OC3 - cardiovascular system Flashcards
what are the three layers of the heart wall?
epicardium
myocardium - cardiac muscle
endocardium
what is the pericardium?
the heart is surrounded by the pericardium
a loose fitting membrane which holds the heart in place
a double-layered sac covering the heart
the outer layer anchors the heart in the chest
the inner layer is attached to the heart wall
lubricating fluid in pericardial space reduces friction.
what is the structure of the heart?
diagram…
4 chambers
valves
what are the four chambers of the heart?
left and right atria - separated by septum
left and right ventricle - separated by intraventricular septum
what is the function of valves in the heart?
prevent back flow of blood
what is the composition of the valves in the heart?
composed of connective tissue - tendon like cords
held in place by muscles
what are the types of valves in the heart?
semilunar
atrioventricular
what are the semilunar valves?
pulmonary valve
aortic valve
the tendinous cords of the semilunar valves prevent the cusps of the valve opening to prevent backwards blood flow from the arteries to the ventricles.
what are the atrioventricular valves?
tricuspid valve - right atrium to right ventricle
bicuspid (mitral) valve - left atrium to left ventricle
the tendinous cords of the AV valves prevent the cusps of the valve opening to allow flow of blood from the ventricles to the atria.
what is the circulation route?
vena cava - right atrium - right ventricle - pulmonary artery - lungs - pulmonary vein - left atrium - left ventricle - aorta
what is the cardiac cycle?
the heart beat is a cycle of cardiac muscle contraction and relaxation.
what is cardiac muscle contraction called?
systole
what is cardiac muscle relaxation called?
diastole
what is atrial systole?
the atria simultaneously contract and send blood to the ventricles
what is ventricular systole?
the ventricles contract forcing semilunar valves to open and send blood into pulmonary artery (R) and aorta (L)
what is complete cardiac diastole?
occurs after systole, the chambers of the heart relax, allowing the blood to return to atria
what are the circulation types?
pulmonary circulation
systemic circulation
what is pulmonary circulation?
the loop of blood from the heart to the lungs
blood is carried from the heart to the lungs by the pulmonary artery and is returned to the heart by the pulmonary vein
blood gets oxygenated
what is systemic circulation?
the loop of blood from the heart to the body
blood is carried from the heart in the aorta, and travels around numerous vessels to be returned to the heart in the vena cava
to provide the body with oxygenated blood.
what are the components of blood?
plasma (55%)
cells (45%)
what is the composition of blood?
plasma - water, proteins, nutrients, hormones
buffy coat - white blood cells, platelets
hematocrit - red blood cells