review question:

explain how you are able to smell and taste freshly baked bread.

corrective lenses help when the lens cannot alter shape properly

 just for funzies

  odorant enters the nasal cavity.
  odorant binds to receptor proteins on the cilia of                              olfactory sensory neurons.
  binding triggers the generation of electrical signals...
     ion channels open allowing sodium to enter the cell
     changing the electrical potential of the cell membrane           triggering an action potential.
 signal sent to the olfactory cortex...the identification
  of smells and the emotional/memory-related responses

different types of taste buds

the ciliary muscle controls the shape of the lens by adjusting the tension on the zonules.
when the ciliary muscle contracts, it reduces tension on the zonules, causing the lens to become more rounded for near vision. when the ciliary muscle relaxes, the zonules tighten, flattening the lens for far vision.

   review question:

explain how do the ciliary body
controls the shape of the lens. 

Why is the lens shape important for ideal vision.

   review question:

explain how you hear.

50-150 taste cells per taste bud

how does sound travel?

different wavelengths of light stimulate different rods to "see" color.

         Part III: Olfaction and Gustation

   review question:

describe how semi-circular canals and otolith organs provide your brain with data re spacial orientation.

  chemical senses functions:
monitor environment
find food/judge food safety
predator avoidance
prey location
pheromones

                      rhodopsin is a pigment found in photoreceptors.
   when light hits rhodopsin, it causes a chemical change in the molecule.  
                          ​rhodopsin is composed of two parts:
a. opsin (a protein)
b. retinal (a light-absorbing molecule made from vitamin A).
                    retinal is embedded in the opsin protein. 

         in the dark, rhodopsin is inactive and ready to absorb light. 
              when light hits the retina, it is absorbed by rhodopsin. 
                this causes the retinal molecule to change shape (cis to trans).
       this retinal change triggers a structural change in the opsin protein. 
 opsin then initiates a series of chemical reactions that send an action                       potential to the brain. the origin of the action potential on the retina is perceived as a light area against the dark areas in its absence...
​                                            hence an image is formed...

 how do these photoreceptors function?

   anatomy review

      as we learned, foods are chemicals.
these chemicals interact with specialized sensory cells that exhibit receptor membrane proteins and channel proteins.
specific chemicals react with specific receptors generating an action potential
which is sent to the gustatory cortex in the frontal lobe.
the brain combines the taste bud info with signals from the olfactory receptors
to create the "flavor".

Part II: Spacial Orientation

how does the eye "see"?

  anatomy review

​2. otolith organs:

hmmm... without functional rods and cones, does color actually exist?

just for funzies...

first, we'll explore light...

the ciliary muscles and
zonules (suspensory ligaments) act on the lens 

      as we learned, foods are chemicals.
these chemicals interact with specialized sensory cells that exhibit receptor membrane proteins and channel proteins.
specific chemicals react with specific receptors generating an action potential
which is sent to the gustatory cortex in the frontal lobe.
the brain combines the taste bud info with signals from the olfactory receptors
to create the "flavor".

   review question:

explain how the eye "sees".

   Sensory Organs

rods and cones are two types of photoreceptor cells in the retina.
The convert light into signals the brain interprets as vision.
rods "see" in low-light conditions.
cones "see" in brighter light and enable color vision.

   Part 1: Vision

    Gustation

   review question:

what is color?

sound waves travel in a path from outer ear to inner ear

Part II:  ​Hearing 

    Olfaction 

taste buds can detect five basic tastes:
​sweet, salty, sour, bitter, and umami 

1. semicircular canals:
​movement "sloshes" endolymph which pushes on cupola which triggers sensory hair cells.

   pupils dilate in low light and constrict in bright light via sphincter muscles

    just for funzies