chapter 13 Flashcards
what is the blood flow starting from the left ventricle
left ventricle, aorta, body, venae cavae, right atrium, right ventricle, pulmonary arteries, lungs, pulmonary veins, left atrium, left ventricle
whats the difference between Systemic circuit and Pulmonary circuit
Systemic circuit
- going to the body from left ventricle
Pulmonary circuit
- to the lungs from right ventricle
what is the difference between Series flow vs. parallel flow
parallel- sending blood on different pathways to different organs at the same time
series- when theres one capillary bed and then that same blood goes to another capillary bed
what is Coronary circulation
first arteries to branch off of the aorta, takes blood to heart
what does autorythmicty mean
ability to generate own rhythm
what are Pacemaker cells and what do they do
autorthmic cells start action potentail, spontaneously depolarizing, contains leaky channels that allow positive ions to enter, open Ca++ channels when thershold is reached, potassuim channels open and repolarize,
what is in charge of the pace of the heart beat
SA node is in charge but AV can take over
what are Conduction fibers
apart of myocardium, it rapidly conducts action potentials
what do Intercalated disks contain
contains gap junction and desmosomes
what is the Spread of excitation through the heart muscle
goes from SA node to the atrium then goes to AV node then goes to AV bundle then goes to right and left bundle branches then goes the apex and then to the purkinje fibers and the whole ventricle
why does the AV node delay before contracting
AV node delays contraction for a second so atrium can finsh contracting and blood is in ventricles
what is the Plateau phase
opening of Ca++ channels and Ca++ goes in while potasium goes out so they are cancelling each other out almost
what are the 7 steps of Excitation-contraction coupling for cardiac muscle
- Action potential enters the cell through gap junctions (similar to smooth muscle) and depolarization occurs.
- Opening of voltage-gated calcium channels in plasma membrane. Calcium enters and triggers calcium release from the SR. Calcium induced calcium release (similar to smooth muscle
- Action potential travels down T-tubules changing shape of DHP receptors which open ryanodine receptors in SR membrane and calcium enters cytosol from SR (similar to skeletal muscle).
- Calcium is released from sarcoplasmic reticulum.
- Calcium binds to troponin causing a shift in tropomyosin (similar to skeletal muscle)
- Binding sites on actin are exposed
- Crossbridge cycle occurs.
what is the P-wave and what does it mean
P-wave- first bump, atrium has depolarized
what is the QRS complex mean
QRS complex- depolarization in the ventricles and atrium repolaritation
what does the T-wave mean
T-wave, repolarization of the ventricles
what is the PQ interval mean
atrium contaction and AV nodal delay
what is the QT interval mean
ventricular systole
what does the TQ segment
ventricular diastole
what is the difference between Systole and Diastole
Systole- ventricle contraction
Diastole- ventricle relaxation
when does AV valves open
open when atrium pressure is greater
when does semilunar valves open
when ventricluar pressure is greater
PHASE 1: name ventricular and atrial contraction, pressure and volume changes in the chambers, and valves opening and closing (identify heart sounds
Ventricular filling
Contraction: ventricles relaxed, atrial contraction
Pressure: ventricular pressure is low
Volume: Volume is high
Valves: AV valves are open, semilunar valves are closed
Heart sounds: no heart sounds
PHASE 2: name ventricular and atrial contraction, pressure and volume changes in the chambers, and valves opening and closing (identify heart sounds
Isovolumetric ventricular contraction
Contraction: ventricles contract
Pressure: ventricular pressure is high and atrium pressure is low
Volume: stays the same
Valves: AV and Semilunar valves are closed
Heart sounds: soft lubb, S1
PHASE 3: name ventricular and atrial contraction, pressure and volume changes in the chambers, and valves opening and closing (identify heart sounds
Ventricular ejection
Contraction: ventricles are contracting
Pressure: pressure is high in ventricles
Volume: ventricular volume decreases as its getting pushed out
Valves: semilunar valves open, AV valves are closed
Heart sounds: no sound
PHASE 4: name ventricular and atrial contraction, pressure and volume changes in the chambers, and valves opening and closing (identify heart sounds
Isovolumetric ventricular relaxation
Contraction: ventricles are relaxed
Pressure: ventricular pressure is low
Volume: volume is low
Valves: AV valves and semilunar valves are closed
Heart sounds: loud dupp, S2
when will the ventricles be the fullest and the emptiest
End-diastolic volume- ventricles will be the fullest
End-systolic volume- ventricles will be empty
how do you fine stroke volume
End-diastolic volume - End-systolic volume = Stroke volume
how do you find cardiac output
Cardiac output = heart rate x stroke volume
what is
Released for sympathetic control of the heart and where
epinephrine from neurons or adrenal medulla
whats the difference between Sympathetic control and Parasympathetic control
Sympathetic control –
- open leaky and calcium channels more so it speeds up heart rate, hyperpolarized
Parasympathetic control
- close positive ion channels so it slows down heart rate, hypopolarized
what is Starling’s law
if the ventricle is too stretched or not stretched enough it will make it harder to push the blood out
whats the difference between preload and after load in the heart
Preload is the stretching of the heart muscle due to the volume of blood entering the ventricles
After load is the resistance the heart faces when it pumps blood out into the arteries
