Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

P.E - E.P Yr 1 > Heart, Venous Return, Receptors > Flashcards

Heart, Venous Return, Receptors Flashcards

1
Q

What happens to venous return during exercise

A

Increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define venous return

A

Return of deoxygenated blood to the right side of heart via vena cava

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the venous return mechanisms

A

Skeletal muscle pump

Respiratory pump

Pocket valves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Explain the skeletal muscle pump

A

When skeletal muscles contract they compress the veins which forces blood toward heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Explain the respiratory pump

A

When muscles contract and relax during breathing in and out, pressure changes occur in the thoracic and abdominal cavities.

Changes in pressure compress nearby veins to assist blood return to heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Explain pocket valves

A

These assist venous return in the veins and venues to prevent backflow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

List 3 other factors affecting venous return

A

Thin layer of smooth muscle in walls of veins helps squeeze blood back towards heart

Gravity helps blood return to the heart from upper body

Suction pump action of heart = pressure difference between atria and veins ‘sucking’ blood towards the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the 2 importances of the venous return mechanism

A

During exercise to meet demands of the activity.

Immediately after exercise by performing active cool down to prevent blood pooling in veins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define stroke volume

A

Volume of blood ejected from left ventricle per beat

ml

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does stroke volume depend on

A

Venous return

Elasticity of cardiac fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define cardiac output

A

Volume of blood pumped out of the heart per minute

l/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What’s starlings law

A

Suggests that SV is dependent on the elasticity of cardiac muscle fibres.

The greater the stretch of cardiac fibres, the greater the force of contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Define the ejection fraction

A

% of blood pumped out of left ventricle per beat.

Rest = normally around 55%
Exercise = rises to over 70%
Elite athletes = around 85% due to training.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the 3 steps to the cardiac cycle?

A

Atrial systole

Ventricular systole

Diastole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does it mean that the heart is myogenic?

A

Generates its own impulses + can contract + relax rhythmically to its own accord.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

List the order of the conduction system in which the impulses spread across the heart

A

SAN fires impulse causing atrial systole

Impulse is delayed at atrioventricular node

Passes through Bundle of His and Bundle branches to the apex of the heart

Along Purkinje fibres to cause ventricular systole

17
Q

How is the delay of the electrical impulse caused?

A

By the non-conducive connective tissue

18
Q

What is heart rate regulated by

A

Neural

Chemical

Intrinsic controls

19
Q

What type of control is the CCC under?

A

Involuntary and is part of the autonomic nervous system

20
Q

What are the two components of the autonomic nervous system

A

Sympathetic - Stimulates heart to beat faster

Parasympathetic - Slows HR down to resting levels

21
Q

Define chemoreceptors

A

Tiny structures in carotid arteries and aortic arch that detects changes in acidity of the blood.

When ⬆️ acidity is detected, receptors stimulate sympathetic nervous system.

22
Q

What lowers the pH of the blood?

A

CO2 and lactic acid = more acidic

23
Q

Define baroreceptors

A

Special stretch receptors in walls of the aorta, vena cava and carotid arteries that detect changes in bp.

⬆️ in arterial pressure = ⬆️ stretch of the baroreceptors = ⬇️ in HR.

⬇️ in arterial pressure = ⬇️ in stretch of baroreceptors = ⬆️ HR.

24
Q

Define proprioceptors

A

Sensory nerve endings in muscles, tendons and joints that detects change in movements and body position.

Start of exercise = send impulse to medulla, then sends through sympathetic nervous system to the SAN to ⬆️ HR.

25
Q

Define thermoreceptors

A

Sensory cells in the body that detect changes in body temp and send info to CCC.

As body temp ⬆️ = thermoreceptors detect this = sends info to CCC to ⬆️ HR

26
Q

Define capillaries

A

Form an extensive network that connects arteries and veins by uniting arterioles and venules.

27
Q

How is blood flow maintained?

A

Cardiac output

Resistance to flow

28
Q

What does resistance to flow depend on?

A

Blood viscosity

Blood vessel diameter

29
Q

Explain vascular shunting mechanism/redistribution of blood during exercise

A

Skeletal muscles require more O2 so more blood is redirected to them to meet demand.

Skeletal muscles = 80-85% of total blood flow during exercise

15-20% to supply remaining organs and tissues.

30
Q

Define the vascular shunting mechanism

A

The redirecting of blood flow to areas where it is needed the most.

31
Q

What is blood pressure and blood flow controlled by?

A

the vasomotor centre in the medulla oblongata

32
Q

Define vasodilation

A

Widening of blood vessels to ⬆️ blood flow to capillaries

33
Q

Define vasoconstriction

A

Narrowing of blood vessels to ⬇️ blood flow to capillaries.

34
Q

Define pre-capillary sphincters

A

Tiny rings of muscle located at the opening of capillaries that help with blood redistribution.

When they contract blood flow is restricted.
When they relax blood flow is ⬆️.

35
Q

How does training affect vasomotor control?

A

Arteries ⬆️ in elasticity = control of blood flow becomes more efficient.

36
Q

Explain how the CCC regulates HR during exercise

A

CCC located in medulla oblongata of brain + stimulated by chemo,baro+proprioceptors.

CCC initiates sympathetic + parasympathetic NS to stimulate SAN.

Symp. NS via accelerator nerve to stimulate heart to beat faster during ⬆️ intensity.

Paras. NS returns HR to resting levels via vagus nerve during ⬇️ intensity.

During exercise =

  • Chemoreceptors detect CO2 ⬆️ to ⬆️ HR
  • Baroreceptors establish a set point for blood pressure so a ⬇️ in arterial pressure = ⬆️ HR.
  • Proprioceptors detect ⬆️ in muscle movement so ⬆️ HR.

P.E - E.P Yr 1 (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions