Senses Ch. 11 COURSE OBJECTIVES

Classify sense organs as special or general

General - free & encapsulated nerve endings, and proprioceptors

Special - eye, ear, nose, and tastebuds

Explain the Basic Differences Between the 2 Sense Organ Groups

general feels sensations such as pain, temp, touch pressure, and body position.

special senses are smell, taste, vision, hearing, and equilibrium

Explain how a stimulus is converted into a sensation.

a stimulus is detected by the sensory pathway, then converted into a nerve impulse and is perceived as a sensation in the CNS

Discuss the general sense organs and their functions.

these are detected by simple microscopic receptors widely distributed throughout the body that are responsible for pain, temp, touch, pressure and body position

Describe the structure of the eye and the functions of its components.

this structure contains 3 layers containing; the sclera, choroid, retina, conjunctiva, and lens. (Choroid prevents scattering of light)

Describe the Function of the Sclera

tough outer coat; white of the eye

Describe the Function of the Choroid

pigmented vascular layer preventing scattering of light

What is the Hole in the Center of the Iris?

the pupil (contraction of this muscle dilates & constricts)

Describe the Function of the Retina

the inner most layer of the eye that detects light (rods & cones)

Describe the Function of the Conjunctiva

mucous membrane covering the front surface of the sclera and lining the eyelid

Describe the Function of the Lens

a transparent body behind the pupil that focuses light

Discuss the anatomy of the ear and its sensory function in hearing and equilibrium.

its anatomy contains an external ear, middle ear, inner ear. Respectively, contains the external acoustic canal, an auditory tube connecting the to throat and finally receptors of balance & organ of corti

Define Equilibrium

mechanoreceptors for our sense of balance

Describe the Anatomy of the External Ear

external is the outer part we can see, containing the eternal acoustic canal.

Describe the Anatomy of the Middle Ear

a epithelium lined cavity that houses the ear ossicles (bones) and contains the auditory tube that connects this middle ear to the throat

Describe the Anatomy of the Inner Ear

a bony labyrinth filled with perilymph that is subdivided into the vestibule, semicircular canals, and cochlea. it contains the cristae ampullae, and organ of corti

Name the chemical receptors and their functions.

Taste Buds (chemoreceptors) Smell (fibers of olfactory nerve lie in olfactory mucosa of nasal cavity) and Integration of All Senses (perceived by the brain)