EASY
True or False: Reflex actions require conscious thinking.
False
What is a stimulus?
Any change in the environment that causes a response.
They protect the body from injury by producing quick responses.
What is a reflex action?
An automatic and rapid response to a stimulus.
Which neuron carries impulses from the receptor to the spinal cord?
Sensory neuron.
Why does a person become aware of a painful stimulus only after withdrawing the hand?
The spinal cord initiates the response before the brain processes the sensation.
Which part of the nervous system mainly controls reflex actions?
Spinal cord.
Which neuron carries impulses from the spinal cord to the effector?
Motor neuron.
Differentiate between a reflex action and a voluntary action.
Reflex action is automatic and involuntary; voluntary action is conscious and controlled by the brain.
Give 4 examples of reflex actions.
Blinking, sneezing, coughing, withdrawing hand from a hot object, etc.
What are effectors?
Muscles or glands that carry out a response.
A student accidentally touches a hot iron. Explain the complete pathway of the nerve impulse.
Receptor → Sensory neuron → Spinal cord (relay neuron) → Motor neuron → Hand muscles → Hand withdrawn.
What is the pathway followed by nerve impulses during a reflex action called?
The pathway followed by nerve impulses is the called the reflex arc.
Arrange these in the correct order: Motor neuron, Receptor, Effector, Sensory neuron, Spinal cord.
Receptor → Sensory neuron → Spinal cord → Motor neuron → Effector.
A person steps on a sharp pin. Explain why the foot is withdrawn immediately even before the person feels pain, and identify all the structures involved in the process.
Receptors in the skin detect the stimulus → sensory neuron carries impulse to spinal cord → relay neuron transmits impulse → motor neuron carries impulse to leg muscles → muscles contract and withdraw foot. The brain receives the information later, so pain is felt after the response occurs.