Cardiovascular (Heart) Flashcards
carries blood to &
from the lungs
Pulmonary Circulation
carries blood to &
from the diff. body tissues except the lungs
Systemic Circulation
What is the size if the heart?
clenched fist
Location of the heart?
Mediastinum
the pointed end of
the heart which rests on the diaphragm & is directed anteriorly, inferiorly & to the left
apex
the uppermost,
broad, posterior surface of the heart
base
a triple-layered sac w/c
surrounds & protects the heart
pericardium
What are the two types of pericardium?
Fibrous and serous
the superficial, outer layer w/c
directly attaches to the diaphragm is made of strong fibrous connective tissue
fibrous pericardium
its keeps the heart from overstretching or overfilling with blood & holds the heart in place at the mediastinum
fibrous pericardium
a double-layered membrane sandwiched bet. the fibrous pericardium & the heart
serous pericardium
outer layer that adheres to the inner surface of
the fibrous pericardium
parietal pericardium
it is also called epicardium
visceral pericardium
considered part of the heart wall
adheres tightly to the surface of the heart
visceral pericardium
the space bet. the parietal & visceral pericardium
pericardium cavity
the serous fluid produced by the epithelial cells of the serous pericardium w/c prevents friction as the heart beats
pericardial fluid
What are the three layers of the heart wall?
Epicardium, myocardium, endocardium
contains blood vessels that supply the myocardium
epicardium
What connective tissue covers the epicardium?
adipose tissue
the middle, muscular layer w/c forms the bulk (95%) of the heart wall and is responsible for the pumping action of the heart
myocardium
What tissue is endocardium made up of?
simple squamous epithelium
provides a smooth lining for the chambers of the heart & covers the valves of the heart
endocardium
is continuous with the endothelial lining of the large blood vessels attached to the heart
endocardium
What is the tissue that makes up the heart’s myocardium?
Cardiac muscle
cardiac muscle- its _______ have the same arrangement of actin & myosin myofilaments & Z lines as skeletal muscle
muscle fibers
Cardiac muscle, unlike skeletal muscle, its fibers are not cylindrical but are arranged in?
latticework
are irregular transverse thickenings of the sarcolemma that connect the ends of cardiac muscle fibers to one another
intercalated disk
are highly folded to increase contact between cells thereby preventing them from pulling apart
intercalated disk
causes a release of Ca++ in the sarcoplasm, then the sliding of myofilaments w/c leads to contraction
depolariza
TRUE OR FALSE: Cardiac muscle tissue has single, centrally located nucleus and is striated?
TRUE
Cardiac muscle is primarily dependent on what respiration?
Aerobic cellular respiration
the ability to contract in response to its own pacemaker cells that initiate an impulse spontaneously & repetitively even w/o external neurohormonal control
autorhythmicity
cardiac muscle is innervated by the autonomic nervous system which controls its?
rate of contraction
the cardiac cells are so interconnected that when one of these cells becomes excited, the action potential spreads to all of them, to the
latticework interconnections
Cardiac muscle is organized in?
spiral sheets or bundles
refers to the contraction of a heart chamber during depolarization of the myocardium
systole
during systole, the heart chamber is ________ & its contents emptied due to high pressure from the contraction
squeezed
refers to the relaxation of a heart chamber during repolarization of the myocardium
diastole
during diastole, the heart chamber _______ as a result of low pressure in the chamber
fills with blood
refers to enlargement or increase in muscle mass as a result of increased workload
hyperthrophy
the two superior receiving/collecting chambers of the heart
rught and left atrium
the hormone produced by the cells of the atria
Atrial Natriuretic peptide
What is the stimulus of the ANP hormone?
stretching of atrial walls, high blood volume and BP
What is the effect of ANP hormone?
it increases sodium excretion in the kidney to decrease the BP and blood volume
the thin partition between the right &
left atria
interatrial septum
an oval depression on the interatrial septum which is the remnant of the foramen ovale
fossa ovalis
an opening in the interatrial septum of the fetal heart that normally closes soon after birth
foramen ovale
the pumps that eject blood into the
arteries
ventricles
TRUE OR FALSE: The walls of the atria is thicker than the walls of the ventricles.
FALSE
Right ventricle receives blood from the right atrium & pumps it into the lungs (pulmonary circulation) through the __________
pulmonary arteries
TRACE: Venae Cavae, coronary sinus —> right atrium —> tricuspid valve —> right ventricle —> ________—> pulmonary trunk —> pulmonary artery
pulmonary semilunar valve
the partition between the right & left ventricles
interventricular septum
receives de-oxygenated blood from areas above the heart & empty it to the right atrium
superior vena cava
four (4) veins that carry oxygenated
blood from the lungs to the left atrium
pulmonary veins
brings de-oxygenated blood mostly from the parts below the heart to the right atrium
inferior vena cava
exits from the right ventricle and splits to give rise to the two (2) pulmonary arteries
pulmonary trunk
the only artery w/c carries oxygen-poor blood
pulmonary artery
exits from the left ventricle & carries oxygenated blood to the systemic circulation
aorta
the remnant of the ductus arteriosus
ligamentum arteriosum
a temporary blood vessel in the fetal circulation w/c shunts blood from the pulmonary trunk into the aorta; it normally closes shortly after birth
ductus arteriosus
ensure the one-way flow of blood by opening to let blood through and then closing to prevent its regurgitation or backflow
valves of the heart
flaps of endocardium reinforced by cores of dense connective tissue
cusps or leaflets
_______ in the heart chambers cause these cusps to open & close
pressure changes
prevents backflow of blood from left ventricle into left atrium during ventricular contraction
bicuspid valve or mitral valve
prevents backflow of blood from right ventricle into right atrium during ventricular contraction
tricuspid valve
during _______, high pressure in the atria causes both valves to open and blood from the atria flows to the ventricles
atrial contraction
tendonlike cords where the cusps of the AV valves are connected
cordae tendineae
the structures where the chordae tendineae are anchored
papillary muscles
operation of the AV valves:
ventricles relax→papillary muscles relax→_________→AV valve leaflets open
chordae tendineae slack
ventricles contract—> _______→chordae tendineae tighten→AV valve leaflets close
papillary muscles contract
are located at the base of the large blood vessels carrying blood away from the ventricles
semilunar valves
prevents backflow of blood from pulmonary trunk into right ventricle during ventricular relaxation
pulmonary valve
prevents backflow of blood from aorta into left ventricle during ventricular relaxation
aortic valve
operation of the semilunar valves:
during ventricular contraction, ______in the ventricles causes both valves to open & blood flows from ventricles to the pulmonary & systemic circulation
high pressure
the characteristic “lub-dup” sound of the heart w/c can be heard using a stethoscope
heart sound
Heart sounds is due to the closure of the _____?
