Human Anatomy and Body Systems

Levels of OrganizationThe human body is organized in several levels, from the simplest to the most complex.

Cells – the basic unit of life

Tissues – clusters of cells performing a similar function

Organs – made of tissues that perform one specific function

Organ Systems – groups of organs that perform a specific purpose in the human body

Organism – the whole human

The 11 Human Body SystemsThe purpose of the 11 organ systems is for the human body to maintain homeostasis

The Digestive SystemPurpose: to convert food particles into simpler

macromolecules that can be absorbed into the bloodstream and used by the body

Major Organs and their Functions:

Mouth – to chew and grind up food

-- saliva also begins the chemical breakdown

Esophagus – pipe connecting mouth to stomach

Stomach – secretes an extraordinarily strong acid (pH = 2) that leads to breakdown of food

-- once the food is broken down in the stomach and mixed with digestive juices, it is called chyme

Pancreas – produces the hormone insulin that regulates blood sugar levels

-- also help neutralize stomach acid

Liver – produces bile, which breaks down fats in foods

Gallbladder – pouch-like organ that stores bile for future use

Small Intestine – after digestion is complete, the chyme enters the small intestine where it is absorbed into the bloodstream

-- the chyme is propelled along by folded surfaces called villi, on the intestine

Large Intestine – removes water from the chyme and gets the waste ready for excretion

Digestive System

• The digestive system is made up of the alimentary canal and the other abdominal organs that play a part in digestion, such as the liver and pancreas.

• The digestive tract is the long tube of organs — including the esophagus, the stomach, and small and large intestines — that runs from the mouth to the anus.

• An adult's digestive tract is about 30 feet long.• The function is to breakdown and absorb nutrients

that are necessary for growth and maintenance.

Digestive System

• The digestive system breaks down food two ways: – mechanical digestion- the chewing (in the mouth) and

churning (in the stomach) that can be used by the body.

– chemical digestion- with the help of enzymes, into substances that cells can absorb and use. This occurs in the mouth, stomach and small intestines.

Image of the Digestive System

POP QUIZ

21. The function of the digestive system is to:a. break down and absorb nutrientsb. support soft tissues and protects organsc. controls activities through electrical impulses

22. The digestive tract contains the following organs:a. heart, lungs, and veinsb. spleen, thymus, and lymph nodesc. esophagus, stomach, and intestines

23. The digestive system breaks down food in two ways:a. mechanical and chemicalb. chemical and physicalc. physical and physiological

24. Chemical digestion occurs in:a. small intestine, stomach, and mouthb. bones, veins, and heartc. spleen, heart, and lungs

The Excretory SystemPurpose: to rid the body of wastes, including excess water and salts

Major Organs and Their Functions

Kidneys – the main organs of the excretory system

-- waste-laden blood enters the kidney and the kidney filters out urea, excess water and other waste

products, which eventually travel out of the kidney as urine

-- eventually they travel through the ureter to the urinary bladder

Rectum – solid (food) waste travels out of the body through the rectum

Skin – sweat glands remove excess water and salts from the body

Lungs – expel the waste gas carbon dioxide

Image of the Excretory System

The Respiratory SystemPurpose: to provide the body with a fresh supply of oxygen for cellular respiration and remove the waste product carbon dioxide

Major Organs and Their Functions

Nose – internal entry and exit point for air

Pharynx – serves as a passage way for both air and food at the back of the throat

Larynx – your “voicebox”, as air passes over your vocal chords, you speak

Trachea – the “windpipe”, or what connects your pharynx to your lungs

-- a piece of skin, called the epiglottis, covers the trachea when you swallow, preventing food from entering

Bronchi – the two large passageways that lead from the trachea to your lungs (one for each lung)

-- the bronchi are further subdivided into bronchioles

-- eventually, the further subdivisions lead to tiny air sacs called alveoli

-- alveoli are in clusters, like grapes

-- capillaries surrounding each alveolus is where the exchange of gases with the blood occurs

The diaphragm is the muscle that causes you to breath

-- hiccups are involuntary contractions of the diaphragm

Respiratory System

• The function of the respiratory system is breathing in oxygen from the air and carbon dioxide is expelled from the body.

