Chapter 1 Flashcards
(148 cards)
what does the vena cava do
brings deoxygenated blood back to the right atrium
what does the pulmonary vien do
delivers oxygentaed blood to the left atrium
what does the pulmonary artery do
leaves right ventricle with deoxygenated blood and delivers it to the lungs and aorta
what does the aorta do
leaves the left ventricle with oxygenate blood and takes it to the body
where is the tricuspid valve located
between right atrium and left atrium
where is the bicuspid valve located
between left atrium and left ventricle
where are the semilunar valves located
between right ventricle and left ventricle and aorta and pulmonary vien
what are the 3 roles of veins
ensure blood flows in 1 direction
open to allow blood to pass through
close to prevent backflow
how does the heart control the rate at which it beats
the SAN creates impulse both atria contract (systole)
impulse reaches AV node
impulse sent on the bundle of HIS
achieve ventricular systole
CARDIAC CONDUCTION SYSTEM
What does:
Sally
Always
Aims
Balls
Past
Vicky
stand for ?
SAN
Atrial systole
AV node
Bundle of HIS
Purkinge fibres
Ventricular systole
what do chemoreceptors do
detect changes in blood acidity caused by an increase or decrease in C02
increased C02 concentration in blood will stimulate the sympathetic nervous system so the heart will beat faster
what do baroreceptors do ?
respond to the strecthing of the arterial wall caused by changes in blood pressure to either increase or decrease heart rate.
establish a set point for blood preussure
what does an increase in arterial pressure mean
causes an increase in in the stretch of the baroreceptors and results in a decreased heart rate
what does an decrease in arterial pressure mean
causes an decrease in in the stretch of the baroreceptors and results in a increased heart rate
what happnes to the baroreceptors set point during exercise
it increases as the body does not want the heart rate to slow down as this would negatively affect performance
what do proprioeceptors do
located in the muscles and provide information about movement and body position
at the start of exercise they detect an increase in muscle movement these receptors then send an impulse to the medulla witch sends an impulse through the sympathetic nervous system to the SA node to increase heart rate
define adrenaline
stress hormone released by the sympathetic nerves and cardiac nerves during exercise
define stroke volume
the volume of blood pumped out the heart ventricles in each contraction
define venous return
volume of blood returning to the heart via the veins if venous return increases so does stroke volume
cardiac output =
stroke volume x heart rate
what are the 5 steps to starlings law
increased venous return
greater diastole filling of the heart
cardiac muscle stretched
more force of contraction
increased ejection fraction
what is the equation for ejection fraction
amount of blood pumped out of the ventricle / total amount of blood in the ventricle
define cardiac output
the volume of blood pumped out by the heart ventricles per minute
what is ml -> l
divide by 1000