The Heart - Anatomy and Physiology Flashcards
How is the structure of the heart affected by Athlete’s Heart?
increased chamber wall thickness and cavity size
How is the function of the heart affected by Athlete’s Heart?
enhanced diastolic filling, augmentation of stroke volume
How is the electricity of the heart affected by Athlete’s Heart?
bradycardia, repolarization anomalies, voltage criteria for chamber enlargement
What is the pericardial sac?
provides lubrication, covers, and protects the heart
What is Pericarditis?
inflamed/infection of pericardium
What are some characteristics of the epicardium?
serous membrane including blood capillaries, lymph capillaries, and nerve fibers
What is the function of the epicardium?
lubricative outer covering
What are some characteristics of the myocardium?
cardiac muscle tissue separated by connective tissues and including blood capillaries, lymph capillaries, and nerve fibers
What is the function of the myocardium?
provides muscular contractions that eject blood from the heart chambers
What are some characteristics of the endocardium?
endothelial tissue and a thick subendothelial layer of elastic and collagenous fibers
What is the function of the endocardium?
protective inner lining of the chambers and valves
What are myocytes?
contractile cells of the heart
What is connexon?
charges/particles flow through
What is a desmosome?
cell adhesion junctions that anchor cell membranes to the intermediate filament network
What are some characteristics of myocytes?
Many mitochondria present in myocardial cells, very dense capillary network (~1/fiber), T tubules
How many atria? How many ventricles?
2 each
Describe the two atria.
walls - 2 thin overlying muscular sheaths
blood reservoirs and pumps
Describe the two ventricles
thicker walls than atria
pump blood from the low pressure venous system to the high pressure arterial system
formed by a CONTINUUM of muscle fibers
left ventricle is much thicker than the right
Describe the muscle fibers that make up the ventricles.
originate at the base of the heart
sweep towards the apex on epicardial surface
change direction 180 degrees from endocardium and papillary muscle
True or false: the right ventricle is larger than the left
False
What are the two semilunar valves?
aortic valve and pulmonary valve
What is the aortic valve?
sits between left ventricle and aorta
What is the pulmonary valve?
sits between the right ventricle and the pulmonary artery
How many cusps to the semilunar valves have?
3 each
What are the two AV valves?
mitral (or bicuspid) valve and tricuspid valve
What is the mitral valve? How many cusps?
between left atria and left ventricle- two cusps
What is the tricuspid valve? how many cusps?
on right between right atria- 3 cusps
What are the cardiac valves?
thin flaps, each cusp has papillary filaments attached, called Chordae Tendineae
What are the thin flaps on cardiac valves?
flexible endothelial covered fibrous tissue
attached at the base to fibrous rings
flaps are twice the size of the opening
describe the Chordae Tendineae.
arise from papillary muscles, prevents valves from protruding too far into atria
Systole vs Diastole
systole=contraction
diastole=relaxation
What results from occlusion of a vessel?
low oxygen or ischemia and necrosis
O2 supply to the heart averages __________
8-10 mL/min/100g of heart
result from high a-vO2 difference?
increase in O2 demand must be met by increasing flow
What nutrients does the heart use for coronary circulation?
fatty acids, some ketone bodies (up to 60%) and (40%) glucose, lactate, or small amounts of pyruvate for fuel
Continuous flow to the periphery occurs by:
distension of the aorta and its branches during ventricular contraction (systole)
elastic recoil of walls of large arteries with forward propulsion of blood during ventricular relaxation (diastole)
Describe the arterial branches as blood moves rapidly throughout them.
they become more narrow and walls become thinner
change histologically toward the periphery
Describe the aorta as blood moves rapidly throughout.
predominantly an elastic structure
peripheral arteries become more muscular until at the arterioles the muscular layer predominates
What is the cardiovascular system made up of?
pump, series of distributing and collecting tubes, extensive system of thin vessels
