L13-14;C6

Question 1

What happens to demand of O2 when we increase metabolic activity?

Answer 1

The demand of O2 will increase with it

Question 2

What are the three major circulatory elements?

Answer 2

1. A pump
2. Channels or tubes
3. A fluid medium

Question 3

Blood flow must meet ______ demands

Answer 3

Metabolic

Question 4

Explain the following:

Myocardium
Desmosomes
Gap junction

Answer 4

Myocardium—> Cardiac muscle fibres connected by intercalated disks special to cardiac muscles
Desmosomes—> holds the cell together, acts as a single unit
Gap Junctions—> rapidly conducts action potential, occurs with unified contraction within ventricles

Question 5

Explain the calcium reduced calcium released method

Answer 5

Stimulation releases Ca, but this isnt sufficient to cause a contraction. But it is sufficient enough to cause stimulation of RYR receptors to release more Ca which eventually causes a contraction

Question 6

What is the main difference in cardiac and skeletal contractions?

Answer 6

The second burst of calcium in cardiac muscles only happen in their tissues

Question 7

With respect to myocardial substrate use,

At rest, heart oxidizes ____ to provide majority of its energy for work
At moderate, there is an equal distribution of _____, ______, and ______
At high, mainly _____ is being used

Answer 7

Fat,
Carbs, fats, lactate
Lactate

Question 8

Training has an effect that there is higher reliance on ______ than _____ in terms of oxidizing. Why?

Answer 8

Fats, carbs

Since ATP synthesis for fats is slower and for lactate it is higher

Question 9

What happens when atrium and ventricle are contracting at the same time? What happens when they are not?

Answer 9

When they are contracting at the same time, it is insufficient to pump blood.

Having a delay allows for ventricles to fill which is good.

Question 10

What innervation is an external factor to allowing control of the heart? What does it do?

Answer 10

Vegas innervation and PNS act through the Vegas nerve. This releases Ach to decrease HR and force of cardiac contraction

Question 11

Strong vagal innervation _____ HR, sympathetic system ______ Hr and contraction

Answer 11

Decreases, increases

Question 12

SNS increases impulse and contraction of heart, causing chronotropic and ionotropic results. What do these mean?

Answer 12

Chronotropic—> referees to rate of heart

Iontropic—> refers to force of contraction of heart

Question 13

What kind of people have higher vagal modulations? Wha does this due to their HR?

Answer 13

Active people, this decreases HR during rest

Question 14

What does less vagal stimulation do?

Answer 14

Increases HR, and increase SNS activity

Question 15

With respect to a cardiograph, explain the following:

P=
QRS=
ST=
T=

Answer 15

P= Atrial depolarization 
QRS= ventricular depolarization 
ST= ventricular repolarization 
T= ventricular repolarizatrion

Question 16

Ventricle systole is ____ to ___ wave

Answer 16

QRS, T

Question 17

Ventricle systole is how much of the hearts cycle? What do the end of contractions mean?

Answer 17

1/3rd the cycle, the contractions mean end diastolic volume

Question 18

Ventricular diastole is from ___ wave to _____

Answer 18

T, QRS

Question 19

Ventricle diastole is how much of the cycle? How much fills passively and actively?

Answer 19

It is 2/3 cardiac cycle, fills 70% passively and 30% actively

Question 20

Blood pressure is mainly driven and drained _______

Answer 20

Passively

Question 21

What happens to a patient when they have a heart transplant with respect to their CO and SV?

Answer 21

They have a depressed CO and increases SV

Question 22

After the translation of a heart, recovery rate is ______ and why?

Answer 22

Decreased, due to no para or sympathetic activity. The nerves were severed. This means there is no vagal activity.

Question 23

Heart rate is _____ before transplant, why?

Answer 23

Lower, since there is no vagal tone to keep HR down. Since HR before will be lower and knows a resting level.

Question 24

What still influences the heart after transplant?

Answer 24

Hormones, more sympathetic stimulation means a greater hormonal release.

Question 25

Why do arterioles veins arteries and venules all have smooth muscle?

Answer 25

For vast constriction and dilation that allows blood to flow

Question 26

Recall, the heart spends ______ in systole, ____ in diastole

Answer 26

1/3, 2/3