Session 3 - Setting The Scene - Anatomy

Question 1

Name the layers of the gut tube

Answer 1

Mucosa
Submoca
Muscle layer
Serosa

Question 2

What are the elements of the mucosa?

Answer 2

Epithelium
Lamina propria
Muscularis mucosa

Question 3

What is the function of the epithelium?

Answer 3

Absorption
Mucus production
Hormone production

Question 4

What is contained in the lamina propria?

Answer 4

Lymphoid nodules

Antibodies (IgA)

Question 5

What is the function of the musclaris mucosa?

Answer 5

Maintains the shape of the epithelium
Keeps the epithelium in contact with food
Prevents stagnation within the crypts.

Question 6

What is contained within the submucosa?

Answer 6

The submucosal plexus.
Blood vessels
Dense connective tissue

Question 7

What is in the external muscle layers?

Answer 7

Circular muscle
Myenteric plexus
Longitudinal plexus.

Question 8

What is in the serosal layer?

Answer 8

Blood vessels

Adipose tissue

Question 9

What type of epithelium is the gut composed of?

Answer 9

In mouth and distal anus - stratified squamous

Everything in between - simple columnar

Question 10

What is the predominant cell of the GI tract?

Answer 10

Enterocyte

Question 11

What features does the enterocyte have to enable it to perform its function?

Answer 11

1 cell layer thick

Microvilli - brush border

Question 12

which cells produce mucus?

Answer 12

Goblet cells

Question 13

What is the protective function of mucus?

Answer 13

Protects against friction
Protects against acid - chemical damage
Protects against bacteria - by forming a physical barrier

Question 14

Which cells secrete mucus in the stomach?

Answer 14

Gastric surface mucus cells

Question 15

where are gastric surface mucous cells found?

Answer 15

Lining the gastric mucosa/gastric pits

Question 16

What do gastric surface mucous cells do ??

Answer 16

Secrete mucus or bicarb to form a barrier against acid.

Question 17

What adaptations does the gut tube have to increase its surface area?

Answer 17

Permanent folds
Villi
Microvilli

Question 18

what adaptation of the stomach makes it easily expandable?

Answer 18

Rugae

Question 19

Where in the intestine are villi found?

Answer 19

Areas of absorption - eg the SI

Question 20

Where are intestinal crypts found?

Answer 20

The small and large intestine

Question 21

What specialised cels do the intestinal crypts contain?

Answer 21

Paneth cells
Enteroendocrine cells
Stem cells

Question 22

How often is the epithelia replaced in the intestine?

Answer 22

Every 2-4 days

Question 23

What is the function of the paneth cell?

Answer 23

Protect stem cells by secreting antibacterial proteins.

Question 24

Describe the feedback cycle of acid production in the stomach - starting with somatostatin production.

Answer 24

D cells produce somatostatin .
Somatostatin negatively feeds back on G cells - less gastrin produced
Reduced gastrin feedback on ECL cells. Less histamine is produced
Less histamine feedback on parietal cells - less hydrogen ionss produced
Less hydrogen ions - D cells stop producing somatostatin

Question 25

Name the layers a needle would o through when performing an aspiration of peritoneal fluid?

Answer 25

``` Skin Fat External oblique muscle Internal oblique muscle Transvese abdominus (+/- rectus abdominus) Transversalis fascia Parietal peritoneum ```

Question 26

Where is the arcuate line?

Answer 26

Halfway between the umbilicus and pubic crest

Question 27

What is the significance of the arcuate line? | DON'T FORGET THE OTHER ONE!!!!

Answer 27

Above the arcuate line the rectus abdominus lies on the aponeurosis of transversus abdominus and internal oblique. Below the arcuate line the rectus abdominus lies only on the transversalis fascia. It is the point at which the inferior epigastric vessels pierce the rectus abdominus

Question 28

Define mesentry?

Answer 28

A double fold of peritoneum which connects abdominal organs to the posterior abdominal wall.

Question 29

Define peritoneal ligament ?

Answer 29

A double fold of peritoneum which connects organ to eachother or the anterior abdominal wall

Question 30

What is an omentum? | Name the origins of the 2 in the body?

Answer 30

A double fold of peritoneum. Greater omentum - hangs off the greater curve of the stomach Lesser omentum - connects the lesser curve of the stomach to the liver.

Question 31

What is the purpose of sphincters in the GI tract?

Answer 31

To divide the tube into segments To control movement of material along the tube To prevent reflux of material