Digestive System Physiology

Question 1

what are the building blocks of food

Answer 1

lipids, carbohydrates, proteins, nucleic acids, and high E compounds

Question 2

what is the Carbon, Hydrogen, Oxygen ratio found in all carbohydrates?

Answer 2

1C:2H:1O

Question 3

what do carbohydrates include?

Answer 3

polysaccharides, which contain disaccharides, which are composed of two monosaccharides

Question 4

what do lipids include?

Answer 4

triglycerides, which are composed of fatty acids and glycerol

Question 5

what are proteins composed of?

Answer 5

peptides, which are composed of amino acids

Question 6

how many types of amino acids are there, and how many proteins can they form?

Answer 6

20 different types of amino acids, a limitless possibility of connections to form proteins

Question 7

what do nucleic acids include?

Answer 7

either RNA or DNA, which is composed of nucleotides

Question 8

what do high energy compounds include?

Answer 8

ATP, which is composed of nucleotides and phosphate groups

Question 9

what is a primary protein structure?

Answer 9

an amino acid sequence

Question 10

what is a secondary protein structure?

Answer 10

hydrogen bounding to peptide ‘back bone’, causing amino acids to ‘fold’ into pleated sheet and alpha helix

Question 11

what is tertiary protein structure?

Answer 11

3-D folding pattern of a protein causing by side chain interactions

Question 12

what are quaternary protein structures?

Answer 12

proteins consisting of more than one amino acid chain

Question 13

what are the 3 salivary glands, and their relative positioning around the mouth?

Answer 13

parotid glands: near the ear

sublingual glands: directly under the tongue

submandibular glands: near the mandibular angle

Question 14

what are the types of digestion that occur?

Answer 14

mechanical digestion and chemical digestion

Question 15

name the 3 muscle layer of the stomach and their function

Answer 15

longitudinal muscle (superficial most layer): pulls the bottom of the stomach up

circular muscle: pulls the stomach side to side

oblique muscle (deepest muscle layer): pulls the stomach diagonally

Question 16

name the alimentary canal structures, in order

Answer 16

mouth/oral cavity, pharynx, esophagus, cardiac sphincter, stomach, pyloric sphincter, duodenum, jejunum, ileum, ileocecal valve, cecum, ascending colon, transverse colon, descending colon, sigmoid colon, rectum, anal canal, anus

Question 17

what protects your body from your stomach juices

Answer 17

thick layer of mucus on the stomach walls (a majority of gastric glands produce this mucus)

Question 18

what are the 5 nucleotides?

Answer 18

adenine (A), cytosine (C), guanine (G), thymine (T), uracil (U)

Question 19

at what temperature do human proteins begin to denature, and at what temperature will a person be declared clinically dead at

Answer 19

proteins denature: 40.5C (105F)

clinically dead: 42.2C (108F)

Question 20

what is the pH of the stomach?

Answer 20

pH of 2

Question 21

what are the 5 cell types in the stomach?

Answer 21

goblet cells, parietal cells, chief cells, D cells, and G cells

Question 22

what do goblet cells secrete in the stomach?

Answer 22

mucus (to protect the stomach lining)

Question 23

what do parietal cells secrete in the stomach?

Answer 23

gastric acid (HCl)

Question 24

what do chief cells secrete in the stomach?

Answer 24

pepsinogen

Question 25

what do D cells secrete in the stomach?

Answer 25

somatostatin (inhibits acid secretion)

Question 26

what do G cells secrete in the stomach?

Answer 26

gastrin (stimulates acid secretions)

Question 27

in what environment can cancer live in?

Answer 27

cancer can ONLY live in an acidic environment

Question 28

how does your body defend against ingesting toxic substances?

Answer 28

spitting out, throwing up, and diarrhea

Question 29

what does everything absorbed via digestion pass through?

Answer 29

everything MUST pass through the hepatic portal vein

Question 30

what is a negative feedback loop?

Answer 30

a physiological process that occurs as a means to regulate homeostasis

Question 31

what is a positive feedback loop?

Answer 31

a physiological process with a definitive end (ex. blood clotting)

Question 32

what is blood sugar managed by?

Answer 32

by the pancreas and the liver

Question 33

what is glycogensis?

Answer 33

the formation of glycogen by liver, caused by production of high blood sugar and pancreatic production of insulin

Question 34

what is glycogenolysis?

Answer 34

the 'chopping' off of glycogen into sugars, caused by production of glucagon by the pancreas

Question 35

how long does it take for all the blood in the body to be replaced?

Answer 35

around 90-120 days

Question 36

what do dead erythrocytes (red blood cells) break down into?

Answer 36

dead erythrocytes break down into hemoglobin

Question 37

what does hemoglobin break down into?

