Chap 12 Flashcards
Sensory receptors
The nerve endings in cells that detect sensory information
•initiate neural impulses
- Different forms of energy stimulate the receptors
Sensation
Occurs when the neural impulses arrive at the cerebral cortex.
Ex) Face may detect warmth of a beam of sunlight and feel the warmth on at cheek
Perception
Each person has a UNIQUE perception.
-cerebral cortex interprets the meaning of the sensory information
Sensory adaptation
When the BRAIN filters out insignificant or REDUNDANT info.
• ex) sensory adaptation has occurred when you gone out clock ticking
Sensory receptors
Are specialized cells or neuron endings that detect specific stimulus.
Humans have 4 categories of receptors
•transduce, convert a form of NRG into electrochemical NRG
1) photoreceptors
Light stimulates this receptor.
•Eyes contains rods and cones in order to see and absorb light
-colours and shades
[damage: loss of associated sense]
2) Chemoreceptors
Stimulated by certain chemicals
-tongue: contains TASTEBUDS that detect various particles in food
3) Mechanoreceptors
Respond to mechanical forces from same form of pressure
•ex) hair cells in inner ear are activated by vibration of sound waves
•SKIN =pain, pressure and light touch
4) Thermoreceptors
In SKIN: detects heat and cold
Human eye: 3 layers
- external
- intermediate
- internal
External eye layer
Sclera and cornea
Sclera
External
•white of the eye/ touch and fibrous protective layer
cornea
LIGHT enters the eye
•clear/transparent dome of the eye
Intermediate layer of eye
Choroid
Iris
Pupil
Choroid
Intermediate
•ABSORBS stray light rays that ARENT detected by photoreceptors
•blood vessels= nourish eye