Cardiac Control

Question 1

What are the neural factors which regulate heart rate?

Answer 1

• Chemoreceptors (lactate, CO2)
• Baroreceptors (blood pressure, artery walls)
• Proprioceptors (movement)

Question 2

What is the process of increasing heart rate by neural control?

Answer 2

• Receptors
• Medulla oblongata, CCC
• Sympathetic nervous system
• Accelerator nerve
• SA node

Question 3

What are the three method of receiving information for the CCC?

Answer 3

• Neural
• Intrinsic
• Hormonal

Question 4

What is the intrinsic process of cardiac control?

Answer 4

• Increased temperature
• Reduction in blood plasma and water
• Higher viscosity
• Increased blood pressure
• Heart works hard to maintain flow
• Viscosity means easier conduction for impulse

Question 5

What is the hormonal process of cardiac control?

Answer 5

• Sympathetic nervous system stimulates adrenal glands, adrenaline and nor adrenaline increase contraction force

Question 6

What is sympathetic nervous stimulation?

Answer 6

• SA node stimulated by accelerator nerve

Question 7

What is parasympathetic nervous stimulation?

Answer 7

• SA node stimulated by vagus nerve, HR reduces

Question 8

What are the functions of the vascular system?

Answer 8

• Transports nutrients
• Protects and fights against disease
• Maintains internal conditions

Question 9

What is the function of arteries?

Answer 9

Carry blood away from the heart under highest possible pressure

Question 10

What is the function of arterioles?

Answer 10

Carries blood from arteries to capillaries. Controls pressure and distribution by vasomotor control

Question 11

What is a pre-capillary sphincter?

Answer 11

• Controls blood flow from arterioles to capillaries

- Controlled by sympathetic nervous stimulation

Question 12

What is a capillary?

Answer 12

• Low pressure, from arterioles to venules, sites of substance exchange

Question 13

What are venules?

Answer 13

Vessels linking capillaries to veins

Question 14

What are veins?

Answer 14

Lowest pressure, working with muscle pump and gravity to return blood to the heart

Question 15

What changes occur during exercise to aid venous return?

Answer 15

• Gravity always used to aid from above heart
• Pocket valves used more
• Muscle pump mechanism
• Vasomotor tone increases a little by smooth muscle
• Size of lumen will increase
• Respiratory pump mechanism

Question 16

What changes occur during vascular shunt?

Answer 16

• Chemoreceptors detect increase in lactate and CO2
• Baroreceptors detect increase in blood pressure (blood vessel walls)
• Information sent to medulla oblongata, VCC
• Sympathetic stimulation increases to arterioles and PCS at useless organs
• Sympathetic stimulation decreases to arterioles and PCS at muscles, heart, skin