1. Human Body Systems

2. I. Integumentary;
A. Main Functions;
1. homeostasis- animal’s regulation of internal environment to help them maintain survival conditions
a. hot temps – blood vessels dilate and body
sweats
b. cold temps- blood vessels constrict directing the blood to the brain and other vital organs.

3. 2. protective barrier against invasive
2. protective barrier against invasive infectious organisms and protection for the body’s internal organs.
3. receptor for the sense of touch- feels pain, pressure, heat, cold
B. Organs;
1. Major organ is the skin (largest organ of the body). It is composed of;
a. epidermis- outermost layer composed of dead cells and mitotic cells.

4. b. dermis- under the epidermis,. contains blood vessels and
b. dermis- under the epidermis, contains blood vessels and nerve endings.
Also location of sweat glands.
c. subcutaneous- below the dermis, is composed of fat and connective tissue.
2. other organs consist of hair, nails and sweat glands

6. On average, a human will shed and regrow outer skin cells about every 35 days.
We shed about 30,000 to 40,000 skin every minute.
There are as many hairs per square inch on human body, as a chimpanzee.
Human hair is generally thinner and/ or lighter in color than chimpanzee hair, so it is less noticeable.

7. II. Skeletal; the adult human body has 206 bones.
Axial (skull, spine and ribs) and appendicular (all other appendages)
A. Main Functions;
1. support for the body
2. protection for internal organs
3. production of blood cells
4. storage of minerals
B. Organs;
1. compact bone- solid bone for support and protection.
2. spongy bone- site of marrow production

8. 3. marrow-
*red marrow- makes blood cells
*yellow marrow- mostly fat
4. cartilage- hard flexible material found in the nose, outer ears and between joints.
5. Ligaments- Long bands of connective
tissue that joins bone to bone at a joint.
C. Movable Joints;
1. hinge- found in the fingers, elbows and knees

9. 2. pivot- Allows the lower arm to turn. Allows the head to turn
3. ball and socket- found in the hips and shoulders
4. gliding- found in the wrists and ankles
Saddle joint- found where the thumb, and fingers attach to the hand.
This allows the fingers to spread and allows the thumb to move back and forth across the hand.

10. D. Fixed Joints; Joints that fuse together and do not allow movement.
These joints include the bones in the skull
and pelvis.
The hardest bone in the human body is the jawbone.
Twenty five percent of a person’s bones are in their feet and hands.
There are 26 bones in each foot and 27 in each hand.

12. III. Muscular; muscles work by alternately contracting and relaxing.
Muscles do not work by pushing.
A. Main Function; is movement
B. Organs/ Cell types; voluntary muscle is consciously controlled, involuntary muscle
is not.
1. cardiac muscle- found only in the heart. Involuntary movement
2. skeletal muscle- (striated) muscle that is attached to the skeleton that is used for
voluntary movement.

13. 3. smooth muscle- muscles of the body’s organs. Involuntary movement
a. peristalsis is the muscular contraction that takes food to the stomach from the esophagus.
4. Tendons- Connective tissue that attaches  
muscle to muscle, or muscle to bone.

15. IV. Digestive; continuous tube
A. Main Function; Break down and absorption of food
B. Organs;
1. mouth- mechanical chewing and chemical saliva
a. amylase is an enzyme in saliva that breaks starches down into simple sugars.
2. esophagus- food tube, uses peristalsis
3. stomach- gastric juices and acid chemically break down food
a. HCl in the stomach denatures proteins (causes them to unfold)
b. pepsin- enzyme that breaks down proteins

16. 4. Chyme is the semifluid food that leaves the stomach.
5. small intestine- small diameter, but very long.
a. duodenum the first part of the small intestine.
*Enzymes from the pancreas and bile from the gall bladder chemically and mechanically break down partially digested food.
Enzymes break down proteins and carbohydrates chemically
Bile mechanically changes lipids into smaller droplets so they can be easily absorbed.

