reflex arc

Question 1

reflex arc

Answer 1

• functional unit of nervous system

- is the pathway followed by impulses from a receptor to an effector to bring about a reflex action

Question 2

reflex action

Answer 2

• fast autonomic response
• somatic reflexes (skeletal muscles)
• autonomic reflexes (activate smooth or cardiac muscle and gland)

Question 3

reflex centres

Answer 3

• brain (controlling sneezing, blinking, breathing)
• spinal chord (controlling primitive reflexes such as the knee jerk or immediate with-drawl of a hand or foot with a pain stimulus)

Question 4

significance

Answer 4

• enables quick response to a stimulus where the higher centres of the brain are not involved) - provides a safety mechanism (protecting the body from danger)

Question 5

examples

Answer 5

• sneezing

- yawning when there is too much CO2 in the blood stream

Question 6

function

Answer 6

• receptors respond to the pain creating impulses
• impulses are conducted along the sensory neuron to grey matter in spinal cord
• synaptic contact with connector neuron
• synaptic contact with motor neuron which relay impulse to effector
• effector cause a contraction to stop the pain stimulus
• impulses also conducted to cerebral cortex which interpret it as pain