Sensory Receptors

Chapter 9 Sensory

The Senses: Sensory receptors receive external and internal stimuli.

-Receptors transform energy of a stimulus into nerve impulses, which go to the brain for interpretation.

-Receptors: specialized portions of sensory neurons that are capable of responding to environmental stimuli and eventually converting the stimuli into action potentials.

-Impulses arriving at any particular area of the brain are interpreted in only one way, and those arriving at another brain area are interpreted differently.

Types of sensation: Somatic and Special

Somatic

Somatic: Temperature, Touch, Vibration, Pressure, Pain

-general sensation “whole body” and detected by the sensory receptors in skin and muscle that are generally spread out over the entire body

-involve receptors from more than one place in the body and may help coordinate muscle movement and maintain body temperature.

-Mechanoreceptors

-Senses we feel with our bodies, which include tough, pressure, pain and temperature and our muscle senses (proprioception).

-if you feel someone touch your arm or face that is a somatic sensation

-Free nerve endings:

*Unencapsulated:Pain. Light pressure, and temperature changes; around hairs and near the skin surface. Different sizes of nerve endings determine the modality of the receptor.

*Light touch and thermoreception

-Encapsulated

*Merkel disks (light touch): are receptors with free nerve endings that detect surface pressure. They are located deep in the epidermis.

*Pacinian corpuscles (deep pressure)

*Meissner’s corpuscles (fast adapting light touch)

*Ruffini endings (slow adapting, pressure)

Special: taste, olfaction, auditory, vestibular, vision

-Specialized organ to them

-supply us with detailed information about the world around us, including the sights, sounds, smells and tastes present in our surroundings

-the wealth of information they provide occupies most of our brain and forms the basis for our logical and...