cardiovascular system - a&p
identify the characteristics of the myocardium
- consists of thick bundles of cardiac muscle twisted & whorled into ring-like arrangements - contracts - reinforced internally by a dense, fibrous connective tissue network called the "skeleton of the heart"
an incompetent aortic semilunar valve would allow blood to backflow from the ________.
aorta to the left ventricle
what are the differences between arteries, veins and capillaries?
- artery walls are usually much thicker than walls of veins - pressure in veins tends to be low all the time - thinner walls - veins have valves - capillaries are only tunica interna to allow for easy diffusion - arteries carry blood to the body's tissues and away from the heart - veins take deoxygenated blood back to the heart
what do the ventricles do?
- discharging chambers or actual pumps of the heart - when they contract, blood is propelled out of the heart & into circulation
what is pulmonary circulation?
- from the right side of the heart to the lungs and back to the left side of the heart - function is to carry blood to the lungs for gas exchange then return it to the heart
what causes varicose veins?
- mostly in people who stand for long periods of time - the overworked valves give way and the veins become twisted and dilated
what is systemic circulation?
- oxygenated blood leaves the left side of the heart via the aorta, through the body and back to the right side of the heart - supplies oxygen-rich and nutrient rich blood to all body organs
what is the job of the semilunar valves? when are they open/closed?
- prevent blood from re-entering the heart - open when ventricles are contracting, closed after cusps fill w/ blood
what does the atria do?
- superior in location, not important in pumping activity of the heart, but blood flows from the vessels into the atria and then into the ventricles
identify the characteristics of the endocardium
- thin, glistening sheet of endothelium that lines heart chambers - continuous w/ linings of blood vessels leaving & entering the heart
identify the characteristics of the epicardium
- tightly hugs external surface of the heart
which valve guards the base of the aorta and opens when the ventricles are contracting?
aortic semilunar valve
which valve is closed during heart relaxation to prevent blood from backflowing from the aorta into the heart?
aortic semilunar valve
list the type of vessels blood travels through (in order) in the systemic circulation (start with arteries and end with veins)
arteries, arterioles, capillary beds, venules, veins
which type of vessel has a thick tunica media?
artery
which of the following is the pathway the aorta takes as it exits the heart?
ascending aorta, aortic arch, thoracic aorta, abdominal aorta
the atrioventricular valves are closed when ________.
atrial pressure is less than ventricular pressure
what part of the heart's intrinsic conduction system carries impulses into the interventricular septum?
atrioventricular (AV) bundle
which of the following occurs when the pressure in the ventricles rises higher than the pressure in the atria?
atrioventricular valves close
the layer of the heart wall synonymous with the visceral layer of the serous pericardium is ________.
epicardium
what is a pulse?
expansion and recoil of an artery w/ each beat of the left ventricle
T or F: a blood pressure reading of 120/80 mm Hg is written with diastolic pressure over systolic pressure.
false
T or F: the inferior vena cava returns blood to the heart from all body regions above the diaphragm.
false
what is the structure that separates the 2 ventricles?
interventricular septum
what is the function of the heart valves?
prevents backflow of blood
what vessels receive blood when both ventricles are in systole?
pulmonary trunk and aorta
which vessels return oxygen-rich blood to the left atrium of the heart?
pulmonary veins
what can be palpated at a pressure point?
pulse
what is tachycardia?
rapid heart rate (over 100 bpm)
which of the following provides the functional blood supply to oxygenate and nourish the myocardium of the heart?
right and left coronary arteries
what is the largest artery in the body? it is in the pulmonary or systemic circulation?
the aorta. it is in the systemic circulation
what causes the "lub" sound?
the closing of the AV valves
what causes the "dup" sound?
the closing of the semilunar valves at the end of systole
what supplies the myocardium with oxygen-rich blood?
the coronary arteries
what part of the heart wall is composed of thin endothelium that lines the heart chambers?
the endocardium
what chamber of the heart will blood enter after passing through the bicuspid valve?
the left ventricle
which chamber has the thickest wall? why?
the left ventricle because that chamber acts as the more powerful systemic pump of the heart
what is systolic pressure. is it on the top or the bottom?
the pressure in the arteries at the peak of ventricular contraction, it is the top number
what is diastolic pressure. it is on the top or the bottom?
the pressure when the ventricles are relaxing, it is the bottom number
what is called the pacemaker of the heart? where is it located?
the sinoatrial node. it is located in the right atrium
what is stroke volume?
the volume of blood pumped out by each ventricle w/ each beat of the heart
what are the chordae tendinae? what do they anchor?
they are the "heart strings" and they anchor the flaps to the walls of the ventricles
through which valve will blood flow when leaving the right atrium?
tricuspid valve
which valve is located between the right atrium and right ventricle?
tricuspid valve
T or F: exchanges between blood and tissue cells occur in capillary beds.
true
T or F: varicose veins result from overworked valves that give way and cause the veins to be twisted and dilated.
true
the correct sequence of layers of a typical blood vessel, from superficial to deep, are ________.
tunica externa, tunica media, tunica intima
which vessel is found in capillary walls?
tunica intima
our vessels lose elasticity as we age, as happens in atherosclerosis. which vessel layer is affected?
tunica media
what is a heart murmur? what causes it?
unusual/abnormal heart sounds, caused by valve problems
what veins empty into the superior vena cava?
veins draining the head and arms
what veins empty into the inferior vena cava?
veins draining the lower body
what valves are closed during systole?
AV valves
what happens in capillary beds?
nutrients, water, oxygen, CO2 are exchanged between the blood and surrounding tissues
what are the layers of a vessel wall? describe them
1. tunica interna - lines the interior of the vessels - thin layer of endothelium - slick surface that decreases friction 2. tunica media - the bulky middle coat - mostly smooth muscle and elastic tissue 3. tunica externa - outermost tunic - its function is to support and protect vessels
a patient who experienced a myocardial infarction (MI) sustained damage to the intrinsic conduction system. Since the nerve impulse still reaches the atria, but does not reach either ventricle, assess the location of the damage.
AV node
where do you find each component of the intrinsic conduction system?
SA node - right atrium AV node - at junction of the atria and ventricles AV bundle - in interventricular septum right & left bundle branches - interventricular septum purkinje fibers - spread within the muscle of the ventricle walls
what is the order of structures that an impulse travels through in the intrinsic conduction system?
SA node to AV node to AV bundle to right and left bundle branches, to the purkinje fibers
which type of vessel is constructed only from tunica intima?
capillaries
which vessel carries oxygen-poor blood from cardiac circulation to the right atrium of the heart?
coronary sinus
what does systole mean?
heart contraction
what does diastole mean?
heart relaxation
what is hypertension?
high blood pressure 140/90 or higher
sustained elevated arterial blood pressure above 140/90 mm Hg is a condition known as ________.
hypertension (high blood pressure)
where is the mitral (bicuspid) valve?
in the left side of the heart
where is the apex of the heart?
it points toward the left hip, rests on diaphragm
where is the base of the heart?
it points toward the right shoulder, lies beneath 2nd rib
what body region is drained by the great saphenous veins?
legs
where is the tricuspid valve?
right side of the heart
what valves are closed during diastole?
semilunar valves
what is brachycardia
slower than normal heart rate (less than 60 bpm)
veins draining from the head and arms empty into the ___________________, which carries blood to the right atrium of the heart
superior vena cava
what is the structure that separates the 2 atria?
the AV valves
what is peripheral resistance?
the amount of friction encountered by the blood as it flows through the blood vessels
the pulmonary semilunar valve is normally open during ________.
ventricular systole