Chapter 12: The Somatic Sensory System

Enables the body to feel, to ache, to sense hot or chill, and to know what its parts are doing.

Somatic sensation

The somatic sensation is sensitive to many kinds of things such as the following three

the pressure of objects against the skin, the position of joints and muscles, distension of the bladder, and the temperature of limbs and of the brain itself.

When a stimuli becomes so strong that they may be ______________ , ________________ , __________________ _______________- is also responsible for the feeling that is most offensive, but vitally important - ________________.

damaging, somatic sensation, pain

The two major types of skin are called, ______________ and ______________(hairless)

hairy and glabrous

most sensory receptors in the sensory system are ___________________ _______________-, which are sensitive to physical distortion such as bending or stretching.

mechanoreceptors

True or False: Messiner's corpucsles andMmerkel's disks had small receptive fields, only a few millimeters wide, while Pacinian corpusucles and Ruffini's endings had large receptive fields that could cover an entire finger or half the palm.

True

The Mechanoreceptor Meissner's corpuscles has a _____________ response rate and a __________ receptive field.

rapid; small

The Mechanoreceptor Merkel's disk has a _______________ response rate and a __________ receptive field

slow; small

The Mechanoreceptor Pacinian corpuscles has a ___________ response rate and a _______________ receptive field.

Rapid; Large

The Mechanoreceptor Ruffini's endings have a _______________ response rate and a ______________ receptive field.

slow; large

True or False: Rapid Responses are presistant.

False

A alpha, A beta, A delta, and C axons are of similar size, but inverting the muscles and tendons are called, _____________________.

Group C

_________________ is/are unmyelinated sheaths.

Group C or Group IV

_________________ is/are myelinated sheaths.

Group I, II, & II

The pathway serving touch is called, ___________ ______________ _____________. _________________ ______________.

dorsal column medial lemniscal pathway

The most complex levels or somotosensory processing occurs in the ______________ ____________.

cerebral cortex

the inability to recognize objects through simple sensory skills seems to be normal

Agnosia

Can not recognize common objects by feeling them

Astereognsia

a part of the body is ignored or simply suppressed and its very existence is denied.

Neglect Syndrome

Pacinian corpuscles are sensitive to _________________ and ____________________.

vibration and deep pressure

True or False: Pacinian corpuscles consist of free nerve endings that are sensitive to pain and temprature

True