PP 52-63 Unit 1A

Central Nervous System

The Brain and Spinal Cord

Peripheral Nervous System

Connects the CNS to the rest of the body and is subdivided between the Autonomic N.S and Somatic N.S

Autonomic Nervous System

Involuntary (Automatic) actions, subdivided between the Sympathetic N.S and Parasympathetic N.S

Somatic Nervous Systen

Voluntary actions, connects the CNS to skeletal muscles

Sympathetic Nervous System

“Flight or Flight” (Arousing)

Parasympathetic Nervous System

Returns to Normal State (Calming)

Neurons

Basic building block that receives, processes, & transmits info to other cells

Glial Cells

Provide nutrients and Myelin, cleans up waste, guides connections, and are involved in learning, thinking and memory

Threshold

The amount needed for an action potential to fire off

Myasthenia Gravis

Produces antibodies that block or destroy receptor sites on dendrites (specifically ACh)

Sensory Neurons

Carries messages from sensory receptors to the CNS

Motor Neurons

Carries messages from the CNS to the muscles and glands

Interneurons

Relay messages between nerve cells (within)

Reflex Arc

Spinal Cord reflex pathway, Includes the Sensory Neurons, Interneurons, & Motor Neurons

All-or-nothing Principle

Fires off completely the same every time

Depolarization

Pores opening to allow intake of positive ions, changes progress down axon

Resting Period

Period that the axon has a slightly negative charge

Refractory Period

A short intermission of the Neuron, where it cannot fire off, regaining a negative charge

Reuptake

Sending Neuron takes back neurotransmitters for reuse

Multiple Sclerosis

Deterioration of the Myelin Sheath, slowing of messages between brain and muscles

Dendrites

Branches that carry info into the neuron

Soma/Cell Body

Contains the nucleus and keeps the cell alive

Axon

Sends messages away from the neurons cell body

Myelin / Myelin Sheath

Fatty Tissue that insulates the axon and speeds up the impulse

Axon Terminal Buttons/ Synaptic end bulbs

Contain neurotransmitters

Neural Impluse / Action Potential

Impulse caused by change in electrical charge across axon

Agonist

Antagonist

Endocrine System