The Senses Flashcards
Define sensation.
A state of awareness of external and/or internal conditions of the body.
Define perception.
Conscious registration of a sensory stimulus.
What four prerequisites are required for a sensation to occur?
- A stimulus capable of initiating a neural response must be present.
- A receptor or sense organ must pick up the stimulus and convert it to a nerve impulse (ex. a muscle spindle or ruffini ending.)
- a sensory impulse must be conducted along a nerve pathway to the brain.
- a specific region of the brain (eg. pain, smell) must translate the impulse into a sensation.
All receptors contain what?
dendrites of sensory neurons
Exteroceptors do what?
Provide information about the external environment, aka transmits sensations of hearing, sight, smell, taste, touch, pressure, temp and pain.
Where are exteroreceptors located?
near the surface of the body
Visceroreceptors
Provide info on the internal environment; sensations may be felt as pain, pressure, hunger, fatigue, thirst, and nausea.
Where are visceroreceptors located?
Within the body in blood vessels and viscera
Proprioceptors
Provide info on body position and movement (golgi tendon and muscle spindles); give info on muscle tension, position and strain/tension of joints, and equilibrium.
Where are proprioceptors located?
Located in muscles, joints, tendons, and the inner ear, and can include eye.
mechanoreceptors
detect mechanical DEFORMATION of the receptor itself or adjacent cells, including touch, pressure, vibration, proprioception, hearing, equilibrium and blood pressure.
Nociceptors
pain, usually due to physical or chemical changes in the tissue.
Photoreceptors
detect light on the retina of the eye.
Chemoreceptors
detect tastes in mouth, smell in nose and chemicals in body fluid such as oxygen, water, co2 and glucose..
