Neuro essentials Flashcards
CN I
Olfactory nerve
Sensory
Lies in the forebrain
Exits skull at cribiform plate
CNII
Optic nerve (vision)
Lies in the forebrain
Exits at the optic canal
CNIII
Oculomotor nerve
Motor: general somatic - innervate extraocular muscles (superior, medial, inferior rectus, levator palprae superioris)
Parasympathetic: general visceral - synapses with ciliary ganglion, pupillary constriction, lens accommodation)
Nuclei (emerges from) the midbrain
Exits skull at superior orbital fissure
CNIV
Trochlear nerve.
Motor: Innervates the superior oblique muscle of the eye.
Emerges from the midbrain
Only cranial nerve that dessucates. Fibres pass around the periaqueductal grey matter to the eye.
Exits skull via superior orbital fissure
CN V
Trigeminal nerve
Sensory: Sensation of the face, mouth, anterior 2/3 of the tongue
Motor: muscles of mastication
Emerges from the middle of the pons
V1: exits at superior orbital fissure
V2: Foramen rotundum
V3: exits foramen ovale
CNVI
Abducent nerve
innervates lateral rectus muscle of the eye
Nuclei lies in the pons
Exits skull via superior orbital fissure
CNVII
Facial nerve
Sensory: external auditory meatus and taste from the anterior 2/3 of tongue
Motor: Muscles of facial expression, stapeidus muscle and part of digastric muscle
Parasympathetic: Lacrimal glands and salivatory glands (except parotid)
Exits skull at stylomastoid foramen
CNVIII
Vestibulocochlear (balance and hearing)
Nuclei on lateral part of the pons
Exits skull via the auditory canal
CN[IX]
Glossopharyngeal nerve
Sensory: Sensation from the EAM, Middle ear, pharynx and posterior 1/3 of the tongue. Taste from posterior 1/3 of the tongue. Chemoreceptors and baroreceptors from carotid bodies
Motor: stylopharyngeus
Parasympathetic: parotid gland
Nuclei in the medulla. Exits skull via jugular foramen
CN[X]
Vagus nerve
Sensory: Sensation from pharynx, infratentorial meninges and region near external auditory meatus. Taste from epiglottis and pharynx and chemo and baroreceptor information from aortic arch
Motor: Pharyngeal and laryngeal musculature
Parasympathetic: Innervation of heart, lungs and gastric system (upper 2/3)
Arises from the medulla, exits skull via the jugular foramen
CN[XI]
Accessory nerve
Motor: Innervate sternocleidomastoid and trapezius
Fibres converge and ascend through the foramen magnum and exits the skull via the jugular foramen.
CN[XII]
Hypoglossal nerve
Innervates muscles of the tongue
Exits via the hypoglossal canal
Dysfunction of the nervous system can manifest as
Loss- sensation or function Gain- appearance of a new feature e.g. Twitch, squint Change- alteration in behaviour/personality or changes in perception
Dysfunction of the nervous system can occur through
Damage through trauma or disease Transmitter dysfunction Effector organ dysfunction
Motor region of brain
Frontal lobe
Parietal lobe
Sensory region
Occipital lobe
Visual region
Language region of the brain
Temporal lobe
Limbic system
Learning and memory
Transmitters of the sympathetic system
Preganglionic - Ach Postganglionic - Ach & Nor
Transmitters of the parasympathetic nervous system
Per and postganglionic - Ach
Organisation of motor control
Cortical regions - planning and control Cerebellum and basal ganglia - fine tuning, corrections Descending tracts - control of reflexes Lower motor neurons - final common pathway
Precentral gurus
Primary motor cortex: controls voluntary movements of the body
Postcentral gyrus
Primary sensory cortex: site of sensory integration from the ody
Brodmann’s areas
Regions of the brain that can be defined according to their cerebral structure
Function of the CSF
Provides support, cushioning, transport
Features of sympathetic nervous response
“Fight of flight” responses Increased heart rate and blood pressure Decreased gut motility and relaxes bladder Relaxes bronchi Dilates pupils Inhibits salivation and tears Directs blood flow to voluntary muscles
Feature of parasympathetic response
Decreases heart rate and blood pressure Increases gut motility Contracts bronchi Stimulates digestion Contracts bladder Constricts pupil Stimulates salivation and tears Eliminates ingested food and water
Define dermatome
Area of skin innervated by dorsal roots of single spinal segment. Dermatomal map used clinically to determine and identify spinal segment damage
Cerebellum
Sequencing and coordination of movement
Brainstem
Control of vital life-preserving primitive functions such as breathing, heartbeat and blood pressure
Frontal lobe
Personality, reasoning, planning, parts of speech, movement, emotions, problem solving
Somatic nervous system
Part of the PNS that controls involuntary actions
Autonomic nervous system
Part of PNS that controls voluntary movement
Drug that activates the sympathetic nervous system
Activates epinephrine
Antagonist of peripheral nervous system
Atropine
Action of beta blockers
Oppose sympathetic nervous system by blocking beta-type adrenoreceptors.
Describe the knee jerk reflex
Striking the patella ligament stretches the quadriceps (extensor) muscle.
Sensory neurons rely information back to the spinal cord (L4), This produces an efferent impulse in motor neurons that supply the quadriceps femoris, causing it to contract.
Sensory neurons also synapse with interneurons that inhibit motor neurons supplying the hamstring muscle which causes it to relax. This jerks the lower leg up.
