Module 6 Flashcards
what are the two divisions of the PNS
sensory (afferent) and motor (efferent)
what are the two divisions of the motor (efferent) nervous system?
somatic (voluntary motor control of skeletal muscles) and autonomic (involuntary motor control of smooth and cardiac muscle)
what are the two divisions of the autonomic nervou system?
sympathetic (fight or flight)
parasympathetic (rest and digest)
where do cranial nerves come from?
cranial nerves emerge in pairs from the brain and brain stem
How many pairs of cranial nerves are there?
TWELVE!!!
What is a good way to remember the 12 cranial nerves?
On Occasions, Our Trusty Truck Acts Funny - Very Good Vehicle Any How
What are the Twelve cranial nerves?
CN I - olfactory CN II - optic CN III - oculomotor CN IV - trochlear CN V - trigeminal CN VI - abducens CN VII - facial CN VIII - vestibulocochlear CN IX - glossopharyngeal CN X - vagus CN XI - accessory CN XII - hypoglossal
function of the olfactory nerve?
smell
function of the optic nerve?
vision
which three nerves are involved in movement of the eye?
- oculomotor nerve
- trochlear nerve
- abducens nerve
function of the trigeminal nerve?
sensory = forehead, eye, upper/lower jaw motor = mastication
function of the facial nerve?
sensory = anterior 2/3 of the tongue, parasympathetic innervation of tear and salivation glands motor = facial expression
function of the vestibulocochlear nerve?
equilibrium and hearing
sensory functions of the glossopharyngeal nerve?
1) sensory innervation of the pharynx
2) posterior 1/3 of the tongue
3) parasympathetic innervation of salivary glands
motor function of the glossopharyngeal nerve?
pharynx muscles
sensory functions of the vagus nerve?
innervation of the larynx, parasympathetic innervation of the thoracic and abdominal organs
motor functions of the vagus nerve?
pharynx and larynx muscles
function of the accessory nerve?
trapezius and sternocleidomastoid muscles
function of hypoglossal nerve?
tongue
how many pairs of spinal nerves are there?
31
how are spinal nerves formed?
by the union of the posterior (sensory) and anterior (motor) roots of the spinal cord
how are spinal nerves classified?
letter = region of spinal cord number = level
Where is the C8 located?
between C7 and T1
in the cervical region, the nerves are labelled _____ their corresponding vertebrae
above
below the neck, the nerves are labelled _____ their corresponding vertebrae
below
what is a nerve plexuses
once the spinal nerve exit the vertebral column, fibers from the anterior roots (motor) come together and then redistribute into new networks of nerves that mostly innervate muscles of the limb
each plexus contains…?
fibers from a combination of spinal nerves (important in case of injury)
what is another name for the autonomic nervous system?
the visceral motor system
what is the autonomic nervous system responsible for?
transmitting involuntary signals from the CNS to smooth muscle, cardiac muscles and glands
between the CNS and any target organ of the autonomic nervous system, there are ____ neurons
two - it’s a “two neuron pathway”
what are the three types of neurons that make up the autonomic nervous system?
- preganglionic
- autonomic
- posganglionic
what is the preganglionic neuron
- cell body within CNS
- axon enters into PNS and travels to autonomic ganglion
what is the autonomic ganglion
where the preganglionic and postganglionic neurons meet/communicate
which two neurons of the autonomic nervous system are located in the PNS
autonomic and postganglionic
Postganglionic neuron
- cell body is in the autonomic ganglion
- axon travels to target organ
what’s the difference between parasympathetic and sympathetic in terms of EFFECT?
sympathetic - widely distributed to many parts of the body
parasympathetic - more limited distribution to target organs, localized effect
where is the origin of the sympathetic nervous system?
spinal cord segment T1 - L2 (also called THORACOLUMBAR division)
where is the origin of the parasympathetic nervous system?
brain stem and spinal cord segment S2 - S4 (CRANIOSACRAL division)
what are the four components of the sympathetic pathway?
1) lateral horn of spinal cord
2) sympathetic trunk
3) ganglion
4) effector organ
what are the three components of the parasympathetic pathway?
