The pipes of the pump
These blood vessels serve as a volume reservoir for blood because of there high ____.
What is capacitance?
High pressure baroreceptors are found here.
What is the carotid sinus and aortic arch?
*Bonus: Where do they send signals if BP is off? Nucleus Tractus Solitarius
Cells that propagate electrical conduction through the heart are found here.
What are the SA/AV nodes, the Bundle of His and the Purkinjie Fibers?
What is full/ just before systole?
This property of veins allows them to hold a larger blood volume than capillaries even through capillaries compromise the largest cross sectional area.
What is having a high capacitance?
These blood vessels serve as a pressure reservoir for blood because of there high ____.
What is collagen?
The SVC and IVC are home to these receptors which activate the RAAS system in the kidneys.
What are low pressure barorecptors?
The following are two methods of circuit re-entry.
What are global and micro re-enrty.
The first valve event on both a PV loop/ Wigger's.
AV valve (Mitral) valve closes
What is inverse?
Myelin insulate cells thus decreasing capacitance and increasing the resistance of the membrane. The opposite is true for non-myelinated cells.
The radius of these vessels is very small making the blood flow ___ which is optimal for the role of capillaries.
What is slow?
Small radius = high resistance = slow flow
Large radius = low resistance = faster flow
What is the sympathetic nervous system (increase MAP via vasoconstrition)?
What is the alpha receptor?
The difference between rate of AP conduction and velocity of AP is explained by this.
The rate of AP conduction = how many AP are generated per minute. These will be highest in the SA node which sets the heart rate.
However, the fastest depolarization does not happen in SA/AV nodal cells because the If and IL channels are slowly depolarizing. Fastest depolarization is facilitated via INat which is in the myocytes thus the Purkinjie Fibers.
The second valve event on a PV/ Wigger's is the aoritc valve opening. This is a result of the following.
The pressure in the ventricle exceeds the pressure in the aorta. This the valve opens to allow blood to move from high pressure to low pressure.
Starting on the venous side the order of blood flow through the heart is.
IVC+SVC --> RA --> Tricuspid--> RV --> Pulmonary valve --> Pulmonic Trunk (PA) --> Lungs --> Pulmonary veins --> LA--> Mitral --> LV--> Aortic Valve --> Ascending Aorta--> Systemic Circulation
As a result of this property, the aorta has a high velocity of blood flow.
What is large radius?
The RAAS System ultimately increases MAP. What key protein causes these effects?
What is ANG II?
*Bonus: What are the downstream effects of ANGII?
Vasoconstriction, Production of Aldosterone (Increasing Na+/H20 retention), Production of ADH and decreasing baroreceptor sensitivity.
The order of structures involved in AP conduction of the heart.
SA--> Atria--> AV --> IV Septum--> LV--> RV --> Purkinjie to Apex --> Enodcardium --> Epicardium --> Up to Base of the heart.
The pressure represented by each of the lines in Wiggers.
From top to bottom: Black dotted = Aortic, Red = Ventricular, Black dotted= Atrial
Do cells in the SA/AV nodes every reach RMP? (Yes/No)
No!
If this were the case we would die. The If channels automatically release Na+ after repolarization which prevents the cells from reaching RMP. This starts the process of depolarizing cells for the next heartbeat.
Arteriole vessels regulate the flow into capillaries because at this point is ___.
What is the point of highest resistance?
Help my BP is high. If I need to decrease MAP what are two ways to do this?
What is secretion of Atrial Natriuretic Peptide (ANP) or activation of PNS to release Ach (M2 receptors)?
The role of Ca2+ in the crossbridge cycle.
What is to induce more Ca2+ release from the SR and binding Troponin-C to begin the cycle.
The changes are expected on a PV Loop for the following conditions:
1) Increased afterload (aortic stenosis)
2) Increased preload (Increased blood volume)
3) Increased contractility (Exercise, Increased Ca2+)
1) Taller and skinner due to increased pressure needed to overcome stenosis of the valve.
2) Wider loop (right shift) (Higher Stroke Volume) but same height due to the increased blood volume.
3) Wider (left shift) and taller due to increased Stroke Volume and the increased pressure to contract harder.
These two methods are used to approximate the pressures in the RA and LA.
What is measuring the IVC diameter on inspiration for the RA?
What is measuring pulmonary artery wedge pressure for the LA?