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Neurology
Lecture 1 Part 1
The Final Frontier
• Space the final frontier?
• The brain, the final frontier!
The nervous system consists of:
• The Brain• Spinal Cord• Peripheral Nerves• Divided system
– Central Nervous System (CNS)• Brain & Spinal Cord
– Peripheral Nervous System (PNS)• Nerves (peripheral &
Cranial)
Nervous System
• Controls and coordinates all parts of the body
• By transmission of electrical impulses (Electrical-chemical system)
Purpose of the Nervous System
• Control Center• Communication
Receive evaluate respond
• Stimulation of Movement
• Maintains Homeostasis– Along with the what
system?• Endocrine
Function of Nervous System
• Coordination & Control1. Receive info (stimuli)2. Computes info
determines responses3. Transmit info action
Neuron
• Basic functional unit– Afferent neuron
• Sensory• Carry info from PNS
CNS– Efferent neuron
• Motor• Carry into from CNS
PNS
Neuron structure
• Cell body/ Soma– Nucleus
• Dendrites– Carry impulses toward
the cell body
• Axons– Carry impulses away
from the cell body
Damaged Neuron
• CNS = – Irreversible
• PNS = – will repair itself if the
cell body is not destroyed
Synaptic Junction
• Neuron connect to each other end to end
• Where two neurons come together– Synaptic junction– Synapse– Inter-neuron space
Synaptic Junction
• Terminal end of Axon = Synaptic Vesicles
• Nerve impulse reaches the vesicle release substance neurotransmitters into the synaptic junction
• Nerve impulses must have a receptor site
Neurotransmitters
• Synthesized in the soma
• Special Properties– Excitability – Inhibitory– Modify
• 30+ neurotransmitters
Excitatory Neurotransmitters
• Serotonin– Sleep– Sensory perception– Temperature– Mood– Inhibits pain
Excitatory Neurotransmitters
• Dopamine– Gross subconscious
movement– Fine motor skills– Emotional responses
Excitatory Neurotransmitters
• Norepinepherine– Maintains arousal – Overall activity– Mood
• Acetylcholine– Vital for short term
memory– Speeds impulse
transmission
Inhibitory Neurotransmitters
• Cholinergics– Stabilizers– Inhibitors
• GABA• Dopamine
– Basal Ganglia– Acetylcholine &
Dopamine are opposites which work together to create homeostasis
Neuropeptides
• Not neurotransmitters• Encephalin• Chemical endorphins
– Suppress pain– Memory– Learning– Sexual activity
Nerve Impulse
• The nervous system is powered by electrical and chemical energy– K+– Na+– Cl-– (Ca+)
Nerve Impulse
• Absolute retraction period– The time interval
phase that occurs when the neuron cannot be re-stimulated