• The system that allows breathing (gas exchange) includes the nose, pharynx, trachea, and lungs.

• Respiratory system provides gas exchange between blood and the environment.

Respiratory System

• Although it may seem easier to breathe through the mouth, it is healthier to breathe through the nose. The hairs and mucus in the nose (part of the nasal cavity) help filter and warm the air as it comes in.

• LUNGS- gases are transferred between lungs and blood from the circulatory system.

• The diaphragm is a muscle beneath the lungs that helps move air in and out of the body.

Image of the Respiratory System

POP QUIZ

9. Function of the respiratory system is breathing in _________ from the air and expelling _________________.

a. oxygen, carbon dioxideb. carbon dioxide, oxygenc. oxygen, nutrients

10. The respiratory system includes the following organs and tissues:a. lungs, heart, and arteriesb. thymus, spleen, and bone marrowc. nose, lungs, and pharynx

11. The diaphragm is a a. gasb. cavityc. muscle

12. Respiratory system provides ________________.a. waste removalb. gas exchangec. food exchange

The Circulatory SystemPurpose: to deliver oxygenated blood to the various cells and organ systems in your body so they can undergo cellular respiration

Major Organs and Their Functions

Heart – the major muscle of the circulatory system

-- pumps blood through its four chambers (two ventricles and two atria)

-- pumps deoxygenated blood into the lungs, where it gets oxygenated, returned to the heart, and then pumped out through the aorta to the rest of the body

-- valve regulate the flow of blood between the chambers

Arteries – carry blood away from the heart and to the major organs of the body

Veins – carry blood back to the heart away from the major organs of the body

Capillaries – small blood vessels where gas exchange occurs

Blood – the cells that flow through the circulatory system

-- red blood cells contain hemoglobin, an iron-rich protein that carries oxygen

-- white blood cells function in the immune system

-- platelets help in blood clotting

Spleen – helps to filter out toxins in the blood

Circulatory System

Arteries Veins• The circulatory system is responsible for bringing

oxygen, nutrients, and hormones to cells.• It’s function is to remove wastes and regulate

body temperature.• The heart is central to the human circulatory

system; it pushes blood through the body’s network of arteries and veins.

• Blood is pumped from the heart to the lungs, acquires oxygen and releases carbon dioxide.

• The blood travels back to the heart and pumps back to the rest of the body.

• Blood passes the body cells, it transfers oxygen to the cells, and picks up wastes.

• It returns to the heart and the process is repeated.

Circulatory System

• Arteries are tubes that carry blood away from the heart

• Veins are tubes that return blood to the heart • Capillaries connect arteries and veins. They are

tiny tubes that exchange food, oxygen and wastes between blood and body cells.

• Pulmonary circulation is the movement of blood between the heart and lungs

• Coronary circulation is the movement of blood from within the heart chambers to the heart tissues themselves

• Systemic circulation is the movement of blood between the heart and the rest of the body

• The circulatory system is pretty important, huh?

Image of the Circulatory System

Circulatory System

Circulatory SongVerse 1: Pump, pump, pumps your blood.

The right atrium’s where the processbegins, where the CO2 blood enters the heart.

Through the tricuspid valve, to the right ventricle, the pulmonary artery, and lungs.

Once inside the lungs, it dumps its carbon dioxide and picks up its oxygen supply. Then it’s back to the heart through the pulmonary vein, through the atrium and left ventricle. Pump, pump, pumps your blood.Pump, pump, pumps your blood. 

Verse 2: The aortic valve’s, where the blood leaves the heart, then it's channeled to the rest of the body.

The arteries, arterioles, and capillaries toobring the oxygenated blood to the cells. The tissues and the cells trade off waste and CO2, which is carried through the ventricles and the veins. Through the larger vena cava to the atrium and lungs, and we're back to where we started in the heart. Pump, pump, pumps your blood.

