Introduction to Nervous System and Cranial Nerves Flashcards
Branches of the NS
Nervous System
Peripheral Central
Autonomic
Somatic
Sympathetic and Parasympathetic
what is the peripheral NS
everything else that is not either the brain or the spinal cord - not C NS
autonomic
think it is automatic while somatic is voluntary eg. speech production
types of neurons
unipolar, bipolar, pseudounipolar, multipolar
what is a neuron
structural and functional unit of the NS
glial cells
- non- neuronal cells that provide service for the neurons eg. nourish, support and protect neurons
- CNS - astrocytes (blood brain barrier), oligodendrocytes (myelin sheath), ependymal cells (CSF, brain metabolism), microglia (infection and inflammation)- PNS - Schwann (myelin sheath), satellite (SNS/PNS), enteric (gut)
components of the CNS
cerebrum, cerebellum, brainstem, spinal cord
cerebrum
- frontal lobe, parietal lobe, temporal lobe, occipital lobe
- primary motor cortex (frontal lobe)
- primary auditory cortex (temporal lobe) - hearing
- primary somatosensory cortex (parietal lobe) - sensations eg. touch
- Wernicke’s area (periotemple area) - comprehension of speech
- Broca’s area (frontal lobe) - productions of speech
cerebellum
coordinates human movement
what are nerves
- nerves transport to and from regions to connect to the CNS (sensory, motor or both)
spinal nerves
- spinal nerves - come from spinal cord and go out. both sensory and motor fibres
and exit and enter the CNS via the spinal cord
cranial nerves
nerves exit and enter the CNS via the cerebrum or brainstem can
be sensory (general and/or special) motor fibres or both sensory and motor
nerve fibre types
nerve fibre types
- motor (efferent) vs sensory (afferent) vs both
- general vs special
- visceral vs somatic
motor and sensory
- sensory fibres - from PNS to CNS (eg. touch of our skin, taste from our tongue)
- somatic sensory (from body wall) and visceral sensory (from organs)
- motor fibre - from CNS to PNS to effect muscles
- somatic motor (to body wall muscles) and visceral motor (to glands or organs)
all possible nerve fibre types / classification
- general somatic afferent
- general visceral afferent
- special somatic afferent
- special visceral afferent
- general somatic afferent
- general visceral efferent
epineurium
wraps around the entire nerve. It is comprised of many
fascicles, arteries, veins and adipose tissue
perineurium nerve fibre
bundles many nerve filaments into fascicles
endoneurium nerve fibre
wraps around each nerve filament
what nerve is sense of smell
olfactory
what nerve is ability to see
optic
what nerve is ability to move and blink your eyes
oculomotor
what nerve is the ability to move your eyes up and down/ back or forth
trochllear
what nerve is sensations in your face and cheeks, taste and jaw movements
trigeminal
what nerve involves ability to move your eyes
abducens
what nerve involves facial expressions and sense of tastr
facial
what nerve involve hearing and balance
vestibulocochlear
what nerve involves ability to taste and swallow
glossopharyngeal
what nerve involves digestion and heart rate
vagus
what nerve involves shoulder and neck muscle movement
accessory
what nerve involves ability to move your tongue
hypoglossal
is olfactory afferent or efferent
afferent
is optic afferent or efferent
afferent
cranial nerves for hearing
Vestibulocochlear Nerve - CN VIII
Vestibulocochlear Nerve - CN VIII
- purely sensory cranial nerve
- combination of two nerves:
- balance - semicircular canals and utricle and saccule
- hearing - cochle
cranial nerves for swallowing
CN V Trigeminal Nerve , CN VII Facial, CN IX Glossopharyngeal, CN X Vagus, CN XI Accessory, CN XII Hypoglossal
CN XII Hypoglossal
- motor nerve
- general somatic efferent to the muscles of the tongue (intrinsic and majority of extrinsic)
CN XI Accessory
motor nerve
- general somatic efferent to some neck muscles
CN X Vagus
- general somatic efferent to muscles of the many of the pharyngeal and velar muscles (for swallowing) and larynx ( voice)
- general somatic afferent from the larynx and pharyngeal region as well as from the ear drum and external ear
CN IX Glossopharyngeal
special visceral afferent for posterior 1/3rd of the tongue (taste)
- contain general somatic afferent (touch, pressure, pain) for pharynx and posterior tongue surfaces
- general visceral efferent fibres to the parotid saliva glands
- general somatic efferent fibres to stylopharyngeus that helps elevate the pharynx in swallowing
CN VII Facial
- general somatic efferent fibres for the muscles of face (expression and lip movement) and one
of the small middle ear muscles that helps in the auditory protective reflex - general visceral efferent fibres to the glands (eg. tears and saliva)
- special visceral afferent fibres to the anterior 2/3rd of the tongue (taste)
- general somatic afferent from posterior ear canal
CN V Trigeminal Nerve - mixed (3 branched) nerve
- 3 branches are - Ophthalmic (CN V1 - sensory), Maxillary
(CN V2 - sensory), Mandibular (CN V3- mixed) - general somatic afferent (touch, pressure, pain) sensation of the face, mucous membrane’s, and other structures of the head
- general somatic efferent fibres to the muscles mastication
anterior
front direction / toward my body
> my stomach is anterior to my spine
posterior
back direction/ rear of the body
> my spine is posterior to my stomach
superior
towards the head/ top of the body
> my chest is superior to my pelvis
inferior
away from head/ towards feet
> my pelvis is inferior to my chest
proximal
toward or nearest to point of origin of a body part
> my elbow is proximal to my wrist
distal
away from trunk/ point of origin
medial
towards the middle
> my nose is medial to my eye
lateral
away from middle > my eye is lateral to my nose
superficial
closer to / on the surface
> my skin is superficial to my bones
deep
further in body/ deeper
> my bones are deep to my muscles
what are the three planes
sagittal plane, horizantal/ transverse and coronel/ frontal plane
sagittal plane
left/ right
transverse
upper / lower
coronel plane
front/ back
flexion
decrease angle of body part or joint eg. bending arm
extension
increase angle of body part or joint eg. stretching arm
adduction and abduction
- abduction = movement away from the body
- adduction = movement towards the body
rotation
pivot around an axis - can be whole body or just body part
gliding
when 2 joints/ body part glide + causes friction eg. chewing
circumduction
combo of movements conducted in circular motion
elevation vs depression
- elevation = movement in a superior direction
- depression = movement in an inferior direction
protraction vs retraction
- protraction = push/ stick out part of a body
- retraction = moves on a parallel plane back into original position