Question

Match the description to the appropriate receptor type.

1.Pain, itch, and temperature receptors

2.Contain intrafusal fibers and flower spray endings

3.Discriminative touch receptors in fingertips

4.Contain nerve endings wrapped around thick collagen bundles

5.Rapidly adapting deep-pressure mechanoreceptors

6.Slowly adapting deep-pressure mechanoreceptors

●Bulbous corpuscles●Tendon organs●Muscle spindles●Free nerve endings●Lamellar corpuscles●Tactile corpuscles

Answer 1

Answer)

1)Pain, itch and temperature receptors - Free nerve endings

Explanation - Free nerve endings are the terminal branches of thin myelinated A delta or unmyelinated C fibers.

They are concerned with perception of pain and injurious(noxious) stimuli. They can also convey sensations of touch and temperature.

2) Contain intrafusal fibers and flower spray endings - Muscle spindles

Explanation - Each muscle spindle contains 8-12 muscle fibers enclosed in a connective tissue capsule called the infrafusal muscle fibers.

The intrafusal fibers are in parallel with rest of muscle fibers because the ends of the capsule of the spindle are attached to the tendons of either end of the muscle.

Muscle spindle is the receptor of stretch reflexes.

3) Discriminative touch receptors in fingertips - Tactile corpuscles.

Explanation -

Tactile corpuscles are meissner's corpuscle and merkle's corpuscle.

These are concerned with perception of touch, therefore called tactile receptors.

They are rapidly acting receptors.

They occur in groups in the cutaneous papillae with maximum density in the skin of fingertips, lips and around the base of hair follicles.

4)Contain nerve endings wrapped around thick collagen bundles- Tendon organs

Explanation - Golgi tendon organs are also know as neurotendinous organ which contains nerve endings wrapped around the thick collagen bundles.

These are located in the musculotendon junction in series with the muscle fibers.

Golgi tendon organ acts as a protective reflex to prevent tearing of muscles and plays a important role in regulating muscle tension during normal muscle activity.

5)Rapidly acting deep pressure mechanoreceptors - Lamellar corpuscles

Explanation - Lamellar corpuscles are also known as pacinian corpuscles.

These are nerve terminals of A beta fibers mainly and concerned with perception of pressure and fast vibrations. These are found in the subcutaneous tissues, mesentry and in the neighbourhood of tendons and joints.

They respond to deformation caused by firm pressure and are quickly adapting.

6)Slowing adapting deep pressure mechanoreceptors - Bulbous corpuscles

Explanation - Bulbous corpuscles are also known as ruffini's corpuscles.

These are encapsulated expanded endings of myelinated A delta or unmyelinated C group of fibers.

They are concerned with perception of sustained pressure and warm.

They are found in the dermis and are supplied by large myelinated axons. They are slowly adapting receptors.