Practical Heart

Question 1

Decrease TPR

Answer 1

Vasodilation

Decrease BP

Increased blood flow

Question 2

Systemic effect from hot water is mediated by what 2 things

Answer 2

Peripheral / hypothalamic thermoreceptors

Question 3

What are the two systemic effects from hot water submersion

Answer 3

Decreased TONIC sympathetic
vasoconstrictor activity

Increased sympathetic cholinergic vasodilator activity (VIP/NO)

Question 4

What is activated as a local effect from hot water submersion

What’s released

Answer 4

Warm sensitive afferent

Increase in NO via eNOS

Question 5

Cold water submersion leads to what thermoreceptors being activated as a systemic response

Answer 5

Peripheral/hypothalamic stimulate SNS

Question 6

What’s up regulated as a local effect from cold water submersion

Answer 6

Unregulated a2c receptors on VSMC

Question 7

What’s inhibited as a local effect from cold water submersion

Answer 7

Inhibition of NO release

Question 8

What acts on the upregulated a2c receptors on the VSMC (Vascular SMC)

Answer 8

Norepinephrine

Question 9

Cold water leads to what in terms of vasculature

Answer 9

Vasoconstriction

Question 10

Why do we measure Bp

Answer 10

We can work out blood flow as it’s indirectly proportional to Bp

Question 11

Why does hypoxia occur

Answer 11

Occlusion of artery

No blood flow

Question 12

What’s built up due to the occlusion

Answer 12

Vasodilator metabolites

CO2

Decrease in pH

Adenosine

Question 13

Why is BF suddenly increased

Answer 13

Vasodilators cause decrease in TPR

Reactive hyperaemia

Question 14

What happens to Be when occlusion is removed

Answer 14

Bp drops as TPR decreases

Question 15

Why does BF restore to normal?

Answer 15

Metabolites washes away

Normal Bp

Question 16

Name 6 physiologic changes that occur with exercise

Answer 16

Increased
 O2 consumption 
CO2 production
CO (HR + contractility)
O2 diffusion capacity

Dilation of muscle blood vessels (B2)

Construction of visceral blood vessels (a1)

Question 17

B1 receptors

Answer 17

Heart

Question 18

What controls HR

Answer 18

Sympathetic B1

Parasympathetic vagus nerve

Question 19

Ve (minute volume) increases what to oxygen consumption during moderate to steady exercise

Answer 19

Proportionally

Question 20

Increasing intensity of exercise means what for O2 uptake

Answer 20

O2 uptake becomes insufficient to provide energy

Question 21

When does anaerobic respiration occur

Answer 21

When O2 uptake isn’t sufficient enough to provide energy

Question 22

What’s formed from anaerobic glycolysis

Answer 22

Lactating Acid —> CO2

Question 23

What receptors are activated due to increase CO2 production

Answer 23

Chemoreceptors

Peripheral / central

Question 24

What does the chemoreceptors do when activated

Answer 24

Send a signal to medulla Via afferent neuron

Increases ventilation rate via efferent neuron

Question 25

Overall what is minute ventilation to oxygen consumption

Answer 25

Minute ventilation increases disproportionately to oxygen consumption

Question 26

Define the anaerobic threshold

Answer 26

Highest sustained intensity of exercise for which O2 can provide energy requirement from ATP

Question 27

After the anaerobic thresholds, what can satisfy this?

Answer 27

Anaerobic glycolysis

Question 28

Minute ventilation

Answer 28

Amount of air expired in litres over a course of a minute

Question 29

Where are chemoreceptors detected

Answer 29

Carotid Aortic bodies

Question 30

Where are baroreceptors located

Answer 30

Catotid sinus Aortic arch