cardiovascular exam

Cardiovascular System

closed system of the heart and blood vessels

-heart pumps blood

-blood vessels allow blood to circulate to all parts of the body

Function of cardiovascular system

deliver oxygen and nutrients and to remove carbon dioxide and other waste products

Location of heart

between the lungs in thoracic cavity

-pointed apex toward the left hip

pericardium

-double serous membrane

visceral pericardium

next to heart

parietal pericardium

outside layer

serous fluid fills the…

space between the layers of pericardium

three layers of the heart

epicardium, myocardium, endocardium

epicardium

visceral layer of serous pericardium, connective tissue layer

myocardium

muscular, middle layer of the heart

endocardium

inner lining of the heart. endothelium

four chambers of the heart

right atrium, right ventricle, left atrium, left ventricle

atria

upper, recieving chambers of the heart

ventricles

lower, discharging chambers of the heart

valves of the heart

tricuspid valve, pulmonary semilunar valve, bicuspid or mitral valve, aortic semilunar valve

valves open as

blood is pumped through

held in place by the

chordae tendinae (Heart strings)

valves close to

prevent backflow

aorta receives blood from the

left ventricle

pulmonary arteries receive blood from the

right ventricle

vena cava

a large vein carrying deoxygenated blood into the heart, blood enters to the right atrium

pulmonary veins

Deliver oxygen rich blood from the lungs to the left atrium

coronary circulation

blood in the heart chambers does not nourish myocardium

-heart has its own nourishing circulatory system

What is the intrinsic conduction system of the heart?

A specialized network of tissue that controls the heart's rhythm.

What sets the pace of the heart?

The sinoatrial node.

What is the function of the atrioventricular node?

It passes electrical impulses through the septum.

What are the components of the conduction system that carry impulses through the septum?

Bundle of His, bundle branches, and Purkinje fibers.

What does the P wave in an electrocardiogram represent?

Impulse across the atria

What does the QRS complex in an electrocardiogram represent?

Spread of impulse down the septum, around ventricles in Purkinje fibers

What does the T wave in an electrocardiogram represent?

End of electrical activity in ventricles

Damage of AV node

release of ventricles from control (slower heart beat)

tachycardia

fast heart rate, over 100 bpm

bradycardia

slow heart rate (less than 60 bpm)

atria contract

simultaneously

systole

Contraction of the heart

diastole

Relaxation of the heart

cardiac output

amount of blood pumped by each side of the heart in one minute

stroke volume

the volume of blood pumped out by a ventricle with each heartbeat

normal cardiac output

5 L/min

entire blood supply passes through body

once per minute

stroke volume usually remains

relatively constant

Starling's law of the heart

the more the cardiac muscle is stretched, the stronger the contraction

most common way to charge cardiac output

changing heart rate

-Decreased blood volume

decreased heart rate

Parasympathetic nervous system

High blood pressure or blood volume

Decreased venous return

congestive heart failure

heart is worn out and pumps weakly.

digitalis

strengthens the contraction of the heart muscle, slows the heart rate, and helps eliminate fluid from body tissues

Causes of congestive heart failure

coronary atherosclerosis (high blood pressure) and history of multiple myocardial infarctions

right side fails

pulmonary congestion and suffocation

left side fails

peripheral congestion and edema (swelling)

blood vessels

arteries, veins, capillaries, arterioles, venules

three layers of blood vessels

tunica intima, tunica media, tunica externa

tunica intima

endothelium

tunica media

smooth muscle, controlled by sympathetic nervous system

tunica externa

mostly fibrous connective tissue

walls of arteries

Thick and elastic and carry blood under high pressure

lumens of veins

larger than arteries

skeletal muscle

milks blood in veins toward the heart

walls of capillaries

only one cell layer thick to allow for exchanges between blood and tissue

most arterial blood is

pumped by the heart veins use of milking action of muscles to help move blood

capillary beds

sites of chemical exchange between the blood and interstitial fluid

vascular shunt

a vessel that directly connects the arteriole and venule at opposite ends of the bed

true capillaries

exchange vessels; oxygen and nutrients cross to cells; carbon dioxide and metabolic waste products cross into blood