Gall bladder

Question 1

What is the function of the gall bladder?

Answer 1

• storage and concentration of bile (up to 50ml)

- secretes bile into the digestive system (when enteroendocrine cells in D2 release CCK, or via vagal stimulation)

Question 2

Describe the anatomy of the gall bladder:

Answer 2

Overview:

• pear shaped muscular sac
• sits in gall bladder fossa on visceral surface of liver
• 7-10cm long
• covered by peritoneum

Neck:

• narrow tapered region
• continuous with cystic duct

Body:

• between neck and fundus
• contacts visceral surface of liver

Fundus:

• wide end
• projects from inferior border of liver

Question 3

What is the neruovascular supply of the gallbladder?

Answer 3

Arterial:
- cystic a (from right hepatic)

Venous:
- cystic v (directly into liver or into portal v)

Neuro:

• PNS: CNX vagus
• SNS: splanchnic nn (T5-9 via celiac plexus)
• sensory: right phrenic n (C3-5)

Question 4

Describe the histology of the gall bladder:

Answer 4

Mucosa:

• simple columnar epithelium
• embedded with microvilli for absorption

Muscularis:

• smooth mm, collagen and elastin
• contracts in response to CCK release and vagal stimulation

Adventitia / serosa:

• surface attached to liver has an adventitia
• peritoneal surface has serosa

(no muscularis mucosae or submucosa)