Topic 9 Gastrointestinal system_5 Liver

Question 1

This organ of the GI tract sits inferior to the diaphragm in the right superior region of the abdominal cavity
Has 2 lobes: larger right and smaller left

Answer 1

Liver

Question 2

The liver receives blood from 2 sources

Answer 2

1) Hepatic artery - oxygenated blood (regular blood supply)
2) Hepatic portal vein - deoxygenated blood containing absorbed nutrients, medications, microbes and toxins

**blood flows past hepatocytes (cells of liver)

Question 3

Type of cells that…
> absorb oxygen, nutrients and toxins
> release nutrients into the hepatic vein

Answer 3

Hepatocytes

*good at storing glycogen

Question 4

Liver cells process
> Blood flows past hepatocytes
hepatocytes
> absorb oxygen, nutrients and toxins
> release nutrients into the hepatic vein
Blood eventually flows into the hepatic veins

Answer 4

x
Hepatocytes also manufacture and secrete bile
> bile is dumped into the gallbladder

Question 5

Other functions of the liver (7)

Answer 5

1) carbohydrate metabolism
2) lipid (fat) metabolism
3) protein metabolism
4) drug & hormone processing
5) bilirubin elimination (yellow pigment - end product of breakdown of RBC)
6) vitamin & mineral storage ( fat soluble)
7) vitamin D activation (starts in the skin)

Question 6

Other functions - Liver metabolism cont’d
> helps maintain blood sugar levels
> can convert some amino acides, lactic acids and other sugars into glucose

Answer 6

Carbohydrate metabolism

Question 7

Hepatocytes break down glycogen and release glucose into the blood (-)

Answer 7

Low blood sugar

Question 8

Hepatocytes remove glucose from the blood and stores it (as glycogen and fats) (+)

Answer 8

High blood sugar

Question 9

Other functions - Liver metabolism cont’d

Hepatocytes store fat, break it down (to make ATP), and make cholesterol

Answer 9

Lipid metabolism

Question 10

Other functions - Liver metabolism cont’d
> makes amino acids available for energy
> can converts amino acids into carbs or fats
> synthesizes most plasma proteins

Answer 10

Protein metabolism

Question 11

Other functions - Liver metabolism cont’d

Detoxifiues/ inactivates substances (drugs, alcohol, hormones.

Answer 11

Drug & hormone processing

Question 12

Related to Drug/hormone processing…

Medication
> onset of action = 1/2 hour
> half life = amount of time to get to 50% of concentration

Answer 12

To calculate 1/2 time…

It’s 30 minutes after medication is injested

Question 13

The liver receives oxygenated blood via_________

and the nutrient rich deoxygenated blood via_______

Answer 13

> hepatic artery
hepatic portal vein

see diag. p 201