Cardiovascular Physiology: Vascular System

Study Notes

The cardiovascular system is made up of the heart, blood vessels, and blood.
Systolic pressure is the pressure created when the ventricles contract.
Diastolic pressure is the pressure created by the recoil of the aorta and closure of the aortic semilunar valve.
Capillary Exchange involves the velocity of blood flow, the cross-sectional area of capillaries, and exchange processes like diffusion and transcytosis.
Pressure gradients drive filtration and colloid osmotic pressure in the capillaries.
Some capillaries have gaps (intercellular clefts) where the plasma membrane is not joined by tight junctions.
Some capillaries also have fenestrations (pores).

The normal range for human blood pressure is variable.
Normal blood pressure is 130–110 mm Hg systolic and 80–75 mm Hg diastolic.
Hypotension is low systolic blood pressure (below 110 mm Hg), and is often associated with illness.
Hypertension is high systolic blood pressure (above 140 mm HG) and can be dangerous if chronic.

Plasma is composed of water (91-92%), plasma proteins (7-8%), and other components like ions, sugars, lipids, amino acids, and vitamins (1-2%).
Albumin, globulin, and fibrinogen are the main types of plasma proteins.

Erythropoiesis is the production of red blood cells.
It requires iron, folic acid, and vitamin B12.
Iron is a key element in hemoglobin's binding to oxygen and is stored as ferritin in the liver.
Folic acid is required for thymine synthesis, important in DNA formation and cell division.
Vitamin B12 is needed for folic acid function and requires intrinsic factor for absorption.
Erythropoiesis is regulated by erythropoietin, a hormone secreted by the kidneys.