Cardiovascular pt 1 Flashcards
Atria
receiving chambers
ventricles
discharging chambers
right and left side act as____
separate pumps
____side receives oxygen-poor blood from tissues
Right
via pulmonary circuit
-pumps blood to lungs to get rid of co2 and pick up o2
____side receives oxygenated blood from lungs
left
via systemic circuit
-pumps blood to body tissues
cardiac muscle cells
-striated, branched, and interconnected
-joined by intercalated discs
cardiac muscle cells depend on
aerobic respiration to make ATP
Coronary arteries
spread over surface, penetrate myocardium
-left CA and right CA branch from aorta
-squeezing of myocardium compresses CAs, blocks blood flow
inner most layer of myocardium is_____
last to receive oxygenated blood
most prone to damage during ischemia
inner most layer of myocardium
collateral circulation
-the heart has connections btwn branches, protects from ischemia
needed for muscle contraction in heart
electrical activity
electrical activity in the heart takes place in
SA- Sinoatrial node (rate of heart beat)
SA sends electric signal to
Right and Left atriums and to Atrioventricular node -AV –>subendocardial branches–> right and left ventricles
innervation of heart originates from
medulla oblongata
Sympathetic NS
Norepinephrine
-leades to incr in Ca2+ release in myocardial cells (accelerated contractions)
-incr ca2+ reuptake (accelerated relaxation)
Parasympathetic NS
Acetylcholine
-opens k+ channels
-hyperpolarizes cell, making it less likely to fire
cardiac output
=stroke volume x heart rate (mL/min)
Stroke volume =
preload, afterload, and contractility
amount leaving with each beat. mL/beat
preload
amount of stretch in a muscle tissue before contraction
-effected by end-dystolic volume and venous return
Afterload
force against muscle, needed to contacts
-effected by aortic pressure and aortic valvular fxn
Contractility
how hard is heart pumping
effected by sympathetic simulation and myocardial oxygen supply
Heart rate
beat/min
-CENTRAL NERVOUS SYSTEM, autonomic NS, neural reflexes, atrial receptors. hormones
Aorta–> capillaries
blood velocity decreases
-further away from heart, are increases, resistance increases.