Senses II

Science of Taste

Article• Read the article “A Natural History

of the Senses” and complete questions:• Responses and Analysis #1 and #2• Personal Experience Application

#1 only

VISION

Vision• Rods- photoreceptors in the retina that

help to see in the dark• Cones- photoreceptors in the retina

responsible for seeing color• Lens- structure that focuses light in the

eye• Iris- colored part of the eye

Vision• Optic Nerve- part of the eye that

carries information from the eye towards the brain• Retina- Layer at the back of the eye

that contains rods and cones; converts light energy to neural responses• Brightness- how intense a color is

Vision• Dark Adaptation- gradual improvement

of the eyes’ sensitivity to the dark• Complementary Colors- colors opposite

each other on the color wheel• Trichromatic Theory- there are 3 types

of color receptors that produce the primary color sensations of red, green and blue

Color Blindness• Color Blindness- the inability to see certain

wavelengths of colors• Most common form is when you cannot

distinguish reds and greens• Most frequent in males

HEARING

Hearing• Auditory Nerve- nerve that carries

impulses from cochlea to the brain• Cochlea- primary organ of hearing;

fluid filled coiled tube located in the inner ear• Basilar Membrane- stimulates hair

cells that produce the neural effects of auditory stimulation

Hearing• Eardrum- thin membrane that takes

sound wave’s vibrations from outer ear to middle ear• Middle Ear Bones- hammer, anvil, stirrup• Pitch- sound quality of high and low tones• Loudness- physical intensity of a sound;

determined by amplitude

Deafness• Conduction Deafness- problem in

conduction of air vibrations to the cochlea• Nerve Deafness- a defect in nerve

impulses or in the auditory nerve

Place Theory• Theory that different frequency

tones produce maximum activation at different locations along the basilar membrane, with the result that pitch can be coded by the place at which activation occurs

SMELL &TASTE

Smell & Taste• Smell consists of 75% of taste

they conspire and work together• Olfactory Bulb- center where

odor sensory receptors send their signals; located below the frontal lobe

Smell & Taste• Pheromones- chemical released by

an organism to communicate to other member species; often sexual signals

Smell & Taste• 5 Tastes:Sweet, Sour, Bitter, Saline (Salt), Umami• Papillae- located on the tongue;

contains clusters of taste buds

PAIN &TOUCH

Pain & Touch• Functions of skin:1.Protect against surface

injury2.Hold in body fluids3.Help regulate body temp4.Sense pressure, warmth,

cold

Pain & Touch• Cutaneous Senses- skin senses that

register sensations of pain• Vestibular Sense- sense that tells

how one’s own body is oriented in the world with respect to gravity

Pain & Touch• Kinesthetic Sense- provides constant sensory feedback

about what the body is doing during motor activities

- concerned with bodily position and movements of the body parts in relation to one another

Pain & Touch• Nociceptive Pain- pain induced by

something in the environment• Neuropathic Pain- caused by

abnormal functioning or over activity of nerves

Pain & Touch• Phantom Limb Phenomenon- approx.

10% of those who have limbs amputated report feeling pain in the limb that no longer exists• Gate Control Theory- proposes that

certain cells in the spinal cord act as gates to interrupt and block some pain signals while sending others on to the brain