Sensory Receptors that detect chemicals
Chemoreceptors
Referred pain results from
Common nerve pathways
What comes first? Sensation or Perception?
What is Sensation
Visceral pain may feel as if coming from some other part of the body; this is called
Referred Pain
•Begins sensation of pain
•Judges intensity of pain
Thalamus
Cerebral Cortex
Main types of proprioceptors
Lamellated (Pacinian) corpuscles,
Muscle spindles,
Golgi tendon organs
•Have receptors in internal organs
•Convey information that includes the sense of fullness after eating a meal as well as the discomfort of intestinal gas and the pain that signals a heart attack
Visceral Senses
CN1 sense of?
Olfactory- sense of smell
CN VIII
Vestibulocochlear Sense of hearing, mechanoreception
Parts of outer ear
Auricle (Pinna), External acoustic meatus, •Tympanic membrane (Eardrum)
Parts of middle ear
Tympanic cavity, Auditory ossicles, Oval window
Three portions of labyrinths
• Cochlea functions in hearing
•Semicircular canals function in dynamic equilibrium
•Vestibule functions in static equilibrium
5 primary taste sensations
Sweet= carbs
sour= acids
Salty=Salts
Bitter=Mg & Ca salts
Umami=MSG
CN VII and CN IX
Sense of taste
Windows of the Inner Ear
Oval and Round Window
blind spot
Optic Disc
•Spiral, snail-shaped tube, widest at its base, becomes narrower toward tip
Cochlea
Sense of Equilibrium
Static Equilibrium
-Senses position of head when body is not moving
-Receptors are found in vestibule of inner ear
Dynamic Equilibrium
-Senses rotation and movement of head and body
-Receptors are found in semicircular canals
CN II
sense of sight - Optic Nerve
wall of eye has 3 layers
•Outer (fibrous) tunic – sclera…the white of the eye
•Middle (vascular) tunic- choroid/ choroid coat…highly pigmented layer that absorbs stray light
•Inner (nervous) tunic – retina …has photoreceptors.
Photoreceptors
Rods and Cones
•Fovea centralis- sharp visions have only cones
The Outer (Fibrous) Tunic
Cornea- window of eue & Sclera - white of eye.. Outer eye layer
Auditory Pathway
Cochlear branch of vestibulocochlear nerve
Medulla Oblongata
Midbrain
Thalamus (switchboard operator)
Auditory Cortex in temporal lobe of cerebrum
Middle (Vascular) Tunic
Choroid coat - Contains melanocytes; melanin absorbs extra light
Ciliary body
Iris •Controls light entering eye- controls the pupil size
Fluid in anterior cavity of eye
Fills both anterior and posterior chambers of anterior cavity; circulates through pupil
Aqueous Humor