Cardiac Physiology Flashcards Preview

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Flashcards in Cardiac Physiology Deck (20)
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1
Q

Mean arterial pressure

A

The difference of systolic maximum pressure exerted on arterial wall during ventricular contraction and diastolic pressure in vasculature in ventricular relaxation.

  • Average pressure for circulation
  • Indication of tissue perfusion
2
Q

Stroke volume x HR = ?

A

Cardiac Output

3
Q

Which 2 factors determine blood pressure?

A

Cardiac output and Systemic vascular resistance

4
Q

Ejection fraction =?

A

Fraction of blood expelled during contraction

Stroke volume/EDV

5
Q

What is a normal EF?

A

60%

6
Q

Hypocalcemia

A

Reduced calcium levels

Depresses the heart

7
Q

Hypercalcemia

A

Prolongs plateau phase of action potential
Makes heart more irritable
Leads to spastic heart contractions

8
Q

Hypernatremia

A

Excessive Na
Inhibits transport of Ca into cells
Blocks heart contraction

9
Q

Hyperkalemia

A

Excessive K
Lowers resting potential
May lead to heart block and cardiac arrest

10
Q

Hypokalemia

A

Life threatening

Heart beets feebly and arrhythmically

11
Q

Where is the CV center in the brain?

A

Medulla

12
Q

Where is the cardioacceleratory center located?

A

This is a sympathetic center
Projects from medulla to the T1 to T5 levels of the spinal cord
Innervates SA and AV node

13
Q

Where does the parasympathetic (cardioinhibitory center) center send signals to?

A

Dorsal vagus nucleus in the medulla.
This is sent via vagus nerve branches to SA and AV node
SLOWS heart rate

14
Q

Pressoreceptors

A

Detect changes in BP

Located in aortic and carotid sinuses

15
Q

Chemoreceptors

A

Detect changes in blood O2 content

Located in aortic and carotid bodies

16
Q

Bainbridge Reflex

A

Acceleration of HR by increased right atrial pressure (increased volume)

17
Q

Alpha receptors …

A

constrict coronary vessels

18
Q

Beta receptors …

A

dilate coronary vessels

19
Q

Impaired contractility + Increased afterload =?

A

Systolic Dysfunction

20
Q

Impaired ventricular relaxation + Increased afterload =?

A

Diastolic Dysfunction