Ch 14 Flashcards
oxygen is moved from the _______ to _______
lungs;
all cells
nutrients and water are moved from the _______ to ________
intestinal tract;
all cells
wastes are moved from ________ to _________
some cells;
liver for processing
immune cells, anti-bodies, clotting proteins are moved from ______ to _______
present in blood continuously;
available for any cell that needs them
hormones are moved from ______ to _______
endocrine cells;
target cells
stored nutrients are moved from ______ to _______
liver and adipose tissue;
all cells
metabolic wastes are moved from ______ to _______
all cells;
kidneys
heat is moved from ______ to _______
all cells;
skin
carbon dioxide is moved from ______ to _______
all cells;
lungs
the heart pumps how much blood a day
7200 L blood/day
“the heart is a workhorse”
pumps blood
-oxygen consumption
-one-w
tubes of the heart include
blood vessels, pulmonary artery, vein, aorta vena cava
fluid of the heart is
blood
blood flows ________ pressure gradients
down
blood flow starting with aorta
aorta -> arteries -> arterioles -> capillaries -> venules -> veins -> venae cavae
blood pressure definition
the pressure that blood exerts on the walls of the blood vessels
pressure in a fluid is
the force exerted by the fluid on its container
hydrostatic pressure is
the pressure exerted with no fluid movement
why does pressure fall over distance
energy is lost due to friction
pressure created by contracting muscles is
transferred to blood
driving pressure for systemic flow is created by
the left ventricle
constriction of blood vessels causes blood pressure to
increase
dilation of blood vessels causes blood pressure to
decrease
volume changes greatly affect ______ in CVS
blood pressure
the heart is composed mostly of ______
myocardium
pericardium definition
membranous fluid-filled sac that encases the heart
the ______ occupy the bulk of the heart
ventricles
The arteries and veins attach to the _____ of the heart
base
the right atrium receives blood from the ______ and sends blood to the _______
venae cavae;
right ventricle
the right ventricle receives blood from the ______ and sends blood to the _______
right atrium;
lungs
the left atrium receives blood from the ______ and sends blood to the _______
pulmonary veins;
left ventricle
the left ventricle receives blood from the ______ and sends blood to the _______
left atrium;
body except for lungs
the venae cavae receives blood from the ______ and sends blood to the _______
systemic veins;
right atrium
the pulmonary trunk receives blood from the ______ and sends blood to the _______
right ventricle;
lungs
the pulmonary vein receives blood from the ______ and sends blood to the _______
veins of the lungs;
left atrium
the aorta receives blood from the _____ and sends blood to the _____
left ventricle;
systemic arteries
what ensures one-way flow in the heart
the heart valves (two sets)
mitral and tricuspid are the _____ valves
atrial ventricular (AV)
the semilunar valves include
pulmonary artery and aorta
action of AV valves during ventricular contraction
the AV valves remain closed to prevent blood flow backward into the atria
action of semilunar valves during ventricular relaxation
the semilunar valves prevent blood that has entered the arteries from flowing back into the ventricles during ventricular relaxation
what differentiates cardiac muscle from skeletal muscle
-smaller and have single nucleus per fiber
-intercalated disks
-t-tubules are larger and branch
-SR is smaller
-mitochondria occupy 1/3 of cell
what do intercalated disks in cardiac muscle do
-desmosomes allow force to be transferred
-gap junctions provide electrical connection
excitation contraction coupling and relaxation in cardiac muscle
like 10 slides
action potential enters from
an adjacent cell
______ channels open and ____ enters the cell
voltage-gated Ca channels;
Ca 2+
where do you find these excitable channels
in the t-tubules
Calcium induces calcium release through
ryanodine receptor-channels (RyR) in the sarcoplasmic reticulum
local release causes
Calcium spark???
summed ______ create a Calcium signal
calcium sparks
Ca 2+ bind to troponin to
initiate contraction
relaxation occurs when
calcium unbinds from troponin
calcium is pumped back into
the sarcoplasmic reticulum for storage
calcium is exchanged with
sodium by the NCX antiporter
sodium gradient is maintained by the
sodium potassium ATPase
cardiac muscle contraction can be “graded” by
calcium concentration
sarcomere length affects
force of contraction
do action potentials vary according to cell type
yes
myocardial contractile cell action potential
phase 0 - Na channels open
phase 1 - Na channels close
phase 2 - Ca channels open; fast K channels close
phase 3 - Ca channels close; slow K channels open
phase 4 resting potential
refractory period in cardiac muscle
long; almost as long as the entire muscle twitch
study table on slide 42
comparison of action potentials in cardiac and skeletal muscle
electrical conduction in the heart begins with
depolarization of the SA node
electrical activity goes rapidly to the _____ via ________
AV node;
internodal pathways
depolarization across the atria occurs _____
slowly
depolarization through the ventricular conduction system….
to the apex of the heart occurs rapidly
AV node function
-routes the direction of electrical signals
-delays the transmission of AP
SA node function
-sets the pace of the heartbeat at 70 bpm
-is not always the pacemaker tho
pathways of electrical conduction in the heart
SA node -> internodal pathways -> AV node -> AV bundle -> bundle branches -> purkinje fibers
what is einthoven’s triangle
ECG tracing that shows electrical potentials generated by cells of the heart
3 major waves of the electrocardiogram
P wave
QRS complex
T wave
The p wave represents
atrial depolarization
the QRS complex represents
ventricular depolarization and also atrial repolarization
the T wave represents
ventricular repolarization
high heart rate is _____
low heart rate is ______
tachycardia;
bradycardia
arrhythmia describes
an irregular heart beat
heart in late diastole
both sets of chambers are relaxed and ventricles fill passively
heart in atrial systole
atrial contraction forces a small amount of additional blood into the ventricles
heart in isovolumic ventricular contraction
first phase of ventricular contraction pushes AV valves closed but does not create enough pressure to open semilunar valves
heart in ventricular ejection
as ventricular pressure rises and exceeds pressure in the arteries, the semilunar valves open and blood is ejected
heart in isovolumic ventricular relaxation
as ventricles relax, pressure in ventricles falls, blood flows back into cusps of semilunar valves and snaps the, closed
stroke volume: what is it
the amount of blood pumped by one ventricle during a contraction
EDV - ESV = stroke volume
-on average 70 mL/beat
cardiac output: what is it?
volume of blood pumped by one ventricle in a given period of time
CO = HR x SV
on average = 5L/min
pathway of sympathetic neurons
NE -> Beta receptors of autorhythmic cells -> increase Na and Ca influx -> increase rate of depolarization -> increase heart rate
pathway of parasympathetic neurons
Ach -> muscarinic receptors of autorhythmic cells -> increase K efflux / decrease Ca influx -> hyperpolarizes cell and decrease rate of depolarization -> decrease heart rate
heart rate is determined by
rate of depolarization in autorhythmic cells
