Anatomy of the gut tube

Question 1

At which vertebral levels does the the oesophagus begin and end?

Answer 1

Begins at C6 at the inferior border of the cricoid cartilage

Ends at T11 at the cardiac orifice of the stomach

Question 2

Name the three constrictions of the oesophagus

Answer 2

Cervical
Thoracic
Diaphragmatic

Question 3

What is the phrenoesophageal ligament? Why is it important?

Answer 3

Connects the oesophagus to the border of the oesophageal hiatus
Allows independant movement of the oesophagus and diaphragm during respiration and swallowing

Question 4

Describe the structure of the muscular part(s) of the oesphageal wall

Answer 4

Inner layer of circular muscle and outer layer of longitudinal muscle
The upper third of the oesophagus is made up of voluntary striated (skeletal) muscle
The middle third contains both smooth and skeletal muscle
The lower third only contains smooth involuntary muscle

Question 5

Which muscle makes up the upper oesophageal sphincter?

Answer 5

Cricopharyngeus muscle (striated muscle)

Question 6

Name the parts of the stomach

Answer 6

Cardia
Fundus
Body
Antrum
Pylorus
Pyloric sphincter

Question 7

How many layers of muscle are present in the stomach wall? Describe these layers

Answer 7

3 - Circular, Longitudinal, Oblique

Made up of smooth muscle

Question 8

What are taenia coli?

What are haustrae?

Answer 8

Taenia coli; longitudinal strips of muscle on the surface of the colon
Haustrae; sacculations of the colon caused by tension of the taenia coli

Question 9

How are the jejunum and ilium attached to the posterior abdominal wall?

Answer 9

Attached by mesentary; they are intraperitoneal (aka mesenteric) organs

Question 10

Describe the jejunum

Answer 10

Located mainly in the upper left quadrant
Thick intestinal wall
Long vasa recta (straight arteries)
Fewer arcades (arterial loops)
More red in colour

Question 11

Describe the ilium

Answer 11

Located mainly in the lower right quadrant
Thin intestinal wall
Short vasa recta
More arcades
More pink in colour

Question 12

Describe the ileocecal junction

Answer 12

This is where the ilium becomes the cecum

The ilium invaginates into the cecum, forming the ileocecal valve

Question 13

What is the role of the ileocecal valve?

Answer 13

Not strong/developed enough to ontrol movement of material from ilium to cecum
Prevents reflux of material back into the ilium from the cecum

Question 14

At what vertebral level does the rectum begin?

Answer 14

S3

Question 15

How does the wall of the rectum differ from that of the colon?

Answer 15

There are no haustrae or taenia coli