senses Flashcards
If injury or damage occurs in the pathway prior to the optic chiasma, what will the visual deficit be?
blindness in the eye on the side of the injury.
Fibers at the center of the optic chiasma can be injured or damaged. An example would be a hypothalamic tumor pushing downward from above the chiasma. This type of injury causes:
blindness of the medial retinas; cannot see left visual field from left eye or right visual field from right eye.
The fibers coming from the fovea centralis of each eye pass to the very tip of the occipital lobe on the same side as the eye. Damage to this specific area of the occipital lobe (such as trauma or other injury) leads to:
central blindness; peripheral vision is not affected.
More extensive injury to one of the occipital lobes would result in partial blindness. For example, injury to just the left occipital lobe would cause:
loss of the right visual field; can’t see anything to the right.
what are changes in the environment are detected by?
what do sensory receptors do?
trigger impulses that travel via sensory pathways to the central nervous system.
what are the general senses?
receptors for touch, pressure, temperature, and pain
structurally simple
found in the skin or deeper tissues.
what are the special senses?
Receptors for vision, hearing, taste, smell, and balance (equilibrium) are more complex in structure.
Touch and pressure stimulate the class of receptors called __________. The senses of taste and smell rely on __________.
mechanoreceptors; chemoreceptors
what are receptors for pain, temperature, itching sensation and very light touch comprised of?
free nerve endings
what are the two groups of receptors for temperature
warm and cold
where are pain receptors found?
the skin and the viscera
function of pain receptors?
respond to mechanical damage and/or the presence of chemicals.
what do touch and pressure receptors in the dermis consist of?
sensory nerve fibers encapsulated in connective tissue.
what do touch and pressure receptors do?
respond to deformation of the tissue and include lamellated and tactile corpuscles.
