Terms to know about sight and hearing

Eye anatomy

– see the list of structures for lab at http://faculty.alverno.edu/bowneps/BI%20231%20course%20documents/Anatomy%20sheets/Sensory%20Organs.htm

Rhodpsin

The colored pigment inside rods which reacts to light. You should know how this pigment affects the rod’s firing

Bipolar cells

Pick up the sensory message from rods and pass it to ganglion cells

Ganglion cells

Carry the sensory message from bipolar cells to the brain. The optic nerves are made up of the axons of all the ganglion cells.

Convergence

When more than one rod attaches to a single ganglion cell. This makes vision more sensitive in low light

Sensitivity

How well you can see in low light. The more rods you have, the more sensitive your vision is

Acuity

How sharp your vision is. Your vision is sharpest if you have only one photoreceptor attached to each ganglion cell.

Optic chiasm

Where half of the axons from the ganglion cells cross over to the other side of the brain

Optic tract

The axons of the ganglion cells as they pass through the tissue of the brain

Superior colliculi

The part of the midbrain that controls eye reflexes

Optic radiation

Where the axons carrying information about sight fan out to attach to cells in the visual cortex

Visual cortex

In the occipital lobe

 

 

Ear anatomy

– see the list of structures for lab at http://faculty.alverno.edu/bowneps/BI%20231%20course%20documents/Anatomy%20sheets/Sensory%20Organs.htm

Conduction

When the pressure waves in the air are transmitted through ear structures

Conductive deafness

When a person becomes deaf because they can’t transmit the pressure waves

Sensorineural deafness

When a person can transmit the pressure waves, but their hair cells don’t fire in response

Bony labyrinth

The ‘tunnels’ and ‘chambers’ in the temporal bone within which the hair cells live

Vestibulocochlear nerve

The axons from the hair cells, going into the brain

Inferior colliculus

The part of the midbrain where reflex responses to sound are initiated

Auditory cortex

In the temporal lobe

Eustachian tube

Connects the middle ear to the throat; helps equalize air pressure on the two sides of the eardrum