atrial reflex
an autonomic reflex initiated by increased venous return and increased atrial filling
auricle
small, wrinkled, protruding appendages
cardiac output
amount of blood pumped out by each ventricle in 1 minute
cardiac reserve
difference between resting and maximal cardiac output
contractility
the contractile strength achieved at a given muscle length
diastole
periods of relaxation
end diastolic volume (EDV)
the amount of blood that collects in a ventricle during diastole
end systolic volume (ESV)
the volume of blood remaining in a ventricle after it has contracted
endocardium
endothelium membrane that lines the interior of the heart; white sheet of endothelium resting on connective tissue
epicardium
superficial layer; an integral part of the heart wall
functional syncytium
myocardium behaves as a single coordinated unit due to a gap junction electrically coupling cardiac cells
intercalated disc
specialized connections between myocardial cells containing gap junction and desmosomes
myocardium
middle layer; composed of muscle
pacemaker
sinoatrial node
quiescent period
period of total heart relaxation
stroke volume
volume of blood pumped out by one ventricle with each beat
systole
periods of contraction
vagal tone
autonomic divisions continuously send impulses to the sinoatrial node but the dominant influence is inhibitory
venous return
amount of blood returning to the heart and distending of its ventricles
ab~
departing from, away from
angin~
choked
brady~
slow
cardi~/cardio~
heart
cusp~
pointed
diastol~
stand apart
extrins~
from the outside
foram~
opening
hyper~
excess
intercal~
insert
intra~
within
macro~
large
meta~
beyond, between, transition
micro~
small
mono~
single
myo~
muscle
para~
beside, near
peri~
around
Re~
back, again
semi~
half
septum~
fence
steno~
narrow
systol~
contraction
tachy~
rapid
~able
able to, capable of
~nom
govern
~some
body
~stitia
come to stand
~tomy
to cut
What are the layers of the pericardium?
fibrous, serous, parietal layer, visceral layer
What are the layers of the heart wall?
epicardium, myocardium, and endocardium
What does sympathetic stimulation?
increases contractility
What does parasympathetic stimulation?
reduces heart rate when a stressful situation has passed
What does epinephrine do?
enhances heartrate and contractility
What does thyroxine do?
increases metabolic rate, production of body heat, enhances epinephrine and norephrine, and causes a sustained increase in heart rate
What do low levels of calcium do?
depress the heart
What do high levels of calcium do?
increase heart rate and contractility
What do high levels of potassium do?
causes heart block and cardiac arrest
What do low levels of potassium do?
make the heart feeble and arrhythmic
What causes high temperatures?
tachycardia
what causes low temperatures?
bradycardia
Describe the generalized flow of blood through the heart in relation to the pulmonary and systemic circuits
blood from the systemic circuit, vena cava, right atrium, tricuspid valve, right ventricle, pulmonary valve, pulmonary trunk, pulmonary arteries, lungs, pulmonary veins, left atrium, bicuspid valve, left ventricle, aortic valve, aorta, blood to the systemic circuit
Describe the intrinsic cardiac conducting system structure and functions
the sinoatrial node (pacemaker) generates impulses (P wave) 2. impulses pause (0.1) at the atrioventricular node 3. the atrioventricular bundle connects the atria to the ventricles (QRS complex) 4. the bundle branches conduct the impulses through the interventricular septum 5. the subendocardial conducting network depolarizes the contractile cell of both ventricles
arteries
move blood away from the heart
elastic arteries
thick walled arteries near the heart, aorta, and it’s major branches; largest in diameter 2.5cm to 1cm; low resistance pathways that conduct blood from the heart to medium sized arteries; inactive in vasoconstriction; pressure reservoirs expanding and recoiling as the heart ejects blood
muscular arteries
delivers blood to specific body organs; most named arteries in the body; thickest tunica media of all vessels
arterioles
smallest of the arteries, resistance vessels, minute to minute flow into the capillary beds is determined by an arteriolar diameter which varies in response to neural, hormonal, and local chemical influences
auscultatory method
wrap the blood pressure cuff snugly around the person's arm superior to the elbow 2. inflate the cuff until the cuff pressure exceeds systolic pressure 3. rescue cuff pressure gradually and listen with a stethoscope for sounds in the brachial artery
baroreceptor
pressure sensitive mechanoreceptors that respond to changes in arterial pressure and stretch; when stretched they send a rapid stream of impulses
capillary
smallest blood vessels; sites of exchange between blood and tissue cells
fenestrated capillary
occur in areas of active filtration or absorption and areas of endocrine hormones secretion, number of fenestrations in capillaries increases during active absorption of nutrients
sinusoid capillary
allow large irregularly shaped molecules and cells to pass; blood flows slowly; macrophages extend processes through the apertures to catch or form part of the sinusoid wall
capillary bed
interweaving networks where blood and nutrients and wastes are exchanged
capacitance vessel
veins
chemoreceptor
receptor sensitive to various chemicals; CO2, O, H+
lumen
cavity inside a tube contains blood
myogenic
physical
precapillary sphincter
a cuff of smooth muscle that acts as a valve to regulate blood flow in a capillary; controlled by local chemical conditions
pressure points
locations that can be compressed to stop blood flow into distal tissues during hemorrhages
pulse
rhythmic expansion and recoil of arteries resulting from heart contraction; can be felt from outside of the body
tunica intima
innermost layer closest to the blood
tunica media
smooth muscle cells and sheets of elastic; the middle layer
tunica externa
composed largely of loosely woven collagen fibers that protect, nourish, and anchor the vessel
vasa vasorum
nourishes external tissue of the blood vessel wall
vascular anastomoses
union or joining of nerves, blood vessels, or lymphatic vessels
vasoconstriction
narrowing of blood vessels
vasodilation
relaxation of smooth muscle and blood vessels
vasomotor tone
atrioles are almost always in a state of moderate construction
vein
brings blood to the heart
venule
small vein; 8 to 100 μm
venous reservoir
veins can store most of the body's blood at anytime
venous sinus
flattened veins with thin walls composed only of endothelium
ac~/acro~
extreme, extremity, peak
anastomoses~
come together
aneurysm
a widening
angi~
vessel
aort~
great artery
auscult~
listen
baro~
pressure
brachi~
arm
brev~
short