neural mechanisms

Question 1

what is the role of the sympathetic nervous system?

Answer 1

stimulates the heart to beat faster

Question 2

what is the role of the parasympathetic nervous system?

Answer 2

returns the heart back to resting level

Question 3

what does the central nervous system (CNS) consist of?

Answer 3

the brain, spinal cord and peripheral nervous system (PNS consists of nerve cells that transmit info to and from CNS)

Question 4

what is the medulla oblongata?

Answer 4

where the cardiac control centre is located and where the parasympathetic and sympathetic system are co-ordinated

Question 5

where are sympathetic nervous impulses sent to?

Answer 5

the sinoatrial node

Question 6

what happens when there is a decrease in in parasympathetic nerve impulses?

Answer 6

heart rate increases

Question 7

what is the cardiac control centre stimulated by?

Answer 7

chemorecptors, baroreceptors and proprioceptors

Question 8

where are chemoreceptors found?

Answer 8

carotid arteries and aortic arch

Question 9

what do chemoreceptors detect?

Answer 9

an increase in carbon dioxide (CO2)

Question 10

what is the role of CO2 when controlling heart rate?

Answer 10

increased concentration of CO2 in the blood will stimulate the sympathetic nervous system = heart beats faster

Question 11

what do baroreceptors contain?

Answer 11

nerve endings that respond to the stretching of the arterial wall

Question 12

what do baroreceptors detect?

Answer 12

change in blood pressure

Question 13

what is the role of blood pressure?

Answer 13

increase in arterial pressure causes an increase of the stretch of the baroreceptor sensors = decreased heart rate
decrease in arterial pressure causes decrease in the stretch of baroreceptors = increased heart rate

Question 14

what do baroreceptors do at the start of exercise?

Answer 14

baroreceptor set point increases = important as body doesn’t want heart rate to slow down

Question 15

what does slow heart rate do to performance?

Answer 15

negatively effects performance due to less oxygen being delivered to working muscles

Question 16

where are proprioceptors located?

Answer 16

muscles, tendons and joints that provide information about movement and body position

Question 17

what are proprioceptors?

Answer 17

sensory nerve endings

Question 18

what do proprioceptors detect?

Answer 18

an increase in muscle movement (at the start of exercise)

Question 19

what do proprioreceptors do with impulses?

Answer 19

send an impulse to the medulla, which sends an impulse through the sympathetic NS to the SAN to increase heart rate
when the parasympathetic system stimulates the SAN, HR decreases

Question 20

what is hormonal control?

Answer 20

the release of adrenaline during exercise

Question 21

what is adrenaline?

Answer 21

a stress hormone that is released by the sympathetic and cardiac nerves during exercise

Question 22

what does adrenaline do?

Answer 22

stimulates the SAN (pacemaker) which results in an increase in speed and force of contraction = increased cardiac output = more blood being pumped to working muscles to receive more oxygen for energy needed