Nerve system more like KMS (copy)

Neuron

Nerve cell that is specialized for intracellular communication

Consists of cell body, axon, and dendrite

Neuroglia or Glial Cell

Cells of the neuron system that support and protect neurons

Central Nervous System

consists of the brain and spinal cord

Peripheral Nervous System

Consists of cranial and spinal nerves and other nervous tissue outside the CNS

Afferent division of the PNS

Sensory tracts that carry information to the CNS

Efferent division of PNS

Motor tracts that carry information away from the CNS to the effector (muscles, glands or adipose tissue)

Receptors

Sensory structures that detect changes or stimuli

Effectors

A gland, muscle or adipose tissue that is innervated by a neuron and produces a response when stimulated.

Somatic nervous system

Efferent division of the nervous system

Controls voluntary skeletal muscle

Autonomic Nervous System

Provides automatic regulation of smooth muscle, cardiac muscle, and granular secretions.

Division of the PNS

Sympathetic

Dominates in stressful situations

fight or flight

Parasypathetic

Dominates in relaxing or non-stressful situations

Rest and Digest

Cell body

contains the nucleus

Dendrite

A cellular process that carries impulses toward the cell body

Axon

Cellular process that carries impulses away from the cell body

Synapse

Site of communication between a neuron and another cell

Neurotransmitter

Chemicals released by a neuron that affect the transmembrane potential of another cell

Neuromuscular Junction

Synapse between a neuron and a muscle cell

Neuroglandular Junction

Synapse between a neuron and gland neuron regulates the glandular activity

Synaptic terminal or Synaptic Knob

Enlarged or rounded end of axon. Axon terminal

Presynaptic membrane

Membrane where the neurotransmitters are released

Postsynaptic membrane

Membrane which contains receptors for the neurotransmitters.

Sensory Neurons

Carry information towards the CNS from receptors

Motor Neuron

Carry impulses away from the CNS to effector

Interneuron

An association neuron found within the CNS

Gangila

Group of cell bodies outside the CNS, part of the PNS

Epedymal Cells

Line the ventricles and central canal of the CNS

Astrocytes

Helps maintain the blood brain barrier

Oligodendrocytes

Produce myelin in the CNS

Microgila

Phagocytic cells of the CNS

Myelin

Insulting sheath around an axon or dendrite.

Increases speed of conduction

Nodes of Ranvier

Unmyelinated areas between the myelin sheaths

Intermode

Areas of axon or dendrite that are wrapped in myelin.

Satellite cells

Neurological cells found in the PNS and help regulate the environment around a neuron

Shwannn Cells

Neurological cells in the PNS which produce myelin.

Demyelination

Progressive destruction of the myelin sheaths of the nervous system

Causes: Heavy Metal poisoning, MS, diphtheria

Saltatory Conduction

Skipping or jumping of action potential down a myelinated axons or dendrite.

Increases speed of conduction

Speen of unmyelinated conduction

2 mph

Speed of myelinated conduction

>260mph

Graded potentials

Aka local potentials

Transmembrane potential decreases in intensity as it moves away from the source

If the graded potential is strong enough to reach threshold it will produce an actin potential

Acton Potential

Propagated or conducted changes in the transmembrane potential

wave of depolarization in a neuron

AP’s trippger the opening of gated NA+ channels

Sympatic activity

involvs release of neurotransmotters and inactive chemicals

Intracellular fluid

Contains high conentrations of K+ and negatively charged particles. Overall neatively charged.

Extracellular Fluid

Contains high conentrations of NA+ & CL. Overall positively charged.

Threshold

Usually around -55mv.

The point at which an action potential is generated.

All NA+ gates open

Resting Membrane potential

Approximatley -70 mv on inside of neuron

Chemically Gated Chemicals

Channels which open or close when they bind to specific chemicals. Ex: neurotransmitters

Voltage gated channels

Channels which opens or close in response to changes in the transmembrane potential

Mechanically gated channels

Channels which opens or close in response to physical distortion of the membrane surface. Ex: sensory receptors

Chemical synapses

most common synapse, involves neurotransmitters

Acetylcholine (Ach)

The most common neurotransmitter released in the CNS & PNS

Cholinergic synapses

a synapse which involves the release of Ach

Summerize the events at the synapse:

-An action potential arrives at the axon terminal synaptic knob or bulb

• Arrival of the action potential stimulates Ca²⁺ to enter the synaptic knob triggering the release of the neurotransmitter

• The neurotransmitter binds to receptors and depolarizes the postsynaptic membrane by opening Na⁺ gated channels (graded potential)

Norepinephrine

a neurotransmitter released in the brain & ANS. Also known as noradrenaline

Dopamine

a neurotransmitter released in the brain with “feel good affects”. Cocaine blocks or inhibits dopamine removal.

Serotonin

CNS neurotranmitter. Affects mood. Antidepressants (SSN) help increase serotonin levels in the brain

GABA

CNS neurotransmitter has an inhibitory effect or calming effect

Neuromodulador (opioids)

Chemicals that alter the rate of neurotransmitters released or change the postsynaptic membrane response to the neurotransmitter. Opioids are used for pain relief

Nicotine

a compound in tobacco that binds to Ach receptor sites & stimulates the postsynaptic membrane

Rabies

a fatal diesease caused by a virus that reaches the CNS via retrograde flow along axons

Endorphins

neuropeptides produced in the brain & spinal cord that relieve pain and affect mood

Neurotoxin

a compound that disrupts normal nervous system function by interfering with the generation or propagation of action potentials