Chapter 33, Problem 23A

Summary Introduction

Introduction :

The most plentiful type of nerve terminations is free nerve endings. They lie close to blood vessels between skin epithelial layers, connective tissues, and cornea and food tract. They are located in joints between the fibrous layers and synovial, and within the same fibrous layer.

Answer to Problem 23A

Correct answer :

The correct answer is option (C) touch.

Explanation of Solution

Explanation/justification for the correct answer :

Option (C) touch. Temperature, mechanical stimulation (touch, strain, stretch), or danger (nociception) can be sensed by free nerve endings. Various free nerve endings thus act as cutaneous mechanoreceptors, nociceptors, thermoreceptors.Free nerve endings are most commonly located in the skin. They reach the dermis and end in the granulosum stratum. They infiltrate dermis middle layers and surround hair follicles. So, this is the correct answer.

Explanation for incorrect answer :

Option (A) taste. Taste bud representing the ends of the sensory nerves. In the anterior two-thirds of the tongue, the taste buds are inherited by the chorda tympani and in the posterior end, there is a lingual branch of the glossopharyngeal nerve. Free nerve endings are produced in the skin by branching out of the sensory fibers. So, this is an incorrect answer.

Option (B) hearing. The vestibulocochlear nerve is responsible for hearing. It is also known as the cranial nerve eight (CN VIII) and is composed of the vestibular and cochlear nerves. So, this is an incorrect answer.

Option (D) sight. The optic nerve is responsible for sight. So, this is an incorrect answer.