PNS Flashcards
What are the 4 types of stimuli receptors?
Mechanoreceptors, thermoreceptors, photoreceptors, chemoreceptors, and nocireceptors
What are the 3 different locations of sensory receptors?
Exteroreceptors, interoreceptors, and proprioreceptors
What are nerves classified by?
The direction of transmission
What are the three types of nerves?
Mixed nerves, afferent nerves, and efferent nerves
What is the most common type of nerve?
Mixed
What are ganglia?
Ganglia are neuron cell bodies located outside the CNS
What are the three connective tissue layers?
Epineuranium, perineurium, and *****
What is the epineurium?
The outermost connective tissue layer
What is the perineurium?
The middle connective tissue layer that divides nerves into fascicles/ axon bundles
What are the 12 types of cranial nerves?
Olfactory, optic, ocularmotor, troclear, trigeminal, abducens, facial, vestibular cochlear, glossopharyngeal, vagus, accessory, and hypoglossal
What is the acronym to remember the cranial nerves?
On occasion, our trusted truck acts funny; very good vehicle any how.
What are the sensory cranial nerves?
Olfactory, optic, and vestibular cochlear
What are spinal nerves named for?
Where they leave the vertebral column
What are the mixed cranial nerves?
Facial, glossophyingeal, vagus, and trigeminal
What are the motor cranial nerves?
Ocularmotor, troclear, abducens, accessory, and hypoglossal
What are the 5 categories of spinal nerves?
Cervical, thoracic, lumbar, sacral, and coccygeal
How many cervical spinal nerves are there and where are they?
8 cervical (C1-C8)
How many thoracic spinal nerves are there and where are they?
12 thoracic (T1-T12)
How many lumbar spinal nerves are there and where are they?
5 lumbar (L1-L5)
How many sacral spinal nerves are there and where are they?
5 sacral (S1-S5)
How many coccygeal spinal nerves are there and where are they?
1 coccygeal (CO1)
What is the reflex arc?
The wiring of a single reflex: sensory, association, and motor neurons
Where does the reflex arc begin and end?
It begins at the receptor and ends at the affector
What does the reflex arc generally oppose?
The reflex arc generally opposes the original stimulus (negative feedback)
What type of reflexes have the least delay? Why?
Monosynaptic reflexes have the least delay between sensory input and motor output
Give an example of a monosynaptic reflex
A stretch reflex
What do interneurons control in polysynaptic reflexes?
Interneurons each control more than one muscle group
What type of reflex arcs occur on the same side of the body?
Ipsilateral reflex arcs
What types of reflexes are ipsilateral reflexes?
Stretch, tendon, and withdrawal reflexes
What are crossed extensor reflexes?
Reflexes that involved a contralateral reflex arc
What type of reflexes involve a contralateral reflex arc?
Crossed extensor reflexes
What type of reflexes occur on the side opposite of the stimulus?
Crossed extensor reflexes
What are ipsilateral reflex arcs?
Reflex arcs that occur on the same side of the body as the stimulus
What are muscle spindles?
The receptors in stretch reflexes
Give an example of a unique receptor
Muscle spindles
What are the receptors in stretch reflexes called?
Muscle spindles
What is a postural reflex?
A stretch reflex
What do postural reflexes help you do?
They help you maintain normal upright posture
What do stretched muscles respond by doing?
Stretched muscle responds by contracting
What does the contracting of stretched muscle help you do?
Stretched muscles respond to stimulus by contracting, which automatically helps you maintain balance
How many paravertebral ganglia are in the sympathetic trunk (chain)?
There are 23 paravertebral vertebrae in the chain
How many cervical paravertebral vertebrae are there in the sympathetic trunk?
3 cervical paravertebral
How many thoracic paravertebral vertebrae are there in the sympathetic trunk?
11 thoracic paravertebral
How many lumbar paravertebral vertebrae are there in the sympathetic trunk?
4 lumbar paravertebral
How many sacral paravertebral vertebrae are there in the sympathetic trunk?
4 sacral vertebrae
How many coccygeal paravertebral vertebrae are there in the sympathetic trunk?
1 coccygeal
How many types of paravertebral ganglia are there in the sympathetic trunk? What are they?
5 types; cervical, thoracic, lumbar, sacral, and coccygeal
How many of each type of paravertebral ganglia are there?
