Circulatory and Respiratory Systems Flashcards
The human cardiovascular system is composed of a muscular, ____ heart, a network of __ ___ and the blood itself.
4-chambered, blood vessels
Blood is pumped into the ___, which branches into a series of _____. These branch into ____ and then into microscopic ____. Exchange of gases, ____, and __ ___ products occurs via diffusion across ___ ____. The capillaries then converge into ___ and eventually into _____ which carry ____ blood back toward the heart.
aorta, arteries, arterioles, capillaries, nutrients, cellular waste, capillary walls, venules, veins, deoxygenated
From the heart, deoxygenated blood is pumped into the ____ where ____ is exchanged for ___, and this oxygenated blood returns to the heart to be pumped throughout the ___ once more
lungs, CO2, O2, body
The heart is the ____ ___ of the circulatory system. The right and left halves can be viewed as two separate _____. The right side of the heart pumps ____ blood into ____ circulation (towards the lungs), whereas the left side pumps ____ blood into ___ circulation (throughout the body).
driving force, pumps, deoxygenated, pulmonary, oxygenated, systemic
The two upper chambers are called ____ and the two lower chambers are called ____. The former are ____, whereas the latter are extremely ____.
atria, ventricles, thin-walled, muscular
The ____ ventricle is more muscular than the ____ because it is responsible for generating the force that propels the ___ ___ and because it pumps against a higher _____. As a result, in patients with increased systemic resistance, the left ventricle can become ____ (enlarged), which over time can lead to ___ ____ ___ and other cardiovascular diseases
left, right, systemic circulation, resistance, hypertrophied, congestive heart failure
Blood returning from the body first flows through the ____ __ into the __ ____, and finally through the ___ ___ ___ into the pulmonary arteries to continue to the lungs.
right atrium, tricuspid valve, pulmonary semilunar valve
Blood returning from the lungs flows through the ___ ___ into the ___ __ then through the __ __ into the left ventricle, and finally out through the __ __ ___ into systemic circulation
pulmonary veins, left atrium, mitral valve, aortic semilunar valve
Located between the atria and ventricles on both sides of the heart and prevent backflow of blood into the atria
atrioventricular valves
The valve on the right side of the heart that has 3 cusps
tricuspid valve
The valve on the left side of the heart that has two cusps
mitral valve
Valves located between the left ventricle and the aorta or right ventricle and pulmonary artery; have 3 cusps
semilunar valves/aortic valves/pulmonic valve
The sound of a heartbeat is made by the successive closing of the ___ and ___ valves
atrioventricular, semilunar
The heart’s pumping cycle is divided into two alternating phases, ___ and ____, which together make up the heartbeat.
systole, diastole
Systole is the period during which the ventricles _____, forcing blood ___ of the heart into the ___ and ___ circulation.
contract, out, pulmonary, systemic
Diastole is the period of cardiac muscle _____ during which blood ____ into all 4 ____.
relaxation, drains, chambers
the total volume of blood the left ventricle pumps out per minute
cardiac output
cardiac output = ______ x _____
heart rate, stroke volume
volume of blood pumped out of the left ventricle per contraction
stroke volume
Cardiac muscle contracts ____ without stimulation from the nervous system, producing _____ that spread through its internal ___ ___.
rhythmically, impulses, conducting system
An ordinary cardiac contraction originates in, and is regulated by the _______ ____ or the ____. This is a small mass of specialized tissue located in the wall of the __ ____. This spreads impulses through both ___, stimulating them to contract _____.
sinoatrial node, pacemaker, right atrium, atria, simultaneously
The impulse arrives at the ____ ___, which slowly conducts impulses to the rest of the heart, allowing enough time for ____ _____ and for the ventricles to fill with ____. The impulse is then carried by the bundle of ______ or the ___ ___, which branches into the ___ and ___ bundle branches. Finally, it passes through the __ __ in the walls of both ventricles, stimulating a strong contraction. This forces blood ___ of the heart into circulation
atrioventricular node, atrial contraction, blood, His, AV bundle, right, left, purkinje fibers, out
The ____ modifies the rate of heart contraction. The PNS innervates the heart via the __ __ and causes a ___ in heart rate. The SNS innervates the heart via the ___ and __ ____ ___ and causes an increase in heart rate. The ___ ___ exerts hormonal control via ____ secretion, which causes an increase in heart rate
ANS, vagus nerve, decrease, cervical upper thoracic ganglia, adrenal medulla, epinephrine
thick walled, muscular elastic vessels that transport oxygenated blood away from the heart
arteries
Only the __ ___ transport ___ blood from the heart to the lungs
pulmonary arteries, deoxygenated
Relatively thin-walled, inelastic vessels that conduct deoxygenated blood towards the heart
veins