Lecture 11 GI Secretion & Absorption

Question 0

what are the 3 types of complex glands

Answer 0

salivary, pancreas, liver

Question 1

What are the 4 gland types

Answer 1

unicellular mucous, crypts of L, tubular, complex

Question 2

what are the mechanisms of stimulation

Answer 2

food contact
autonomic stimulation
higher brain centers
hormones

Question 3

what are some functions of mucous

Answer 3

adhere to food
coat gut wall to prevent actual contact of food
resistant to digestion by GI enzymes
cause fecal adherence

Question 4

what are the 2 types of salivary gland secretions and what do they consist of?

Answer 4

parotid - serous

sublingual/mandibular - mixed

Question 5

Where does the 1st stage of salivary secretion of ions occur?

Answer 5

acini

Question 6

what do salivary secretions contain and what are they typical of

Answer 6

ptyalin (alpha amylase)

ECF

Question 7

where does the 2nd stage of salivary secretion occur?

Answer 7

salivary duct

Question 8

give the reabsorption / secretion of ions and whether it is passive or Active transport

Answer 8

Na - active reabsorption
Cl - passive reabsorption
K - active secretion
HCO3- (bicarb) - active/passive secretion

Question 9

TRUE or FALSE

nervous regulation of salivary secretion is normally parasympathetic system?

Answer 9

TRUE

Question 10

The facial nerve supplies what ganglion and gland?

Answer 10

submandibular ganglion

submandibular and sublingual glands

Question 11

the glossopharyngeal nerve supplies what ganglion and gland?

Answer 11

Otic ganglion

parotid gland

Question 12

what chief cells secrete?

how is their release stimulated?

Answer 12

pepsinogen and intrinsic factor

Ach from Vagus nerve or gastric enteric nervous plexus or acid in stomach

Question 13

what do parietal cells secrete?

Answer 13

HCl

Question 14

What ion leaks outside the cell but is transported back in by the ______ pump?

Answer 14

K+

by H-K ATPase pump

Question 15

what ion is reabsorbed into the cell due to the _______ pump?

Answer 15

Na+

Na-K basolateral pump

Question 16

How are chloride ions secreted?

Answer 16

through chloride channels into the canaliculi

Question 17

what are the 2 forms of gastrin and which is more abundant?

Answer 17

G-34 and G-17 (more abundant)

Question 18

What is gastrin released by?

Answer 18

in response to proteins in the pyloris

Question 19

what does gastrin cause?

Answer 19

enterochromaffin-like cells to release histamine

Question 20

what does histamine do?

Answer 20

cause secretion of HCl

Question 21

what are the 3 phases of gastric secretions?

Answer 21

cephalic
gastric
intestinal

Question 22

what are the digestive enzymes for proteins?

what are they secreted by?

Answer 22

trypsin, chymotrypsin, and carboxypolypeptidase
trypsin inhibitor

glandular cells

Question 23

what is the digestive enzyme for carbs?

Answer 23

pancreatic amylase

Question 24

what is the digestive enzyme for fat?

Answer 24

pancreatic lipase, cholesterol esterase, phospholipase

Question 25

where is Ach from?

Answer 25

PS nerves and enteric nervous system

Question 26

what stimulates CCK release? what is the result of the release?

Answer 26

presence of food in upper intestine increase in secretion of pancreatic enzymes

Question 27

what stimulates secretin's release? what does it release?

Answer 27

presence of acidic foods in upper intestine large amounts of sodium bicarbonate

Question 28

what stimulates release of bile from the gall bladder?

Answer 28

presence of fatty food in the duodenum

Question 29

how is bile concentrated in the gall bladder?

Answer 29

by active transport of sodium ions, secondary absorption of chloride ions and water

Question 30

outline the synthesis of bile salts in the liver

Answer 30

cholesterol converted to cholic acid or chenodeoxycholic acid, then conjugated with glycine or taurine

Question 31

what are the functions of bile?

Answer 31

emulsify fat | complex with lipids to form micelles for absorption

Question 32

what are the causes of gallstones?

Answer 32

too much absorption of water from bile too much absorption of bile acids from bile too much cholesterol in bile inflammation of the epithelium

Question 33

what do Paneth cells secrete?

Answer 33

alpha defensins

Question 34

what do goblet cells secrete?

Answer 34

mucous

Question 35

what do enterocytes secrete?

Answer 35

water and electrolytes, also reabsorb it

Question 36

Describe the absorption of glucose in the small intestine

Answer 36

Sodium secondary Active co-transport mech

Question 37

what does the absorption of peptides/aa in small intestine use?

Answer 37

sodium co-transport mech

Question 38

how are fats in the small intestine absorbed

Answer 38

by micelles and chylomicrons