POP QUIZ5. The circulatory system is responsible for bringing

_____________________to the cells.a. gas, carbon dioxide, and the environmentb. oxygen, nutrients, and hormonesc. white blood cells, pathogens, and bone marrow

6. Arteries are tubes thata. return blood to the heartb. exchange food, oxygen and wastes between the blood and body cellsc. carry blood away from the heart

7. Pulmonary circulation isa. the movement of blood between the heart and the lungsb. the movement of blood from within the heart chambersc. the movement of blood between the heart and the rest of the body

8. Blood is pumped from the heart to the lungs and acquires ______________ and releases _________________________.

a. carbon dioxide , oxygenb. oxygen, carbon dioxidec. oxygen, nutrients

The Nervous SystemPurpose: to coordinate the body’s response to changes in its internal and external environment

Major Organs and Their Functions

Brain – control center of the body, where all processes are relayed through

-- consists of cerebrum (controls though and senses) and cerebellum (controls motor functions)

Spinal Cord – sends instructions from the brain to the rest of the body and vice versa

-- any organism with a major nerve cord is classified as a chordate

Nerves – conduct impulses to muscle cells throughout the body

Nervous System

• The brain, spinal cord, and network of nerves (peripheral nervous system) receive messages from inside and outside the body and transmit instructions about how to respond.

• The nervous system is the control center of the body; it interprets the senses and enables you to respond.

• Smell, taste, touch, sight, and sound are controlled by this system.

Nervous System

• Things to know about the nervous system:– A neuron (nerve cell) is the basic unit of

structure and function of the nervous system.

– A response that is made automatically is a reflex.

– Your spinal cord is made of bundles of neurons that carry impulses from all parts of the body to the brain and from the brain to all parts of your body.

– The spinal cord is about as big around as an adult thumb and 43 cm long.

Diagram of a Nerve Cell

POP QUIZ

17. The nervous system controls cells:a. by releasing hormonesb. through electrical impulsesc. through muscular movement

18. The organs of the nervous system are:a. brain, spinal cord, and nervesb. nerves, capillaries, and lungsc. spinal cord, trachea, and esophagus

19. A reflex:a. works in pairsb. is an automatic responsec. occurs in the blood system

20. The function of the nervous system is:a. to push blood through the arteries and veinsb. breath in oxygen and breathe out carbon dioxidec. to receive messages from inside an outside of the body and

transmits instructions about how to respond

The Endocrine SystemPurpose: to control growth, development, metabolism and reproduction through the production and secretion of hormones

Major Organs

-- hypothalamus

-- pituitary gland

-- thyroid

-- parathyroid

-- adrenal glands

-- pancreas

-- testes

-- ovaries

The Skeletal SystemPurpose: to provide structure and support to the human body

Bones are where new blood cells are generated (in the marrow), and require the mineral calcium for strength

Major Bones of the Human Body

-- femur (thigh bone) -- humerus (upper arm)

-- radius and ulna (lower arm) -- cranium (skull)

-- sternum (breastbone) -- clavicle (shoulder blade)

-- fibula and tibia (calf) -- vertebrae (back)

-- scalpula (shoulder) -- pelvic bone

-- coccyx (tail bone) -- phalanges (fingers/toes)

Skeletal System

• The function of the skeletal system is to give the body support and protect vital organs.

• Without a skeletal system, the human body would be limp and floppy.

• The skeletal system consists of bones, ligaments, cartilage, and tendons.

• Your skull, a series of fused bones, acts like a hard protective helmet for your brain.

• The bones, or vertebrae, of your spinal column surround your spinal cord; a complex bundle of nerves.

Skeletal System

• The skeletal system provides attachment sites for the organs.– Imagine what could happen to your heart

and lungs without the protective armor of your rib cage!

• How many bones do humans have? When you were born you had over 300 bones.

• As you grew, some of these bones began to fuse together. – The result? An adult has only 206 bones!

Skeletal System

• Bones are living structures with 5 functions:– protect internal organs – support the body – make blood cells – store minerals – allow for muscle attachment

• A point where two or more bones connect is called a joint.

• There are two different types of joints in the body:– Movable joints (like ball-and-socket, hinge,

gliding and pivot joints) – Immovable joints (like the bones of the skull and

pelvis) which allow little or no movement • You have over 230 moveable and semi-moveable

joints in your body.

