The brain Stem Flashcards
(37 cards)
1
Q
what makes up the brainstem
A
- midbrain
- pons
- medulla
2
Q
autonomic tracts in the brainstem
A
- sympathetic: no modified-strictly passes through
- parasympathetic: axons synpase with parasympathetic nuclei OR pass through
3
Q
What are the longitudinal sections of the brainstem
A
- basilar section
- tegmentum
- tectum
4
Q
Basilar section
general
A
- motor
- in the anterior portion of the brainstem
5
Q
Generally
what is the tegmentum section
as general functions
A
- posterior
- sensory and crainial nerve portions
- adjusts general level of neural activity
- integrates sensory information and cranial nerve function
6
Q
generally
what is the tectum section
A
- midbrain ONLY
- eye reflexes and reflexive head movements
7
Q
What does the basilar section primarily contain
A
motor system structures such as
- descending cortical axons/tracts - motor tracts
- motor nuclei
- pontocerebellar axons
- penduncles connect pons to cerebellum (white matter)
8
Q
what does the tegmentum contain
A
- sensory nuceli
- ascending sensory tracts
- cranial nerve nuclei (sensory and motor)
- reticular formation
- medial longitudinal fasciculus (MLF)
9
Q
What does the tectum contain
A
- only found in midbrain
- structures involved in reflex control of eye and head movement
- pretectal area
- superior colliculus
- inferior colliculus
10
Q
What does the pretectal area do
A
- pupilary light/consenual reflex
11
Q
What does the superior colliculus do
A
- eyes to sound
12
Q
What does the inferior colliculus do
A
- attention to sound
13
Q
What is the reticular formation and what are the main functions
A
complex neural network
functions:
- modulates nociceptive information
- inhibits pain perception
- enhances pain perception - if you should be paying attention to the pain
Regulates:
- somatic motor activity
- autonomic function (HR, breathing)
- consciousness
14
Q
What is the reticular nuceli
made of
A
- ventral tegmental area
- pedunculopontine nucleus
- locus coeruleus
- raphe nuclei
- each area releases a NT that has a specific role and are slow acting
15
Q
Reticular nuclei
ventral tegmental area
A
- found in midbrain
- Neurotransmitter: dopamine
- projects to cerebral areas responsible for motivation, decision making, pleasure/reward
16
Q
Reticular nuclei
what is the ventral tegmental area involved in
A
- dopamin released
- addiction to amphetamines, cocaine, morphine,
- schizophrenia: perception disorder
- obesity: food addiction
17
Q
Reticular nuclei
Pedunculopontine nucleus
A
- midbrain
- projects to cerebral cortex and thalamus
- influences movement
- neurotransmitter: acetylcholine
- involved in parkinsons and freezing of gait
18
Q
Reticular nuclei
locus coeruleus
A
- active when person is attentive/inactive during sleep
- ability to direct attention
- direct inhibition of spinothalamic neurons conveying pain information
- regulation of autonomic functions
- neurotransmitter: norepinephrine
19
Q
Reticular nuclei
raphe nuclei
A
- midline down length of brainstem
- projects to cerebrum, cerebellum, spinal cord
- neurotransmitter: serotonin
functions:
- mood
- modulate neural activity in spinal cord, brainstem, cerebellum
- descending pain inhibition
20
Q
vital function control
what do the areas in the medulla regulate
A
- heart rate
- respiration
- vasoconstriction/vasodilation
21
Q
vital function control
what do areas in the pons regulate
A
- respiration
22
Q
conscioudness
what is consciousness
A
- awareness of self and surroundings
- consciousness system governs alertness, sleep attention
23
Q
consciousness
what are the brainstem components of consciousness system
A
- reticular formation and ascending reticular activating system
- project to cerebral components of consciousness system
24
Q
medulla structures
inferior olivary nucleus
A
- located in medulla
- receives input from motor area in brain and spinal cord
- projects to cerebellum via olivocerebellar tract
- neurons are important for motor learning and timing and control of ongoing movement
25
# medulla structures
solitary nucleus
- medulla
- relay station for taste
- taste from CN 7 and 9 afferents
- autonmic afferents from CNs 9 and 10
26
What is the major difference between upper and lower medulla
- lower medulla has the pyrmids
- more cranial nerves are located in the upper medulla
27
functions of the medulla
coordinates:
- cardiovascular control
- breathing
- head movement
- swallowing
CN nuclei
- IX through XII
- eye movements and head movements in MLF
28
Medial medullar syndrome
| What can cause it? typical presentation
- occlusion of ASA or vertebral arteries
- contralateral UE/LE weakness (motor tracts)
- contralateral decreased position and vibration sense (medial lemniscus)
- ipsilateral tongue weakness (CN XII)
29
Lateral medullary syndrome
- wallenbergs syndrome
- PICA syndrome
- ipsilateral ataxia
- ipsilateral leaning
- vertigo, nausea, vomiting
- decreased pain and temperature on ipsilateral face
- dysphagia/dysphonia CN XII
30
The pons
- between midbrain and medulla
- most vertical tracts pass through pons
31
what tracts DO NOT pass through pons
- corticopontine tracts: synpase on pontine nuclei, axons form pontocerebellar tracts
- corticobrainstem: synpase with trigemeninal motor nucleus, fascial nucleus
32
Structures in the pons
- descending cortical tracts: corticospinal, corticobrainstem, corticopontine
- pontine nuclei: pontocerebellar axons
- spinal nucleus and tract CN V-VIII
33
What is the major difference between the upper and lower pons
- upper CN 5
- lower CN 6-8
34
functions of the pons
- process motor information from cerebral cortex via cerebral penuncle
- forwards information to the cerebellum
- processes sensory information from face
- controls muscles of mastication, eye, abduction, fascial expression (CN V-VII)
35
Common dysfunctions in the pons
- medial pontine syndrome *similar to medial medullary syndrome*
- lateral pontine syndrome *similar to lateral medullar syndrome*
- anterior pons/basilar artery = locked in syndromes
36
functions of the midbrain
- postural control
- control of all eye movements except abduction
- occular reflex control
- orient head to sight and sound
37
what are the main symptoms of brainstem dysfunction
*four Ds*
- dysphagia: difficulty swallowing
- Dysarthria: difficulty speaking
- Diploplia: double vision
- Dysmetria: lacing coordination of movement
