the heart Flashcards
describe the double layered membrane sac around heart
1 x visceral layer
(attached to heart surface);
1 x parietal layer
(outer pericardial layer)
Lubricating fluid between layers (reduces friction)
where is the systemic circuit
left
where is the pulmonary circuit
right
what is the function of the inferior and superior vena cavas
superior - returns blood from head, upper limbs
inferior - returns blood from trunk, legs
what is the heart muscel controlled by
ANS
what does isotonic (bicycling) stress lead to
leads to increased volume load and chamber dilation.
what does isometric (weightlifting) stress lead to
leads to pressure load and chamber hypertrophy.
fibrous ring encircles which valves
The left fibrous ring encircles the left atrioventricular valve (mitral valve) and the right fibrous ring surrounds the right atrioventricular valve (tricuspid valve
when does a valve open
when pressure is greater behind the valves
what is aortic stenosis
calcium biuld up narows aortic valve opening and restricts blood flow to heart
what is hypertrophy
refers to the thickening of the heart muscle (myocardium), particularly in the ventricles. This occurs when the heart has to work harder than normal, leading to an increase in muscle mass.
what are the branches of the right coronary artery
Right Marginal Artery
Posterior Descending Artery
Sinoatrial (SA) Nodal Artery
Atrioventricular (AV) Nodal Artery
what are the branches of the left coronary artery
Left Anterior Descending Artery
Left Circumflex Artery
Posterior Descending Artery
what are the 4 valves of the heart
tricuspid
mitral (bicuspid)
pulmonary
aortic
what are the locations of the valves of the heart
Tricuspid Valve – Between the right atrium and right ventricle.
Pulmonary Valve – Between the right ventricle and the pulmonary artery.
Mitral Valve – Between the left atrium and left ventricle.
Aortic Valve – Between the left ventricle and the aorta.
which valves are semilunar
pulmonary and aortic - prevent backflow into the ventricles.
which valves are atrioventricular
bicuspid and tricuspid - prevent backflow into the atria
what are the layers of the heart
Endocardium- inner, layer of endothelial cells
Myocardium- middle, cardiac muscle
Epicardium- outer, external membrane, connective tissue
what is the role of the valves during Diastole (Relaxation Phase)
AV valves open (tricuspid & mitral) → Blood flows from the atria into the ventricles.
Semilunar valves close (aortic & pulmonary) → Prevents backflow from arteries into ventricles.
what is the role of the valves during Systole (Contraction Phase)
AV valves close → Prevents backflow into atria.
Semilunar valves open → Allows blood to be pumped into the aorta and pulmonary artery.
what is the function of the right atrium
Receives deoxygenated blood from the body via the superior and inferior vena cava.
Pumps blood into the right ventricle through the tricuspid valve.
what is the function of the right ventricle
Receives blood from the right atrium.
Pumps deoxygenated blood to the lungs via the pulmonary artery through the pulmonary valve
what is the left atrium
Receives oxygenated blood from the lungs via the pulmonary veins.
Pumps blood into the left ventricle through the mitral (bicuspid) valve.
what is the left ventricle
Receives blood from the left atrium.
Pumps oxygenated blood to the body via the aorta through the aortic valve.
It has thicker muscular walls to generate the high pressure needed for systemic circulation.
describe the main blood vessles of the heart
Superior & Inferior Vena Cava – Carry deoxygenated blood from the body to the right atrium.
Pulmonary Artery – Transports deoxygenated blood from the right ventricle to the lungs.
Pulmonary Veins – Bring oxygenated blood from the lungs to the left atrium.
Aorta – Carries oxygenated blood from the left ventricle to the body.
what is the function of the papillary muscles and chordae tendineae
Prevent AV valves from inverting during ventricular contraction.
what is the function of the Sinoatrial (SA) Node
initiating electrical impulses.
what is the function of the Atrioventricular (AV) Node
Delays impulses before sending them to the ventricles.
what is the function of the Bundle of His & Purkinje Fibers
Conduct impulses through the ventricles, triggering contraction.
what is Pathological Hypertrophy
Harmful & Irreversible if untreated - Can lead to arrhythmias, heart failure
Caused by chronic high blood pressure (hypertension), heart valve disease, or heart failure.
what is Physiological Hypertrophy
Beneficial & Reversible - improves metabloism and enhances function
Occurs due to regular exercise or pregnancy.