17. b. Villi - (finger-like projections)
absorb digested food and move it into the bloodstream.
The villi increase the amount of surface area in the small intestine, to maximize the amount of nutrients absorbed.

18. 6. colon (large intestine)- Water and salts are
6. colon (large intestine)- Water and salts are absorbed making the indigestible material more solid
7. rectum/ anus- removes waste in the form of feces

20. A. Function; Exchange of gases for cellular respiration.
V. Respiratory
A. Function; Exchange of gases for cellular respiration.
By diffusion, oxygen in the lungs diffuses into the blood stream, and carbon dioxide in the blood stream diffuses into the lungs.
B. Organs
1. trachea- windpipe
2. bronchi- divides trachea so that air goes to each lung.
3. lungs- main organ of the system. Inhaling takes air into the body, exhaling pushes air out.

21. a. alveoli- air sacs one cell layer thick allow
a. alveoli- air sacs one cell layer thick allow gases to diffuse into and out of the lungs.
The diaphragm is a muscle that controls breathing.
When the diaphragm contracts, it flattens, and air is pulled into the lungs.
When it relaxes, it rises and pushes the air out.

22. VI. Circulatory;
A. Function; Transport of blood throughout the body.
Part of the body’s immune system (white blood cells).
B. Organs
1. Heart- made of cardiac muscle, pumping causes blood to circulate through the body.
a. atria- the two upper chambers of the heart
b. ventricles- the two lower chambers of the heart
2. arteries- vessels that take blood away from the heart.
3. veins- vessels that take blood toward the heart. Contain valves to keep the blood moving in the right direction.

24. 4. capillaries- smallest blood vessels (microscopic).
Only one cell layer thick, and they are so thin they only let one blood cell pass through at a time.
Capillaries allow the diffusion of gases into and out of the circulatory system.
They are the transition vessels between veins and arteries

25. C. Blood tissue;
1. plasma- 55% of volume of blood. Fluid part of the blood.
2. white blood cells - 1% volume. Work with immune system to fight disease.
3. red blood cells- 44% carry oxygen to cells, and some carbon dioxide away from cells.
a. hemoglobin- protein that bonds oxygen and some carbon dioxide to red blood cells.
4. platelets- cell fragments that aid in clotting the blood. (mixed into the plasma)

27. VII. Nervous;
A. Function; Control of thought, senses, and all body systems.
B. Neurons; Nerve cells
1. cell body- main part of the cell, containing the nucleus
2. dendrite- receives nerve impulse and sends it to the cell body
3. axon- receives the impulse from the cell body and passes it to the next neuron.

28. 4. synapse- the gap between the axon of one
4. synapse- the gap between the axon of one neuron and the dendrite of another neuron.
Direction of impulse movement →

29. C. Neuron Types;
1. sensory- sends nerve impulse from the peripheral nervous system (PNS) to the central nervous system (CNS).
2. motor- sends nerve impulses from the CNS to the PNS
3. interneuron- found in the brain and spinal cord. Processes incoming impulses and passes them to the motor neurons.

30. D. Regions;
1. Central Nervous System (CNS)- Includes the brain and spinal cord.
a. cerebrum- divided into two hemispheres. Each hemisphere controls the opposite side of the body.
*frontal- reasoning, personality, judgement. Voluntary movement and speech
*parietal- sensory information coordinated here. Sense of touch.
*temporal- memory, hearing, speech interpretation
*occipital- all visual information processed here.

31. b. cerebellum- controls balance and coordination
c. brain stem- connects various parts of the brain, and controls involuntary muscles.
* midbrain- some reflexes such as pupil dilation.
*pons- regulates breathing and connects brain to spinal cord.
*medula oblongata- controls heart, swallowing, coughing

32. d. spinal cord- connects the CNS to the PNS.
2. Peripheral Nervous System (PNS); All of the nervous
system outside of the central nervous system.

