GI Histology

Question 1

define submucosal plexus

Answer 1

collection of ganglia, interneurons of ENS responsible for regulating epithelial fxn & circular smooth muscle fxn

Question 2

define myenteric plexus

Answer 2

collection of ganglia, interneurons of ENS responsible for regulating longitudinal & circular smooth muscle fxn

Question 3

Name the layers of digestive tract from superficial to deep

Answer 3

serosa => muscularis externa => submucosa => mucosa

Question 4

What are the 3 layers of the mucosa

Answer 4

epithelium;
lamina propria;
muscularis mucosa

Question 5

what is unique about the esophageal muscle?

Answer 5

1st 1/3 is skeletal;
2nd 1/3 is mixed skeletal and smooth;
3rd 1/3 is smooth

Question 6

for the stomach, what is unique about the layers of the digestive tract?

Answer 6

stomach smooth muscle contains oblique layer bw submucosa & circular layer of smooth muscle

Question 7

what are the major histo characteristics of the esophagus?

Answer 7

nonkeratinized stratified squamous epithelium;
skeletal muscle in muscularis externa (upper 1/3);
smooth muscle (lower 1/3)

Question 8

major histo characteristics of stomach (body and fundus)

Answer 8

Rugae=> shallow pits; deep glands

Question 9

major histo characteristics of pylorus

Answer 9

deep pits; shallow branched glands

Question 10

major histo characteristics of small intestine

Answer 10

villi, plicae, crypts

Question 11

major histo characteristics of duodenum

Answer 11

Brunner glands

Question 12

action of the brunner glands of duodenum

Answer 12

discharge alkaline secretion

Question 13

major histo characteristics of jejunum

Answer 13

villi;
well developed plica;
crypts

Question 14

major histo characteristics of ileum

Answer 14

Payer patches=> aggregations of lymph nodules

Question 15

major histo characteristics of large intestine

Answer 15

lacks villi; crypts

Question 16

mucosal cell types at surface of body and fundus of stomach

Answer 16

mucous cells;
chief cells;
parietal cells;
enteroendocrine (EE) cells

Question 17

function of mucous cells

Answer 17

secrete mucus; form protective layer against acid;

tight jxns bw cells contribute to acid barrier of epithelium

Question 18

functions of Chief cells

Answer 18

secrete pepsinogen and lipase precursor

Question 19

function of parietal cells

Answer 19

secrete HCl and intrinsic factor

Question 20

function of EE cells in body and fundus of stomach

Answer 20

secrete variety of peptide hormones

Question 21

mucosal cell types at surface of pylorus

Answer 21

mucous cells;
parietal cells
EE cells

Question 22

function of EE cells in pylorus

Answer 22

high concentration of gastrin

Question 23

mucosal cells types of small intestine at the surface

Answer 23

columnar absorptive cells

Question 24

mucosal cells types of duodenum at the surface

Answer 24

goblet cells;
paneth cells;
EE cells

Question 25

mucosal cells types of jejunum at the surface

Answer 25

goblet cells; paneth cells; EE cells

Question 26

mucosal cells types of ileum at the surface

Answer 26

M cells found over lymphatic nodules and payer patches

Question 27

mucosal cells types of large intestine at the surface

Answer 27

mainly mucus secreting and absorptive cells

Question 28

functions of columnar absorptive cells

Answer 28

contain numerous microvilli that greatly increase luminal surface area, facilitating absorption

Question 29

functions of Goblet cells

Answer 29

secrete acid glycoproteins that protect mucosal linings

Question 30

functions of paneth cells

Answer 30

contains granules that contain lysozyme=> may help regulate intestinal flora

Question 31

functions of EE cells of duodenum and jejunum of small intestine

Answer 31

high concentration of cells that secrete cholecystokinin and secretin

Question 32

functions of M cells

Answer 32

endocytose and transport antigen from lumen to lymphoid cells

Question 33

functions of mucus secreting and absorptive cells of large intestine

Answer 33

transports Na+ (actively) and water (passively) out of lumen