For exam 2 lecture 3 Flashcards
What are the 5 functions of the cardiovascular system?
1) Distribution of O2 and nutrients to all the tissues of body
2) Transport of CO2 and metabolic waste products from the tissues to the lungs and excretory organs
3) Distribution of water, electrolytes, and hormones through out the body
4) Contributing to the infrastructure of the immune system
5) Thermoregulation
The three basic components are?
Blood, heart, blood vessels
Blood is composed of plasma that is?
An aqueous solution containing electrolytes, proteins, other molecules and formed elements (red blood cells, white blood cells and platelets)
The formed elements of blood comprise?
40-50% of blood volume and are mainly red blood cells (erythrocytes)
Blood serves as a?
Transport medium within which materials being transported are dissolved or suspended.
The heart is a pump because?
It pumps blood
The period of ventricular contraction is termed?
Systole
The maximum pressure during systole (contraction) is called?
Systolic pressure. It serves to drive (pump) blood through the circulation.
The period of relaxation, ventricular filling, is called?
Diastole
Pressure in the circulation during this phase of the cardiac cycle is called?
Diastolic pressure
What is the difference btwn systolic and diastolic pressure called?
Pulse pressure
Why is the heart also an endocrine organ?
Because it releases a hormone, Atrial Natriuretic Peptide from atrial muscle cells when atrial blood pressure increases.
What does ANP do?
Acts to lower blood pressure by increasing the rate of urine production, this reducing blood volume.
Blood flows from where to the major arteries?
Aorta
The division of arteries to smaller muscular arteries which give rise to?
Arterioles - arteries with very small diameters. They are the area of major resistance in the circulation.
What are the walls of arteries and arterioles have circumstantially arranged layers?
Smooth muscle
The lumen of the entire vascular system is lined by a monolayer of endotheial cells which?
Secrete vasoactive substances and serve as a barrier, restricting and controlling the movement of fluid, molecules and cells into and out of the vasculature.
The arterioles lead to the smallest vessels called?
Capillaries, which form a dense network within all body tissues.