1 Cranial Nerves Flashcards
General difference between CN and SN
Cranial nerves contain inflow/outflow of brain
Spinal nerves contain inflow/outflow of spinal cord
Classification of CN based on what?
Embryological, structural/anatomical, and functional characteristics
Neurons carrying similar modalities are called ___ and arise from ___.
functional components; functional columns
what can be sensory, motor, or both (mixed)?
cranial NERVES
what can be sensory or motor but never both?
cranial nerve NUCLEI
is there a one-to-one correlation between cranial nerves and functional columns?
can a particular cranial nerve carry several distinct functional modailities?
NO, YES
the alar plate gives rise to ___ nuclei from the ___ horn
sensory; dorsal
the basal plate gives rise to ___ nuclei from the ___ horn
motor; ventral
differences between CN nuclei vs. dorsal and ventral horns
- lateromedial vs. dorsoventral (anterior/posterior) column organization
- neuronal migration is more extensive in brain stem
- discontinuous columns
how does the brainstem develop?
starts posteriorly at dorsal sensory or alar plate
opens up laterally like a book
Motor nuclei are [continuous/discontinuous] and sensory nuclei are [continuous/discontinuous].
discontinuous; continuous
where are the motor nuclei columns located in relation to sulcus limitans?
medial
where are the sensory nuclei columns located in relation to sulcus limitans?
lateral
1st letter: G
General
types of neurons found BOTH in spinal nerves and cranial nerves
1st letter: S
Special
types of neurons ONLY FOUND in cranial nerves NOT spinal nerves
2nd letter: S
Somatic
types of neurons innervating structures derived from somites (skin, skeletal m., cartilage etc.)
2nd letter: V
Visceral
types of neuron innervating:
- viscera: cardiac ms, smooth ms, and glands
- structures derived from or associated with pharyngeal arches
3rd letter: E
Efferent
MOTOR neurons to skeletal, cardiac, and smooth muscle; also secretomotor neurons to glands
3rd letter: A
Afferent
SENSORY neurons
what classifications can be used for spinal nerves
GSA, GVA (pain), GVE, GSE
what classifications can be used for cranial nerves?
GSA, GVA (reflex), GVE, GSE
SSA, SVA, SVE
what carries pain, temp, and mechanical info from receptors in skin, muscles and joints
General Somatic Afferent (GSA)
what carries sensory info from receptors in visceral structures (pain/reflex)
General Visceral Afferent (GVA)
what contains preganglionic autonomic fibers
General Visceral Efferent (GVE)
(typically the para/sympathetics)
what innervates skeletal muscle (alpha and gamma motor neurons)
General Somatic Efferent (GSE)
(something you control)
what supplies special senses of vision, auditory sensation and vestibular (balance equilibrium) apparatus?
Special Somatic Afferent (SSA)
what supplies chemical senses of taste and smell?
Special Visceral Afferent (SVA)
what innervates striated ms derived from pharyngeal arches?
Special Visceral Efferent (SVE)
CN in telencephalon
CN I - olfactory
olfactory receptor neuron is derived from ___
nasal placode
olfactory bulb is derived from ___
telencephalon
what type of neurons are the olfactory receptor
bipolar neurons
where are olfactory receptors found
within olfactory epithelium lining the superior nasal chonca
axon bundles from the olfactory nerve penetrate the ___ and synapse with ___ in the ___.
cribiform plate; mitral and tuft cells; olfactory bulb
CN in diencephalon
CN II - optic
what is CN II derived from?
Optic vesicle (outpouching of diencephalon)
CN in midbrain
CN III - oculomotor
CN IV - trochlear
where does CN III emerge from
interpeduncular fossa - space between cerebral peduncles