Cardiac Function: Structure of the Cardiovascular system

Question 1

outline the heart and label its structures

Answer 1

do this on own, I can’t put pics in bc then I have to pay which is kind of weird but idk.

Question 2

list four structural changes in the aging heart (geriatric considerations)

Answer 2

• size of the heart increases due to hypertension and thickening of the heart wall
• conduction system slows, producing a slower heart rate d/t a LOF of the cells throughout the conduction system
• aging leads to stiffening of the valves, preventing them from closing properly. this leads to murmurs and backflow.
• stress/decline in health puts more pressure on the heart and thus the heart is unable to respond as quickly upon exertion, causing the elderly to be SOB and fatigued a lot.

Question 3

explain the differences between arteries and veins (structure and function)

Answer 3

structure: arteries are thick walled vessels with large amounts of elastic fibers, whereas veins are thin walled, distensible, and collapsible vessels.

function: the arteries need to be thick because a lot of blood rushes through them, and they need to be stretchy because they can’t be overwhelmed when the heart pumps the blood.
They also need to recoil well. The arteries push the blood away and are a high pressure system.

The veins are a low pressure system because all they do is bring blood back to the heart. However, they can contract/expand to carry varying amounts of blood. the veins also have valves to prevent retrograde blood flow.

Question 4

describe events in the cardiac cycle: ventricular diastole and systole, ventricular ejection

Answer 4

ventricular systole is when the ventricle contract to push the blood out (either to the aorta or to the pulmonary vein). The blood is pumped through either the left (tricuspid/mitral) or the right (bicuspid) AV valve.
SYSTOLE

ventricular diastole is when the ventricles relax to allow blood to pool while getting ready for the next systole.
DISATOLE

ventricular ejection: the amount of blood that the ventricle pushes out, written as a fraction.
SYSTOLE

Question 5

describe events in the cardiac cycle: isovolumetric contraction and relaxation

Answer 5

isovolumetric contraction is a short period of time when the ventricular blood volume remains the same because all 4 valves (the AV and SL valves) are closed due to blood pressure created in the chambers during the beginning of ventricles systole (isovolumic).
SYSTSOLE

isovolumetric relaxation: Ventricular pressure then declines exponentially during isovolumetric relaxation, when both the aortic and mitral valves are closed. This begins the ventricular diastole.
DIASTOLE

Question 6

describe events in the cardiac cycle: ventricular filling and atrial contraction

Answer 6

Ventricular filling is the pressure that builds up in the ventricle as the ventricle is being filled with blood, typically equivalent to the mean atrial pressure in the absence of A-V valvular gradient.
DIASTOLE

atrial contraction is when the atria contract to push the blood out (either to pulmonary or systemic circulation)
SYSTOLE

Question 7

write the equation to calculate cardiac output

Answer 7

Cardiac Output (CO) = Stroke Volume (SV) x Heart Rate (HR)

Question 8

state the main factors that can affect both stroke volume and heart rate

Answer 8

factors that can affect stroke volume:
contractility, preload, and afterload
CPA

factors that can affect heart rate:
exercise, emotional distress, blood pressure, high cholesterol, weather, etc.

Erin 
Ethan (&) 
Bob Poppen 
Helped 
Charlie 
With 
(his) Easel

Question 9

how does Frank Starling’s law relate to preload?

Answer 9

Starling’s Law states that the heart will eject a greater stroke volume if it is filled to a greater volume at the end of diastole. The volume of the heart at end diastole is related to the filling pressure of the heart (preload).

Question 10

compare the function and distribution of blood flow and blood pressure in the systemic and pulmonary circulations

Answer 10

the pulmonary system is considered a low blood pressure system, but there is a substantial distribution of blood flow to the places.

the systemic circulation is a lot higher pressure of a system, and a lot more blood flows through it.

Question 11

explain autoregulation of blood flow and the role of nitric oxide

Answer 11

Autoregulation of tissue blood flow is a mechanism by which tissues control their own blood supply. The mechanism is dependent on an intrinsic capacity of tissues to vary their arteriolar resistance in relation to their needs.

Nitric oxide is produced by nearly every type of cell in the human body and one of the most important molecules for blood vessel health. It’s a vasodilator, meaning it relaxes the inner muscles of your blood vessels, causing the vessels to widen. In this way, nitric oxide increases blood flow and lowers blood pressure.

Question 12

describe the humoral control of blood flow with vasodilator and vasoconstrictor substances in the blood.

Answer 12

humoral just means cell-mediated.
in this way, the cells secrete vasodilator and vasoconstrictor substances into the blood and the blood vessels respond in accordance.

Question 13

review norepinephrine, epinephrine, angiotensin, histamine, and know their effects on blood flow.

Answer 13

NE: triggers vasoconstriction to decrease blood flow so increase BP
E: dilates the vessels in the skeletal muscle and liver, so increases blood flow
ANG: decrease blood flow, increase blood pressure by vasoconstriction
HIST: dilates the vessels, and increases blood flow,