Physiology

Question 1

What 3 nervous systems control the gut

Answer 1

Sympathetic, parasympathetic and enteric

Question 2

What are the 2 plexuses in the enteric nervous system

Answer 2

Myenteric and submucosal

Question 3

Where is the gut wall is the submucosal plexus found

Answer 3

Between the muscular layer and mucosa

Question 4

Where in the gut wall is the myenteric plexus found

Answer 4

Between the 2 muscle layers

Question 5

Which 3 nerves coming from the sympathetic nervous system control the gut

Answer 5

Greater, lesser and least splanchnic nerves

Question 6

True or false: the sympathetic nervous system shuts off blood supply to the lungs

Answer 6

True - shutting off GI functions

Question 7

What nerves from the parasympathetic nervous system control the GI

Answer 7

Vagus nerve and pelvic splanchnic nerve

Question 8

True or false: the parasympathetic nervous system shuts off blood supply to the GI

Answer 8

False - it increases blood supply

Question 9

What hormones are produced in the GI tract

Answer 9

Gastrin, CCK, secretin, GIP

Question 10

What does gastrin do

Answer 10

Causes gastric acids secretion

Question 11

What cells produce gastrin

Answer 11

G CELLS

Question 12

What does CCK do

Answer 12

Stimulates secretions from pancreas and gallbladder

Question 13

Where is CCK secreted

Answer 13

Duodenum and jejunum

Question 14

What does secretin do

Answer 14

Causes an increase in bicarbonate production

Question 15

What does GIP stand for

Answer 15

Gastrin inhibitory polypeptide

Question 16

What is peristalsis

Answer 16

Muscular contractions to propel the bolus of food

Question 17

True or false: the muscle behind the bolus relax during peristalsis

Answer 17

False - they contract, the muscles in front relax

Question 18

What is segmentation

Answer 18

Contraction of the smooth muscle to split up the bolus

Question 19

Why does segmentation occur

Answer 19

To increase the SA of the food and the epithelium

Question 20

Which NS (sympathetic or parasympathetic) increases motility of the GI tract

Answer 20

Parasympathetic

Question 21

Why do you get central abdominal pain first in appendicitis

Answer 21

The appendix inflames and irritates the visceral membrane which hasn’t got its only nerve supply. The region covering the appendix is supplied by the lesser splanchic nerve which comes from T10. Therefore, the body presumes the pain is coming from the T10 dermatome which covers the umbilicus giving pain in this area

Question 22

Why do you get lower right abdominal pain following central pain in appendicitis

Answer 22

The appendix inflames so much that it now touches the parietal membrane which has different mesoderm derivative from visceral so gives localised pain

Question 23

What structures give back pain

Answer 23

Retroperitoneal structures are they irritate nerve plexuses in the back

Question 24

what are the 4 layers of the gut

Answer 24

mucosa
submucosa
muscle layer
serosa

Question 25

what are the 3 layers in the mucosa

Answer 25

epithelia lamina properia muscularis externa

Question 26

what type of epithelia lines the GI tract

Answer 26

simple squamous in the oesophagus and rectum | simple columnar everywhere else

Question 27

what is found in the lamina properia

Answer 27

lymphoid tissue

Question 28

what is found in the submucosa

Answer 28

lymphoid tisse, glands, submucosal plexus, blood vessels, dense CT

Question 29

how many muscle layers are there in the external muscle layer

Answer 29

2 (circular and longitudinal) | however, there is a 3rd oblique layer in the stomach

Question 30

irritation of the visceral peritoneum from structures arising from the foregut gives pain where

Answer 30

epigastric region

Question 31

irritation of the visceral peritoneum from structures arising from the midgut gives pain where

Answer 31

periumbilical region

Question 32

irritation of the visceral peritoneum from structures arising from the hindgut gives pain where

Answer 32

suprapubic region

Question 33

which sphincter is the only one under voluntary control

Answer 33

external anal

Question 34

what are enterocytes

Answer 34

the epithelia lining the GI tract - they allow for absorption

Question 35

what are goblet cells

Answer 35

mucus producing cells

Question 36

what is the difference between goblet cells and gastric mucous cells

Answer 36

gastric mucus cells are found in the stomach and produce a more bicarbonate rich mucus

Question 37

what are the permeant folds in the intestines called

Answer 37

pliace circulares

Question 38

what are the temporary folds in the stomach called

Answer 38

folds of rugae

Question 39

what do the folds of rugae allow

Answer 39

expansion the stomach to hold food, without increasing in pressure

Question 40

what are paneth cells

Answer 40

cells found in crypts which secrete antibacterial proteins to protect stem cells

Question 41

why are there stem cells found in crypts

Answer 41

to allow regeneration of the epithelia due to the acidic environment

Question 42

what is the rectus sheath

Answer 42

the sheet of tendons from the muscles external oblique, internal oblique and transverse abdominis. this sheet envelops the rectus abdominis muscle

Question 43

what is the arcuate line

Answer 43

where there is a change in the rectus sheath as all the muscle tendons now pass over rectus abdominis covering it anteriorly only, instead of both anteriorly and posteriorly

Question 44

where is the arcuate line found

Answer 44

half way between the umbilicus and pubic symphysis

Question 45

what are peritoneal ligaments

Answer 45

double folding of peritoneum that links 2 organs together or links the abdominal wall to a organ

Question 46

what does the gastrocolic ligament connect

Answer 46

stomach and transverse colon

Question 47

what does the gastrosplenic ligament connect

Answer 47

stomach to the spleen

Question 48

what does the falciform ligament connect

Answer 48

liver to abdominal wall

Question 49

what does the triangular ligament connect

Answer 49

liver to diaphragm

Question 50

what is the arterial blood supply to the GI

Answer 50

coeliac trunk for the foregut superior mesenteric artery for the midgut inferior mesenteric artery for the hingut

Question 51

what is the venous drainage of the GI

Answer 51

all veins from the GI tract enter the liver via the portal vein, where it is then drained into the hepatic vein into the IVC

Question 52

what structures are a part of the foregut

Answer 52

oesophagus, stomach, pancreas, liver, gall bladder, duodenum

Question 53

what structures are a part of the midgut

Answer 53

jejunum, ileum, caecum, ascending colon, proximal ⅔ transverse colon

Question 54

what structures are a part of the hindgut

Answer 54

distal ⅓ transverse colon, descending colon, sigmoid colon, rectum, upper anal canal