Neuroanatomy Flashcards
Lateral Spinothalamic Tract (function, receptors, path, lesion)
- Pain and temp
- Free nerve endings
- Ascends in lateral column of spinal cord (decussates at anterior commissure immediately); goes to sensory cortex in parietal lobe
- Lesion causes loss of pain and temp (half spinal cord will cause contralateral loss below level and ipsi at level)
Anterior Spinothalamic Tract (function, receptors, path, lesion)
- Crude touch and pressure
- Merkel’s discs and Ruffini corpuscles and free nerve endings
- Ascends in anterior white column (decussates immediately); goes to sensory cortex
- Half lesion = ipsi loss at level and contra below
Dorsal Columns (function, receptors, path, lesion)
- Fine touch, conscious proprio, vibration
- Pacinian corpuscles, Merkel’s discs, Meissner’s
- Ascends in dorsal column and crosses in medulla to go to sensory cortex
- Lesion below medulla = ipsilateral loss; above medulla = contra loss
Lateral Corticospinal (function, path, lesion)
- Primary motor
- Descends from primary motor and crosses in pyramids; synapses in anterior horn in spinal cord to alpha motor neuron
- Lesion above medulla = contralateral loss
Anterior Corticospinal (function, path, lesion)
- Primary motor (10% that cross at level of innervation)
- Travel in ventral white column
- Lesion of half the cord = loss of 10% contralaterally
Olfactory Nerve (function, test, damage)
- Smell
- Introduce non irritating smells to one nostril at a time
- Anosmia (inability to detect smells; seen in temporal lesions)
Optic Nerve (function, test, damage)
- Vision
- Visual acuity, peripheral vision
- Blindness, honomynous hemianopia
Oculomotor Nerve (function, test, damage)
- Motor - inferior oblique and medial, superior and inferior rectus, levator palpebrae
Autonomic - sphincter papillae and cilliary muscles (pupillary reflex) - Look at pupil size, shape, equal, light reflex, follow finger
- Absence of pupillary reflex, unequal pupils, pupil dilation
Trochlear Nerve (function, test, damage)
- Superior oblique muscle
- Test with oculomotor nerve, isolated eye movements
- Eyes can’t look down when adducted
Trigeminal Nerve (function, test, damage)
V1 - ophthalmic - sensory for scalp and forehead
V2 - maxillary - sensory for area below eyes and above mouth
V3 - mandibular - sensory for lower lip, chin, jaw, muscles of mastication
- Pain and light touch on face, open and close against resistance
- Numbness, weakness of mastication, jaw deviation when opened to ipsilateral side
Abducens Nerve (function, test, damage)
Motor - lateral rectus
- Observe eye position
- Eye pulled inward, can’t look out
Facial Nerve (function, test, damage)
Sensory - taste from ant 2/3 of tongue
Motor - muscles of facial expression
Autonomic - parasympathetic control of lacrimal, nasal mucosal, submandibular and sublingual glands
- Motor function of facial muscles looking for asymmetry
- Bell’s palsy (LMN = ipsi; UMN = conta)
Vestibulocochlear Nerve (function, test, damage)
Sensory - hearing, head position in space
- Examine balance, gaze stability, auditory
- Can cause vertigo, disequilibrium, nystagmus, deafness, tinnitus
Glossopharyngeal Nerve (function, test, damage)
Sensory - touch and taste post 1/3 of tongue, visceral sensory from carotid bodies
Motor - pharyngeal muscle
Autonomic - increase secretion from parotid salivary gland
- Voice quality, swallowing, uvular deviation, gag reflex
- Dysphonia, dysphagia, absent gag reflex
Vagus Nerve (function, test, damage)
Sensory - visceral sensation
Motor - pharyngeal and laryngeal muscles and muscles at base of tongue, elevates soft palate, controls uvula
Autonomic - smooth muscle/glands of heart, lungs, larynx, trachea and most abdominal organs
- Test with glosso