heart valves
The lub sound due to the closure of atrioventricular valves
S1 heart sound
the dup sound due to the closure of the semilunar valves
S2 heart sound
From the pulmonary arteries, blood enters the capillaries associated with the _____ (microscopic air sacs) of the lungs.
alveoli
Gases are exchanged between blood in the _____ (carbon dioxide or CO2) and air in the alveoli.
capillaries
the network of blood vessels that carry blood to & from the myocardium
coronary circulation
carry oxygenated blood to the
myocardium
coronary arteries
coronary arteries are _____ when the ventricles are contracting & fill when the ventricles are relaxed
compressed
branch into smaller arteries & arterioles, then to capillaries which diffuse O2 & nutrients to the myocardium
coronary arteries
supply blood to the left atrium, most of the left ventricle & part of the right anterior ventricle
left coronary artery
What are the two main branches of left atrium?
left anterior descending artery
circumflex artery
has smaller branches that supply blood to the right atrium, most of the right ventricle & part of the left posterior ventricle
right coronary artery
drain blood that has passed through
myocardial capillaries
coronary veins
carry CO2 & waste products from the myocardium
coronary veins
an enlarged vein on the heart’s posterior surface
coronary sinus
consists of a period of relaxation called DIASTOLE, during which the heart fills with blood then followed by a period of contraction known as SYSTOLE.
cardiac cycle
TRACE the cardiac cycle
Atria and ventricles relax (diastole —> Atria contracts (atrial systole) —> ventricles contract (ventricular systole
a sequence of mechanical events that is regulated by the electrical activity of the heart which begins with nerve impulses generated by the heart’s pacemaker cells & these impulses are propagated along the _________
cardiac conduction pathway
What generates nerve impulses in the heart?
pacemaker cells
a specialized group of cardiac muscle cells located in the wall of the right atrium just below the opening of the superior vena cava where heart’s electrical activity begins
Sinoatrial node
it has the highest rate of depolarization in the whole pathway, it starts each heartbeat & sets the pace for the whole heart
Sinoatrial node
located at the junction between atria & ventricles
atrioventricular node
where impulses from the AV node travel to
atroventricular bundle or bundle of his
where impulses from the bundle of His travel to
right and left bundle branches
spread the action potential within the myocardium of the ventricle walls causing ventricular depolarization, resulting in ventricular systole
Purkinje fibers
is a recording of the electrical changes in the myocardium during a cardiac cycle
electrocardiogram
What wave reflects atrial depolarization?
P wave
a series of waves which reflect
ventricular depolarization
QRS complex
what wave reflects venticular repolarization?
T wave
ventricular repolarization begins at the ____ and progresses superiorly
apex
refers to the volume of blood ejected per minute from the left ventricle to the aorta
cardiac output
the amount of blood ejected by the left ventricle during each contraction
stroke volume
What is the average bpm of the adult?
60 - 100 bpm
the number of heartbeats per minute
heart rate
refers to the degree of stretch in the ventricle before contraction
Preload
What law states this: the more the cardiac muscle fibers are stretched, the more forcefully they contract?
Frank Starling’s law of the heart
^ venous return or blood flow into the heart (e.g. during exercise) → ______→ ^stroke volume & cardiac output
high preload
refers to the amount of
resistance that the ventricles need to overcome to eject blood out of the heart
Afterload
if high afterload (e.g. narrowed aortic valves )—> _____ stroke volume & cardiac output
low
are sensory receptors located in carotid sinus & aortic arch w/c sense changes in BP and send signals to the brain via CN IX & X.
baroreceptors
sense changes in the O2 & CO2 content of blood & also send signals to the brain via CN IX & X
chemoreceptors
area of the brain stem which contains 2 cardiac centers: the accelerator & inhibitory centers
medulla oblongata
sends impulses along parasympathetic nerves, mainly the vagus nerve → acetylcholine heart rate
inhibitory center
sends impulses along sympathetic nerves→norepinephrine & epinephrineheart rate & force of contraction
accelerator center
low BP, high blood CO2 and low blood O2?
increase in heart rate
If the temperature is high what receptor senses the change and directs the actions?
chemoreceptors
increased levels of these hormones increase metabolism & thereby heart rate
T3 and T4
heart rate of < 60 bpm
bradycardia
heart rate of > 100 bpm
tachycardia
