Bile and the Biliary System

Fill in the blanks to describe the journey bile takes from synthesis to secretion into the duodenum. Bile is secreted by the [blank_start]polygonal[blank_end] cells of the liver into [blank_start]cananliculi[blank_end] between cells. These drain into the [blank_start]ductules[blank_end] of liver following nto [blank_start]perilobular[blank_end] ducts and then into [blank_start]interlobular[blank_end] ducts. From here, bile drains into the [blank_start]septal[blank_end] ducts followed by the [blank_start]lobar[blank_end] ducts and then the left and right [blank_start]hepatic[blank_end] ducts which merge to form the [blank_start]common[blank_end] hepatic duct. As the common hepatic duct passes the [blank_start]cystic[blank_end] duct it becomes the common [blank_start]bile[blank_end] duct which drains into the ampulla of [blank_start]Vater[blank_end] and finally into the duodenum via the sphincter of [blank_start]Oddi[blank_end].

FIll in the blanks to label these parts of the liver and GI tract involved in bile secretion.

In the fasting state, what happens to bile?

The wall of the gallbladder concentrates bile by the reabsorption of what substances? Check all that apply.

Bile has a lower osmolarity than blood plasma.

Which statements regarding bile secretion are true?

What hormone is released from the intestine to cause strong gallbladder contraction?

Secetin increases what by stimulating the secretion of water, HCO3- and bile salts into the common hepatic duct?

The stimulation of the vagus nerve will increase bile secretion.

Stimulation of which nerves causes decreased bile flow?

What hormone is released from neurons innervating the gallbladder?

What is the action of vasoactive intestinal polypeptide (VIP)?

Serotonin stimulates net fluid and electrolyte reabsorption in the gallbladder.

Bilirubin is one of the waste materials found in bile to be excreted in the faeces. What is bilirubin the metabolic product of?

Bilirubin is bound to [blank_start]albumin[blank_end] in the plasma. It is taken up by the liver where it crosses the [blank_start]basolateral[blank_end] membrane and is transported in the [blank_start]endoplasmic reticulum[blank_end]. Here, it is conjugated to [blank_start]glucuronic acid[blank_end]. This facilitates the excretion of bilirubin into bile. If the bile ducts become blocked, conjugated bilirubin will reenter the [blank_start]systemic[blank_end] circulation leading to [blank_start]jaundice[blank_end].

What name is given to the circulation of biliary acids, biliribuin and drugs etc from the liver into the bile into the small intestine before absorption by an enterocyte and transport back to the liver?

Which is correct regarding the reabsorption of bile acids?

What is a bile acid?

Bile acids are acids derived from what?

The presence of lipid-rich chyme in the duodenum stimulates the secretion of what?

Bile salts have both a hydrophilic and hydrophobic region. They are...

The amino acid heads of bile salts are hydrophilic and the cholesterol-derived portions are hydrophobic.

Bile acids [blank_start]emulsify[blank_end] fats into smaller droplets which increase their surface area to make [blank_start]lipase[blank_end] action more efficient. Bile acids also form [blank_start]micelles[blank_end] with fatty acids, monoglycerides etc to [blank_start]solubilise[blank_end] them and prep them for transport.

Bile acid deficiency means that lipids cannot be effectively digested and [blank_start]absorbed[blank_end] in the intestines. This leads to [blank_start]fat[blank_end]-soluble vitamin deficiencies ([blank_start]A[blank_end], D, E, [blank_start]K[blank_end]). It can also cause [blank_start]jaundice[blank_end] due to a lack of bilirubin excretion. It may also cause stunted/abnormal growth, diarrhea, and liver failure.

What bile acid is this?

What bile acid is this?