Highlights Chapters 14-15 Flashcards
What are the 4 main groups of things found in the brainstem?
1) Cranial nerve nuclei and related structures
2) Long tracts
3) Cerebellar circuitry
4) Reticular formation and related structures
1) Descending sympathetic pathway runs through what?
2) What does damage to this cause?
1) Runs through lateral brainstem
2) Horner’s Syndrome
In Locked-In-Syndrome:
1) Motor function is ________
2) Sensation and cognition are ________
3) What two tracts are affected?
1) Absent
2) Intact
3) Corticospinal and corticobulbar
True or false: Locked-In-Syndrome is a type of coma
False; they’re different
1) What is the end goal of the rostral end of the reticular formation?
2) What is the end goal of the caudal end of the reticular formation?
1) The rostral end functions to maintain an alert conscious state.
2) Carry out motor reflex and autonomic functions
List and define the 3 processes that control the levels of consciousness
1) Alertness: normal functioning of the brainstem and arousal circuits
2) Attention: same circuits as above plus the frontoparietal association cortex
3) Awareness: a combination of multiple higher order systems from different regions of the brain into a summary of mental activity that can be remembered at a later time
What activates the 5 arousal systems that maintain normal consciousness?
Reticular formation and related structures that receive input from sensory pathways
Numerous regions of the ___________ project to the reticular formation so that _______________________ can lead to an increased level of alertness through this system.
association cortex; cognitive processes and emotions
1) Is glutamate excitatory or inhibitory?
2) What does GABA promote?
1) Excitatory
2) Deep sleep
1) What NT causes muscle contraction?
2) What disorder involves this NT?
1) Acetylcholine
2) Myasthenia gravis
What does dopamine cause and act on?
Causes feelings or pleasure, satisfaction and motivation. Works on reward center.
What is an NT used in sympathetic response?
Norepinephrine
What NT functions in attention?
Norepinephrine
Which NT is sometimes referred to as the “feel good” chemical?
Serotonin
What is histamine used to regulate?
Alertness and wakefulness
Most histamine in the body is found outside of the CNS in __________ playing a role in _______________________________
mast cells; immune responses and allergic reactions
1) Histamine outside the CNS is found where?
2) What does it play a role in here?
1) In mast cells
2) Immune responses and allergic reactions
1) Unarousable, unconsciousness with closed eyes has to last how long to be considered a coma?
2) What is it a dysfunction of?
1) > 1 hour
2) Upper brainstem reticular formation
If the __________________ is spared, consciousness is typically spared
reticular formation
What is a very important thing to include in an exam of a patient in a coma?
Check their pupils
Define dissociative state. What neurologically is wrong?
Non-responsiveness (but not unconscious) from severe emotional trauma, neuro exam is normal
Patients with Akinetic Mutism, Catatonia display what?
Profound deficits in response to initiation
Define brain death
Based on clinical exam: no evidence of forebrain or brainstem function; no sleep-wake cycles
What does the Pre-Botzinger Complex of the medulla do?
Pacemaker for respirations
What do the Phrenic nerve efferents do?
Control diaphragm during inspiration
What can lesions in the medulla lead to?
Respiratory arrest and death
1) Where is the nucleus solitarius?
2) What is it? Where does it get input from?
1) In the medulla
2) Cardiorespiratory nucleus (controls heart rate and BP); receives inputs from baroreceptors in carotid body and aortic arch via CNs 9 and 10
What type of lesions typically cause uncoordinated movements called ataxia?
Cerebellar
What do the inferior vermis and flocculonodular lobes of the cerebellum do?
1) Regulate balance (proximal trunk muscle control)
2) Interact with vestibular circuitry (vestibulo-ocular control)
What do the anterior lobes of the cerebellum do?
Responsible for proprioception
What do the intermediate cerebellar regions do?
Control distal limbs
What do the lateral cerebellar hemispheres do?
Motor planning of distal extremities
Deficits in coordination occur ___________ to the lesions of the cerebellum
ipsilateral
What do medial cerebellar lesions do?
