Components of Map
Which nervous system controls heart rate
(Bonus if you can say where in the brain heart rate is controlled)
Autonomic Nervous System
(Medulla Oblongata)
What type of receptors detect the stretch in the arteries and are involved in maintaining MAP
Baroreceptors
Which patient is more at risk for poor organ perfusion? Patient A: 120/80, Patient B: 100/50
B
You stand up suddenly and get a head rush. Is this positive or negative MAP in that moment? Why?
Negative. A temporary drop leads to less brain perfusion
Where is professor Atrill from?
Tasmania
Define Cardiac Output
what is a measurement of the amount of blood pumped by each ventricle in a minute
In the RASS System what is the purpose of renin and where can it be found?
In the blood stream and its main purpose is to convert the protein angiotensinogen to angiotensin I.
A patient is given a vasodilator drug. Explain how this affects MAP and why
MAP decreases because total peripheral resistance drops
You just finished a workout and experience a flushed face, warm skin, and heavy breathing. Is this positive or negative MAP in that moment? Why?
Positive. MAP is being maintained and blood flow is reaching muscles.
What molecule does tissue perfusion deliver to support cell metabolism?
Oxygen
What is perfusion
What is the movement of blood in the tissues
(this is what MAP maintains)
This vascular response lowers total peripheral resistance and helps decrease mean arterial pressure after elevated baroreceptor firing.
What is vasodilation?
If systolic pressure increases significantly but diastolic stays the same, why doesn’t MAP increase proportionally?
If you are sitting and talking normally but feel like you might pass out when you close your eyes, is your MAP likely normal, low, or on the edge? Why?
Right on the edge. You are still conscious, meaning that perfusion isn’t completely failing, but the symptom suggests cerebral perfusion isn’t fully adequate.
In grade three which animal did professor Atrill bring to class
A Sheep
Compliance - the ability of any compartment to expand to accommodate increased content.
Blood volume - hypovolemia, hypervolemia
Blood viscosity - the thickness of fluids that affects their ability to flow.
Blood vessel length - does not typically change in adults, but increases as we grow
Blood vessel diameter - can be altered by vasoconstriction (narrowing) or vasodilation (widening)
In RAAS, the kidneys initiate the response, the lungs provide ACE activity, the adrenal glands release aldosterone, and this gland releases ADH.
What is the pituitary gland
A patient comes into the ER after not drinking water all day at a music festival. They’re dizzy, tired, and complain about feeling “off”. What is happening physiologically?
Low blood volume causes low cardiac output, decreased MAP, and reduced perfusion, causing symptoms.
A system has steady pressure, but only operates properly when external assistance is constantly pushing fluid. Is this good or bad MAP? Why?
Bad. MAP isn’t being maintained independently and could collapse without the assistance.
As the aortic valve opens and closes, describe how the ventricles respond during systole and diastole.
When the aortic valve opens, the ventricles are in systole and actively contracting to eject blood into the aorta. When the aortic valve closes, the ventricles begin diastole, relax, and ventricular pressure falls so the chambers can eventually fill again.
List the three components of stroke volume and briefly explain each.
What is: Preload, Contractility and Afterload
Preload:How full is the heart prior to contraction. Similar to end diastolic volume.
Contractility - the force of the contraction of the heart muscle. This is the main determinant of ESV, and therefore, impacts SV.
Afterload - to the tension that the ventricles must develop to pump blood effectively against the resistance in the vascular system.
This is the most direct reason angiotensin II can restore MAP faster than aldosterone can, even though both are activated in the same pathway.
What is that angiotensin II directly causes vasoconstriction, while aldosterone works more slowly through renal sodium and water retention?
Two patients walk into the ER. One looks flushed, warm, and relaxed. The other looks pale, cold, and tense. Both patients have the same MAP. Who worries you more, and why?
The cold, pale patient. Their body is likely using vasoconstriction to maintain MAP, which can reduce actual blood flow to tissues.
In situation A, water flows slowly but evenly through every pipe in a system. In situation B, water pressure is high, but most pipes are tightly narrowed. Which situation represents a better MAP state? Why?
A. narrow pipes can lead to poor flow that reduces complete perfusion.
Bonus Question worth 1000 (must be answered in the last minute): What sparked Professor Atrill's interest in human physiology
attending the Rotary National Science and Technology Forum in New Zealand