Week 20 (upper GI tract anatomy part 2)

Question 1

how long is the oesophagus

Answer 1

25 cm long

Question 2

at what cerebral levels does the oesophagus begin and end

Answer 2

C2->T10

Question 3

within the epithelium of the oesophagus what is the epithelial structure of the mucosa

Answer 3

stratified squamous epithelium

Question 4

in the mucosa what cells help in immunity in the GI tract

Answer 4

langherhans cells

Question 5

within the mucosa, what glands help the lamina propria in lubricating boluses of food

Answer 5

cardiac glands

Question 6

cardiac glands in what layer help lubricate boluses of food (with thick mucus)

Answer 6

lamina propria

Question 7

why is the lamina propria fibroelastic

Answer 7

needs to resist abrasive forces

Question 8

what gland is situated in the submucosa in the epithelium of the oesophagus

Answer 8

oesophageal glands

Question 9

within the oesophageal epithelium why is the muscularis externa unique

Answer 9

the upper 1/3rd contains skeletal muscle

Question 10

how is the muscularis externa in the oesophagus structured

Answer 10

upper 1/3rd skeletal muscle
middle 1/3rd skeletal smooth muscle
lower 1/3rd smooth muscle

Question 11

the muscularis externa contributes to what movement of boluses

Answer 11

peristaltic

Question 12

the muscularis externa contributes to peristaltic movement of boluses of food from where to where

Answer 12

oropharynx to stomach

Question 13

reflux of a bolus is prevented by what

Answer 13

sphincters

Question 14

facilitating peristalsis (pinching motion) occurs in what direction

Answer 14

from head down to anus

Question 15

what is the role of the upper and lower sphincters

Answer 15

to prevent accidental aspiration and prevent reflux of boluses

Question 16

why does the lower sphincter close after bolus of food passes

Answer 16

closes to keep the acid in stomach

Question 17

what happens if there is an issue with the lower sphincter (not closing properly)

Answer 17

leads to metaplasia of stratified epithelium
->adenocarcinoma

Question 18

how can barrett’s oesophagus be classified

Answer 18

metaplasia of oesophageal epithelium in lower portion of the oesophagus

Question 19

in barrett’s epithelium how does the epithelial structure change

Answer 19

stratified columnar epithelium -> simple columnar epithelium

Question 20

in Barrett’s oesophagus premalignant changes can lead to development of what

Answer 20

adenocarcinoma

Question 21

how is the anatomy of the stomach divided

Answer 21

4 regions
fundus
cardia
body pyloric (antrum and canal)

Question 22

what is the vertebral level the stomach reaches

Answer 22

T10 - L1

Question 23

the stomach can be thrown into folds by what

Answer 23

muscularis externa

Question 24

what sphincter separates the stomach from the small intestine

Answer 24

pyloric sphincter

Question 25

what acid is secreted from the cells in the stomach

Answer 25

hydrochloric acid

Question 26

within the epithelium of the stomach the mucosa can be thrown into folds called what

Answer 26

rugae

Question 27

gastric pits are present in what layer of the epithelium

Answer 27

mucosa

Question 28

the gastric pits in the stomach are composed how of many different cell types

Answer 28

5

Question 29

what are the 5 different cell types that compose the gastric pits in the stomach

Answer 29

superficial epithelial cell mucous neck cell stem/progenitor cell parietal cell chief cell enteroendocrine cell

Question 30

what are the 3 functions of the gastric pits

Answer 30

secrete: HCl Mucus Bicarbonate (HCO3-)

Question 31

in the stomach, what does the cardia primarily secrete

Answer 31

mucus

Question 32

in the stomach, what does the fundus and the body primarily secrete

Answer 32

mucus, HCl, and pepsinogen

Question 33

in the stomach, what does the pylorus primarily secrete

Answer 33

gastrin and somatostatin

Question 34

what do superficial epithelial cells secrete

Answer 34

visible mucus and bicarbonate

Question 35

in the stomach epithelium, what do the superficial epithelial cells do

Answer 35

retain secreted bicarbonate at the apical surface of the stomach epithelium to prevent autodigestion

Question 36

what allows the mucus to stick to the epithelium of the stomach and allows the bicarbonate to stick there

Answer 36

thick and sticky

Question 37

what is the role of bicarbonate in the stomach

Answer 37

acts as a buffer in the stomach so the stomach doesnt digest itself

Question 38

where are mucous neck cells located

Answer 38

in the "neck" of the gastric pit

Question 39

what do mucous neck cells secerete

Answer 39

soluble mucous

Question 40

what is the role of the soluble mucus that mucous neck cells secrete

Answer 40

lubricates and reduces friction

Question 41

mucous neck cells secrete a more soluble viscous mucus that help with digesting what kind of food

Answer 41

rough food such as salt and vinegar crisps

Question 42

what is the purpose of stem/progenitor cells

Answer 42

dont secrete anything but can proliferate to replace all cell types in epithelium of stomach

Question 43

how often do stem/progenitor cells proliferate to replace new cells

Answer 43

every couple of days

Question 44

what do parietal cells secrete

Answer 44

HCl and intrinsic factor

Question 45

what are the 2 states of parietal cells

Answer 45

resting and active

Question 46

how does HCl worl

Answer 46

steralises food and aids in digestion

Question 47

what is the structure of parietal cells

Answer 47

atypical and pyramidal

Question 48

when would a parietal cell be in a resting state

Answer 48

between meals

Question 49

when would a parietal cell be active

Answer 49

once you have had a meal

Question 50

what happens when a parietal cell is in its active state

Answer 50

villi like structures form along the apical membrane and increases the Surface area of the cells

Question 51

what are chief cells responsible for secreting

Answer 51

pespsinogen and lipase

Question 52

what membrane domain are chief cells located on

Answer 52

apical membrane

Question 53

what secretory vesicles are chief cells containing

Answer 53

zg secretory vesicles

Question 54

in chief cells, what is the role of pepsinogen

Answer 54

breaksdown peptides and proteins

Question 55

in chief cells, what is the role of lipase

Answer 55

breakdown of lipids or fats

Question 56

what are some characteristics of the submucosa in the stomach

Answer 56

dense and irregular and rich with vascular and lymphatic supply

Question 57

how many layers in the muscularis externa in the epithelium of the stomach made up of

Answer 57

3

Question 58

what are the 3 layers that make up the muscularis externa in the epithelium of the stomach

Answer 58

innermost oblique layer middle circular layer outer longitudinal layer

Question 59

what are characteristics of the serosa in the epithelium of the stomach

Answer 59

very thin, simple squamous epithelium capacity to secrete lubricating factors that help churn the stomach

Question 60

why is there rich vascular supply and lymphatic supply in the submucosa in the epithelium of the stomach

Answer 60

contraction of muscle which coordinates the ability to churn immune cells to deal with threats

Question 61

what is the product of surface epithelial cells

Answer 61

visible mucus and bicarbonate

Question 62

what is the product of mucous neck cells

Answer 62

soluble mucous

Question 63

what is the product of parietal cells

Answer 63

HCL and intrinsic factor

Question 64

what is the product of chief cells

Answer 64

pepsinogen and lipase

Question 65

what is the prodcut of D cells

Answer 65

somatostatin

Question 66

what is the product of G cells

Answer 66

Gastrin

Question 67

what causes gastric ulcers

Answer 67

infection with H. Pylori

Question 68

what is a gastric ulcer

Answer 68

disruption of gastric epithelium and inflammatory changes lead to ulceration

Question 69

what can cause gastric ulcers

Answer 69

overuse of NSAID's (ibuprofen) and anti-inflammatory drugs