1) sacrum
2) autonomic ganglia
3) head
what are the special visual receptors which are located at the back of the eye?
photoreceptors
what are the accessory structures of the eyeball?
- eyelid (palpebrae)
- lacrimal gland
- extrinsic eye muscles (extraocular)
eyelid
contains the levator palpebrae superioris muscle, which controls opening the eyelid
lacrimal gland
produces tears, which keep the cornea (outside surface of eyeball) moist and clean
what do the extrinsic eye muscles do?
allow you to move your eyes to increase your range of vision
what are the six extrinsic eye muscles?
- medial rectus
- superior oblique
- superior rectus
- lateral rectus (cut)
- inferior rectus
- inferior oblique
what are the three chambers of the eye?
- anterior cavity
- lens
- posterior cavity
the eye is separated into _______
two fluid-filled cavities
what fills with the chambers of the anterior cavities
aqueous humour (watery-type fluid)
what fills the posterior cavity
vitreous humour (gelatinous fluid)
what are the three layers of the eye
- outer layer (fibrous)
- middle layer (vascular)
- deep layer (sensory retina)
what are the two parts of the fibrous layer of the eye?
the sclera and the cornea
cornea
external aspect of the eye, located anterior to the lens
sclera
internal aspect of the fibrous tunic, located posterior to the lens
what are the three components of the vascular layer of the eye?
- choroid
- ciliary body
- iris
choroid
contains the blood vessels that supply the eye with oxygen
what is in the ciliary body?
ciliary muscles (intrinsic eye muscles)
IRIS
contains the sphincter and dilating muscles (intrinsic eye muscles) which control the narrowing/widening of the pupil. Also contains pigments that create eye colour
what are the four components of the deep layer of the eye?
- neural layer
- optic disc
- macula
- CN II (optic nerve)
what are located in the neural layer of the eye?
photoreceptors (rods and cones)
what do the photoreceptors do?
light sensitive cells that send signals to smaller nerves that converge to form CN II
OPTIC DISC
where smaller nerves converge becoming CN II
MACULA
area lateral to optic disc
The ear is divided into what three parts?
- External ear
- middle ear
- inner ear
the part of the ear you can touch is called ?
The external ear
how to sound waves travel through the external ear?
sound waves travel through the external auditory canal to reach the tympanic membrane, which marks the boundary of the external and middle ear
what is the auricle?
the hard part around the edge of the ear
what are the ceruminous glands?
present in the external auditory canal and secrete EAR WAX
which bone of the skull are the middle and inner ear located within?
temporal bone
the middle ear spans from the ______ to the ______
tympanic membrane to the oval window
what are the three main components of the middle ear
- tympanic cavity
- eustachian tube
- ossicles
TYMPANIC CAVITY
chamber in the temporal bone
eustachian tube
connects the middle ear to the nasopharynx
ossicles
three small bones that help transmit sound waves to the receptors in the inner ear. Also help dampen very loud noises
what are the names of the three ossicles?
- malleus (hammer)
- incus (anvil)
- stapes (stirrup)
the inner ear houses the ______
receptors responsible for hearing and equilibrium
what is the vestibular apparatus?
contains the receptors for equilibrium
______ contains the receptors for hearing and looks like a sea shell
cochlea
the cochlea and vestibular apparatus are structures as two ______
labyrinths
what are the names of the two labyrinths formed in the inner ear?
- membranous (within bony)
2. bony
the two labyrinths are filled with what?
fluids that allow us to hear or perceive equilibrium
endolymph fills what structure?
the membranous labyrinth
the bony labyrinth is filled with _____
perilymph
what components of the vestibular apparatus detect positional movement?
utricle and saccule
what do the semicircular canals do?
detect rotational motion
what are the three ducts of the cochlea?
- vestibular
- tympanic
- cochlear
what is corti made up of?
specialized cochlear hair cells that rest on a basilar membrane
how does the corti function
when the membrane is moved by sound waves, the hair cells interpret this information and send it to the brain through CN VIII
