reticular formation Flashcards
(42 cards)
what are the charecteristics of the functions of the reticular formation
Tasks involve nervous system as a
whole
Functions are integrative
intergrative fucntions of the reticular formation
Sleep, wakefulness, alertness, consciousness
Coordination of visceral functions
(homeostasis)
Responses to pain; pain modulation
Body posture
Mental stat
what is the defintion of the reticular formation
Defined as the gray matter that composes the
core of the brain stem (excluding cranial nerve
nuclei and ascending and descending tracts)
what does the RF consist of
Consists of networks of branched neurons
reticu.ar foramtion is related to ___ ____ ____ ____ in the nervous system
so many other parts
how are the nuclei of the RF defined histologically
not as well defined as other nuclei
what are the afferetn connections of the RF
All sensory systems (not specific)
Many other areas
efferent connections of the RF
- widespread
RF has a ____ function
intergrative
where is RF located in the brain
gray matter in core of brainstem
what size cells does the RF have
- what is the organixation of the dendritic web
Large and small cells
Dendritic web of large cells is oriented
perpendicular to axis of brain stem
what are the charecteristics of the axons of the RF?
- where do they travel
- how many branches?
- how many synaptic connections
- Output neurons have long axons. -
- The axons ascend all the way to the cortex, or descend to the spinal cord.
- They’re wide
spread and have numerous collaterals (branches) along the way. - These axons make a huge number of synaptic connections, and so there are many pathways throughout the body.
what are orientation of of these dendrites
- axons are traverse ( perpenducular) to the long axis of the brainstem
- RF axons/dendrites are picking up info from ascending and descending tracts
Serotonergic pathways
raphe nuclei
- location
- what do they produce
- where do efferent branches reach
- do they have topographic organization ?
Midline of medulla, pons, midbrain
Serotonergic
Efferent branches reach many parts
of nervous system including spinal
cord
Little topographic arrangement
noradrenergic pathways
locus coerulus is located in the causal midbrain and sends projections all over the brain
locus coeruleus
- location
- what does it release
- where fo effernt branches reach
- waht is the arrangement
Near mesencephalic V, under
superior cerebellar peduncle
Noradrenergic
Efferent branches reach many parts
of nervous system
Little topographic arrangement
dopaminenergic pathway
- what releases dopamine
- substantia nigra and tegmentum release dopamine
- they project muptiple places in the brain
Electroencephalogram (EEG)
- sleep conciousnes
- important in understadning sleep and wakefullness
- electrodes record electrical activity og the brain
- pick up corticol actvity and the electrical filter out spikes so youre left with the synaptiv activity of the brain
categories of the EEG waves
beta waves - awake state when the cortex is bust
alpha waves - if you close eyes and relax you get alpha waves
theta waves- falling asleep
Delta- deep sleep
realtionship of EEG frequency waves
- as you fall asleep you get higher amplitude slow frequency and more sychronixationtion and high voltage
- when you are awake they are high frequency and desychranized with low voltage
EEG waves during sleep and
wakefulness
Awake state- high frequency, low
amplitude
Sleep state- low frequency, high
amplitude (synchronized)
rapid eye movement / REM sleep
-a few times during the nigh you go from sychrnized to desycronized and “wake up”
- as it becomes desychrnoized you get REM sleep and dream
-
how deoes REM sleep look like in a EEG
desychronized as if youre awake
