Lecture 1: Overview Of Cardiovascular System Flashcards
What are 5 functions of the cardiovascular system?
- Transport essential substances to tissues
- Remove by-products of metabolism
- Regulation of body temperature
- Humoral communication throughout body
- Adjustments of oxygen and nutrient supply in different physiologic states
What are the basic parts of the circulatory system?
- Pump (has an electrical system for regular running)
- Series of distributing/collecting tubes
- Extensive system of thin vessels–permits rapid exchange between the tissues and vascular channels
What are the 2 pumps of the heart?
- Right ventricle–pulmonary circulation
- Left ventricle–systemic circulation
What do valves do?
-Cause unidirectional flow in the heart
Total blood volume (%) in the aorta, arteries, and arterioles
10%
Total blood volume (%) in the capillaries
5%
Total blood volume (%) in the venules, veins, and vena cava
70%
What happens in the aorta during systole?
-Distension of the aorta and its branches (contraction)
What happens during diastole?
-Ventricular relaxation–elastic recoil of the large arteries with forward propulsion of blood, allowing the ventricles to fill
Blood flow is essentially ___ at the capillary level
-Non-pulsatile
What is the relationship between blood flow velocity and cross-sectional area?
-Inverse relationship–blood flow velocity is very slow in the capillaries (large cross-sectional area), which makes conditions ideal for exchange of diffusable substances
What is the basic theory of circulatory function with regards to blood flow to each tissue of the body?
-The blood flow to each tissue of the body is almost always precisely controlled in relation to tissue needs
Basic theory of circulatory function–cardiac output is controlled mainly by…
-The sum of all the local tissue flows
Basic theory of circulatory function–in general, the arterial pressure is controlled…
-independently of either local blood flow or cardiac output control