33. VIII. Endocrine; Works with the nervous system
VIII. Endocrine; Works with the nervous system Hormones are chemicals that travel through the blood stream.
A. Main Function; Secretion of hormones to control the functions of the other body systems.
B. Glands; structures that secrete hormones in the endocrine system.
1. hypothalamus-
a. location- in the middle of the brain.
Connects brain to the rest of the endocrine system.
b. function- makes hormones and controls the pituitary gland.

34. 2. pituitary –
a. location- with the hypothalamus, located in the middle of the brain.
b. function- controls the release of hormones by the other endocrine glands.
3. thyroid-
a. location- around the trachea.
b. function- controls growth, development and metabolism.
Helps with digestion and controls energy levels.

35. 4. thymus-
a. location- upper chest
b. function- causes reproduction of white blood cells
* disappears as you mature
5. adrenal glands-
a. location- at the top of each kidney.
b. production of adrenaline for stressful situations.
Increases heart rate, breathing, and alertness

36. 6. pancreas-
a. location- between stomach and intestines
b. regulates the storage of glucose.
* insulin- removes sugar from the bloodstream
* glucagon- adds sugar to the bloodstream
7. gonads- produce sexual hormones.
a. female- ovaries produce estrogen and progesterone
b. male- testes produce testosterone

37. IX. Excretory;
A. Function; Removal of waste from the body, and regulating the amount of water in the body.
B. Organs of Urinary tract-
1. Kidneys- the main organ within this system.
There are two kidneys, but if one fails, the other will increase in size and take over the work of failed kidney.

38. a. nephrons- a series of small tubes that filter impurities
a. nephrons- a series of small tubes that filter impurities from the blood.
Each kidney has about a million nephrons.

39. 2. ureters- tubes that transport urine from the kidneys to the bladder
3. bladder- bag for holding urine. An average human bladder can hold about 2 cups of urine when full.
A signal goes to your central nervous system when you have about 7 ounces of urine in the bladder, letting you know you need to eliminate the urine.
4. urethra- tube that empties the bladder

41. C. Other excretory-
1. Colorectal- removal of solid waste from the digestive system.
2. Sweat glands- sweat contains a small amount of urea (found in urine).

42. X. Reproductive
A. Function; Formation of gametes, fertilization, and development of a new person.
B. Organs
1. Male-
a. testes- form the sperm
b. epididymis - tube in which sperm mature
c. vas deferens- transports sperm from epididymis to ejaculatory ducts.
d. seminal vesicles- glands at the base of urinary bladder that secrete mucous like fluid

43. e. prostate gland- donut shaped gland. below. bladder
e. prostate gland- donut shaped gland below bladder. Secretes fluid to help sperm move and survive.
f. bulbourethral glands- beneath prostrate. Produces fluid that neutralizes acidic environment
g. semen- sperm and all of the other reproductive fluids

44. 2. Female-
a. ovaries- form the eggs
b. fallopian tube- tube to transport egg from ovary to uterus
c. uterus- during pregnancy, this is where the fetus develops
d. cervix- opening into the vagina from the uterus

45. XI. Lymphatic System;
A. Functions
1. Immunity; filters out pathogens, forms acquired immune response, uses white blood cells to destroy or trap pathogens
2. Maintains homeostasis of body fluids; Returns fluids to the blood stream once they have leaked into the body tissues.
B. Organs and Cells; tissue fluid that enters the lymph vessels is called lymph.
1. Thymus gland; located above the heart. Converts white blood cells into pathogen fighting cells.

46. 3. spleen; stores lymphocytes, filters and destroys
3. spleen; stores lymphocytes, filters and destroys pathogens, but does this by filtering blood instead of lymph.
4. tonsils; located at the back of the throat, work the way lymph nodes do
5. Lymph veins; flow toward the heart, and return lymph to the blood stream at the lymphatic and thoracic ducts.
* There are no lymph arteries