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51 terms

Heart

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Circulation
continuous one way circuit of blood through the blood vessels
Endocardium
the membrane that lines the cavities of the heart and forms part of the heart valves, inner layer of the heart wall consisting of epithelium and connective tissue as well as some specialized muscle tissue
Myocardium
the middle muscular layer of the heart wall - the thickest and pumps blood through the vessels
Epicardium
(thin outer layer) serous (watery) membrane attaches to the pericardium
Pericardium
protective sac enclosing the heart composed of two layers with fluid between
Functions of the Myocardium
-lightly striated
-have a singular nucleus
-involuntary controlled
-Intercalated disks
-branching of muscle fibers
these fibers are interwoven so that stimulation that causes the contraction of one fiber results in the contraction of a whole group. The intercalated disks and the branching cellular networks allow for the cardic muscles to contract in a coordinated manner
Pulmonary Circuit
system of blood vessels that carries blood between the heart and the lungs
Systemic Circuit
Circuit of blood that carries blood between the heart and the rest of the body.
Atria
the two upper chambers of the heart. There is a right atrium (which receives unoxygenated blood returning from the body) and a left atrium (which receives oxygenated blood returning from the lungs).
Ventricles
the two lower chambers of the heart, and they pump blood out to the lungs and body.
Right Atrium
receives oxygen-poor blood from all tissues, except the lungs, through the superior and inferior venae cavae
Right Ventricle
the chamber on the right side of the heart that receives venous blood from the right atrium and pumps it into the pulmonary trunk
Left Atrium
the left upper chamber of the heart that receives blood from the pulmonary veins
Left Ventricle
the chamber on the left side of the heart that receives arterial blood from the left atrium and pumps it into the aorta
Septum
a wall of tissue that separates the left and right sides of the heart
Inter-atrial
Pertaining to between the atria., seperates the right and left atrium
Interventricular
pertaining to between ventricles, septum
Right AV valve
Tricuspid valve - prevents blood from flowing back up into the right atrium when the right ventricle contracts - SYSTOLE
Left AV valve
bicuspid or mitral valve - prevents blood from flowing back upinto the left atrium when the left ventricle contracts - SYSTOLE
Pulmonary semi-lunar valve
valve with 3 half moon shaped cusps - prevents blood from flowing back into the right ventricle when the right ventricle relaxes - DIASTOLE
Aortic semilunar valve
valve with 3 half moon shaped cusps - prevents blood from flowing back into the left ventricle when the left ventricle relaxes - DIASTOLE
Systole
the contraction of the chambers of the heart (especially the ventricles) to drive blood into the aorta and pulmonary artery
Diastole
the widening of the chambers of the heart between two contractions when the chambers fill with blood, The stage of the heart cycle in which the heart muscle is relaxed, allowing the chambers to fill with blood.
Cardiac cycle
atrial systole/ventricular diastole, ventricular systole/atrial diastole, brief complete diastole
Cardiac output
the amount of blood pumped out by the ventricles in a given period of time, Stroke Volume X Heart Rate
Stroke Volume
the volume of blood pumped out by a ventricle with each heartbeat
Heart Rate
number of beats per minute
sinoatrial node
a specialized bit of heart tissue that controls the heartbeat, the heart's pacemaker, located in the wall of the right atrium
atrioventricular node
neurological tissue in the center of the heart that receives and amplifies the conduction of impulses from the SA node to the bundle of His
Purkinje fibers
fibers in the ventricles that transmit impulses to the right and left ventricles, causing them to contract
internodal pathways
consists of anterior, middle, and posterior divisions that distribute electrical impulse generated by the sa node throughout the right and left atria to the artioventriuclar node
Sinus rhythm
A heart rhythm initiated by the SA node; a normal rhythm.
Bradycardia
abnormally slow heartbeat
Tachycardia
abnormally rapid heartbeat (over 100 beats per minute)
Sinus arrhythmia
change in heart rhythm due to respiration
Premature beat
originates in an irritable automaticity focus that fires spontaneously, producing a beat earlier than expected in the rhythm
Murmur
an abnormal sound of the heart
Bundle of his
a bundle of modified heart muscle that transmits the cardiac impulse from the atrioventricular node to the ventricles causing them to contract
Cardiac Reserve
the ability to respond to demands (exercise, stress, hypovolemia) by altering cardiac output threefold or fourfold.
AV bundle
Bundle of His
Epicardium
Visceral Pericardium
Serous Pericaridum
Parietal - Pericardium Cavity - Visceral Pericardium
Coronary Circulation
supplies blood to the muscles of the heart to meet the high oxygen and nutrient demands of the cardiac muscle cells - blood vessels that supply the heart
Coronary Sinus
the vessel that drains blood from the heart muscle tissues into the right atrium
0.8 seconds
is an average time of a cardiac cycle
stethoscope
a medical instrument for listening to the sounds generated inside the body
electrocardiography
process of recording the electrical activity of the heart
echocardiography
a noninvasive diagnostic procedure that uses ultrasound to study to structure and motions of the heart
catheterization
n this test a long, thin tube is inserted into the patient's body to inject a special dye, which can show narrowed areas in arteries due to plaque buildup and find other problems.
lub sound
sound is caused by the closure of the atrioventicular valves
dub sound
sound is caused by the closure of the semilunar valves