Anatomy – the study of the structure of an organism and/or its parts

Body Systems

Physiology?

= the study of what structures do.

Muscle contraction

Homeostasis – the foundation of physiology

- maintenance of a “steady state” condition.

- the sum of all processes is called…

Why is homeostasis important?

Homeostasis – involves thousands of chemicals and their reactions

Can you think of any other chemicals that are in our bodies which help maintain our ‘steady state’ ??

How do these chemical exchanges/reactions take place??

• What are the 2 environments which are important in maintaining homeostasis?

• External environment & internal environment

What would happen if homeostasis were not maintained??

Sickness and eventual death of the organism

Levels of Body Structure

What is an ‘Organ System’?

Organ System -

• Multiple organs that together perform a vital body function.

• What level of structure is higher than an organ system?

• The whole organism!

• What are some organ systems that you can think of? There are 12 !

Integumentary System• Largest organ yet only

about 2mm thick!• Epidermis – outer most

layer; dead cells• Melanin – bottom region

of the epidermis; cells are alive and give skin its color

• Dermis- skin layer below the epidermis, supports the epidermis

• Hypodermis- tissue layer below the dermis which contains adipose tissue (fat-storing cells and blood vessels)

Skeletal SystemProvides strong framework and maintains body shape.The backbone (spinal cord) consists of vertebra and cartilage.Included in this system is ligaments

Bones contain tissue called marrow.

Muscular System

• Many different kinds of muscles (i.e. skeletal, cardiac, smooth, etc.)

• Included in the system are tendons (connective tissue which holds muscle to bone)

Digestive System• Breaks down food

to enable nutrient absorption.

• Needed for re-absorption of water in the body.

• Consists of multiple organs

Circulatory SystemCirculation, transportation and distribution of materials.

What kind of materials???

Respiratory System

Allows gas exchange because cellular respiration requires…………..

Nervous System

Allows the body to sense, feel and coordinate its movement.

Consist of many different kinds of neurons which serve different purposes.

Lymphatic System

• Collects and returns most of the blood which leaves the circulatory system into the interstitial tissue.

• This collected fluid is called lymph

Immune System• Protects the organism against disease• Acts as a line of defense against pathogens

Endocrine System

• Endocrine glands secrete regulatory hormones (>40).

• These hormones maintain homeostasis

• What are some examples of hormones and what they regulate?

Excretory System

• Eliminates metabolic waste

• Regulates the intake and loss of water

• Role in homeostasis?

Reproductive System:producing offspring is necessary for survival of the species

Major systems in animals

Digestive System & Nutrition (Ch. 29)

• What is the purpose of the digestive system? • How does it accomplish this?

• What are the 2 types of digestion which take place in us?

• Mechanical- the physical breaking down of food.

• Chemical- the breaking down of the chemical bonds of larger molecules to produce smaller molecules which our body can absorb.

Types of Digestion video

Nutrition : Heterotrophic creatures must obtain materials for energy and synthesis

4 Stages of food processing:

IngestionDigestionAbsorptionElimination

Is this true in humans as well?

Alimentary Canal Systems: tube-within-a-tube body plan •Ingested food enters mouth and is digested extracellularly in the organs of the systems.•The end products of digestion are absorbed into transport system.

Human Digestive System

Mouth:Ingestion and mechanical digestion when food is chewedMechanical digestion increases surface area Chemical digestion of starches due to amylase in the saliva

Digestion inMouth video

Swallowing ReflexHow is the food kept out of trachea?

Esophagus: peristalsis pushes food down;no enzymes here only mucous.

Stomach: Begins digestion of protein with protease enzymes. Gastric juice: contains hydrochloric acid (pH 2-3) Malfunctions: Heartburn and Ulcers

What happens in the Stomach video

Small Intestine begins with the DuodenumBile made by liver is stored in the gall bladder. Emulsify fats.Pancreas releases bicarbonate which neutralizes acidic chymePancreas adds many enzymes to the small intestine.

