GI

Question 1

Describe the brief role of the mouth and oesophagus in digestion.

Answer 1

Mastication (chew)

Salivation

• protect mouth
• lubricate food
• starts digestion

Swallowing
-forms bolus

Question 2

What is the role of the stomach in digestion?

Answer 2

Stores food

Mixes and disrupts

• secretes acids and enzymes to break down tissues and disinfect
• now called CHYME

Question 3

What does the duodenum do to chyme in digestion?

Answer 3

Dilutes and neutralises it

Question 4

What is the role of the small intestine in digestion?

Answer 4

Absorbs nutrients and electrolytes

Absorbs MOST water

Question 5

What is the role of the large intestine in digestion?

Answer 5

Small bit of water absorption
Sloooow transit
Faeces form and accumulate in descending and sigmoid colon

Question 6

Is chyme hypertonic, hypotonic or isotonic?

Answer 6

Hypertonic

Question 7

What is the name of the subdivision of the autonomic ns that controls the GI tract?

Answer 7

Enteric nervous system

Question 8

What is dysphagia?

Answer 8

Difficulty swallowing

Question 9

What type of tumour affects the superior oesophagus and which inferiorly?

Answer 9

Superior-squamous cell carcinoma

Inferior-adenicarcinoma

Question 10

A defect in which sphincter causes reflux?

Answer 10

Lower oesophageal sphincter

Question 11

What causes Barrett’s oesophagus and what metaplasia occurs?

Answer 11

Reflux

Stratified squamous to simple gastric columnar (stomach epithelial)

Question 12

What causes oesophageal varices?

Answer 12

Cirrhosis causing overload in venous portal system

-blood diverted to to oesophagus through connecting vessels leading to dilation of submucosal veins in lower oesophagus

Question 13

What causes peptic ulceration?

Answer 13

Irritation from gastric acid

Question 14

How can you tell if someone has pancreatitis?

Answer 14

Release of amylase into bloodstream

Question 15

What causes pre and post hepatic jaundice?

Answer 15

Pre-excess Hb breakdown

Post-blockage of bile duct causing backing up of bile containing bilirubin

Question 16

How are gallstones formed and what type of pain do they produce?

Answer 16

Precipitation of cholesterol and bile acids in gallbladder

If moving around can cause biliary colic

Question 17

At what vertebral level does appendicitis visceral pain occur?

Answer 17

T10 level of umbilicus

Question 18

What condition causes blood to be present in stools due to inflammation of anal vessels?

Answer 18

Haemorrhoids

Question 19

What is prolapse?

Answer 19

Organs falling out of place e.g. Rectum

Question 20

Define sigmoid colon diverticulum

Answer 20

Most common place due to high vasculature and weak area

Pouch formation due to high pressure

Question 21

What is meckels diverticulum? List five features

Answer 21

Small outpouching from small intestine formed as a remnant of vitelline duct 
Present in:
-2 yr olds
-2% population
-2:1 ratio of male to female

Site for ectopic gastric secretion causing irritation

• 2 feet proximal to ileocecal valve
• 2 inches in length

Question 22

What 2 structures run through the inguinal canal in males and females?

Answer 22

Both-ilioinguinal nerve
Male-spermatic cord
Female-round ligament of uterus

Question 23

Name the borders of hesselbachs triangle.

Answer 23

Inferior-inguinal ligament
Medial-lateral border of rectus abdominis
Lateral-inferior epigastric artery

Question 24

Where do epigastric hernias occur?

Answer 24

Midline between xiphoid process and umbilicus through linea alba

Question 25

What are the lateral and medial borders of the femoral canal?

Answer 25

Lateral-femoral vein | Medial-lacunar ligament

Question 26

Where can a femoral hernia protrude to and what gender are they more common in and why?

Answer 26

Saphenous opening | Females-wider pelvis

Question 27

What are the borders of the inguinal canal?

Answer 27

Roof-internal oblique and transversus abdominus Floor-inguinal ligament Anterior-aponeurosis of external oblique Posterior-transversalis fascia

Question 28

What cells produce HCL?

Answer 28

Parietal

Question 29

What do chief cells produce?

Answer 29

Pepsinogen and gastric lipase

Question 30

What cells produce mucous in the stomach?

Answer 30

Surface and neck mucous cells

Question 31

What type of cells produce gastrin?

Answer 31

G cells

Question 32

What do enterochromaffin like cells (ECL) produce? What other type of cell also produces the same substance as ECL cells?

Answer 32

Histamine | Mast cells

Question 33

What cells produce somatostatin?

Answer 33

D cells

Question 34

Parietal cells have many mitochondria allowing them to produce a lot of H+ ions. These shouldn't stay within cells, so how is H+ excreted?

Answer 34

Invagination in cell wall with cannaliculi | Contain proton pump which pumps h+ out against conc gradient making it an energy intensive process

Question 35

What three things stimulate parietal cell secretions?

Answer 35

Gastrin, Ach, histamine (gah!!)

Question 36

What inhibits gastrin release?

Answer 36

Low Ph in stomach (neg feedback)

Question 37

Digestion is aided by which part of the autonomic nervous system?

Answer 37

Parasympathetic

Question 38

What, about food, stimulates Ach release? Give three

Answer 38

Sight of food Smell of food Swallowing Distension of stomach

Question 39

How does arrival of food at the stomach stimulate gastrin release?

Answer 39

Slightly alkali and buffers Ph causing it to rise and thus gastrin disinhibited

Question 40

Give two occasions when gastrin secretion is reduced.

Answer 40

Chyme enters intestine (food no longer buffers PH and it decreases) Hormones CCK and GiP (gastric inhibitory polypeptide)

Question 41

What two substances act on parietal cells BUT also upregulate histamine action on parietal cells?

Answer 41

Gastrin | Ach

Question 42

Name two ways acid secretion can be inhibited and give a named example for each.

Answer 42

Histamine H2 receptors Cimetidine (removes amplification by Ach and gastrin) PPI Omeprazole (stops excretion of H+ ions from parietal cells)

Question 43

How does mucus prevent dissolving of stomach mucosa?

Answer 43

Sticky and basic Stops ions moving through it easily H+ reacts with basic groups on mucus and secreted HCO3-

Question 44

What is the PH around surface cells of stomach?

Answer 44

Well above 6

Question 45

What stimulates HCO3- and mucus secretion from surface and neck cells?

Answer 45

Prostaglandins

Question 46

What three things breach the stomachs defences and why?

Answer 46

Alcohol disssolves mucus and so acid attacks stomach H pylori infect surface cells, reducing mucus and HCO3- secretion NSAIDS inhibits prostaglandins reducing defences

Question 47

What does breaching of the stomachs defences result in?

Answer 47

Peptic ulcers

Question 48

How would you treat peptic ulcers and breaching of the stomachs defences?

Answer 48

That h pylori with antibiotics | Use acid secretion methods (H2 antagonist and PPis)

Question 49

How does the vagus nerve asssist in limiting reflux?

Answer 49

Relaxes stomach wall as food passes down oesophagus | Pressure does not increase in stomach, allowing large meals to be consumed

Question 50

Name the two types of muscle in the stomach

Answer 50

Circular and longitudinal

Question 51

What causes the peristalsic contractions in the stomach?

Answer 51

Pacemaker cells in cardia region causes peristaltic contractions towards pylorus

Question 52

What three things slow gastric emptying?

Answer 52

Fat, low PH and hypertonicity in duodenum