Studied by 35 people
heart, blood vessels, blood
components of the circulatory system
veins
carry blood to heart
arteries
carry blood away from heart
bulk flow
Heart moves blood through blood vessels via generation pressure gradient
transportation
main function of cardiovascular system
oxygen, nutrients, water
substances coming into the body
waste, immune cells, hormones, stored nutrients
substances exchanged between cells
waste, heat, CO2
substances leaving the body
heart
Acts as a mechanical pump in cardiovascular system
pressure generated by heart
moves blood throughout closed vascular system
capillaries
where does exchange between blood and tissues occur?
plasma, blood cells, platelets
elements that make up blood
between the lungs in the thoracic cavity
where is the heart located?
pericardium
connective tissue membranes surrounding the heart that protect and anchor it
apex
free surface of the heart located down and to the left
base
area of heart that has connections and is found under sternum
4 chambers, septum, and valves
basic anatomy of the heart
septum
wall that divides the left region of the heart from the right
right atrium
-receives blood from body via vena cavae
-deoxygenated
left atrium
- receives blood from pulmonary veins
- oxygenated
pulmonary vein
vein that carries oxygenated blood
right ventricle
pumps blood to lungs via pulmonary trunk (arteries)
left ventricle
-contracts to send blood to body via aorta
ensure one way flow
function of heart valves
Tricuspid
right side AV valve
Bicuspid
left side AV valve
atrioventricular
valves found in between the atrium and ventricles
Aortic valve
valve found between LV and Aorta
Pulmonary valve
valve found between RV and pulmonary trunk
pulmonary artery
artery that carries deoxygenated blood
pulmonary circulation
flow of blood from heart to lungs
systemic circulation
circulation of blood throughout the body
venous return
what is it called when blood returns to right side of heart?
right atrium, tricuspid valve, right ventricle, pulmonary semilunar valve, pulmonary trunk, lungs, pulmonary veins
how does blood flow through the right side of the heart?
pressure
what drives blood forward in circulation
pulmonary veins, left atrium, bicuspid valve, left ventricle, aortic semilunar valve, aorta, systemic circulation
how does blood flow through the left side of the heart
coronary circulation
Arteries supply blood to heart muscle, veins drain blood
coronary sinus
end of coronary circulation
portal system
circulation where blood flows through 2 capillary beds on the way to the heart
hepatic portal system
Blood directly from intestines to liver via hepatic portal vein
contractile, autorhythmic
cardiac muscle is made of mostly ___________ muscle fibers with a few specialized __________ cells
contraction
main function of the heart
single nucleus, single branched cells, mitochondria, striation
characteristics of cardiac muscle cells
intercalated disks
special connections b/w cardiac cells
desmosomes
cells anchored together and connections cause forceful contraction
gap junctions
electrically coupled junctions for cytoplasmic connection coordinate movemnet
paler, no sarcomeres, specialized ion channels
appearance of autorhythmic cells
Calcium
signaling molecule that controls contraction
Ca2+, Na+
during cardiac relaxation, _______ is pumped out of the cell while ______ is pumped in
-90
what is RMP in mV?
depolarization
gap junctions
-inc. membrane potential
-opens v-g Na+ and Na+ influx (+ 20 mV)
initial repolarization
Fast v-g K+ channels open,
-K+ efflux
plateau
v-g Ca2+ Channels open,
-Ca2+ influx
rapid repolarization
Slow v-g K+ opens
Sinoatrial (SA) Node
location of autorhythmic cells where contraction begins
Atrioventricular (AV) Node
Electrical depolarization travels here which causes contraction of atria
AV bundle
Electrical depolarization travels from AV node to __________ towards the apex
Purkinje Fibers
pale, branching fibers that spread electrical depolarization to ventricles
Electrocardiogram
shows record of electrical activity of the heart over time
heart rate and rhythm
what variables are measured by an ECG?
P wave
point on ECG where atria depolarize (contract)
QRS Wave
point on ECG where ventricles depolarize (contract) and atria repolarize
T wave
point on ECG where ventricles repolarize
PR segment
represents conduction through AV node and bundle
ST segment
duration of ventricular contraction
TP segment
electrically quiet until next cycle
systole
cardiac contraction
diastole
cardiac relaxation
isovolumic
what type of contraction occurs during the QRS phase?
ventricles contract while AV and semilunar valves are closed so no blood moves
what happens in the process of isovolumic contraction
pressure increases in ventricles and when it becomes greater than pressure in pulmonary artery semilunar valves open and blood flows out
What happens in the ejection phase of contraction?
50-60mL
what is the end systolic volume after contraction?
semilunar valves close after ventricular pressure closes, AV valve is closed so no volume is changed while the heart is relaxed
what happens in isovolumic relaxation?
passive filling
• once atrial Pressure > ventricular pressure the AV valves will open,
• blood flows from atria into ventricles
depolarization of SA node leads to atrial contraction which actively pumps blood into ventricles
What happens during active filling?
120-130mL
what is the approximate end diastolic volume after filling
AV valves, Semilunar valves
S1: Sound of _________ closing
S2: Sound of __________ closing
valves closing
what sound do doctors listen to in your heart?
heart murmur
Caused by turbulent blood flow
Regurgitation
Caused by backward flow of blood from valvular insufficiency
stenosis
Ex. Systolic ejection murmur
• Valve opening narrows
• Increased pressure and turbulent flow
Wiggers Diagram
Relates electrical, mechanical, volume and pressure events in the heart
cardiac output
volume of blood pumped out of the heart per unit time
stroke volume and heart rate
two factors that account for cardiac output
stroke volume
volume of blood ejected from left ventricle per beat
mL
units of stroke volume
epinephrine
produced by adrenal medulla in response to stress
norepinephrine
production stimulated by sympathetic nerves in cardiac modulation
increase rate of cardiac action potentials and increase force of contraction
what do adrenergic receptors do when norepinephrine and epinephrine bind?
Adrenergic receptors
where do norepinephrine and epinephrine bind?
decrease
the parasympathetic nervous system can __________ the rate of cardiac Action Potentials
by changing end diastolic volume
how is stroke volume changed?
skeletal pump
compresses veins
Respiratory pump
pressure changes in abdominal and thoracic cavities during respiratory cycles
frank-starling law
Indicates optimal sarcomeric overlap to generate maximal force
Note 
Flashcard (87)