Reflex Arc Function and Components

The video tutorial explains the concept of reflexes, focusing on the pain withdrawal reflex. It defines reflexes as rapid, unconscious responses to stimuli and details the roles of sensory and motor neurons. The tutorial includes a diagram to illustrate the pain withdrawal reflex, highlighting the sensory neuron, relay neuron, and motor neuron pathways. The importance of using diagrams to effectively communicate understanding in exams is also discussed.

What is a reflex?

• A rapid, unconscious response to a stimulus

• A voluntary action initiated by the brain

• A slow, conscious response to a stimulus

• A delayed reaction to external factors

Which part of the reflex arc is responsible for detecting the stimulus?

• Effector

• Sensory receptor

• Relay neuron

• Motor neuron

In the pain withdrawal reflex, where does the sensory neuron synapse?

• In the dorsal column of the spinal cord

• In the brain

• In the effector muscles

• In the sensory receptors

What is the role of the relay neuron in the reflex arc?

• To transmit signals to the brain

• To connect sensory and motor neurons

• To detect external stimuli

• To contract muscles

How does the motor neuron contribute to the reflex action?

• It detects the initial stimulus

• It processes the sensory input

• It transmits signals to the effector muscles

• It synapses with the sensory neuron

What happens to the finger muscles during a reflex action?

• They remain unchanged

• They relax

• They send signals to the brain

• They contract

Why is it beneficial to draw a diagram of the reflex arc?

• It helps in memorizing the definitions

• It visually demonstrates the process

• It replaces the need for explanations

• It is required for all exams

What is the final outcome of the pain withdrawal reflex?

• The brain processes the pain

• The finger moves away from the stimulus

• The sensory neuron stops functioning

• The effector muscles relax

Which component of the reflex arc is known as the effector?

• Finger muscles

• Relay neuron

• Sensory neuron

• Motor neuron

What is the primary function of the sensory neuron in the reflex arc?

• To contract the effector muscles

• To transmit signals to the spinal cord

• To initiate voluntary actions

• To process information in the brain