3 cervical, 11 thoracic, 4 lumbar, 4 sacral, and 1 coccygeal
How many layers make up the eye?
3
What are the three layers of the eye?
The fibrous, vascular, and nervous tunics
What is the outermost layer of the eye?
The fibrous tunic
What makes up the fibrous tunic?
The sclera and the cornea
What makes up 5/6 of the fibrous tunic?
The sclera
Describe the sclera
It’s firm, white, and it’s the outermost connective tissue layer
What maintains the shape of the eye?
The sclera
What makes up 1/6 of the fibrous tunic?
The cornea
Describe the cornea
It’s the transparent anterior of the fibrous tunic
What does the cornea do?
It allows light to enter the eye
What are the two parts of the vascular tunic of the eye?
The choroid and the ciliary body
What are three other things that are part of the middle layer of the eye, but aren’t part of the vascular tunic?
The iris, the lens, and the pupil
What is the vascular tunic? What does it contain?
The vascular tunic is the middle layer of the eye that contains the blood supply
What layer contains the eye’s blood supply?
The vascular tunic/ middle layer
Where is the choroid located? What’s it associated with?
It’s the posterior part of the vascular tunic that’s associated with the sclera
What makes up the choroid?
It’s a vascular network that contains cells with melanin, and it’s black
What does the ciliary body contain?
It contains smooth muscles that attach to the lens
Where is the ciliary body located?
It’s the anterior part of the vascular tunic
What is the iris, and where is it located?
It’s the colored part of the eye, and it’s anterior to the lens
What makes up the iris?
The iris is made up of smooth muscle, and it’s contractile
Describe the lens
It’s a flexible and bicovex transparent disc
What is the pupil/ what does it do?
It’s the opening in the iris that lets in light
What is the nervous tunic?
It’s the retina, and the innermost layer
What is the innermost layer of the eye?
The nervous tunic/ retina
What are the parts of the retina?
The rods, cones, and optic nerve
Describe the rods
They’re more common than cones, and they have no color but they help you see in dim light
Describe the cones
They require more light than the rods to be activated, but they help you see color
What is the optic nerve?
The place in the retina where the nerves in the eye converge posteriorly
Where is the external/outer ear
It extends from the outside of the head to the eardrum
What are the parts of the middle ear?
Malleus, incus, and stapes
Describe the auricle
It’s fleshy and external
What does the auricle do?
It focuses sound waves into the external auditory meatus
What is the external auditory meatus
It’s a passageway that leads to the eardrum
What is the external auditory meatus lined with?
It’s lined with hairs and glands that produce cerumen (earwax)
What is earwax called?
Cerumen
What are the parts of the external ear?
The auricle, the external auditory meatus, and the tympanic membrane
What is does the tympanic membrane do?
It vibrates with sound waves / eardrum
What is the tympanic membrane?
It’s a thin layer of connective tissue sandwiched by epithelial tissues
What is the middle ear?
An air-filled chamber
What is the malleus?
The hammer
What is the malleus attached to?
It’s attached to the tympanic membrane
What do the small muscles attached to the malleus do?
They dampen sound noises to protect the ear (tensor tympani)
What are the two transition parts of the rear?
The oval window and the auditory tube/ eustacian
What is the incus?
The anvil
What does the incus do?
It connects the malleus to the stapes
What is the stapes? Where is it located?
It’s shaped like a stirrup and it’s seated against the oval window
What does the stapes have that the malleus also has?
The stapes has a dampening muscle like the malleus (stapedius)
Describe the oval window
It’s 20 times smaller than the eardrum and sound amplifies by 20
What does the eustacian/auditory tube do?
It opens into the pharynx and allows the equalization of air pressure in the middle ear
What does the inner ear do?
It helps with hearing and balance
What are the three parts of the inner ear?
The cochlea, the vestibule, and the semicircular canal
What does the cochlea do and what is it shaped like?
The cochlea is involved in hearing and it’s shaped like a snail’s shell
What are the two chambers of the vestibule?
The urtricle and the saccule
What is imbedded in the vestibule?
Hair calls are embedded in a gelatinous mass that shifts with gravity
What does the semicircular canal do?
It maintains kinetic equilibrium
What is embedded in the semicircular canal?
Hair cells are embedded in the cupola of the semicircular canal
