chemorceptors

sense chemicals in the environmet

(taste and smell)

-in muscles, tendons and joints

-provide a sense of body position

respond to internal stimuli

ex) heart rate, blood pressure

deliver info from the skin

ex0 temp. pain, touch

-more cold recpetors than hot

-located by epidermis

-stimulated by cold and inhibited by heat

-deeper to dermis

-excited by heat and inhibited by cold

-sensed by capsaicin receptor

ion channel for sodium and calcium

-pain receptor

-sharp pain thats transmitted by this

-pain receptor

-dull, persistant pain

1. fungiform- anterior surface

-travels by facial nerve

2. circumvallate- posteri surface

3.  foliate- sides

-travels by glassopharyngeal n.

1. light passes througt the cornea and the into the anterior chamber of eye

2.  passes through the pupil

-changes shape to allow more in

3.  Passes through the lense

-changes shape to focus the image

4. Hits the retina

-photoreceptos are found here

-bends the light

-this allows fine control of focus

-the image is flipped upside down

-suspend from suspensory ligamets

-attached to ciliary bodies

1. Cose- contraction of the ciliary m. allow the ligaments to relax and the lens to thicken

2. distant- the lens thins

nearsightedness

-due to elongated eyeball

-need concave glasses

farsightedness

-due to short eyeball

-need convex glasses

Neuron axons gathered here called the optic disc

-blood vessels are here

-photreceptors un the inner layer

-photorector in the retina

-allow black and white in low light

-absorbs green light best

-less sensitive

-allow colore vision  

-3 wavelengths

S: short waves, blue

M: medium waves, green

L: long waves, red

- high velocity

-good when reading because it keeps the image focused

- photpigment of own called melanosin

-sends info. about illumination

-helps with constriction in bright light

-sets cirardian rythyms