Paramedic Resource Manual Section 3

Question 1

3 layers of the heart

Answer 1

• endocardium (lining)
• myocardium (muscle)
• epicardium (outer layer)

Question 2

What part of the heart is the main contractile force?

Answer 2

ventricles

Question 3

What are the 2 AV valves?

Answer 3

• mitral
• tricuspid (tri is on the right)

Question 4

What is the name of the sack that encloses the heart?

Answer 4

Pericardium

Question 5

What are the chordae tendinae?

Answer 5

guide wires that stop the valves from backflowing into the atria

Question 6

What is the only artery that transports deoxygenated blood?

Answer 6

Pulmonary artery (moves blood from right ventricle to the lungs)

Question 7

What are the only veins that transport oxygenated blood?

Answer 7

pulmonary veins - from lungs to the left atrium

Question 8

What is causing the first sound when you listen to the heart?

Answer 8

closure of the AV valves

Question 9

What is the second sound you hear when the you listen to the heart?

Answer 9

closure of the aortic and pulmonary valves

Question 10

At rest, where is sodium and potassium located in the cardiac cell?

Answer 10

potassium inside the cell and sodium outside the cell, this creates a negative charge in cell

Question 11

What creates the action potential in a cardiac cell

Answer 11

Sodium rushes in - Sin
Potassium rushes out - Pout

Question 12

How does calcium play a role in action potentials?

Answer 12

calcium closes the gates that control access to the sodium channels

Question 13

What is the flow of conduction through the heart

Answer 13

• SA node
• AV node
• Bundle of His
• purnikje fibres

Question 14

What occurs during the PR interval?

Answer 14

physiological delay from the AV node

Question 15

What occurs during the QRS complex

Answer 15

ventricular depolarization and then immdiately ventricular contractions

Question 16

What occurs during the T wave

Answer 16

repolarization of the ventricles

Question 17

What is the Frank Starling Law?

Answer 17

the greater the diastolic filling (the filling of the ventricles during diastole) the greater the cardiac output

Question 18

When it comes to cardiac output, if there is sympathetic stimulation

Answer 18

there would be an increase in both the rate and the strength of the contraction. the inverse would occur of thre was parasympathetic stimulation

Question 19

High level of potassium in the blood will lead to…

Answer 19

a dilated, flaccid heart with a slower heart rate and delayed transmission through the AV node.

Question 20

High levels of calcium in the blood will lead to

Answer 20

spastic heart contractions

Question 21

High levels of sodium depresses

Answer 21

cardiac function

Question 22

Temp increases cause what with the heart?

Answer 22

increases hr and contractility

Question 23

What are the 3 layers of the arteries?

Answer 23

Intima - the smooth inner lining of endothelial cells)
Media - (the thick middle layer of muslce and elastic fibers
Adventilita - the outer layer of fibrous, collagenous tissue

Question 24

What is the main difference in the composition between arteries and veins

Answer 24

veins are a lot less muscular than the arteries

Question 25

In what layers of the artery would a dissection occur?

Answer 25

intimal and media

Question 26

When do you start hyperventilating a pt with suspected ICP

Answer 26

- kusmals reps - posturing - fixed pupils

Question 27

When hyperventilating a pt with suspected cerebral herniation what end tidal are you aiming for?

Answer 27

somewhere between 30-35 mmHg

Question 28

What is the patho behind stretch receptors lowering BP

Answer 28

- stretch receptors go off when the BP is too high - Stretch receptors send signal to vasomotor centre of the medulla or up to the vagus nerve - this leads to excitation of the vagal nerve - this causes decrease in HR, contractility, and dialtion of the peripheral vessels