Central Nervous System - Nov. 25th Flashcards
Mastery
Afferent and Efferent Neurons
which way, where are dendrites, terminal end, start, where synapse
EFFERENT: what type of nerves and where
GANGLIA
Afferent neurons (Ascending)
Dendrites in periphery
Terminal end in CNS
- end in CNS
- only synapse in CNS
Efferent neurons (Descending)
Dendrites in CNS
Terminal ends in periphery
Interneurons - all in CNS
- START in CNS
- Only synapse in CNS
99% of all neurons
Only autonomic nerves have synapses
outside the CNS
- ganglia, SYNAPSE IN GANGLIA
GLIAL cells. How many and what volume, what do they do?
Glial Cell Types
NEUROGLIA
What do astrocytes do?
Make up 90% of CNS cells and ~1/2 the
volume
Support cells
Physical and metabolic support for the CNS
Glial Cell Types
AMEO
Astrocytes, Microglia, Ependymal cells Oligodendrocytes
**Microglia
* Immune cells
* Protect from pathogens
Astrocytes
Hold neurons in place
General maintenance of space
* Metabolic support and repair
Helps form blood-brain barrier
Myelin uses and where, what are they produced by?
Ependymal Cells. What do they line? Secrete, made where? Functional uses? Where does it flow and absorbed by?
Myelin
Increases conduction velocity
Secreted by Schwann cells in PNS
Secreted by oligodendrocytes in CNS
Ependymal Cells
- Ciliated epithelial membrane lining ventricles
- Secrete cerebrospinal fluid (CSF)
- Shock absorption
- Nutrients
- CSF made in choroid plexus
- Flows through ventricles, into sub-arachnoid space, Absorbed – arachnoid villi
Electroencephalogram (EEG). Summation of what
different types of Brain waves
when we sleep what do we alternate between
what occurs in REM
External recording of brain wave patterns
Summation of AP’s, EPSP’s, and IPSP’s
ABTD
Alpha: Lower frequency, Relaxed state (eyes closed)
Beta: Higher frequency, Alert and concentrating
Theta: Light sleep
Delta: Deep sleep (eg. Babies)
Alternate between non-REM and REM sleep
Stage 1→4→1 NR. ALPHA TO THETA TO DELTA, then back. Then REM sleep. Back to Non-REM. back to stage one is REM
Non – REM sleep (4 stages)
- Rest and repair
- Theta and delta waves
REM sleep
- Dream state
- Rapid eye movement
- Problem solving
- Reverse learning
- - Elevated breathing and HR
Beta waves
Comparison of slow wave and paradoxical sleep (just a table turn over and look)
What are association areas
Speech Areas
Limbic System
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
- Emotion, Learning and Memory
- Hippocampus. Learning and memory
- Inputs to hypothalamus
Short term vs Long Term Memory. Capacity, retrieval, trace.
Transfer from STM to LTM
Memory - Habituation and Sensitization
Short term
- Limited capacity
- Fast retrieval
- Temporary neural trace (minutes to hours)
Long term
- Huge capacity
- Slower retrieval
- Permanent neural trace. days to years
Relates to past events and memories
Emotional response related to memory
Repetition
Sleep
Exercise and diet
Habituation
- Decreased response to repeated what you don;t care type of stimuli
- Decreased calcium at synapse
Sensitization
- Increased response to mild stimuli
- More calcium released at the synapse
Eg. Emotional response involved
Spinal Cord
Two vital functions
sensory input from where. Motor output from where
Grey and White Matter
Neuronal link between brain and PNS
Integrating center for spinal reflexes
- Sensory input via the dorsal root
- Motor output via the ventral root
Gray matter
- Unmyelinated nerve cell bodies.
- Dendrites of EFFERENT
- Axon terminals of AFFERENT
White matter. FAST TRACT
- Myelinated axons
- Contains very few cell bodies
Spinal Reflexes
Protective reflexes
Autonomic Reflexes
Skeletal Muscle Reflexes
Proprioceptors
Alpha motor neurons
Stretch Reflex
what does the GTO do
Faster when brain is not involved
* After-thought message only
Often monosynaptic. No slow synapses!!!
Some visceral reflexes are spinal reflexes. Extra synapse in the ganglion
Proprioceptors
- Golgi Tendon Organ and Muscle spindle
- located in muscle, joints and ligaments. carry input to CNS
Alpha motor neurons
- Carry input to muscle
Stretch of receptor sends AP’s up sensory neuron
Increases firing of motor neuron. Reflex CONTRACTION and get rid of stretch
Prevents over-stretch of the tendon
Triggers reflex relaxation in the muscle. SUDDEN FAIL OF MUSCLE. AUTOGENIC
Withdrawal Reflex
Flexion Reflex and the Crossed Extensor Reflex
Triggered by pain receptor
Synapses with motor neurons to flexors
* Contract to withdraw
Synapses with motor neurons to extensors
* Inhibits
Simultaneous with Crossed Extensor Reflex
Opposite side
* Contraction of extensors
* Inhibition of flexors
PUT WEIGHT ON OTHER LEG AND EXTEND EXTENSORS AND RESTRACT OTHER LEGS( EPSP TO FLEXORS IPSP TO EXTENSORS
Autonomic Nervous System
Autonomic reflexes. Sympathetic NS. Parasympathetic NS
Autonomic reflexes
- Control of cardiac and smooth muscle, and
glands in homeostasis
Sympathetic NS
- Fight or flight. AdrenalinE rush
Parasympathetic NS
Rest and digest
The Hypothalamus, Pons, and Medulla
The Hypothalamus, Pons, and Medulla
Coordination of homeostatic responses
Autonomic
Endocrine
Behavioural
