Unit 3 Digestive System

Question 1

digestive general structure

Answer 1

tube with 4-layered wall: 
mucosa
submucosa
muscularis externa (propria)
serosa adventitia

Question 2

digestive function

Answer 2

ingest, digest, absorb

Question 3

digestive components

Answer 3

1. oral cavity
2. pharynx
3. esophagus
4. stomach
5. small intestine
6. large intestine
7. rectum
8. anus

Question 4

associated digestive glands

Answer 4

1. salivary glands
2. liver
3. pancreas

Question 5

mucosa functions

Answer 5

a) selective barrier
b) secretion
c) absorption

Question 6

mucosa components

Answer 6

a) epithelial layer
b) lamina propria – loose connective tissue
c) muscularis mucosa – smooth muscle

Question 7

submucosa

Answer 7

1. loose connective tissue
2. blood and lymphatic vessels
3. Meissner’s plexus – part of the autonomic nervous system
4. glands in the esophagus and duodenum

Question 8

muscular externa

Answer 8

1. usually two layers of smooth muscle

2. Auerbach’s (myenteric) plexus – part of the autonomic nervous system

Question 9

serosa/adventitia

Answer 9

1. adventitia in areas where organ is embedded in other tissue
2. serosa with mesothelium where there is a free surface

Question 10

esophagus function

Answer 10

transport food from mouth to stomach

Question 11

esophagus mucosa

Answer 11

stratified squamous nonkeratinized epithelium

Question 12

esophagus submucosa

Answer 12

secretory glands

Question 13

muscularis externa

Answer 13

upper 1/3 – skeletal
middle 1/3 – skeletal and smooth
lower 1/3 – smooth

Question 14

serosa/adventitia

Answer 14

adventitia above diaphragm

serosa below diaphragm

Question 15

stomach functions

Answer 15

1. convert ingested food to acidic chyme
2. secretes pepsin (exocrine)
3. secrete hormones (endocrine)

Question 16

stomach regions

Answer 16

cardia
fundus & body (histo-identical)
pylorus

Question 17

stomach rugae

Answer 17

1. longitudinal folds of mucosa and submucosa

2. not permanent – disappear when stomach fills

Question 18

stomach mucosa

Answer 18

1. pits and glands

2. cells

Question 19

stomach mucosa cells

Answer 19

1. stem cells: in neck region and mucous neck cells
2. parietal cells : HCl and intrinsic factod chief cells
3. Chief cells: zymogenic granules contain pepsinogen and gastric lipase
4. enteroendocrine cells

Question 20

stomach submucosa

Answer 20

course collagenous fibers, elastic fibers, blood/lymph vessels, nerves and plexus of Meissner. No glands

Question 21

stomach muscularis externa

Answer 21

1. inner oblique
2. middle circular
3. outer longitudinal

Question 22

small intestine function

Answer 22

1. final digestion
2. absorption
3. endocrine secretion

Question 23

small intestine segments

Answer 23

1. duodenum
2. jejunum
3. ileum

Question 24

small intestine muscosa

Answer 24

1. structural increase in SA
2. crypts of Lieberkuhn
3. cells
4. Peyer’s patches (lamina propria of ilium)

Question 25

structural increase in SA

Answer 25

plicae circulares (permanent folds) villi microvilli

Question 26

cells of mucosa

Answer 26

a) intestinal absorptive cells b) goblet cells c) Paneth cells d) enteroendocrine cells

Question 27

intestinal absorptive cells

Answer 27

enterocytes; columnar epithelial cells with microvilli

Question 28

intestinal goblet cells

Answer 28

protection and lubrication; increase in number as approach the ileum

Question 29

intestinal Paneth cells

Answer 29

base of crypts; secrete lysozyme

Question 30

enteroendocrine cells

Answer 30

(1) cholecystokinin(CCK) | (2) secretin

Question 31

cholecystokinin (CCK)

Answer 31

stimulates secretion of pancreatic enzymes; stimulates contraction of gall bladder

Question 32

secretin

Answer 32

stimulates pancreas to release bicarbonate and water

Question 33

small intestine submucosa

Answer 33

Brunner's glands in duodenum secrete alkaline mucous

Question 34

large intestine functions

Answer 34

1. absorb water 2. produce mucous 3. form feces

Question 35

large intestine components

Answer 35

1. cecum 2. ascending colon 3. transverse colon 4. descending colon 5. sigmoid colon 6. rectum

Question 36

large intestine mucosa

Answer 36

1. no villi 2. glands of Lieberkuhn a) absorptive cells b) goblet cells 3. extensive diffuse lymphoid tissue in lamina propria

Question 37

large intestine muscularis externa

Answer 37

outer longitudinal layer – three bands called teniae coli

Question 38

rectoanal junction mucosa

Answer 38

1. epithelium changes abruptly from simple columnar to stratified squamous nonkeratinized 2. muscularis mucosa disappears

Question 39

rectoanal submucosa

Answer 39

hemorrhoidal veins

Question 40

rectoanal muscularis externa

Answer 40

inner circular layer forms internal anal sphincter