A&P Unit 6 - Cardiovascular System

atrioventricular valves

valves between the atrium and ventricle (ex: tricuspid, bicuspid)

semilunar valves

valves between the ventricle and arteries (ex: pulmonary valve, aortic valve)

path of blood flow through the heart

vena cavas → right atrium → right ventricle → pulmonary artery → lungs → left atrium → left ventricle → aorta → body

pulmonary circuit

blood flows from the right side of the heart to the lungs and back to the left side of the heart

systemic circuit

blood flows from the left side of the heart through the body tissues and back to the right side of the heart

arteries

a vessel that carries blood away from the heart

veins

a vessel that carries blood away from the tissues and toward the heart

capillaries

a minute blood vessel connecting arterioles to venules

path of action potential through the heart

P wave (atrial depolarization) → P-Q interval → QRS complex (ventricular depolarization, atrial repolarization) → S-T segment (ventricular depolarization) → T wave (ventricular repolarization) → heartbeat complete

SA node

“Pacemaker” of the heart, determines heart rate, triggers atria to contract

AV node

causes delay, allows atria to empty blood into ventricles

AV bundle

sends impulses to bundle branches, also known as Bundle of His

bundle branches

send impulses to purkinje fibers

purkinje fibers

carries impulses through the ventricles and cause them to contract

cardiac diastole

part of cardiac cycle when all chambers are relaxed. ventricles at rest, atria become filled with blood. AV valves open, SV valves closed

atrial systole

part of cardiac cycle when atria contract first. pushes blood into lower ventricles. AV valves open, SV valves closed

ventricular systole

part of cardiac cycle when ventricles contract and push blood out of the body. AV valves closed, SV valves open

systolic pressure

blood pressure at the peak of ventricular contraction

diastolic pressure

blood pressure when ventricles relax

blood pressure

the force exerted by blood against the walls of an artery

normal blood pressure

120/80 mmHg

hypertension

high blood pressure, systolic above 140 mmHg

hypotension

low blood pressure, systolic below 110 mmHg

nervous system, kidneys, diet, temperature, drugs

what factors affect blood pressure?

bradycardia

slow heart rate

tachycardia

fast heart rate

plasma

55% of blood, made up of 90% water and 10% dissolved substances (salts, minerals, proteins, hormones, gases)

erythrocytes

also known as red blood cells, carries oxygen through blood using hemoglobin. no nucleus, live 80-100 days, 45% of your blood

leukocytes

also known as white blood cells, aid in immune response against disease and infection. contain nuclei, live 8-10 days, less than 1 percent of blood

thrombocytes

also known as platelets, responsible for clotting process when a wound occurs. lack a nucleus, made from frag,ents of megakaryocytes,