Human Physiology

Question 1

mechanical digestion

Answer 1

the physical breakdown of food into smaller pieces, chewing and grinding

Question 2

chemical digestion

Answer 2

the breakdown of food into its basic components, uses enzymes

Question 3

starch (carbohydrate)

Answer 3

• pancreatic amylase
• source: pancreas
• LAC: small intestine
• optimal pH: 7.5-7.8
• EP: maltose

Question 4

protein

Answer 4

• pepsin
• source: stomach
• LAC: stomach
• optimal pH: 2
• EP: small polypeptides+single amino acids

Question 5

lipids (triglycerides)

Answer 5

• pancreatic lipase
• source: pancreas
• LAC: small intestine
  - use of liver bile to emulsify fats
  - use of pancreatic bile to neutralize pH
• optimal pH: 7.2
• EP: glycerol+fatty acids

Question 6

absorption

Answer 6

• the movement of nutrients from the digestive system into the body (blood)
• most nutrients are absorbed: stomach, small intestine, large intestine

Question 7

active/co-transport

Answer 7

glucose, amino acids

Question 8

osmosis

Answer 8

water

Question 9

facilitated diffusion

Answer 9

monosaccharides

Question 10

simple diffusion

Answer 10

triglycerides

Question 11

pinocytosis

Answer 11

• mode of endocytosis
• process by which fluid/dissolved substances are ingested
• allows materials to be ingested in BULK+takes LESS time

Question 12

small intestine

Answer 12

• folds in the lining of the small intestine increases surface area
• muscular layers allow for peristalsis

Question 13

peristalsis

Answer 13

wave of contraction and relaxation of the longitudinal and circular muscles of the alimentary canal, by which the contents are forced along the tube

Question 14

muscularis

Answer 14

consists of 2 smooth layers:

• thin outer longitudinal layer: shortens+elongates the intestine
• thicker inner circular layer of smooth muscles: causes constriction

Question 15

• many villi
• rich blood supply
• villi project into the lumen of the gut
• microvilli are outward folds of plasma membrane
• contains lacteals

Answer 15

• increases SA
• aids in absorption of nutrients into blood
• increases SA by 10x
• increases the SA another 10x
• aid in absorption of lipids

Question 16

mouth

Answer 16

location where food enters and mechanical/chemical digestion begins

Question 17

tongue

Answer 17

pushes food back into the mouth to help ingestion

Question 18

salivary glands

Answer 18

produces saliva to assist with digestion and swallowing. moistens food into a bolus, and begins polysaccharide digestion (amylase)

Question 19

esophagus

Answer 19

a hollow tube connecting the oral cavity to the stomach (separated from the trachea by the epiglottis). food is mixed with saliva and then is moved in a bolus via the action of peristalsis.

Question 20

stomach

Answer 20

a temporary storage tank where food is mixed by churning and protein digestion begins. it is lined by gastric pits that release digestive juices, which creates an acidic environment (pH of 2)

Question 21

liver

Answer 21

takes raw materials absorbed by small intestine and uses them to make key chemicals. roles include detoxification, storage, metabolism, bile production and hemoglobin breakdown

Question 22

gallbladder

Answer 22

gallbladder stores the bile produced by the liver (bile salts used to emulsify fats). bile stored in the gallbladder is released into small intestine via common bile duct.

Question 23

pancreas

Answer 23

produces a broad spectrum of enzymes that are released into the small intestine. also secretes hormone (insulin+glucagon), which regulate blood sugar concentrations

Question 24

small intestine

Answer 24

a long, highly folded tube where nutrients are absorbed. 3 sections-duodenum, jejunum, and ileum

Question 25

large intestine

Answer 25

final section of the alimentary canal, where water+dissolved minerals (ex: ions) are absorbed. 3 sections-ascending, transversal, descending colon

Question 26

rectum

Answer 26

leads to the anus, receives stool from colon

Question 27

anus

Answer 27

structure that controls the digestion of solid waste

Question 28

stomach acid

Answer 28

contains gastric glands which release digestive acids to create a low pH environment. this denatures proteins and other macromolecules aiding in overall digestion. stomach epithelium contains a mucous membrane which prevents the acids from damaging the gastric lining. pancreas releases alkaline compounds which neutralize the acids as they enter the intestine

Question 29

bile

Answer 29

contains bile salts which interact with fat globules and divide them into smaller droplets (emulsification). emulsification of fats increases the total SA availability for enzyme activity (lipase)