Autonomics & Sensory organs Flashcards
unipolar
bipolar
multipolar
classification of neurons
unipolar
bipolar
multipolar
classification of neurons
- most common sensory neuron
- single short cell process extends from cell body, fusion of 2 processes into 1 long axon
ex) motor sensory neurons
describe unipolar classification of neuron
- uncommon, 2 nerve cell processes extend from cell body
ex) olfactory epithelium, retina
describe bipolar classification of neuron
- most common type of neuron
- multiple nerve cell processes extend from the body usualy one axon, many dendrites
ex) interneurons, motor neurons
describe multipolar classification of neuron
-sensory
-detect stimuli from body and transmit to CNS
-unipolar
a for arrive
afferent neurons
-motor
-conduct nerve impulses from CNS to muscle or glands
-multipolar
efferent neurons
-found only in the CNS
-facilitates communication between afferent and efferent neurons
-multipolar
interneurons
- astrocytes
- microglial cells
- ependymal cells
- oligodendrocytes
CNS glial cells (AMEO)
-star-shaped, most common type of glial cell.
-in contact with neurons and capillaries
- form BBB and replace damaged neurons
what is an astrocyte
- small cell with slender branches, least common type
*defend against pathogens and remove debris (phagocytizes- eats garbage)
what is a microglial cell
- simple cuboidal epithelia cell lining in brain and spinal cord
- secrete cerebral- spinal fluid
- lines ventricles of brain and central canal of spine
what is an ependymal cell
- rounded, bulb cell with small projections
- extensions wrap around CNS
- myelinates and insulated CNS axon, allows for faster nerve impulse conduction
what is an oligodendrocyte
Satellite cells
neurolemmocyte (Schwann)
PNS Glial cells
(SL/ SS)
- flattened cell clustered around neuronal cell bodies in ganglion
- protects/ regulates nutrients for cell bodies in ganglion
what is a satellite cell
myelinated and insulates PNS axon which allows for faster nerve conduction through axon
what is a neurolemmocyte (Schwann)
- high lipid content that wraps around axon and gives nerves their glossy- white appearance
- neurolemmocyte myelinates one axon
- oligodendrocytes myeline many axons
what is the myelin sheath
- maintain homeostasis
- pre-ganglionic cell bodies (found in brainstem, S2, S3, S4)
- local response
- long preganglionic axon
- short postganglionic axon
- no rami communicates
parasympathetic functions
- prepares body for emergencies
- preganglionic cells found in T1- L2 (thoracolumbar)
- short preganglionic axon with many branches
- white rami attach T1-L2
- mass and local activations
sympathetic functions
receptive fields, varies across the body
- don’t need super specific touch on back
- DO need specific touch detection in fingers because they are in charge of precise movement
sense of touch
exteroreceptors
interoceptors
proprioceptors
types of sensory receptors
detect stimuli in external environment
ex) sensory receptors within skin, nose, mouth
exteroreceptors
detect stimuli within body
ex) sensory receptors within blood vessel walls
interoceptors
detect stimuli within joint, skeletal muscle and tendons
ex) joint receptors, spindles
proprioceptors
chemicals dissolved in fluid
ex) taste
what are chemoreceptors
changes in temperature
ex) skin
what are thermoreceptors
changes in light intensity, color and movement
ex) eye
what are photoreceptors
physical deformation of plasma membrane due to touch, pressure, or vibration
ex) tactile receptors in skin
what are mechanoreceptors
detect pain stimule
ex) pain receptors present in almost all organs
what are noiciceptors
gustation
what is the sense of taste called
taste buds
where are gustatory cells found
- gustatory cells: detect tastant
- supporting cells: sustain gustatory cells
- basal cells: replace short-lived gustatory cells
3 things a taste bud contains
filiform
fungiform
vallate
foliate
papillae of the tongue
short, bristle-like, found on anterior 2/3 of tongue.
mechanical function
no gustation role
filiform papillae
mushroom shaped
found on tip/sides of tongue
each contain only a few taste buds
fungiform papillae
least numerous, but very large.
found as inverted V on back on tongue
surrounded by deep depression where taste buds are found
vallate papillae
extend as ridges on posterior lateral tongue.
have few taste buds during infancy/ childhood, but go away as we age
foliate papillae
- sweet
- salty
- sour
- bitter
- umami (meaty flavor)
gustatory discrimination
olfaction
sense of smell
molecules must be dissolved in the mucus of nasal cavity to be detected
describe olfaction
- olfactory receptor cells
- supporting cells
- basal cells
- lamina propria
4 parts to olfactory epithelium
detects odor, olfactory neurons
what do olfactory receptor cells do
sandwich olfactory neurons and sustain the receptors, sustentacular cells
supporting cells
function as neuronal stem cells, continually replace olfactory receptor cells
olfactory cells are one of the few neuronal types that get replaced
basal cells
areolar CT that houses the olfactory glands that produce mucus that convert the olfactory epithelium
lamina propria
vision
sense of sight
- eyebrows
- eyelashes
- eyelids
- medial and lateral palpebral commissures (corner of eye)
external anatomy of eyes
external accessory structure of eye
- special stratified columnar epithelia
- forms continuous lining over external portion of eye
- maintains goblet cells that lubricate the eye
conjunctiva
fibrous tunic/ external layer
2 layers of epithelium with collagen in the middle, forms anterior layer of the eye, transmits/ retracts incoming light
cornea
fibrous tunic/ external layer
dense regular CT
posterior covering of the eye: the ‘white’ of the eye
supports eye shape/ protects it
sclera
vascular tunic/ middle layer
areolar CT, highly vascularized-(full of blood vessels)
forms posterior 2/3 of middle wall of eye. supplies nourishment to retina***
choroid
vascular tunic/ middle layer
ciliary smooth muscles and inner secretory epithelium.
between choroid and iris anteriorly
ciliary body
vascular tunic/ middle layer
2 layers of smooth muscle with central opening (pupil)
control pupil diameter- which allows a certain amount of light in
iris
retina/ internal layer
pigmented epithelial cells/ supporting cells.
outermost portion of retina- directly adheres to choroid.
absorbs extraneous light, provides vitamin A to photoreceptors
pigmented layer
retina/ internal layer
photoreceptors, bipolar neurons and ganglion cells.
inner portion of retina
detects incoming light rays; which are converted to nerve impulses and transmitted to the brain
neural layer
cavity of eye
strong, deformable transparent structure held in place by dense fibrous capsule
lens
cavity of eye
gel-like substance found in space between lens and retina
vitreous humor
ear and hearing
what deals with equilibrium and hearing?
(external ear)
skin covered cartilaginous structure
auricle
(external ear)
funnel-shaped tube
external acoustic meatus
(external ear)
delicate epithelial sheet, separating the external and middle ear
tympanic membrane
(middle ear, tympanic cavity)
Eustachian tube
auditory tube
(middle ear, tympanic cavity)
connects middle ear and where our mouth/ nose connect
- malleus
- incus
- stapes
*stapes articulates with oval window to transmit sound waves to the inner ear
auditory ossicles
hammer
what does the malleus look like?
anvil
what does the incus look like?
stirrup
what does the stapes look like?
(inner ear) CN VII
anterior, posterior, horizontal fluid movement within these canals help the brain determine movement of body
semicircular canals
(inner ear) CN VII
utricle and saccule= sense gravity and linear acceleration to maintain equilibrium and balance
vestibule
(inner ear) CN VII
sense sound as vibrations and turn these vibrations into nerve impulses which are perceived as audible sound in the brain
cochlea
classification of neurons
unipolar
bipolar
multipolar
