Special Senses Flashcards
the raw input from the peripheral nervous system that arrive at the central nervous system
sensation
the interpretation of the sensations
perception
cells that detect stimuli
sensory receptors
sensory receptors that respond to physical stimuli such as sound and touch
mechanoreceptors
sensory receptors that respond to temperature
thermoreceptors
sensory receptors that detect tissue damage, extreme heat and cold, and chemicals released from damaged cells
pain receptors
sensory receptors that respond to light
photoreceptors
sensory receptors that detect chemicals
chemoreceptors
sensory receptors that detect position of body parts
proprioreceptors
the process by which a sensory receptor converts energy from a stimulus into electrical signals (action potentials)
transduction
a phenomenon in which sensations become less noticeable with prolonged exposure to the stimulus
sensory adaptation
generate fewer action potentials under constant stimulation
the response returns only if the intensity of the stimulus changes
sensory receptors
the __________ __________ detect touch, temperature, or pain with any part of the skin and in the internal organs
general senses
sense organ: skin
stimulus: pressure vibration
type of receptor: mechanoreceptor
touch
sense organ: skin
stimulus: heat, cold
type of receptor: thermoreceptor
temperature
sense organ: everywhere except the brain
stimulus: damage to body tissues
type of receptor: pain receptor
pain
sense organ: joints, muscles, ligaments
stimulus: stretching of muscles and ligaments
type of receptor: proprioceptor
position of body parts
the __________ __________ have specialized structures for vision, olfaction, gustation, hearing, and equilibrium
special senses
sense organ: nasal cavity
stimulus: airborne molecules
type of receptor: chemoreceptor
smell
sense organ: mouth and tongue
stimulus: dissolved molecules
type of receptor: chemoreceptor
taste
sense organ: eyes
stimulus: light
type of receptor: photoreceptor
vision
sense organ: ears
stimulus: air pressure waves
type of receptor: mechanoreceptor
hearing
sense organ: ears
stimulus: motion of fluid in inner ear
type of receptor: mechanoreceptor
equilibrium
elastic movable folds of skin over the eyes, protects the eyes from debris and or trauma
eyelids (palpebrae)
hair that grows at the edge of the eyelids for protection and aesthetics
eyelashes
hairy area of coarse skin above the eye for aesthetics and enhancement of facial expressions
eyebrows
consists of the lacrimal gland and ducts that drain lacrimal secretions into the nasal cavity
lacrimal apparatus
produces tears that cleanses, lubricates and protects the eyes
lacrimal gland
what is the enzyme in tears that destroys bacteria
lysozyme
tears drain to the minute opening called the __________ __________
lacrimal punctum
mucous membrane that lines the eyelids and covers part of the outer surface of the eye
conjunctiva
a thin transparent membrane that covers and protects the anterior portion of the white sclera
bulbar conjunctiva
coats the insides of the eyelids
palpebral conjunctiva
forms the junction between the bulbar and palpebral conjunctivas, loose and flexible, allowing the free movements of the lids and eyeballs
fornix conjunctiva
innervated by the cranial nerves controlling the movement of the eyes
the coordinated action of these allow the eyes to move in tandem, ensuring clear vision
extra-ocular muscles
what are the three cranial nerves that control eye movement
CN III Oculomotor, CN IV Trochlear, and CN VI Abducens
controlled by CN III Oculomotor; elevation, also contributes in abduction and medial rotation of the eyeball (upward)
superior rectus
controlled by CN III Oculomotor; depression, also contributes to adduction and lateral rotation of the eyeball (downward)
inferior rectus
controlled by CN III Oculomotor; adduction (inward)
medial rectus
controlled by CN VI Abducens; abduction (outward)
lateral rectus
controlled by CN IV Trochlear; depresses, abducts and medially rotates the eyeball (downward and outward)
superior oblique
controlled by CN III Oculomotor; elevates, abducts and laterally rotates the eyeball (upward and outward)
inferior oblique
what are the three layers of eye tunics (from superficial to deep)
fibrous layer (sclera & cornea)
vascular tunic (choroid, ciliary body, & iris)
nervous tunic (retina)
outer layer, superficial coat of the eyeball
fibrous layer (tunica fibrosa)
the white coating of the eye, white tough fibrous connective tissue protecting the inner structures of the eye
it helps maintain the shape of the eyeball
sclera
the sclera becomes __________ because of hepatitis
yellow