QS Study

Gallbladder

It is a pear-shaped sac lying on the under the surface of the liver. The gallbladder’s main function is to store bile, which helps the body break down and digest fats that you eat. It is generally connected to the liver substance by connective tissue and has venous communications with it.

Fig: Relative position of gallbladder

Capacity: 30 to 50 ml.

Length: 7 – 10cm. It is located in the right upper quadrant of your abdomen, right below the liver.

Breadth: 3 cm (widest part).

Parts: Three parts –

  1. Fundus – It projects into the inferior surface of the liver in the mid-clavicular line.
  2. Body – It lies adjacent to the posteroinferior aspect of the liver, transverse colon and superior part of the duodenum.
  3. Neck – The gallbladder tapers to become continuous with the cystic duct, leading into the biliary tree.

Relations – The gallbladder is entirely surrounded by peritoneum and is in direct relation to the visceral surface of the liver.

(a) Anteriorly –

  • The anterior abdominal wall;
  • The inferior surface of the liver.

(b) Posteriorly –

  • The transverse colon;
  • The 1st and 2nd parts of the duodenum.

Blood supply – It might originate from the primary trunk of the hepatic artery, from the left hepatic artery, or from the gastroduodenal artery.

  • Arterial supply – By cystic artery, a branch of the right hepatic artery.
  • Venous drainage – Drained by cystic vein, which drains into the portal vein. The venous blood is drained by the cystic vein directly into the portal vein.

Fig – Blood supply of gallbladder

Nerve supply – Sympathetic and parasympathetic fibers reach the organ from the celiac plexus. The gallbladder gets its Nerve Supply via cystic plexus created by the sympathetic fibers (T7 T9), parasympathetic fibers (left and right vagus nerve), and fibers of the right phrenic nerve.

  • Sympathetic – T7 to T9; Vasomotor and motor to sphincters.
  • Parasympathetic – Vagus; Motor to musculature.

Histological structure (Outer to inner)

(a) Serous coat,

(b) Fibromuscular coat,

(c) No submucosa,

(d) Mucosa (lined by columnar epithelium).

Development

It develops from the hepatic bud as a solid outgrowth of cells. The end of the outgrowth expands to form the gallbladder, while the narrow stem remains as the cystic duct. Later these become canalized.

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