Coordination and Response

Which part of the nervous system is responsible for processing information and coordinating responses?

• Peripheral nervous system

• Central nervous system

• Motor neurons

• Endocrine system

Answer explanation

The central nervous system (CNS), comprising the brain and spinal cord, is responsible for processing information and coordinating responses, making it the correct choice over the peripheral nervous system and other options.

The peripheral nervous system (PNS):

• Includes the brain and spinal cord

• Transmits signals only to muscles

• Connects the CNS to the rest of the body

• Produces hormones

Answer explanation

The peripheral nervous system (PNS) connects the central nervous system (CNS) to the rest of the body, facilitating communication between the brain, spinal cord, and peripheral organs, unlike the other options.

Which neuron carries impulses from a receptor to the CNS?

• Relay neuron

• Motor neuron

• Sensory neuron

• Synaptic neuron

Answer explanation

The sensory neuron is responsible for carrying impulses from sensory receptors to the central nervous system (CNS), making it the correct choice for this question.

Which structure transmits impulses away from the cell body?

• Dendrite

• Nucleus

• Axon

• Synapse

Answer explanation

The axon is the structure that transmits impulses away from the cell body, allowing communication with other neurons or muscles. Dendrites receive signals, while the nucleus and synapse play different roles in neuron function.

Neurotransmitters are released from which part of the neuron?

• Dendrites

• Synaptic terminals

• Cell body

• Axon hillock

Answer explanation

Neurotransmitters are released from the synaptic terminals, which are the ends of axons. This is where signals are transmitted to other neurons, making synaptic terminals the correct answer.

Which type of neuron is only found in the CNS?

• Sensory neuron

• Motor neuron

• Relay neuron

• Effector neuron

Answer explanation

Relay neurons, also known as interneurons, are exclusively found in the central nervous system (CNS). They connect sensory and motor neurons, facilitating communication within the CNS, unlike sensory and motor neurons which extend to the peripheral nervous system.

A reflex arc is best described as:

• A voluntary action controlled by the brain

• A conscious movement of muscles

• A fast, automatic response to danger

• The pathway of hormonal secretion

Answer explanation

A reflex arc is a neural pathway that controls a fast, automatic response to stimuli, often to protect the body from danger, without involving conscious thought or brain processing.

Reflex actions are important because they:

• Require decision-making by the brain

• Are slow but accurate

• Protect the body from danger

• Always involve the cerebrum

Answer explanation

Reflex actions are crucial as they protect the body from danger by enabling quick responses to harmful stimuli, bypassing the slower decision-making processes of the brain.

What ensures impulses travel in one direction across a synapse?

• Myelin sheath

• Neurotransmitters only released from presynaptic neuron

• The presence of dendrites

• Voltage difference between neurons

Answer explanation

Impulses travel in one direction across a synapse because neurotransmitters are only released from the presynaptic neuron. This ensures that signals are transmitted to the postsynaptic neuron, preventing backward flow.

In the eye, which part controls the amount of light entering?

• Lens

• Retina

• Pupil

• Iris

Answer explanation

The iris is the part of the eye that controls the size of the pupil, thereby regulating the amount of light that enters the eye. It adjusts in response to light conditions, making it the correct answer.