CFR 2 Notes

These flashcards cover key concepts related to the cardiovascular system, including blood vessels, fluid dynamics, and capillary functions.

What are the two main types of circulatory systems?

Open systems and closed systems.

What is the primary function of the blood vascular system?

To transport materials necessary for cell metabolism and remove waste products.

What are the three types of blood vessels?

Arteries, veins, and capillaries.

What is the relationship between blood vessels and tissues?

Blood vessels adapt and grow based on the needs of the tissues.

What are the three layers of blood vessel walls?

Tunica Intima, Tunica Media, Tunica Adventitia/Externa.

What distinguishes elastic arteries from muscular arteries?

Elastic arteries have a larger elastic component and predominance of elastic tissue in the tunica media.

What is the function of vasa vasorum?

Small blood vessels in the wall of a large vessel that supply the connective tissue.

What are capillaries primarily made of?

A single layer of endothelial cells.

How does blood flow through capillary networks?

Blood does not flow continuously; it is regulated by precapillary sphincters.

What are the four pressures involved in fluid exchange in capillary beds?

Capillary hydrostatic pressure, Plasma colloid osmotic pressure, Interstitial fluid pressure, Interstitial fluid colloid osmotic pressure.

What is the typical diameter of capillaries?

Generally 8-12 micrometers, but can be as small as 3 micrometers.

What are the components of blood plasma?

About 92% water and 8% solids, primarily proteins.

What regulates blood flow in arterioles?

Sympathetic nervous system through smooth muscle contraction.

How many capillaries are estimated to be in the human body?

About 10 billion capillaries.

How does interstitial fluid pressure affect fluid movement?

Negative interstitial fluid pressure sucks fluid into the tissue.

What is the net body filtration rate in capillaries?

1.7 - 3.5 ml/min or 2.5 - 5.0 litres/day.

What does reabsorption in capillaries mainly depend on?

Osmotic pressure of proteins in the plasma.

What do preferential channels do in capillary beds?

They shunt blood directly from the arterial to venous side.

What is the primary force that causes fluid to leave the capillary?

Capillary hydrostatic pressure.

What is the typical amount of blood volume in adult males and females?

5-6 litres for males and 4-5 litres for females.

What is the primary role of lymphatic capillaries?

To collect fluid left in the interstitial space and return it to circulation.

What is the significance of diffusion in capillary networks?

Diffusion occurs in both directions, facilitating nutrient and waste exchange.

What provides the osmotic pressure in the blood?

Proteins in the plasma, especially albumin.

What happens to fluid at the venous end of capillaries?

Most fluid is reabsorbed due to osmotic pressure.

How does the structure of arteries differ from that of veins?

Arteries have thicker walls and are more round; veins have thinner walls and larger lumens.

What is the function of valves in veins?

To prevent backflow and ensure unidirectional blood flow to the heart.

What role do precapillary sphincters play in circulation?

They regulate blood flow into capillary beds.

What is the primary medium for nutrient exchange at the cellular level?

Interstitial fluid.

What is the main purpose of erythrocytes in blood?

To transport oxygen throughout the body.

How does the body prevent excessive fluid loss from capillaries?

By maintaining high osmotic pressure in plasma proteins.

What is the approximate average blood pressure in capillaries?

Around 25 mmHg at the arterial end.

What is the primary difference between fenestrated and non-fenestrated capillaries?

Fenestrated capillaries have small pores that increase permeability.

What happens to blood flow when oxygen levels decrease in local tissues?

Smooth muscle relaxes, sphincters open, and blood flows through capillaries.

What markers are used to identify endothelial cells?

CD31 is an endothelial cell marker.

How does inflammation affect lymphatic return to the bloodstream?

Increased monitoring of returned fluids to avoid excess inflammatory fluid.

Which fluid system communicates with all others in the body?

The blood vascular system.

What is the purpose of haematocrit testing?

To separate blood cells from plasma in order to analyze components.