Gastrointestinal Tract Anatomy

Question 1

what are the 5 standard layers of the GI tract and their sublayers

Answer 1

mucosa
- epithelium
- lamina propria
- muscularis mucosae
submucosa
muscularis
- circular muscle
- longitudinal muscle
serosa
- areolar connective tissue
- epithelium
mesentery

Question 2

what are the salivary glands called and what do they secrete

Answer 2

submandibular
parotid
sublingual

salivary amylase

Question 3

3 parts of pharynx

Answer 3

naso
oro
laryngo

Question 4

3 parts of pharynx

Answer 4

naso
oro
laryngo

Question 5

oesophagus or trachea more posterior

Answer 5

oesophagus

Question 6

what cell type lines the oesophagus

Answer 6

squamous epithelium until last cm where is becomes columnar epithelium

Question 7

what type of muscle is the oesophagus

Answer 7

1st third - voluntary - striated
2nd third - mixed
3rd third - involuntary - smooth

Question 8

what are the sphincters of the oesophagus

Answer 8

lower and upper oesophageal

Question 9

what muscle forms the majority of the upper oesophageal sphincter

Answer 9

cricopharyngeus

Question 10

function of upper oesophageal sphincter

Answer 10

stops air getting into the gut

Question 11

function of lower oesophageal sphincter

Answer 11

prevents acid and food reflux

Question 12

what makes up the lower oesophageal sphincter

Answer 12

thickened muscular layer of the cardia of the stomach intrinsically and the diaphragm extrinsically

Question 13

where does the stomach move in a sliding hiatal hernia

Answer 13

above diaphragm but within oesophagus

Question 14

where does the stomach move in a paraoesophageal hiatal hernia

Answer 14

outside of the oesophagus and above diaphragm

Question 15

4 parts of the stomach

Answer 15

cardia
fundus
body
antrum

Question 16

where does food exit the stomach

Answer 16

pylorus/pyloric sphincter

Question 17

what adaptation to the standard 4 layers does the stomach have

Answer 17

the mucosa is folded into rugae and between these are gastric pits

Question 18

which direction do muscle layers lie in the stomach

Answer 18

oblique

Question 19

what is the function of the glands found in the gastric mucosa

Answer 19

they secrete mucous which protects the mucosa from the acid

Question 20

what do chief cells secrete

Answer 20

pepsin

Question 21

what do parietal cells secrete

Answer 21

HCl acid
instrinsic factor

Question 22

what is the function of intrinsic factor

Answer 22

it is important for B12 absorption

Question 23

what do endocrine cells secrete in the stomach

Answer 23

grelin and gastrin

Question 24

what does grelin do

Answer 24

hormone which promotes appetite

Question 25

what is gastrin

Answer 25

a digestive hormone

Question 26

what is absorbed in the stomach

Answer 26

B12
water
alcohol
some drugs

Question 27

where does the duodenum become the jejunum

Answer 27

at the duodenojejunal flexure (where it abruptly turns downwards)

Question 28

how many sections is the duodenum split into and what are the sections

Answer 28

4
1. pylorus - superior duodenal flexure
2. descending part
3. horizontal part
4. ascending part

Question 29

where does the ileum end

Answer 29

the ileo-caecal valve

Question 30

what is different about the small intestine mucosa

Answer 30

it is folded into villi

Question 31

what is contained in each vili

Answer 31

blood vessels
lymph vessel

Question 32

what cells are found on the surface of villi and what are they characterised by

Answer 32

enterocytes
they have microvilli

Question 33

which cells secrete mucus in the small intestine

Answer 33

goblet cells

Question 34

what cell type is found in the deep crypts of the small intestine

Answer 34

stem cells

Question 35

what are the sections and subsections of the large intestine

Answer 35

caecum
colon
- ascending
- transverse
- descending
- sigmoid
rectum
anal canal

Question 36

what cell type do cells transition to at the anal canal

Answer 36

squamous mucosa

Question 37

what makes up the anal sphincter

Answer 37

an internal smooth muscle and external striated muscle

Question 38

describe the mucosa of the colon

Answer 38

there are crypts but not villi

Question 39

how are the muscles of the colon grouped

Answer 39

grouped into dense strips called teaniae coli
these are shorter than the colon and mean haustra are formed

Question 40

what are the two most common positions of the appendix

Answer 40

retrocaecal
pelvic

Question 41

what are the two layers of the peritoneum and which layer cover the organs and which covers the abdo wall

Answer 41

visceral - lines organs
parietal - abdo wall

Question 42

retroperitoneal organs

Answer 42

pancreas
kidneys
adrenal glands
urinary tract
parts of duodenum
parts of colon
parts of rectum

Question 43

function of mesentary

Answer 43

prevents knotting of the small intestine

Question 44

function of omentum

Answer 44

can wrap around perforation of inflammation and seal it

Question 45

describe mucosa of gallbladder

Answer 45

rugae

Question 46

what hormone triggers the gallbladder to empty

Answer 46

cholecystokinin

Question 47

where does the common bile duct enter the duodenum

Answer 47

merges with pancreatic duct then enters at the ampulla of vater

Question 48

how is the exocrine pancreas arranged

Answer 48

acinar arrangements

Question 49

where are endocrine cells of pancreas

Answer 49

islets of langerhans