Cardiovascular Terms Flashcards
afterload
the pressure in the wall of the left ventricle during ejection
aorta
major artery of the systemic circulation that receives blood from the left ventricle
aortic valve
the left semilunar valve; blood from the left ventricle flows through it into the aorta
apex of heart
pointed, caudal end of the heart
arteries
carry blood away from the heart
arteriole
the smallest branches of the arterial tree, their small diameter help provide pressure resistance, therefore maintaining blood pressure
atrioventricular node
located in the atrioventricular septum receives the impulse generated by the SA node to complete a contraction
atrioventricular septum
formed by the interventricular septum and the interatrial septum
atrioventricular valve
aka, AV valves; located between the atria and the ventricles
atrium
receive blood into the heart
auricle
ear shaped appendage of either atrium of the heart
auscultation
listening with the ear or with a stethoscope to the sounds of the body
autorhythmic
does not need outside stimulus to start beating in a steady rhythm
base of heart
the rounded cranial end of the heart
bicuspid valve
the left AV valve composed of 2 cusps, aka the mitral valve
blood pressure
a measure of the amount of pressure flowing blood exerts on the arterial walls
bundle of his
bundle of cardiac muscle fibers that conducts the electrical impulses that regulate the heartbeat, from the atrioventricular node in the right atrium to the septum between the ventricles and then to the left and right ventricles
capillaries
form the transition between arteries and veins
cardiac cycle
generated by the SA node; produces one heartbeat; one cycle of atrial and ventricular contraction and relaxation
cardiac output
the amount of blood that leaves the heart
cardiovascular system
aka, the circulatory system; responsible for the movement of blood and everything it carries throughout the animal’s body
carotid artery
located near the jugular vein, carries blood very quickly to the brain, can cause seizures if anything is injected into it
cephalic vein
located on the thoracic limb
chordae tendonae
fine, thread-like cords that connect the two atrioventricular valves to the appropriate papillary muscles in the ventricles
coccygeal vein
in ruminants and rodents, carries blood from the tail to the vena cava
coronary artery
branch off the aorta just past the aortic valve (left semilunar valve)
coronary sinus
a channel formed where the coronary veins join together near the right atrium to drain blood directly into the right atrium
coronary vein
where blood enters after passing through the myocardium from capillaries
cusps
three flaps of endothelium that compose the right AV valve
depolarization
a reduction in the voltage across a neuron or muscle cell membrane from its normal polarized state (resting membrane potential), this results in action potential (nerve impulse) in the case of a neuron or the initiation of contraction in the case of a muscle cell
diastole
the part of the cardiac cycle associated with relaxation of the atria and ventricles and the filling of the chambers with blood
diastolic blood pressure
the second number in a recorded reading, measures the pressure remaining in the artery during left ventricular diastole when the ventricle is relaxing and refilling with blood
doppler echocardiogram
more sophisticated ultrasound procedure that measures blood flow through the heart and adds color to the image , useful for evaluating valvular stenosis and insufficiency
ductus arteriosus
the 2nd bypass that allows fetal blood the bypass lung tissue
echo/echocardiography
cardiac ultrasound; uses ultrasound to bounce sound waves off parts of the heart to watch the heart beating
elastic artery
have the greatest ability to stretch when blood passes through them because they have a large number of elastic fibers in the middle layers of their walls; found closest to the heart
electrogradiogram
a recording of the electrical activity of the heart
electrocardiography
produces an electrocardiogram based on electrical activity of the heart
endocardium
the innermost layer of the heart
endothelium
composed of simple squamous epithelium and it lines the heart, blood vessels and serous cavities of the body
epicardium
outermost layer of the heart
femoral vein
located on the pelvic limb of dogs and cats, carries blood to the iliac vein, which joins with the vena cava
foramen ovale
the first bypass between the right and left atria that allows fetal blood to bypass the lung issue because blood has already been oxygenated by the mother
heart rate
how often the heart contracts, stated in beats per minute
interatrial septum
a continuum of the myocardium that separates the left atrium and the right atrium
interventricular groove
the area of the interventricular septum that is visible on the outside of the heart; contains blood vessels and is frequently filled with fat
interventricuar septum
continuation of the interatial septum; separates the left and right ventricles
jugular vein
travel in muscular grooves along the ventral aspect of each side of the neck, from mandible to shoulder
mean arterial pressure
third value in a reading, the average pressure during one cardiac cycle and can be used as an indication of tissue perfusion in an anesthetized animal
mediastinum
the area of the thorax between the lungs, contains the heart and most of the other thoracic structures such as the trachea, esophagus, blood vessels, nerves and lymphatic structures
mitral valve
aka bicuspid valve; separates the left atrium and ventricle and protects the pulmonary venous system from the high pressures in the left ventricle during systole
murmur
the turbulence in the blood flow of valvular insufficiency
muscular artery
