exam 2 buzzers

Question 1

can secretions release across apical membrane of endocrine glands?

Answer 1

no, in unicellular glands, they cannot
so this would NOT occur in the stomatch or instinces where simple columnar epitheleal cells line the lumen

Question 2

what is the built in buffers that help the body maintain a neutral pH? where is it found in the body

Answer 2

Carbonic anhydrase is an enzyme made by GI tract/ accessory organ cells

Question 3

know the organization of the nervous system:
CNS vs PNS
autonomic, somatic, enteric
what each control

Answer 3

Question 4

what is the salivary gland modification in snakes?

Answer 4

venom is a derivative of saliva and starts the digestive process in snakes

Question 5

what are the five salivary enzymes?

Answer 5

1. lingual lipase
2. salivary amylase
3. lysozyome proteins
4. IgA immunoglobulin
5. mucin protein

Question 6

what does lingal lipase, salivary amylase, lysozymes, IgA, and mucin break down?

Answer 6

1. lingual lipase: triglyceride into monoglyceride and free fatty acids
2. salivary amylase: glucose (starch) polymers into disaccharides
3. lysozyome proteins: breaks down microbial cell walls
4. IgA immunoglobulin: binds to and neutralizes pathogens
5. mucin protein: hydrophillic oligoprotein

Question 7

what is a reflex arc and what are the two reflex arcs types of the ENS?

Answer 7

reflex arc: a rapid and involuntary response to stimulus that does not require integration (no CNS) in the brain
1. short reflex
2. long reflex

Question 8

what is the short reflex arc?

Answer 8

it is a response mediated entirely by the ENS and does NOT require CNS (spinal chord) integration as the stimulus is from within the GI tract

Question 9

what is the long reflex arc?

Answer 9

response that involes CNS regulation that is stimulated from external or interal triggers of the GI tract

Question 10

function of adult human teeth:
inscisors
cainines
premolars
molars

Answer 10

inscisors: used for cutting off pieces of food, bitting chunks
cainines: for tearing, ripping, piercing, grasping food
premolares: transitional teeth of cainine “tearing/ pirecing” and transfering to molars
molars: upper and lower lock to grind food together

Question 11

which tooth type grows continuously long in rodents and lagomorphs?

Answer 11

inscisors

Question 12

what is the crop?

Answer 12

storage organ in some bird’s esophagus for food because they have to quickly ingest and move as they are prey to many animals

Question 13

what are the three swallowing phases in humans?

Answer 13

1. buccal: voluntary movementin the mouth using teeth to create bolus
2. pharyngeal: involuntary smooth muscle movement where uvula rises to block nasocavity, larnyx rises to block epiglottis, and UES relaxes so bolus can move into esophagus
3. Esophageal: involuntary as *UES contracts *after bolus enters, peristaltic movement, *LES relaxes *for bolus to move into stomach

Question 14

function of the fundus

Answer 14

dome shaped portion that stores gas and makes contact with the diaphragm and has gastic glands that secrete most stomach enzymes and acids

Question 15

what are the functions of the four gastric gland cells? which are endocrine? exocrine?

Answer 15

1. mucous neck cells: exocrine cells that secrete acidic mucus
2. parietal cells: exocrine cells secrete hydrochloric acid (HCl) as seperate ions into stomach lumen by proton pump (H+)
3. chief cell: exocrine cells that produce and secrete pepsinogen (the zymogen precursor of pepsin)
4. enteroendocrine cells: endocrine cells secrete substance into the lamina propia (D and G cells) mostly in the antrum

Question 16

proton pump: what is into to the cell? out of the cell? how does it neutralize? integreal chemical compound incorporated?

Answer 16

governed by parietal cells, the proton pump uses a H+-K+ ATPase to pump H+ into the lumen and K+ into the cells (which eventually leaves down the concentration gradient with no added energy) after H+ dissociates from HCO3- from Carbonic anhydrase

Question 17

how does pepsinogen become pepsin?

Answer 17

pepsinogen is the zymogen precusror that is excreated by cheif cells to become activated pepsin (protease) after cleaveage by stomach’s low pH to denature proteins

Question 18

where are D and G cells primarily located along the digestive tract?

what are they?

Answer 18

secreted from stomach enteroendocrine cells, D and G cells are in the antrum of the stomach (first 1/3) of the pyloric part

Question 19

what is the function of the two enteroendocrine cells?

Answer 19

G cells: gastrin stimulates the secretion of HCl from parietal cells and increases “gastric juice”
D cells: somatostatin (growth inhibiting hormone) inhibits gastrin from accumulating excess acidity

Question 20

what are the two types of enteroendocrine intestinal cells?

Answer 20

I cells: produces chloecystokinin to increase the secretion of the pancrease and slow down movement in the stomach to ensure digestion
S cells: produces secretin

Question 21

what are the five parts of the large intestine?

Answer 21

from the ileocecal valve to anus
1. cecum: recieves chyme from the SI
2. appendix: contains masses of lyphoid tissue
3. colon: water absorbed, four regions, indigestible matter made into feces
4. rectum: storage for fecal matter
5. anal canal: the exit of the abdominopelvic cavity, two sphincters (interal, smooth and external, skeletal)