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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

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