Sensory receptors in muscles and joints

What are proprioceptors?

Sensory receptors that provide information about body position and movement.

What are muscle spindles?

Proprioceptors located within skeletal muscle that detect changes in muscle length and the rate of change.

What types of sensory fibres are found in muscle spindles?

Type Ia fibres (detect muscle length and rate of change) and Type II fibres (mainly detect muscle length).

What is the main function of muscle spindles?

To sense muscle stretch and initiate the stretch reflex to maintain muscle tone.

What are Golgi tendon organs?

Proprioceptors located at the junction of muscle and tendon, detecting muscle tension (force of contraction).

What type of sensory fiber is associated with Golgi tendon organs?

Type Ib afferent fibers.

What is the function of Golgi tendon organs?

To prevent muscle overload by sensing tension and triggering muscle relaxation.

How do muscle spindles and Golgi tendon organs differ?

Muscle spindles detect muscle stretch (length), while Golgi tendon organs detect muscle tension (force).

Where are Golgi tendon organs located?

At the junction between muscle fibers and tendons.

What is a spinal reflex?

A simple, automatic response to a stimulus that does not involve the brain (e.g., stretch reflex).

What are the basic components of a reflex arc?

Sensory receptor, sensory neuron, integration center (spinal cord), motor neuron, and effector (muscle).

What is the stretch reflex?

A reflex that contracts a muscle in response to it being stretched (e.g., knee-jerk reflex).

What is the role of Type Ia fibers in the stretch reflex?

They sense rapid muscle stretch and send signals to the spinal cord to trigger muscle contraction.

What is the role of Type II fibers in muscle spindles?

They sense static muscle length (maintained stretch).

Why are Golgi tendon organs considered high-threshold receptors?

They only activate when significant tension is generated in the muscle.

How do Golgi tendon organs prevent muscle damage?

By triggering inhibitory signals to the muscle, causing relaxation when tension is too high.

What is the difference between Type Ia and Type II fibers?

Type Ia detects both dynamic (changing) and static (constant) stretch, while Type II mainly detects static stretch.

What is the role of antagonistic muscle pairs?

To produce opposing movements (e.g., biceps flexes the elbow, triceps extends it).

What is the role of proprioceptors in fine motor control?

They ensure proper tension is maintained, enabling precise movements (e.g., gripping objects).

What is a monosynaptic reflex?

A reflex involving only one synapse between the sensory and motor neurons (e.g., stretch reflex).