Session 1 - Overview Of The GI

Question 1

What is the function of the mouth and oesophagus in terms of digestion?

Answer 1

• Mastication
• Produce saliva (wets, lubricates food and starts digestion)
• Swallowing (forms bolus)

Question 2

What is the function of the stomach in the GI?

Answer 2

• Storage of food
• Initial disruption (both physically and chemically)
• Deliver chyme to duodenum slowly

Question 3

What is the function of the duodenum?

Answer 3

• To dilute and neutralise the chyme

- Enzymes are also added from liver and pancreas here

Question 4

What is the function of the Small intestine?

Answer 4

• Absorb nutrients and electrolytes

- Absorb the vast majority of the water

Question 5

What occurs in the large intestine?

Answer 5

• Final absorption of water
• Production of faeces
• Accumulation of faeces prior to expulsion

Question 6

Name the three salivary glands.

Answer 6

• Parotid
• Submandibular
• Sublingual

Question 7

What are four main regions of the colon?

Answer 7

• Ascending limb
• Transverse limb
• Descending limb
• Sigmoid region

Question 8

What three parts make up the Mucosa in the alimentary canal?

Answer 8

• Epithelial lining
• Lamina Propia
• Muscularis Mucosa

Question 9

Describe the build up of the Muscularis Externa.

Answer 9

• Two layers of smooth muscle; inner circular and outer longitudinal
• Myenteric Plexuses lie on the inner and outer surfaces of the layer

Question 10

How does the enteric nervous system relate to the autonomic nervous system?

Answer 10

The enteric nervous system is a sub-division of the autonomic nervous system that directly controls the GI

Question 11

Does sympathetic or parasympathetic have the most important role in control of the GI?
And what is slightly unusual about how the messages are transmitted using this system?

Answer 11

Parasympathetic

They use a wide range of neurotransmitters not just Ach like in the majority of the body as a whole.

Question 12

Describe Dysphagia.

Answer 12

The condition in which people have difficulty swallowing.

May be cause by a physical blockage or a neurological condition

Question 13

What is Barrett’s Oesophagus?

Answer 13

Metaplasia of the lower oesophagus to protect it against acid reflux
Squamous -> Columnar

Question 14

What is oesophageal varices?

Answer 14

• The portal venous system overloaded due to cirrhosis
• blood is diverted to oesophagus
• leads to dilation of submucosal veins in lower oesophagus

Question 15

What are haemorrhoids? And how may the present?

Answer 15

• Vascular structures in the anal canal that aid with stool control that may become inflamed and swollen
• Will present as painful, potentially itchy and with blood in the patient’s stools

Question 16

What is Diverticula?

Answer 16

• The pressure gets too high in the colon
• Outpouching of the colon wall occurs to form a hollow
• Sigmoid colon most at risk
• Creates a space where stasis can occur and infection is likely