POP QUIZ

1. Skeletal system supportsa. chemical reactions in the bodyb. supports soft tissues and protects organsc. carries oxygen-rich blood to cells

2. Bonesa. support the bodyb. provides protection from diseasec. digest food

3. Skeletal system is made ofa. nose, pharynx, trachea, and lungsb. lungs, heart, arteries, and veinsc. ligaments, cartilage, bones, and tendons

4. Which is NOT a role of the skeletal system?a. provide gas exchangeb. support the bodyc. protect vital organs

The Muscular SystemPurpose: works with the skeletal and nervous system to produce movement, also helps to circulate blood through the human body

-- muscle cells are fibrous

-- muscle contractions can be voluntary or involuntary

Major Muscles in the Human Body

-- biceps -- triceps -- deltoids

-- glutes -- hamstrings

Muscular System• There are 600 muscles in the body, both voluntary

and involuntary.– Voluntary muscles are muscles that you can

move whenever you want to. – Involuntary muscles contract and relax

automatically inside your body. We can not control our involuntary muscles.

• Muscle contracts to move bones and body parts. • Muscles look either striated or smooth:

– Striated muscle has stripes or striations in it. – Smooth muscle does not have striations.

• The cardiac muscle is unique in the human muscular system because it is made of smooth and skeletal muscle, controls the heart and is involuntary.

Muscular System

Function:• Controls movement of internal organs such

as the stomach, intestine, heart, and circulatory system.

• Controls contractions of the heart.• Works with skeletal system to move the

body. • Skeletal muscles work in pairs. When one

contracts, the other relaxes.• They are attached to bone by bands of

tissue called tendons.• Helps circulate blood and move food

through the digestive system.

POP QUIZ

13. What one organ is formed of cardiac muscle?a. the spleenb. the liverc. the heart

14. What muscle of the muscular system makes up the walls of the stomach, intestines, and blood vessels?

a. skeletalb. smoothc. striated

15. The function of the muscular system controls movement ofa. internal organsb. external organsc. the dermis

16. What are the three types of muscles in the human body?a. peripheral, neural, and cardiacb. smooth, autonomic, and skeletalc. skeletal, smooth, and cardiac

The Immune SystemPurpose: to remove infectious diseases and other pathogens from the human body

Major Organs and Their Functions

Skin – also called the integumentary system, the skin is the body’s first line of defense

White Blood Cells – recognize disease agents (antigens) and create antibodies to tag and remove these antigens

-- phagocytes are the white blood cell type that actually eats and destroys these antigens

Lymph Nodes – help restore fluid lost by the blood and return it to the circulatory system

Immune System

• Your immune system is like an army that protects you from disease.

• Your skin is the first wall of protection against disease causing agents called pathogens.

• The second line of defense are fluids like mucus found in your respiratory system and tears from your eyes.

• If the pathogens do pass through these defenses there is an army battalion of white blood cells and their weapons that fight the germs.

Immune System

• Bone Marrow– is the soft tissue found in the hollow interior of

bones. It is the place where most new blood cells are produced.

• Thymus– is an organ located in the upper anterior portion

of the chest cavity. It is of central importance in the maturation of T cells.

• Spleen– is an organ of the upper abdomen, where it

functions in the destruction of old red blood cells and holding a reservoir of blood.

• Lymph Nodes– act as filters that collect and destroy bacteria and

viruses. – When the body is fighting an infection,

lymphocytes multiply rapidly and produce a characteristic swelling of the lymph nodes.

POP QUIZ

25. The immune system:a. provides attachment sites for the organsb. protects you from diseasec. a complex bundle of nerves

26. All of these systems of the body are part of your immune system EXCEPT

a. skeletalb. circulatoryc. respiratory

27. White blood cells fight:a. red blood cellsb. gasc. germs

28. Organs of the immune system are:a. arteries, veins, capillaries, and circulation b. stomach, intestine, heart, and circulatory systemc. lymph nodes, bone marrow, thymus, and spleen

Reproductive System• Purpose: to create sex cells for the purpose of

creating new organisms

• Major Organs and their functions:

Integumentary System• Purpose: to protect the internal organs from

the outside world; to create a semi-permeable barrier

• Major Organs and their functions:

• Skin– Hair– Nails– Glands