Answer 37

hemi and globin

Question 38

what is hemi turned into?

Answer 38

hemi gets turned into iron and bilirubin -the iron goes into the bone marrow, which in turn produces more erythrocytes -the bilirubin turns into bile by the liver before being stored in the gallbladder

Question 39

what does globin turn into?

Answer 39

globin is recycled into amino acids

Question 40

what does the liver make as a by-product of digestion?

Answer 40

the liver makes urea, which is the #1 molecule found in urine

Question 41

why is not using the restroom so dangerous?

Answer 41

uric acid can form in the blood and turn into ammonia (deadly!)

Question 42

how does your body get rid of urea?

Answer 42

via urination and via sweat

Question 43

what are the stages of digestion?

Answer 43

ingestion, digestion, absorption, assimilation, and egestion

Question 44

what is ingestion?

Answer 44

the taking in of food into the body

Question 45

what is digestion?

Answer 45

the break down of food into smaller, simpler compounds

Question 46

what is absorption?

Answer 46

the diffusion of food nutrients into the blood

Question 47

what is assimilation?

Answer 47

the usage of digested materials to make new materials

Question 48

what is egestion?

Answer 48

the removal of undigested waste from the body (the removal of fecal matter is defication)

Question 49

what is peristalsis?

Answer 49

peristalsis is a rhymic, wave-like contraction that happens in the gut wall via the contractor of antagonistic muscles that push food into the body

Question 50

what does bile do?

Answer 50

bile emulsifies fats, increasing their surface area for digestion

Question 51

what does a lacteal do?

Answer 51

lacteals absorb fat as fine droplets into the lymphatic system

Question 52

what are the 7 main functions of the liver?

Answer 52

production of heat, regulation blood sugar concentration, detoxification the body, create bile, storage of iron, syntization of proteins, and deamination of amino acids

Question 53

what type of tissue is the area between the mouth and esophagus called?

Answer 53

striated epithelial tissue (sheets of flat, shedding tissue)

Question 54

what type of tissue is the area between the stomach and the large intestine called?

Answer 54

columnar epithelial tissue (boxy, secreting and absorbing cells)

Question 55

what does the suffix 'ase' mean when referring to enzymes

Answer 55

enzymes that are functional

Question 56

what does the suffix 'gen' mean when referring to enzymes

Answer 56

the enzymes must be activated

Question 57

what are the different parts of the stomach lining?

Answer 57

mucosa, submucosa, muscularis, serosa

Question 58

what is a function/characteristic of the stomach layer mucosa?

Answer 58

contains gastric pits and glands that secrete mucus

Question 59

what is a function/characteristic of the stomach layer submucosa?

Answer 59

contains bloodvessels

Question 60

what is a function/characteristic of the stomach layer muscularis?

Answer 60

contains the muscles of the stomach (oblique, circular, and longitudinal)

Question 61

what is a function/characteristic of the stomach layer serosa?

Answer 61

a connective tissue layer, visceral peritoneum

Question 62

what does the stomach typically absorb?

Answer 62

water, monocaccharides, alcohol, and asprin

Question 63

what is the length of the small intestine, both postmortem and during life?

Answer 63

postmortem: 20 ft during life: 12 ft

Question 64

what is the small intestine lining made out of? (elaborate more than just the tissue layer)

Answer 64

composed of columnar epithelial cells that contain a brush border of microvilli

Question 65

what is a lumen?

Answer 65

the cavity or channel, in the small intestine it contains villi, and the microvilli brush border

Question 66

what does a villi do?

Answer 66

absorbs water soluble nutrients into the blood stream

Question 67

what does lacteals do?

Answer 67

absorb fat into the lymphatic system

Question 68

what does the sphincter of oddi do?

Answer 68

controls flow of fluid from the pancreatic duct and common bile duct

Question 69

what does the duodenum do?

Answer 69

enzymatic digestion of chyme

Question 70

what does the jejunum do?

Answer 70

absorption of sugars and amino acid actively transported across mucosal lining

Question 71

what does the ileum do?

Answer 71

absobtion

Question 72

what does the pancreas do?

Answer 72

manufactures hormones and digestive enzymes (such as insulin) and regulates blood sugar

Question 73

what is the downside of pancreaticly produced enzymes?

Answer 73

the insufficient and often slow delivery of products into the duodenum via pancreatic duct

Question 74

what cell aids in the production of bile ?

Answer 74

Kupffer cells, which eat dead erythrocytes

Question 75

fun fact: how many layers of cells protect your body from the deadly gastric juices

Answer 75

1 layer of cells

Question 76

what is the longest part of the small intestine?

Answer 76

the ileum (~12 ft long)