Capillaries

Question 1

Capillary Structure

Answer 1

Endothelium: The innermost layer of capillaries, composed of endothelial cells.
Elastin: Provides elasticity to the capillary walls.
Smooth Muscle: Although minimal in capillaries, it is more prominent in larger vessels.
Collagen: Provides structural support.

Question 2

What are continuous capillaries

Answer 2

Structure - Continuous capillaries have a continuous structure with no significant gaps. They are surrounded by pericytes and have a continuous basement membrane.
Solute Transfer - Solute transfer occurs through paracellular and transcellular pathways, which can be active, passive, or involve transcytosis.
Location - Continuous capillaries are found in the lungs, muscle, adipose tissue, and the central nervous system.

Question 3

What are fenestrated capillaries

Answer 3

Structure - Fenestrated capillaries have openings in their endothelium known as fenestrations or fenestrae, which are approximately 60-100 nm in diameter.
Solute Transfer - These capillaries facilitate the transfer of water, ions, and small molecules.
Location - Fenestrated capillaries are found in organs where exchange is critical, such as the kidney, intestines, and endocrine glands.

Question 4

What are discontinuous capillaries

Answer 4

Structure - Discontinuous capillaries have large gaps in both the endothelial layer and the basement membrane, allowing for significant permeability.
Solute Transfer - These capillaries permit the transfer of water, ions, small molecules, large molecules, and even cells through their structure.
Location - Discontinuous capillaries are found in the liver, spleen, bone marrow, adrenal glands, and endocrine glands.

Question 5

Equation of flow in a capillary

Answer 5

Question 6

Facilitated Diffusion

Answer 6

Question 7

Lymphatics

Answer 7

Question 8

Glycolalyx

Answer 8

The glycocalyx is a fuzzy, gel-like coating made mostly of sugars (glycoproteins, glycolipids, and proteoglycans) that covers the surface of many cells, especially endothelial cells lining blood vessels.

It acts like a protective barrier, shielding cells from mechanical damage and pathogens.

It helps regulate fluid exchange, controls inflammation, and prevents blood clotting by keeping blood cells from sticking to vessel walls.

It also plays a role in sensing blood flow and transmitting signals into the cells.

Question 9

Oedema

Answer 9

Question 10

comparisons of capillaries

Answer 10