Central Nervous System Flashcards
Ascending and Descending
Ascending is afferent neurons, sensory information from peripheral to CNS. Dendrites in periphery, Terminal ends in CNS
Sensory stimuli or Visceral stimuli (Gut/PH)
Descending is motor commands, efferent neurons, information going from CNS to peripheral. Dendrites in CNS, terminal ends in periphery
- Somatic nervous system (Muscle, motor neuron, skeletal muscle) or Autonomic nervous system (automatic)
-autonomic has sympathetic (fight or flight) or parasympathetic (rest and digest)
Interneuron: all in CNS
-99% of neurons
Efferent Neurons
Only autonomic nerves have synapses
outside the CNS, peripheral
- ganglia synapses found in peripheral
Glial cells and types
Make up 90% of CNS cells and ~1/2 the
volume
Support cells
- Physical and metabolic support for the CNS
Astrocytes, Microglia, Ependymal cells,
Oligodendrocytes
Microglia, astrocytes, Ependymal cells
Microglia: Immune cells
-Protect from pathogens
Astrocytes: Hold neurons in place
-General maintenance of space (ions)
-Metabolic support and repair
- Helps form blood-brain barrier
Ependymal Cells:
-Ciliated epithelial membrane lining ventricles
- Secrete cerebrospinal fluid (CSF)
- Shock absorption (slosh around)
- Nutrients (brings in)
CSF made in choroid plexus
-Flows through ventricles
-Into sub-arachnoid space
-Absorbed – arachnoid villi
Myelin
-Increases conduction velocity
-Secreted by Schwann cells in PNS
-Secreted by oligodendrocytes in CNS
For pain and somatic neurons
Electroencephalogram (EEG)
External recording of brain wave patterns. the internal neural activity in the brain
Summation of AP’s, EPSP’s, and IPSP’s (internal)
Eyes closed, alpha waves
Concentrating, Beta waves
Brain waves
Alpha
- relaxing (eyes closed
- lower frequency
Beta
- awake and concentrating
-higher frequency
Theta, light sleep
Delta, deep sleep
alternate between non- REM and REM sleep
Stage 1→4→1 NR
Then REM sleep
Back to Non-REM
Stage 1, Theta
Stage 4, delta
REM gets longer more you sleep
REM is dream state, beta waves like awake
Sleep patterns
Non – REM sleep (4 stages)
-Rest and repair
- Theta and delta waves
REM sleep
-Dream state
-Rapid eye movement
- Problem solving
- Reverse learning, get rid of info you don’t need
-Elevated breathing and HR
- Beta waves
Sleep medication and alcohol make it harder to get into REM
Association areas and speech areas
Occipital = vision
Sensory = partial
Hearing = temporal
Motor = frontal
Link sensory input and motor output areas
Broca’s area
-Speech
Wernicke’s area
-Speech comprehension
Dyslexia
- Poor connections between visual and language areas
Or between areas
Limbic system and memory
Limbic system - functional zone not a structure
emotion, hearing and memory
Hippocampus- learning and memory
- it inputs into hypothalamus (hormone zone)
Short term vs Long term Memory
In hippocampus
Short term
-Limited capacity
-Fast retrieval
- Temporary neural trace (minutes to hours)
Long term
-Huge capacity
-Slower retrieval
- Permanent neural trace
* days to years
Transfer from STM to LTM
-Relates to past events and memories
-Emotional response related to memory
-Repetition, talk and rewrite
-Sleep
- Exercise and diet
Memory
Habituation
-Decreased response to repeated indifferent stimuli
- Decreased calcium at synapse
-repeated stimulus but not care, decrease response
Sensitization
-Increased response to mild stimuli
- More calcium released at synapse
Eg. Emotional response involved
-intrested in
Spinal cord
Two vital functions
-Neuronal link between brain and PNS
-Integrating center for spinal reflexes
Sensory input via the dorsal root
- coming in
Motor output via the ventral root
-going out
Grey and white matter
Gray matter
-Unmyelinated nerve cell bodies
- Dendrites
- Axon terminals
White matter
-Myelinated axons
-Contains very few cell bodies
