Unit 2 Intro to Neuro Flashcards
Nervous System Function
- React to continuous changes in internal & external environment
- Controls & integrates bodily activity
Nervous System Cells
- Neurons
- Neuroglia
Neuron Types
- Multipolar motor neuron
- Pseudounipolar sensory neuron
Neuroglia
- Non-excitable cells
- 5x abundant as neurons
- Support cells for neurons
CNS Neuroglia Characteristics
- Several myelin sheaths
- Myelinates sections of several axons
- Nucleus in cell body
PNS Neuroglia Characteristics
- Single wrappings around neurons
- Forms 1 myelin sheath
- Myelinates 1 sections of an axon
- Nucleus part of myelin sheath
Neuroglia CNS Cells
- Oligodendroglia
- Astrocytes
- Ependymal
- Microglia
Neuroglia PNS cells
- Satellite
- Schwann
Motor Neuron Cell Body Function
- Integrate signals
- Decision to send action potential
- End of axon
Motor Neuron Dendrites Function
- Collect information from cell body
- Synapse with other neurons
Motor Neuron Axon Function
- Connects cell body to periphery
- Transmits signal
Motor Neuron Axon Hillock Function
- Trigger zone
- Sum information together
Motor Neuron Communication
- Brain to periphery
Motor Neuron Locations
- ANS
- Skeletal muscle
Sensory Neuron Communication
- Periphery to brain
Sensory Neuron Cell Body
- Middle of axon
Sensory Neuron Dendrites
- Connect directly to axon
CNS Multiple Sclerosis
- Slow progression
- Onset between ages 20-50
- Decreases life expectancy by 7-14 years
- No cure, possibility of remission
- Oligodendrocytes won’t repair
- Secondary demyelination
PNS Guillain-Barré Syndrome
- Rapid progressions (days/weeks)
- Effects any age (more common 40+)
- 80-90% recover within 2-4 weeks
- Schwann cells dedifferentiate, proliferate
- Remyelinate bare axons over time
Trigger Zone
- Multiple stimuli sum to initiate action potential
- Received through dendrites
Conduction Velocity Factors
- Fiber diameter
- Myelination
PNS Components
- Cranial nerves
- Spinal nerves
- Ganglia
- Enteric plexuses
- Sensory receptors
Sensory Information Pathway
- Come in through peripheral NS
- Travel up spinal cord
- Arrive at central NS
Motor Information Pathway
- Start in brain
- Travel down spinal cord
- Peripheral NS
- Exit body
Somatic Sensory Nervous System
- Sense of touch from body
- Goes to peripheral NS
Autonomic Nervous System
- Goes to peripheral NS
- Involuntary feedback
Somatic Motor System
- Voluntary control
- Goes to peripheral NS
- Skeletal muscle
Autonomic Motor System
- Visceral motor
- Heart rate
- Goes to peripheral NS
CNS Grey Matter
- Cortex
- Nucleus
PNS Grey Matter
- Ganglion
CNS White Matter
- Axons with myelin sheath
- Pathways
PNS White Matter
- Axons with myelin sheath
- Nerves