All Exams Test series for 1 year @ ₹349 only
Question

Reflex arcs are evolved in animals for quick and efficient responses. Which one of the following sequences correctly represents a reflex arc?

This question was previously asked in
CDS I 2023 English Previous Year Paper (16-April-2023)
The correct answer is

Receptor - Sensory neuron - Relay neuron in spinal cord -Motor neuron - Effector

The correct answer is Option 1.
Solution Explanation
A reflex arc is the neural pathway that mediates a reflex action. Its primary function is to allow for an immediate and involuntary response to a stimulus, often to protect the body from harm. This is achieved by processing the signal at the level of the spinal cord, bypassing the brain for a quicker reaction.
Let's break down the correct sequence as shown in Option 1:
Receptor: This is a specialized cell or nerve ending that detects a specific stimulus (e.g., heat, pain, pressure). For instance, pain receptors in the skin of your hand.
Sensory Neuron (Afferent Neuron): When the receptor is stimulated, it generates a nerve impulse. The sensory neuron transmits this impulse from the receptor towards the central nervous system (in this case, the spinal cord).
Relay Neuron (Interneuron) in Spinal Cord: The sensory neuron synapses with a relay neuron within the grey matter of the spinal cord. This relay neuron acts as an intermediary, processing the signal and passing it from the sensory neuron to the motor neuron. This is the integration center for the reflex.
Motor Neuron (Efferent Neuron): The relay neuron activates a motor neuron. The motor neuron carries the nerve impulse away from the spinal cord to the part of the body that will respond.
Effector: The effector is the muscle or gland that receives the impulse from the motor neuron and carries out the response. For example, the biceps muscle in your arm contracts to pull your hand away from a hot object.

Was this answer helpful?

Similar Questions

  1. Which one of the following is the correct sequence of organs that occur in the path of urine flow in human body?

  2. Which one of the following is the Structure of a cardiac muscle cell ?

  3. Which one of the following cell organelles mainly functions as storehouse of digestive enzymes?

  4. The causal organism of dengue fever is a mosquito-borne virus which belongs to which one among the following categories?

  5. Which of the following statements is/are correct about vaccination that provides
    protection against an infectious disease?

    1. It blocks the entry of the infectious agent into body.

    2. It produces antibodies against infection.

    3. It kills the infectious agent when it enters in the body.

    Select the correct answer using the code given below. 

  6. Which one of the following hormones contains peptide chain?

  7. Which one of the following body parts/organs of the human body does not have smooth muscles?

  8. Which of the following cells are destroyed by the HIV virus which results in the weakening of the immunity of a person?

  9. Which one of the following hormones is essential for the uptake of glucose by cells in the human body?

  10. Which of the following cells do not contain a nucleus?

    1. Root hair cells

    2. Red blood cells

    3. Platelets

    4. Monocytes

    Select the correct answer using the code given below.

Important Questions from Human body

  1. A resting person, usually has a pulse rate between ______ and ______ beats per minute

  2. In humans, neck and head are joined by which joint ?

  3. The human skeleton is composed of around ______ bones at birth.

  4. Identify the disease that is not caused by virus.

  5. Which one of the changes observed during adolescence is not associated with boys?

Need Expert Advice?
Test Series
CDS img
Defence
UPSC CDS 2026 Mock Test Series
536 Tests 4 Tests Free
1746 Attempts
4.3(174)
English, Hindi
More Questions from CDS

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App