Physiology

Question 1

hepatocytes are organized into functional zones: z

Answer 1

zone 1 (periportal), zone 2 (midzonal), and zone 3 (pericentral)

Question 2

Liver cells can be classified into 3 groups:

Answer 2

parenchymal cells, including hepatocytes and bile duct epithelia; sinusoidal cells, which are composed of hepatic sinusoidal endothelial cells.
Kupffer cells (hepatic macrophages)
perisinusoidal cells, which consist of hepatic stellate cells and pit cells.

Question 3

Hepatocytes

Answer 3

comprise 60% of the adult liver cell population, representing approximately 78% of the tissue volume

Question 4

Their plasma membranes have 3 distinct domains:

Answer 4

(1) the sinusoidal surface (∼37% of the cell surface) that comes in direct contact with plasma through the fenestrae of the specialized hepatic sinusoidal endothelial cells;
(2) the canalicular surface (∼13% of the cell surface) that encloses the bile canaliculus (BC); and
(3) contiguous surfaces.

Question 5

The space between the endothelia and the sinusoidal villi

Answer 5

space of Disse

In this space, there is bidirectional exchange of liquids and solutes at the sinusoidal surface between the plasma and hepatocytes.

Question 6

also known as Ito cells, vitamin A–storing cells, fat-storing cells, and lipocytes.
These cells are a part of the stellate cell system, which includes similar cells in the pancreas, lung, kidney, and intestine.

Answer 6

Hepatic stellate cells (HSCs)

HSCs are located between the endothelial lining and hepatocytes

Question 7

the natural killer (NK) cells of the liver, are located mainly within the sinusoidal lumen, close to Kupffer cells.

Answer 7

Pit cells

Question 8

Components of the Extracellular Matrix

Answer 8

The liver contains
5 types of collagen (I, III, IV, V, and VI) and 7 classes of noncollagenous glycoproteins (fibronectin, laminin, entactin/nidogen,
tenascin, thrombospondin, SPARC [secreted protein, acidic, and rich in cysteine], and undulin).

Question 9

The most common lipid abnormality in patients with chronic liver disease is

Answer 9

hypertriglyceridemia (plasma levels of 250 to 500 mg/dL), which is found in patients with alcoholic or viral liver disease and tends to resolve when the liver disease improves.

Question 10

_____may be a useful prognostic marker in patients with noncholestatic liver diseases.

Answer 10

The serum cholesterol level