have more smooth muscle fibers, found further away from the heart usually direct blood to specific organs and tissues
myocardium
the middle layer of the heart and the main muscle layer responsible for contraction during systole
oscillometric method
a cuff is placed over the area of an artery and inflated until blood flow either stops if nearly stops, the air is gradually released from the cuff and the magnitude and frequency of pulsations is recorded
p wave
the time it takes the wave of depolarization to travel from the SA node through the atria
papillary muscle
muscular, nipple like projections in the heart that anchor the chordae tendonae, when contracted they act to open the atrioventricular heart valves
parietal layer of the serous pericardium
a smooth, moist serous membrane that lines the pericardial sac
pericardial fluid
fluid within the pericardial space that lubricates the parietal and visceral membrane layers of the serous pericardium to prevent friction during contraction and relaxation of the heart
pericardial sac
fibrous sac of the pericardium, lose to allow beating, but not elastic, so it can not stretch if the heart becomes abnormally large
pericardial space
the area between the 2 serous membranes (parietal and visceral) and is filled with pericardial fluid
pericardium
tissue that forms a sac around the heart to protect it and control the movement of the heart within the thorax
preload
the volume of blood the ventricle receives from the atrium
pulmonary artery
artery arising from the right ventricle that delivers blood into the pulmonary circulation
pulmonary circulation
part of the circulatory system that delivers un-oxygenated blood to the lungs and oxygenated blood to the left side of the heart; controlled by the right side of the heart
pulmonary valve
a semilunar valve that separates the right ventricle and the pulmonary artery during ventricular diastole
pulse
the rate of alternating stretching and recoiling of the elastic fibers in an artery as blood passes through it with each heart beat
pulse wave
stretching and recoiling that travels through all the arteries and arterioles and dissipates in the capillaries
purkinje fiber system
fibers that pick up impulses, makes a u-turn, then caries them from the bundle of his up into the right and left ventricular myocardium
qrs complex
the time of ventricular depolarization
repolarization
the process following depolarization wherein potassium ions diffuse rapidly out of the neuron
saphenous vein
located in the pelvic limb, commonly used in dogs, carries blood to the femoral vein
semilunar valve
the 2 valves that control blood flow out of the ventricles and into arteries
serous pericardium
part of the pericardium; consists of 2 membranes layers, the parietel and visceral layers
sinoatrial node
a group of specialized cardiac muscle cells in the wall of the right atrium of the heart that act as the heat’s pacemaker; the impulse that starts each heartbeat is initiated in the SA node
sphygmomanometer
instrument for measuring blood pressure
stroke volume
the amount of blood ejected with each cardiac cycle
systemic circulation
the part of the circulatory system that produces blood flow to and away from all the body tissues except the lungs, controlled by the left side of the heart
systole
period in the cardiac cycle of contraction when the chambers discharge blood out to the rest of the body, it is the time interval between the first and second heart sounds
systolic blood pressure
first pressure reading; should be the highest number, produced by the ejection of blood from the left ventricle into the systemic circulation by way of the aorta
systolic discharge
aka stroke volume; the amount of blood ejected with each cardiac cycle
t wave
the time of ventricular relaxation (repolarization)
tricuspid valve
aka right atrioventricular valve; separates the right atrium and ventricle
umbilical artery
arteries that carry carbon dioxide-rich waste filled blood from the fetus to the placenta through the umbilical cord ]
umbilical vein
the vein in the umbilical cord that carries oxygen and nutrient-rich blood from the placenta to the fetus
valvular insuffienciency
a heart condition where one or more of the cardiac valves don’t close all the way
valvular stenosis
a heart condition where any one or more of the cardiac valves don’t open all the way
veins
carry blood toward the heart
vena cava
the large vein that brings deoxygenated blood from the systemic circulation to the heart
ventricle
pump blood out of the heart
venule
tiny veins formed by capillaries, eventually form veins once they expand in diameter
visceral layer if the serous pericardium
the part of the serous pericardium that lies directly on the surface of the heart
startling’s law
the stroke volume of the heart increases in response to an increase in the volume of blood filling the heart when all other factors remain constant
phases of the cardiac cycle
diastole and systole
lub (s1)
tricuspid and mitral (atrioventricular) valves snap shut to prevent back flow and pulmonary and aortic valves are opening; occurs at the beginning of ventricular contraction
dub (s2)
pulmonary and aortic (arterial) valves are snapping shut and the tricuspid and mitral valves are opening; occurs at the beginning of ventricular relaxation
role of the atria in cardiac cycle
ensures the maximum filling of the ventricles; atrioventricular valves remain open as the atria contracts and the semilunar valves are closed during atrial contraction
phases of the cardiac cycle
- ventricular filling and atrial filling 2. ventricular contraction - period of isovolumetric contraction - systole 3. ventricular contraction - period of ejection - systole 4. reduced ventricular ejection - protodiastole 5. isovolumetric relaxation 6. rapid filling 7. reduced filling
