Flashcards in For exam 2 lecture 3 Deck (45):
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
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?
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?
Pressure in the circulation during this phase of the cardiac cycle is called?
What is the difference btwn systolic and diastolic pressure called?
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?
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?
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.
Site of exchange btwn the blood and tissues is the?
Capillaries merge into?
Venules which also have thin walls.
Venules merge into larger venules with?
An increasing content of smooth muscle cells as they widen.
Larger venules converge to become?
Vains give rise to?
Superior and inferior venae cavae.
What is unique about veins?
have large diameter then arteries and thus offer relatively little resistance to flow.
Blood from the venae enters the right atrium and then?
The right ventricle through the tricuspid valve.
Contraction of the right ventricle, simultaneous with that of the left ventricle forces blood through the?
Pulmonary valve into the pulmonary artery, which progressively subdivides to form the arteries, arterioles and capillaries of the pulmonary circulation.
Functions of the blood vessels?
Serve as the passageways through which blood is directed and distributed form the heart to all parts of the body and subsequently returned to the heart.
What lines the inner surface of the blood vessels?
What are two important endothelial vasodilators include?
What are two important endothelial vasoconstrictors include?
Individual blood vessels function in?
Small arteries and arterioles regulate the amount of blood flow to the tissues by dilating or constricting.
Capillaries are the exchange vessels
What percentage of blood is in the veins?
70% and arteries only have 17%
Veins can increase the cardiac output by?
Shifting blood from the peripheral circulation into the heart and arteries by constricting.
Rate at which blood is pumped form each ventricle.
Rate at which blood is returned to the atria from the veins.
The volume of blood pumped out of each ventricle with each contraction, or beat, of the heart.
Period of cardiac contraction and emptying.
The highest arterial pressure measured during a cardiac cycle. The pressure in the artery after blood has been ejected from the left ventricle during systole.
The period of relaxation and filling.
The lowest arterial pressure measured during a cardiac cycle.
The pressure in the artery when no blood is being ejected from the left ventricle.
The difference between systolic and diastolic pressure.
The magnitude of the pulse pressure reflects the volume of blood ejected form the left ventricle on a single beat
End-diastolic volume (preload)
Volume in the ventricle before ejection.
Volume in the ventricle after ejection.
Mean arterial blood pressure
The average pressure responsible for driving blood forward into the tissues throughout the cardiac cycle.