24: Digestive Sytem

Question 1

What are the 4 functions of the digestive system?

Answer 1

1. Ingests food
2. Breaks down food into smaller molecules
3. Absorbs nutrients in molecules
4. Eliminates indigestible waste

Question 2

Where does the digestive tract begin?

how does this organ break down food?

Answer 2

• mouth
• teeth tear and grind food
• salivary glands release the enzyme amylase to degrade carbohydrates

Question 3

What is the passage the digestive and respiratory system share?

Answer 3

pharynx

Question 4

Flow of food

Answer 4

1. mouth
2. pharynx
3. esophagus
4. stomach

Question 5

What is peristalis?

Answer 5

rhythmic contractions of the esophagus that moves food to the stomach

Question 6

Where are proteins and food digested?

Answer 6

stomach

Question 7

How does the stomach digest proteins?

Answer 7

low pH of the stomach and the presence of the enzyme pepsin accomplish the digestion of proteins

Question 8

What regulates the digestion of food into the intestine?

Answer 8

sphincter

Question 9

What is chyme?

Answer 9

digested food material the exits the stomach and enters the small intestine

Question 10

What are the 2 functions of the small intestine?

Answer 10

1. Additional digestion of food material
2. Absorption of nutrients

Question 11

What are the organs that assist the small intestine?

Answer 11

1. Liver
2. Gallbladder
3. Pancreas

Question 12

What does the liver produce?

What does it do?

Answer 12

• bile
• emulsify fats for digestion and absorption.

Question 13

Where is excess bile stored?

Answer 13

gall bladder

Question 14

What does the pancreas produce?

Answer 14

juice that contains substances that enhance digestion

• Sodium bicarbonate, to increase chymal pH
• Pancreatic enzymes

Question 15

What are the 4 pancreatic enzymes? What do they digest?

Answer 15

1. Pancreatic amylase to digest starches
2. Trypsin to digest protein
3. Lipase to digest fats
4. Nuclease to digest nucleic acids

Question 16

What is villi?

Answer 16

• hair like projections that help absorb nutrients
• microvilli to increase surface area

Question 17

What does the large intestine do?

Answer 17

absorbs water, salts, and some vitamins.

further digestion

Question 18

Where is the appendix found?

Answer 18

pouch in the large intestine

Question 19

What are the 2 functions of the pancreas?

Answer 19

1. endocrine gland: secretion of insulin and glucagon into the bloodstream.
2. exocrine gland: secretion of pancreatic juice into the small intestine.

Question 20

What are the 6 functions of the liver?

Answer 20

1. Removal of poisons/toxins from the blood
2. Production of plasma proteins
3. Destruction of old red blood cells
4. Production of bile
5. Storage of glucose as glycogen
6. Production of urea (nitrogenous waste)
   • transported by the bloodstream to kidneys

Question 21

What are the 3 disorders of the liver?

Answer 21

1. Jaundice: excessive concentration of bile pigments in the blood
2. Hepatitis: viral infection of the liver
3. cirrhosis: liver tissue becomes fatty and then non-functional scar tissue.

Question 22

What does the respiratory system do?

Answer 22

allows for the exchange of gases between the blood and the external air

Question 23

What are the 2 steps of respiration?

Answer 23

• inspiration (inhalation) and expiration (exhalation) of breathing
• External gas exchange between air and blood in lungs
• Internal gas exchange between blood and body fluids

Question 24

What lines the respiratory ducts? why?

Answer 24

• cilia
• to filter debris and dust.

Question 25

What are the 3 structures of the upper respiratory tracts?

Answer 25

1. Nasal cavities and interconnected sinuses 2. pharynx 3. larynx (voice box) and vocal cords

Question 26

what is at the junction btwn the mouth and the larynx?

Answer 26

tonsils (lymphatic tissue)

Question 27

What is the opening btwn the pharynx and the larynx?

Answer 27

glottis

Question 28

What are the 4 parts of the respiratory tree?

Answer 28

1. *trachea* (windpipe) 2. primary *bronchii* leading to each lung 3. smaller *bronchioles* within each lung 4. sac-like *alveoli* (at the end of each bronchiole where gas exchange occurs)

Question 29

What does the contraction of the diaphram allow? How?

Answer 29

breathing * Contraction of the diaphragm creates a negative pressure that causes inspiration * Relaxation of the diaphragm causes expiration

Question 30

What do the bronchioles and alveoli of the lungs create?

Answer 30

large surface area for gas exchange * alveoli are in close contact with blood vessels, forming the respiratory membrane which facilitates gas exchange

Question 31

What are the 3 functions of the kidneys?

Answer 31

1. Excretion of nitrogenous wastes 2. Maintenance of water-salt balance of blood 3. Maintenance of the blood pH

Question 32

Flow of urine (4)

Answer 32

1. kidneys 2. ureter 3. urinary bladder 4. urethra

Question 33

What are the 3 regions of the kidney?

Answer 33

1. renal *cortex* is the outer region. 2. renal *medulla* lies underneath the cortex. 3. renal *pelvis* is the innermost layer

Question 34

What are nephrons?

Answer 34

urine producing cells of the kidneys

Question 35

What are the 5 parts of the nephron that help form urine?

Answer 35

1. nephron *capsule**:* allows for the diffusion of molecules from the blood 2. proximal *tubule*: packed with microvilli 3. nephron *loop*: has a descending and ascending limb 4. *distal* tubule 5. *collecting* duct

Question 36

What are the 3 steps of urine formation? 1. What occurs during each?

Answer 36

1. **Filtration**: small molecules pass from the blood into the nephron capsule 2. **Reabsorption**: Nutrients and other molecules move back to the blood 3. **Secretion**: wastes are selectively transported into the distal tubule

Question 37

What are 3 kidney diseases? What are they caused by?

Answer 37

1. **Renal disease** and failure can be caused by hypertension or diabetes 2. **Kidney stones** can form from pH imbalances, excess Ca, or urinary tract infections 3. **Edema** (build up of fluid) can occur if too many nephrons are blocked or are not functioning.