Cardiovascular Flashcards
the heart can be found within the…
mediastinum of the medial cavity of the thorax
the heart is ______ to vertebral column
anterior
the heart is _____ to sternum
posterior
the heart is _____ to diaphragm
superior
the superior margin of the heart can be identified close to the
2nd rib
the inferior margin can be deduced close to the…
5th intercostal space
60% of the mass can be found to the
left of midline
the base of the heart faces
right shoulder
the apex of the heart points…
inferiorly toward left hip
the apex of the heart contacts the chest wall between
5th and 6th ribs
define pericardium
is a double layered, closed sac that surrounds the heart
there are 2 main pericardiums, name them
fibrous pericardium
serous pericardium
the fibrous pericardium is made up of
dense irregular connective tissue
what does the fibrous pericardium do?
protects heart
anchors heart to surrounding tissues
prevents over-filling
the serous pericardium is made up of these 2 layers:
parietal layer
visceral layer
the parietal layers makes up the
internal space of the fibrous pericardium
the visceral layer can also be called the
epicardium
the visceral layer does what?
covers heart surface
what is between the serous layers?
pericardial cavity
the pericardial cavity is filled with?
serous pericardial fluid
what is the function of serous pericardial fluid?
reduces friction between serous membranes
the fibrous pericardium is continuous with…
the connective tissue coverings of the great vessels
the fibrous pericardium is inferiorly attached to
diaphragm
name the 3 layers of heart
epicardium
middle myocardium
deep endocardium
define epicardium
thin serous membrane that constitutes the smooth, outer surface of the heart
the epicardium is made up of what kind of cells?
simple squamous
the myocardium is the ____ middle layer
thick
________ is responsible for the heart’s ability to contract
myocardium
the myocardium is made up primarily of
cardiac muscle
the cardiac muscles of the heart are arranged…
in circular bundles
what does the fibrous skeleton of the heart do?
holds cardiac muscle together
what is the endocardium?
the smooth inner surface of the heart chambers and myocardial surface
the endocardium lines…
heart and connective tissues of the valves
what kind of cells make up the endocardium?
squamous epithelium
the heart is divided longitudinally by the
interatrial septum
interventricular septum
name the 4 chambers of heart
right atrium
right ventricle
left atrium
left ventricle
the atria ________ blood
receive returning
on top of the atria, you can find __________- that increase atrial volume
auricles
define fossa ovalis
residual impression of fetal foramen ovale
define fetal foramen ovale
an opening between the right and left atria in the embryo and the fetus that allowed blood to bypass pulmonary circulation
name the 3 main veins of the right atrium
superior vena cava
inferior vena cava
coronary sinus
what does superior vena cava do?
return flow from regions superior to diaphragm
what does inferior vena cava do?
return flow from regions inferior to diaphragm
what does coronary sinus do?
drain blood from myocardium
name the veins of the left atrium
4 pulmonary veins
where does blood travel to when in the pulmonary veins?
from lungs, back to heart and to the left atrium
its in the ventricles that blood ______ the heart
leaves
T/F the ventricles make up the least mass of the heart
false; it makes the most
name the 2 muscles of the ventricles
trabeculae carneae
papillary muscles
define trabeculae carneae
crossbars found in the inferior walls of ventricles
papillary muscles work on
valve function
the ___________ is connected to the right ventricle
pulmonary trunk
the pulmonary trunk routes blood towards…
lungs
the left ventricle is connected to the
Aorta
the aorta leads blood to _____ circulation
systemic
name the 3 circuits of blood flow
pulmonary circulation
systemic circulation
the pulmonary circulation begins at
right ventricle
the pulmonary circulation ends at
left atrium
in pulmonary circulation, blood returning from body to right atrium is ________________ concentration
low O2
describe blood flow of pulmonary circulation
right atrium right ventricle pulmonary artery lungs gas exchange O2 rich blood travels into pulmonary veins left atrium
where does the systemic circulation begin
left ventricle
describe systemic circulation
left ventricle towards aorta body has exchange occurs and low O2 blood inferior vena cava right atrium
which circulation does more work?
systemic circulation
which ventricle is bigger?
left ventricle
what is the purpose of valves?
prevent backflow into atria
the valves are _____ during ventricular contraction
closed
name the Right AV valve
tricuspid valve
“Try to be Right”
the tricuspid valve has how many cusps?
3
name the left AV valve
bicuspid valve
how many cusps doe the bicuspid valve have?
