Anatomy Flashcards
What are the layers of the meninges?
Pia mater
Arachnoid mater- CSF
Dura mater- 2 layers, one on skull and one on brain
What secretes CSF?
Choroid plexus in lateral ventricles, third and fourth ventricles
What is the blood supply of the dura mater?
Middle meningeal artery- susceptible to injury (epidural hematoma) because located at weakest point of skull
Falx Cerebri
Reflection of dura mater- hard
Tenotorium cerebelli
Hard reflection of dura mater
Basal ganglia
Function: initiation and modulation of movement
Receives and relays info back to cerebral cortex
Includes caudate nucleus, globus pallidus, putamen
Basal ganglia
Function: initiation and modulation of movement
Receives and relays info back to cerebral cortex
Includes caudate nucleus, globus pallidus, putamen
Dorsal horn spinal cord
Where sensory fibers go in grey matter
synapse in dorsal root ganglion
Ventral horn spinal cord
Where efferent motor fibers go, and have their cell bodies
Spinal nerves
31 pairs mixed afferent (posterior) sensory and efferent (anterior) motor
Corticospinal pathway
Major descending tract of somatic motor system
Upper motor neuron: motor cortex to spinal cord via internal capsule, crosses
Lower motor neuron: spinal cord to body
Corticobulbar pathyway
Descending tract of somatic motor system
Upper motor neuron: motor cortex to cranial nerves
Lower motor neuron: cranial nerves to facial muscles
Horizontal pathways
Descending pathway of somatic motor system
Cerebellum and basal ganglia modulate the motor system
Basal ganglia
Initiation and modulation of movement
Caudate nucleus, putamen, globus pallidus
substantia nigra
Upper motor neuron lesion findings
Increased muscle tone Increased tendon reflexes Babinski sign Clonus No wasting
Lower motor neuron weakness
Decreased muscle tone No clonus Decreased or absent tendon reflexes Muscle wasting Fasciculations
Olfactory Nerve
Cranial Nerve 1
forebrain to olfactory bulb
No associated brainstem nuclei
Optic Nerve
Cranial Nerve 2
forebrain to optic canal, split at optic chiasm (pituitary!)
Occulomotor nerve
Cranial Nerve 3
Innervates: superior, medial, inferior recti, inferior oblique muscles, levator palpebrae superioris
Parasympathetic to spincter pupillae and ciliary muscles
Close to pituitary and carotid
Affected by intracranial pressure
Trochlear nerve
Cranial Nerve 4
Innervates: superior oblique muscle
Pathway: dorsal aspect of brainstem
Susceptible to head trauma injury: vertical diplopia and head tilt
Trigeminal nerve
Cranial Nerve 5: emerges from pons
Somatic only
V1: opthalmic branch- sensory top half of face, corneal reflex
V2: Maxillary branch: face over maxilla, upper teeth, palate
V3: mandibular branch: face over mandible, lower teeth, motor muscles mastication
Medullary pyramids
Spot in medulla oblongata that motor system decussates
Medial lemniscal system
Function: discriminative touch, vibration, proprioceptio
First order neutron: skin to spinal cord
Second order: crosses behind medullary pyramids to medial lemniscus to thalamus
Third order: thalamus to primary sensory cortex
When you break the cribiform plate what are you worried about?
Damage to olfactory nerve
Abducens nerve
Cranial nerve 6 Emerges from pons Pass through superior orbital fissure Innervates lateral rectus muscles Mass lesion may cause double vision due to medial deviation of eye
Facial nerve
Cranial nerve 7: nuclei in pons to face via stylomastoid foramen, through parotid gland
Motor: facial expression
Sensory: taste anterior 2/3 of tongue and palate (special sensory)
Vestibulocochlear nerve
Cranial nerve 8
Hearing, equilibrium
Glossopharyngeal nerve
Cranial nerve 9
Sensory: Posterior third of tongue taste
Posterior pharynx
Parasympathetic: parotid gland
Vagus nerve
Cranial nerve 10: nucleus in medulla
Motor: muscles of larynx and esophagus
Parasympathetic: thoracic, foregut, midgut
Sensory: visceral sensation in abdomen
Spinal accessory nerve
Cranial nerve 11
Sternocleidomastoid and trapezius
Hypoglossal nerve
Cranial nerve 12
Tongue muscles
