Cardiovascular

Question 1

Explain the functional structure of the heart

Answer 1

• Four-chambered muscle organ encased in a pericardiac sac
• Two atria, receive blood and two ventricles pump blood.
• Right atrium receives blood from superior and inferior vena cavas and the coronary sinus.
• Blood exits aorta
• Tricuspaid valve, right ventricle, and atria
• Mitral (Bicuspid) valve, left ventricle and atria

Question 2

Define blood pressure, cardiac output and stroke volume

Answer 2

• Blood Pressure: The force of circulating blood on the walls of the arteries.
• Cardiac output - The amount of blood the heart pumps through the circulatory system in a minute.
• Stroke volume - the amount of blood pumped by the left ventricle of the heart in one contraction.

Question 3

By what mechanism do pharmacological interventions alter blood pressure?

Answer 3

• centrally acting drugs decrease arterial pressure by decreasing systemic vascular resistance and cardiac output.

Question 4

Detail how capillary blood flow increases by 15 – 20 times during high-intensity exercise.

Answer 4

• Increased number of blood vessels

- Capillary density is known to increase with endurance training,

Question 5

Is it correct to assume that arterial blood is oxygenated and venous blood is deoxygenated? Explain your response.

Answer 5

Yes

Question 6

• Which exercise type will see the greatest increases in blood pressure?

Answer 6

High intensity

- Aerobic activities such as swimming, cycling, and running put additional demands on your cardiovascular system

Question 7

Outline how total peripheral resistance affects blood pressure during exercise.

Answer 7

• Blood pressure increases with increased cardiac output, peripheral vascular resistance, volume of blood, viscosity of blood and rigidity of vessel walls

Question 8

Define the rate-pressure product

- and how is it calculated

Answer 8

• Rate pressure product is a measure of the stress put on the cardiac muscle based on the number of times it needs to beat per minute (HR) and the arterial blood pressure that it is pumping against (SBP).
• RPP = SBP x HR

Question 9

List the four components of the cardiovascular system.

Answer 9

• Heart, Veins, arteries, blood

Question 10

List the four main components to the conduction of cardiac impulse.

Answer 10

• The sino-atrial (SA) node.
• The atrio-ventricular (AV) node.
• AV bundle (Bundle of His)
• The Purkinje fibres

Question 11

Relate the normal ECG waves to components of the cardiac cycle

Answer 11

P wave (atrial depolarization )
a QRS complex (ventricular depolarization)
and a T wave (ventricular repolarization)
the U wave ( Purkinje repolarization),

Question 12

What area of the brain controls cardiovascular function?

Answer 12

Medulla oblongata

Question 13

How would you explain the neural regulation of cardiovascular function during exercise?

Answer 13

The cardiovascular center is a part of the human brain found in the medulla oblongata, responsible for regulation of cardiac output
- also regulated by the PNS

Question 14

Define anticipatory response to exercise

Answer 14

• When you are about begin exercising, your heart rate will likely increase before you begin moving. The phenomenon is called the ‘anticipatory rise’. The anticipatory rise is the mind’s response to the body’s need to prepare for exercise

Question 15

Detail the role of chemoreceptors and baroreceptors in altering cardiovascular responses during exercise.

Answer 15

• The function of the baroreceptors is to maintain systemic blood pressure at a relatively constant level,
• Their function is to sense pressure changes by responding to change in the tension of the arterial wall. The baroreflex mechanism is a fast response to changes in blood pressure.
• Arterial chemoreceptor increases sympathetic vasoconstrictor outflow to muscle, and increases cardiac sympathetic activity to increase heart rate and contractility.

Question 16

What causes heart rate to change during exercise?

Answer 16

• Increased stroke volume as your muscles need more oxxygen

Question 17

Explain which factors may influence changes in cardiac output.

Answer 17

• heart rate and stroke volume
• blood volume reflexes, autonomic innervation, and hormones.
• Secondary factors include extracellular fluid ion concentration, body temperature, emotions, sex, and age.
• Contractility

Question 18

• What does a plateau in cardiovascular response represent?

Answer 18

indicates that a steady state has been achieved

Question 19

Define cardiovascular drift

Answer 19

• , the progressive increase in heart rate and decrease in stroke volume

Question 20

• Provide an example of where cardiovascular drift may occur during exercise. What physiological factors may explain an associated reduction in exercise performance?

Answer 20

• Cardiovascular drift occurs when a person has a higher RPE (Rate of Perceived Effort); tThis creates a mental block that can inhibit performance greatly
• This results in a decrease in pulmonary arterial pressure and reduced stroke volume in the heart]. To maintain cardiac output at reduced pressure, the heart rate must be increased.

Question 21

What are the layers of the heart

Answer 21

Epicardium - the outer layer.
Myocardium - the middle, muscular layer.
Endocardium - the inner layer.