Taste Response as a Function of Locus of Stimulation on the Tongue and Soft Palate. Perception & Psychophysics, 16: 169-174. 7. www.med.mun.ca/anatomyts/digest/gut97a.htm. 8. www.vivo.colostate.edu/hbooks/pathphys/digestion/liver/histo_lobule.html. 9. http://en.wikipedia.org/wiki/Lymph_node.10. Victor P.Eroschenko, Atlase of histology with functional correlations.