animal responses

Question 1

what is the function of a reflex

Answer 1

help the organism survive

Question 2

give the structure and function of relay neuron

Answer 2

transmit impulses between neurons

has lots of short axons and lots of dendrons and dendrites
makes the structure highly branched

Question 3

define the reflex arc

Answer 3

coordinate reflex actions by sequence of neurons

Question 4

describe the reflex arc of Jack, who put his hand on a hot pan

Answer 4

the stimulus is the heat of the pan which is detected by a (thermo)receptor in the skin, which converts thermal energy of the pan into electrical energy, leading to depolarisation

an action potential is initiated in the sensory neuron which travels to the spinal cord, where the action potential is passed through a relay neuron before before it travels through a motor neuron to the effector – Jack’s muscles in his hand which contract to lift his hand from the pan.

Question 5

describe the pupil reflex in bright conditions

Answer 5

radial muscles relax and elongate allowing the

circular muscles to contract and rotate, constricting the pupil

Question 6

describe the pupil reflex in dim conditions

Answer 6

radial muscles contract

circular muscles relax and rotate, dilating the pupil

Question 7

describe a reflex response a 3-year-old child would make to an object moving towards their eyes and
explain the advantage of this response

Answer 7

involuntary closing of the eyes

rapid and unconsious