Unit 6: Sensory Systems Flashcards
Sensory receptors are also called
Transducers
Sensory receptors convert _______ to _______
stimuli to electrochemical activity
What are the 3 types/categorizations of sensory receptors
By modality, by origin of stimuli, and by distribution
Give a few examples of modality sensory receptors
Thermoreceptors, chemoreceptors, nociceptors, photoreceptors
What are the 3 origins of stimuli for sensory receptors
Interoreceptors (within)
Proprioceptor (movement)
Exteroceptor (external)
What are the 2 types of distribution categories for sensory receptors
General
Special senses (taste, sight, hearing, etc.)
Somesthetic sense pathways are AKA as
General sense pathways
How many neurons are involved in a somesthetic sense pathway
3
First order neurons originating from cranial nerves travel through the
pons and medulla
First order neurons originating from spinal nerves travel through the
dorsal horn of the spinal cord
Large and fast myelinated axons deliver what type of senses
Touch, pressure, proprioception
Small and slow unmyelinated axons deliver what type of sense
Temperature
What do second order neurons do
Transmit message to opposite side of medulla OR spinal cord, ultimately ending in the thalamus
What do third order neurons do
Extend from the thalamus to the primary somesthetic cortex of the cerebrum
The somesthetic cortex is in which lobe of the cerebrum
Parietal
Pain receptors are called
Nociceptors
Nociceptors are found
Everywhere except for the brain
Fast pain is described as ________ and travels at _______ m/s along myelinated axons
Sharp, local, stabbing
30 m/s
Slow pain is described as ______ and travels at ____ m/s along unmyelinated fibers
Long-lasting, dull, diffused
2 m/s
Somatic pain comes from
the surface (skin, joints, muscle)
Visceral pain comes from
Stretching of organs, chemical irritants, ischemia
5 tastes
Salty, bitter, sweet, sour, umami
Taste is affected by
Texture, smell, temperature, appearance, spice
Molecules must be ______ to be tasted
soluble in saliva
Tastes are detected where on the tongue
All over
Which nerves are involved with taste
7 (facial)
9 (glossopharyngeal)
10 (vagus)
When tasting, messages are sent along fibers from ______ to _______ and _______, then to the _______, ending in the _________
medulla
hypothalamus and amygdala
thalamus
postcentral gyri of cerebrum
Smell receptor cells form the
olfactory mucosa
Olfactory neurons have # _______
20 cilia
Smell travels from ______ through the ______ to _________
axons through the cribriform plate to olfactory bulb
T/F Olfactory neurons are mitotic
True
Explain the path that sound travels through the ear
Through external auditory meatus to vibrate the tympanic membrane, auditory ossicles vibrate, then cochlear membrane vibrates which bends cilia causing ion channels to open and depolarize = msg sent
Where is sound perceived
Temporal lobe
Where are the auditory ossicles
Middle ear
What are the auditory ossicles
Stapes
Incus
Malleus
What connects the middle ear to the pharynx and why
auditory/eustachian tube
relieves air pressure
The inner ear has pathways to the temporal lobe called
Bony labyrinth and membranous labyrinth
The labyrinths in the ear and filled with
Electrolyte fluids
Stereocilia are surrounded by
Potassium
What causes ion channels to open in ear
Cochlear membrane bends the stereocilia
Which nerve is supports hearing
Vestibulocochlear nerve (8)
What are crista ampullaries and what is their purpose
Gelatinous membranes within the semicircular canals
Move when body moves which alerts body to change in orientation, helps with equilibrium
Define conjuctiva
sensitive and vascular mucous membrane around eyelid and most of eyeball
Define lacrimal apparatus
produces tears to clear eye
What are the layers of the eye from outer to inner
Fibrous
Vascular
Sensory
What is included in the fibrous layer
Scelra and cornea
What is included in the vascular layer
Choroid, ciliary body, and iris
What is included in the sensory layer
Retina and optic nerve
What are the 4 optical components
Cornea
Aqueous humor
Lens
Viterous humor
Define optical component
transparent parts of the eye which bend light to focus it on the retina
Define cornea
Transparent covering of eye
Define aqeous humor
clear serous fluid between cornea and lens
Define lens
Bends to focus light and is suspended by suspensory ligaments
Define viterous humor
Jelly filled space between lens and retina
Where is your blind spot
Optic disk
Define optic disk
Area where optic nerve exits eyeball
Define pupillary constrictor
Circular muscle of iris, smooth muscle around pupil
Define pupillary dilator
Radial muscle of iris, spokelike
Define emmetropia
Easily focused on long distance
For near sight, what 3 things must happen
Convergence of the eyes
Constriction of the pupil
Accommodation of lens (shape change)
Define hyperopia
Farsighted
Define myopia
Nearsighted
What is responsible for color vision
Cones
What allows us to see white and black
Rods
What is primarily used for night vision and where are they located
Rods
Around edge of retina
What is primarily used for day vision and where are they located
Cones
Center of retina (fovea)
______ have a direct line to the brain (vision)
Cones
What requires extensive neuronal convergence (vision)
Rods
Which is higher resolution: rods or cones
Cones
Define photopsins
Absorption peaks of cones
Red, blue, green
