Sensory Physiology

Receptor Cell

- Electromagnetic

- Mechanical

- Chemical

 

labelled lines

 

Somatosensation

• Dif receptors found in skin

• up labelled lines

 

Vision

Structure:

• many parts

• retina -

fovea

color blindness

blind spot

 

Photochemistry

Rods

• rhodopsin - conjugate of

         retinal (aldehyde of Vitamin A)

         protein opsin - 38,000-49,000 daltons - embedded in membrane

 

                        light

1) cis ----------> trans retinal

2) ----> cGMP decr

3) ---> Na+ channels close

4) ---> hyperpolarize

5) ---> decr release of neurotransmitter (glutamate)

DO NOT EQUATE EXCITEMENT WITH DEPOLARIZATION

 

Bleaching and Afterimages

Rods

Cones

 

Adaptation and Amplification

Processing

1) Retina

Lateral Inhibition

2) Lateral geniculate of thalamus

3) Visual cortex

4) Visual association

 

Mechanoreception and Audition

(Handout)

3 parts

• External Ear/Auricle

• Middle ear - air filled

• Inner ear - fluid filled

 

Pressure waves (sound)

• collected by external ear, travel down auditory canal

• vibrate eardrum

• 3 bones (incus, malleus, stapes)

• oval window - cochlea

Impedence matching

cochlea -

Excitation

Intensity coding

Direction coding

Frequency Detection

Chemoreception

Taste

• 4 basic taste qualities

• short lifetime

• high thresholds

 

Olfaction

Anatomy:

Physiology: