Brainstem (2) Flashcards
What information does the brainstem integrate?
Sensory, auditory, vestibular, and cortical
What does the brainstem regulate?
Somatic motor activity (Reticulospinal tracts for tone, balance, and posture)
Autonomic function (cardiac and vasomotor centers)
What does the brainstem play an important role in?
Sleep and consciousness
What are the red flags for brainstem dysfunction?
Dysphagia
Dysarthria
Diplopia
Dysmetria
What are the reticular nuclei?
Clusters of cell bodies distributed throughout brainstem
What are the types reticular nuclei?
Ventral tegmental area (dopamine)
Pedunculopontine nucleus (acetylcholine)
Locus coeruleus (norepinephrine)
Raphe nuclei (serotonin)
What does the ascending reticular activating system regulate?
Consciousness (sleep/wake cycles and attention)
What are the descending tracts from reticular formation?
Reticular tracts (raphe nuclei)
Cerulospinal tract (locus coeruleus)
Raphespinal tract (raphe nuclei)
What is the role of the reticular tracts?
Posture and gross movement
What is the role of the ceruleospinal tract?
Autonomic function- physiologic response to stress and panic
Alertness
What is the role of the raphespinal tract?
Sensory, autonomic, and motor
(Influence on cardiovascular system and inhibition of pain)
What are the altered states of consciousness?
Coma
Stupor
Obtunded
Vegetative state
Minimally conscious state
Syncope
Delirium
Coma
Unarousabale (no response to strong stimuli)
Stupor
Avoidable only by strong stimuli (strong pinching of Achilles)
Obtunded
Sleeping more than awake (confused when awake)
Vegetative state
Complete loss of consciousness, without alteration of vital functions
What signs distinguish vegetative state from a coma?
Eye opening
Regular sleep/wake cycles
Normal respiratory patterns
Minimally conscious state
Severely altered consciousness with at least 1 behavioral sign of consciousness
What are behavioral signs of consciousness?
Following simple commands
Yes/no responses
Intelligible speech
Movements that are not reflexive
Syncope
Brief loss of consciousness due to drop in BP
Delirium
Reduced attention, orientation, and perception (associated with confusion and agitation)
What responses do you look for in the Glasgow coma scale?
Eye
Verbal
Motor
What does the superior Cerebellar arteries supply?
Superior half of cerebellum and part of midbrain
What does the anterior inferior Cerebellar arteries supply?
Anterior inferior portion of cerebellum
What does the posterior inferior Cerebellar arteries supply?
Posterior inferior portion of cerebellum
What does disruption to the posterior inferior Cerebellar arteries result in?
Lateral medullary syndrome
What is ischemia in the brainstem?
Rapid onset of symptoms (visual disturbance, weakness, incoordination, and somatosensory disturbances)
What is a red flag of vertebrobasilar artery insufficiency?
Neck extended and rotated provokes symptoms
Where is the corticospinal tract in the medulla?
Ventral portion
Where is the spinothalamic tract located in the medulla?
Medial
Where is the spinocerebellar tract located in the medulla?
Lateral
Where are the trigeminal and medial lemniscus located in the medulla?
Ventral and medial
What is the small hole in the middle of the midbrain?
Cerebral aqueduct
What is the function of the red nucleus?
Unconscious coordination of motor activities
What is the function of the pariaqueductal gray?
Somatic and autonomic reactions to pain (fight or flight)
What is the function of the superior tectum?
Orienting eyes to external stimuli
What is the function of the inferior tectum?
Hearing and relating auditory information to the superior colliculi
What cranial nerves is the pons involved in?
5, 6, 7, and 8
