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 & Control 1. Receive info (stimuli) 2. Computes info  determines responses 3. 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