What Happens in the Small Intestine video

Small IntestineComplete chemical digestion with enzymes.Villi provide high surface area for absorption of digested nutrients

Role of Circulation video

Large Intestine: absorption of fluids released into alimentary canal. Home to symbiotic bacteria (E. coli). Malfunctions: diarrhea and constipationAppendix is vestigialRectum: storage of feces

What Happens in the Large Intestine video Final Stages video

Enzymes of the digestive system

Malfunctions of the Digestive System:

Ulcers: erosion of the surface of the alimentary canal

Constipation: too much water is reabsorbed and solid waste hardens, elimination is difficult

Diarrhea: decreased water re-absorption and increased peristaltic activity in the large intestine. Results in increased, multiple, watery feces. Dehydration possible

Digestive System Accessory Organs

Appendicitis: inflammation of the appendix due to infection

Gallstones: accumulation of hardened cholesterol and/or calcium deposits in the gall bladder.

NUTRITIONWhy is nutrition important to an organism? Why do we eat?

Essential Nutrients: required materials animals must consumeWhy must we consume them?What happens when your diet is deficient in these nutrients?

Carbohydrate: roughage, starch and sugarsFats: fatty acids, cholesterolProteins: amino acidsVitamins: coenzymes, water and fat soluble MineralsWater

Closer Look at Nutrients Video

Maintain a Healthy Body video

Eating disorders and their effects

• Malnutrition: deficiencies of essential nutrients. Ex: lack of Vit. C ->……..?

• Undernutrition: not enough calories/food energy in diet

• Obesity: being seriously overweight can increase your risk of………….

• Eating Disorders: Bulimia, anorexia, binge/purge – can ultimately result in …….

Integumentary System (skin &….)

• Epidermis – outermost layer; mostly dead cells

• Melanin- pigment containing cells which are found in the bottom-most layer of epidermis

• Dermis-supports the epidermis; mostly made of fibrous connective tissue (elasticity); contains hair follicles, nerve endings, sweat glands, blood vessels

• Hypodermis-contains adipose tissue which includes fat storage and blood vessels

Integumentary System

• Hair and Nails – also part of this system; made of keratin.• How does your hair maintain homeostasis?

Protects head from UV radiation from the sun

Provides layer of insulation from changing outside temps

Are there any other functions of hair?

Integumentary System

How is the skin important ?

Physical barrier against dirt and microorganisms entering the body

Acts as insulation (layers!)

Cushions internal organs against injury

Maintains homeostasis by regulating body temperature and water content

Is this system foolproof??

Skeletal System

• Bones are organs made up of living connective tissue!

• Bone matrix (giving bones rigidity) is made up of collagen, calcium and phosphate.

Skeletal System

Marrow: cells found inside large bones; yellow marrow (fat storage-energy supply), red marrow (new blood cells).

Ligaments: strong fibrous connective tissue holding 2 bones in a movable joint together.

Cartilage: softer than bone; offers cushioning protection where 2 bones come together. Bones and Cartilage

Skeletal System

• Movable joints: – Pivot joint: where one bone

can rotate around another– Ball & socket joint: enables a

bone to rotate back and forth and side to side [allows greatest range of motion]

– Gliding joint : allows bending and flexing movement

– Hinge joint: allows only back and forth movement

Can you think of some examples of these types of joints?

Skeletal System Disorders

arthritis: inflammation – joints become swollen, stiff and sore

[rheumatoid arthritis is an immune system disorder]

osteoporosis: bones become thinner, porous and brittle.

Consume calcium now!!!

Muscular System

Works in conjunction with the skeletal system (connected to bone by tendons)

Why is this system important for us?

Muscular System

Allows LOCOMOTION:

Muscular System

• Muscles can only pull – cannot push

• Muscles work in pairs-antagonistically

• Triceps relaxed and biceps contracted.

Muscular System• Muscle fiber is made of

smaller units called myofibrils

• Myofibrils are made up of repeating units called sarcomeres.

• Sarcomeres are the basic unit of action-it is the unit that contracts and is made up of 2 kinds of filaments: thin (actin) and thick (myosin)

Muscle Contraction

• As sarcomeres shorten, the muscle contracts.

End of Chapter 27

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