Week 5 - Revision Cardiac output and BP

Question 1

Cardiac output

Answer 1

the volume of blood leaving the heart each minute = Heart Rate (bpm) x stroke volume

Question 2

Heart rate

Answer 2

number of heart beats per minute

Question 3

Stroke volume

Answer 3

volume of blood leave the blood with each beat

Question 4

Bradycardia

Answer 4

slow resting heart rate (<60bpm)

Question 5

Tachycardia

Answer 5

rapid resting heart rate (<100bpm)

Question 6

Systolic blood pressure

Answer 6

force exerted by circulating blood on the walls of the arteries during systole

Question 7

Diastolic blood pressure

Answer 7

force exerted by circulating blood on the walls of the arteries during diastole

Question 8

Pulse pressure

Answer 8

SBP minus DBP

Question 9

Basal HR

Answer 9

HR while at rest in a neutrally
temperate environment, digestive
system is inactive (about 12
hours)

Question 10

Resting HR

Answer 10

Awake but lying down and not
having immediately exerted
themselves

Average 60-80 beats per minute (bpm)

Question 11

Pre-exercise HR

Answer 11

Physiological anticipation of
exercise
Increased sympathetic neural
drive

Question 12

Steady State HR

Answer 12

Work rate is held constant at submaximal
levels of exercise.

Question 13

Maximum HR

Answer 13

Highest HR value achieved in an all
out effort to the point of
exhaustion.

220 - age

Question 14

How much does metabolic rate increase during activity?

Answer 14

10-20x

Question 15

Intrinsic control of heart rate (4) conductions

Answer 15

SA node in right atrium through internodal pathways to AV node in right atrium, through Bundle of His between ventricles, it parts to left and right bundle where purkinje fibers break off and innervate the ventricles

Question 16

What extrinsic influences have a direct change on the intrinsic control of the heart

Answer 16

Direct nerve supply to myocardium, hormones in the blood, central nervous system Somatomotor regions

Question 17

What region of the brain is the cardiovascular control centre?

Answer 17

Ventrolateral Medulla

Question 18

What does the Ventrolateral Medulla regulate

Answer 18

*Regulates heart’s output & blood distribution
*Continually evaluates and processes sensory input from the brain and peripheral NS
*Modulates sympathetic and parasympathetic nervous activity

Question 19

Extrinsic influence - parasympathetic

Answer 19

Slows heart rate through vagus nerve cell bodies which originate in cardio inhibitory centre

Question 20

Extrinsic influence - sympathetic

Answer 20

Increases heart rate by increasing activity of the SA node and increase atrial and ventricular contractile force and HR

Question 21

Extrinsic influence - What hormones have an extrinsic influence on the cardiovascular system and where is this from?

Answer 21

Adrenaline and noradrenaline from the adrenal medulla

Question 22

Difference between Parasympathetic and Sympathetic nerve endings in the heart

Answer 22

Parasympathetic concentrate in the L & R atria, including SA and AV nodes.

Sympathetic fibers supply SA, AV nodes and the muscle of the atria and ventricles.

Question 23

Where is the adrenal medulla located? And how does it send it’s hormones through the body? Fast or slow acting?

Answer 23

On the apex of the kidney and these hormones are released through the blood.

Slow acting.

Question 24

Noradrenaline effects

Answer 24

*Increased contractility
*Increased relaxation rate
*Increased heart rate
*Increased conduction velocity

Question 25

Noradrenaline effects during exercise

Answer 25

*blood shunted from the skin & viscera to the skeletal
muscles, coronary arteries, liver, & brain
*Vasoconstriction
* increased blood sugar
*increased metabolic rate
*bronchi dilate
*pupils dilate
*hair stands on end (“gooseflesh” in humans)

Question 26

How is BP determined?

Answer 26

Volume of blood pumped and the resistance of arterial walls against the blood.

E.g. vasoconstriction = higher resistance, higher BP

Question 27

Autonomic nervous system regulates blood vessels how?

Answer 27

Vasodilation of arterioles to exercising muscles
Vasoconstriction of arterioles to non exercising muscles
Vasoconstriction of venous vasculature