2
what doe chordae tendineae do?
heart strings that attach to cusps to anchor them on top papillary muscles
during ventricular contraction, intraventricular pressure ____
rises
the rise in intraventricular pressure during ventricular contraction makes blood
go against valve flaps
name the 2 semilunar valves
aortic semilunar valves
pulmonary semilunar valve
the aortic semilunar valves is between?
left ventricle and aorta
the pulmonary semilunar valve is between?
right ventricle and pulmonary trunk
the semilunar valves open during?
ventricular contraction
right and left coronary arteries arise from
base of aorta
the left coronary artery supplies
left side of heart
name the 2 branches off the left coronary arteries
circumflex artery
anterior interventricular artery
the right coronary artery supplies
right side of heart
name the 2 branches off right coronary artery
marginal artery
posterior interventricular artery
flow to myocardium occurs only during _____
diastole
the cardiac veins form the
coronary sinus
the coronary sinus drains into
right atrium
name the 3 veins that form coronary sinus
great cardiac vein
middle cardiac vein
small cardiac veinn
the anterior cardiac veins empty into
right atrium
angina pectoris results in
temporary deficient blood flow to the myocardium
a myocardial infarction is
heart attack
due to a myocardial infarction, the cardiac cells…
die
cardiac cells are ______
amitotic
cells that die due to a heart attack are replaced with
non-contractile scar tissue
O2 deficiency causes…
necrosis
__________ are branched, short, and interconnected fbers
cardiac muscle
cardiac muscles contract by
sliding filament mechanism
cardiac muscle fibers are connected by
intercalated discs
intercalated discs are anchoring
desmosomes
intercalated discs do what to cardiac muscle cells
connect them
the entire myocardium acts as a
single unit
__________ are used to hold cell together when heart contacts
desmosomes
all cardiac muscle ccells contract as a
single unit
cardiac muscle is self
excitable
cardiac muscles can initiate what?
action potentials
what are intrinsic conduction system?
non contractile cardiac cells that initiate and distribute impulses
describe the events of pacemaker potential
- Prepotential
Na+ influx (entering) offset by K+ efflux (leaving)
K+ permeability gradually decreases (K channels close) - Influx of Na+ depolarizes the cardiac cells
depolarization phase
this opens fast Ca+ channels at threshold
Ca2+ influx from extracellular space causes rising phase of action potential
repolarization phase
repolarization causes K+ channels to open and Ca+ channels to close
cardiac cells repolarize
where can autorhythmic cells be found
only in right atrium
the SA node is a
pacemaker
depolarization leaves SA node and enters
AV node
the AV node is located
in interatrial septum
impulse from AV node passes towards
bundle of His
bundle is His is located in
inferior interatrial septum
the impulse later travel from bundle of His into
left and right bundle branches
the impulse travels from bundle branches into
purkinje fibers
describe cardiac action potential
Resting membrane phase (phase 4)
Depolarization phase (phase 0) where there is rapid influx Na+
Inactivation of the fast Na+ channels (phase 1) Cl- enters and K+ leaves
Plateau phase (phase 2) balance between K+ and Cl-
Ca2+ flows through L-type Ca2+ channel
Repolarization (Phase 3)
L-type Ca2+ channels close and K+ still leaves
define arrhythmias
uncoordinated contractions of atria and ventricles
define fibrillation
rapid, ireegular contractions
define ectopic focus
excitable tissue other than SA node controls heart contractions
a heart block is cause by
damage to AV node
name the cardioacceleratory center
medulla and sympathetic NS
w
name the cardioinhibitory center
vagus nerve and parasympathetic system
define P wave
depolarization moving from SA node through atria
define QRS complex
ventricular depolarization that precedes contraction
define T wave
ventricular repolarization
define PR interval
from beginning of atrial excitation and ventriculation excitation
define QT interval
ventricular depolarization through repolarization
define systole
contraction (depolarization)
define diastole
relaxation (repolarization)
the 1st heart sound can be heard when
AV valves close during onset of systole
during ventricular diastole, ventricular volume….
increases
during ventricular systole, diastolic pressure…
increases or is at its highest
the 2nd heart sound can be heard when
semilunar valves close and beginning of ventricular diastole
during ventricular systole, ventricular volume…
decreases
when the AV valves are open, the semilunar valves are
closed
during ventricular systole, AV valves are
closed
when are both AV valves and semilunar valves both closed
at the beginning of ventricular systole
describe what happens during ventricular systole
isovolumetric contraction phase is where blood pressure in aorta and pulmonary trunk exceed intraventricular pressure
pressure in ventricles increases without volume changing
intraventricular pressure exceeds pressure in large vessels and then the semilunar valves open and blood is propelled
during the T wave, intraventricular pressure
drops
which sound is louder and longer?
sound 1
define cardiac output
amount of blood pumped by each ventricle each minute
how to calculate cardiac output
stroke volume X Heart rate
define stroke volume
volume of blood pumped out of each ventricle per beat
how to calculate stroke volume
difference between EDV and ESV
Define EDV
end diastolic volume
length of ventricular diastole
define ESV
end systolic volume
name the 3 factor that affect stroke volume
preload degree of stretch prior to contraction (most important for EDV)
contractility (decrease ESV)
afterload-arterial blood pressure
define afterload-arterial blood pressure
pressure ventricular contraction must overcome
the parasympathetic system is mediated by
acetylcholine
Epinephrine ___ HR
increases
Ca2+ decreases causes
depressed heart function
name physical factors that affect heart
age (inverse relation_
gender (female is faster)
exercise
body temp (HR is lowered when cold)
