Question

name the following:-

i) The largest portion of the brain.

ii) It coordinates the muscular activities of the body.

iii) The quick automatic involuntary response to a stimulus from a receptor to the
effector.

iv) The shortest pathway to the nerve impulse from a receptor to the effector.

v) It controls the reflexes below the neck.​

Answer 1

$\Large\bold{\underline{ANSWER-}}$

i) The largest portion of the brain

Ans - $\bold{\red{Cerebrum}}$

→ Cerebrum is the largest part of brain and consitutes two-third mass of the brain alone .

It has four lobes as well .

$\rule{200}2$

ii) It coordinates the muscular activities of the body

Ans - $\bold{\red{Cerebellum}}$

→ The cerebellum is the part of the hindbrain and receives information from the sensory systems, the spinal cord and other parts of the brain and then regulates motor movements.

$\rule{200}2$

iii) The quick automatic involuntary response to a stimulus from a receptor to the effector.

Ans - $\bold{\red{Reflex\:Action}}$

→Reflex actions are the involuntary act done in immediate response to something.It is rapid and automatic.

$\rule{200}2$

iv) The shortest pathway to the nerve impulse from a receptor to the effector.

Ans - $\bold{\red{Reflex\:Arc}}$

→ Reflex arc is the nerve pathway involved in a reflex action, including at its simplest a sensory nerve and a motor nerve with a synapse between.

$\rule{200}2$

v) It controls the reflexes below the neck

Ans - Basically $\bold{\red{brain\:and\:Spine}}$ controls such actions, moreover there is something called Neck Righting Reflex which means the Neck reflexes are mainly controlled by that.

$\rule{200}2$

Answer 2

Answer:

i) The largest portion of the brain is cerebrum.

• It is the part of the fore brain.
• It is the thinking part of the brain.
• It controls voluntary actions.
• The actions controlled by it are:- taste, learning, emotions, etc.

ii) The part of the brain that coordinates the muscular activities of the body is cerebellum.

• It is the part of the hind brain.
• It mainly controls body movements.
• It also controls the posture and balance of the body.
• It is located at the backside of the head.

iii) The quick automatic involuntary response to a stimulus from a receptor to the effector is called to be reflex action.

• Reflex action is a sudden, unconsciousness and involuntary response of the effectors to a stimulus.
• The pathway through which this takes place is called reflex arc.
• It includes receptors, sensory nerves, spinal cord, motor nerves and effectors.

iv) The shortest path way to the nerve impulse from a receptor to effector is called as reflex arc.

• The reflex arc is the pathway of the reflex action.
• It includes the sense organs called as receptors, which detects the stimuli.
• Further, the sensory nerves pass on the information about the stimuli to the spinal cord.
• The spinal cord gives the effect that has to be given in response to the stimuli.
• The information is then passed through motor nerves to the effectors.
• The effectors gives the response to the stimuli. It is actually the muscles or the glands.

v) Peripheral nerves and spinal cord control the reflexes below the neck.

• The reflexes below the neck are controlled by spinal cord.
• The peripheral nerves help in passing the information.
• The peripheral nerves goes from spinal cord to the arms, hands, legs and feet.

----------------------