Affect the trunk muscles bilaterally
The cerebellum is attached to the ____________ and ________________ by 3 ________________.
dorsal pons and rostral medulla; peduncles
Name 2 things vermis or flocculonodular cerebellar lobe lesions affect
1) Unsteady gait
2) Trunk control
Where are the cerebellar tonsils found?
Inferior surface
What connect the cerebellum to the brainstem?
The peduncles: superior, middle and inferior
What are the conditions for something to be a coma
1) Unarousable (even with sternum rub, smelling salts, etc)
2) Unconsciousness with closed eyes
3) For greater than 1 hour
What 3 things should you give via IV to a patient in a coma?
Thiamine, glucose and naloxone
Melatonin is produced by what? In what pattern?
Pineal gland; circadian pattern
What condition does a patient appear fully awake, but not respond?
Akinetic Mutism, Catatonia
What state is caused by emotional trauma and accompanies a normal neuro exam?
Dissociative
What is required to declare brain death?
Clinical exam
What type of unconscious state involves sleep-wake cycles and other responses or reflexes?
Vegetative state
Aneurysm of posterior communicating artery can cause what?
CNIII palsy
During the pupillary light reflex, after the fibers synapse at the superior colliculus, where do they go? What does this contain?
Edinger–Westphal nuclei; contain preganglionic parasympathetic neurons
Where is the Pre-Botzinger Complex?
In the medulla
1) Heart rate and BP are controlled by what?
2) What does this place receive input from?
1) Nucleus solitarius (of medulla)
2) Baroreceptors in carotid body and Aortic arch (via CNs 9 and 10)
What controls the proximal trunk?
Vermis
1) What part of the cerebellum does proprioception?
2) What does motor planning of distal extremities?
1) Anterior lobes
2) Lateral cerebellar hemispheres
Name 1 thing in the medulla
Respiratory pacemaker
True or false: the 4th ventricle is found in the brainstem
False; stops at the brainstem
What is the role of the reticular formation?
Coordinating vital functions
What 3 nerves play a role in mediating vestibulo-ocular reflexes?
CNs 3,4, and 6
Damage to the descending sympathetic pathway that runs through the lateral brainstem can cause what symptoms?
Ptosis, miosis, anhidrosis
What is formed by the fronto-parietal association cortex with the arousal circuits in the upper brainstem?
Consciousness system
Which condition causes an autoimmune antibody block of acetylcholine receptors on skeletal muscle?
Myasthenia gravis
Having too much of what neurotransmitter would be a finding in schizophrenia?
Dopamine
Having too little of what neurotransmitter would cause depression, inattentive/ ADD?
Norepinephrine
What area of the brainstem is thought to contain sleep promoting regions?
Medulla’s Reticular formation
Upper brainstem reticular formation dysfunction can cause what?
Coma
Akinetic Mutism/catatonia may improve a deficit in response to initiation by what?
Dopamine agonist
How does a vegetative state differentiate from brain death?
1) Can have sleep wake cycles
2) Possible brainstem reflexes
3) May make sounds
An aneurysm of the posterior communicating artery most commonly causes what?
CN 3 palsy
Where are preganglionic parasympathetic neurons of the optic tract located?
Edinger-Westphal nuclei
A patient who is in what kind of coma would have small but light responsive pupils bilaterally?
Pontine lesion
Which area of the brainstem is involved in controlling heart rate and BP and receives inputs from baroreceptors in the carotid body and aortic arch via CN IX and X?
Nucleus solitarius
What gives rise to many branches that supply the brainstem and cerebellum?
Vertebrobasilar system
What is the most medial functional portion of the cerebellum called?
Vermis
What area of the cerebellum is responsible for regulating balance and vestibulo-ocular control?
Inferior vermis and flocculonodular nodes
1) What function is the anterior lobes of the cerebellum responsible for?
2) What function is the intermediate cerebellar region of the cerebellum responsible for?
3) What function is the lateral cerebellar hemispheres of the cerebellum responsible for?
1) Proprioception
2) Control of distal limbs
3) Motor planning of distal extremities
1) Deficits in coordination occur _______ to cerebellar lesions, while medial lesions affect the trunk muscles __________.
2) A lesion where would cause unsteady gait, trunk control, posture, and balance?
1) Ipsilaterally, bilaterally
2) Vermis/Flocculonodular nodes
