Let's get Physical
The ________ prevent the backflow of blood and are found in the _______ and _________.
Valves, heart, veins
Can we recall the valves of the heart? Whiteboard.
This period of the cardiac cycle represents the greatest cardiac output.
Ventricular Systole
This node is the primary pacemaker of the heart.
What is the SA node?
The formula to calculate cardiac output.
Cardiac output = heart rate x stroke volume
Define each of these.
This part of the heart is enriched with thick muscles for pumping blood under great pressure.
Left ventricle
Two differences between the pulmonary and systemic circuits.
The pulmonary circuit is smaller and is a low-pressure system. It distributes blood to the lungs from the right ventricle. Deoxygenated blood is oxygenated. While the systemic circuit is larger and is a high-pressure system. It distributes blood to the whole body from the left ventricle. Oxygenated blood becomes deoxygenated.
Try to represent this on the whiteboard.
The point on the EKG that represents the atrial depolarization.
P wave
What about the QRS and T waves?
The flow of action potentials through the heart.
SA node -> AV node -> Bundle of His -> Purkinje fibers
Refer to diagram.
Blood pressure is the function of _______ and ________.
cardiac output and total peripheral resistance
Define blood pressure.
The difference between diastole and systole.
Diastole= relaxation
Systole= contraction
Let's use our hands to remember!
The _______ connect cardiomyocytes to the extracellular fluid, facilitating the propagation of action potentials, while the ______ allow action potentials to be propagated from cell to cell, creating a functional syncytium.
T-tubules, Gap junctions within intercalated disks.
You can try drawing this out.
End diastolic volume
The volume of blood in the ventricles before contraction.
The effect of the parasympathetic nervous system on cardiac output.
Parasympathetic NS decreases heart rate by decreasing the rate of depolarization of the pacemaker cells. Note that the Parasympathetic NS cannot affect blood vessels.
How would this affect blood pressure assuming that all other factors remain constant?
______ is the tendency of fluid to move away, while ________ is the tendency of fluid to move towards proteins.
Hydrostatic pressure, Colloid osmotic/oncotic pressure
These are 3 functions of the cardiovascular system.
Transport of nutrients from the digestive tract to the tissues and to and from organs that transform and store nutrients.
Transport of waste products from tissues where they are produced to the organs where they are excreted.
Transport of oxygen from lungs to tissue.
Transport of carbon dioxide from tissues to lungs.
Transport of heat from the tissues to skin and respiratory organs where it is dissipated.
Transport of hormones from the endocrine glands to target cells.
Transport of white blood cells and antibodies to protect against infection.
Three differences between pacemaker cells and contractile cells.
Contractile cells- make up 99% of the heart, display stable resting membrane potential, and must be stimulated to bring about contraction.
Pacemaker cells (autorhythmic cells) - make up 1% of the heart, are found in specific regions of the heart, generate action potentials spontaneously, undergo slow depolarization, and do not have a stable resting membrane potential.
You can use a table to compare the 2.
The 3 events of diastole and 2 events of systole.
Diastole: the ventricles relax and fill with blood. It includes (1) isovolumetric ventricular relaxation, (2) rapid ventricular filling, and (3) atrial contraction or atrial systole
Systole: the ventricles contract and eject blood into the aorta and pulmonary arteries. It includes (1) isovolumetric ventricular contraction and (2) ventricular ejection.
Let's talk about the position of the valves. Use a table here.
Three differences between the action potential of a contractile cell vs that of a pacemaker cell.
Pacemaker cell - (1) unstable resting membrane potential (2) Funny channels and influx of Na+ starts prepotential (3) Transient Ca2+ channels allowing influx of Ca2+ allows threshold to be reached (4) Depolarization is due to influx of Ca2+ (5) No plateau during repolarization
Contractile cell - (1) Stable resting membrane potential (2 and 3) No prepotential nor funny channels, etc. (4) Rapid depolarization due to influx of Na+ (5) Plateau during repolarization due to influx of Ca2+ and efflux of K+.
You can use a table to compare the 2. Also, can you draw the graph for each? Also, what is the similarity between the two?
The Starling forces that promote net filtration.
Capillary hydrostatic pressure
Negative interstitial fluid hydrostatic pressure
Interstitial fluid colloid osmotic pressure
Define each. Draw a diagram to represent these (refer to the diagram in your notes).
Blood ____ is the volume of blood flowing through a tissue per unit time and unit weight. Blood ________ is the volume of blood transported through a blood vessel per unit time.
Perfusion, flow
The flow of blood through the various chambers and valves of the heart.
Draw a diagram to represent this.
Vena cava -> right atrium -> inlet valve (tricuspid) ->right ventricle -> outlet valve (pulmonary valve)-> pulmonary artery -> lungs -> pulmonary vein -> left atrium -> inlet valve (bicuspid) -> left ventricle -> outlet valve (aortic valve) -> aorta
The 2 phases of the cardiac cycle in which both the inlet and outlet valves are closed.
Isovolumetric relaxation and isovolumetric contraction
In which 2 phases are the inlet valves open and the outlet valves closed?
The comparison of the skeletal muscle action potential with that of the 2 types of cardiomyocytes.
Skeletal muscle AP - Influx of Na+ causes depolarization; there is no plateau during repolarization; there is hyperpolarization
Contractile cardiomyocyte AP - Influx of Na+ causes depolarization; there is a plateau during repolarization due to influx of Ca2+ and efflux of K+; there is no hyperpolarization
Autorhythmic cardiomyocyte (pacemaker) AP - Influx of Na+ then Ca2+ during prepotential; influx of Ca2+ causes depolarization; there is no plateau during repolarization; there is no hyperpolarization or stable resting membrane potential
You can use a table to compare and contrast all 3.
Ways by which the sympathetic nervous system influences cardiac output.
The sympathetic NS increases cardiac output by increasing the following:
(1) Heart rate by increasing the rate of depolarization of the pacemaker cells
(2) Stroke volume by:
(a) Increasing venous return through venous constriction and activity of the pumps thereby increasing the end diastolic volume
(b) Increasing the contractility of the heart
The differences among the various blood vessels of the cardiovascular system.
Arteries - resistant component, carries blood away from heart to body, high pressure, thick walls, smaller lumen than veins.
Veins - capacitance component, carries blood away from body to heart, lower pressure, thin walls, large lumen, has valves.
Capillaries - area of exchange at tissues, low pressure, thinnest walls and smallest lumen