Nervous System

Sympathetic

The fight or flight system. Energy is used and spent when this system is at work. Chemicals sent from brain to sympathetic sites stimulating action like naturally occurring epinephrine & norepinephrine which opens up airways & circulatory passages and can make heart race, pupil dilation, bronchodilation, startled animal. Increased heart rate, respiratory rate and blood flow to the muscles. Sensory nerves are at alert

Parasympathetic

The rest and repose system

Neuron

The main cell of the nervous system

Synapses

Nerve impulses from one neuron to another

Dendrites

Carry impulses towards the cell body

Dendr/o

Dendrite

Axon

Carry impulses away from the cell body

Ax/o

Axon

Myelin

Protective covering over some nerve cells. Electrical insulator. Lipoprotein surrounding axon. Made by Schwann cell. Nerve impulses are increased by its presence. Nodes of Ranvier

Lipoprotein

Complex molecules that transport lipids, like cholesterol, triglycerides, and phospholipids, through the blood and between cells

Nodes of Ranvier

Characterized by short, specialized regions in the axonal membrane that are not insulated by myelin

Synapse

Space between two neurons OR Neuron and receptor and axon terminates

Synaps/o, Synapt/o

Synapse

Forebrain

Contains the Cerebrum, Hypothalamus and the Thalamus. Contains 90% of all the neurons in the entire nervous system. Outer layer is grey matter or cerebral cortex

Thalamus

A brain structure that acts as a relay station for sensory and motor information

Cerebrum

Involves the processing, memory, systems control and data storage

Midbrain

Acts as a pathway between forebrain and hindbrain

Hindbrain

Consists of Cerebellum, pons, and Medulla Oblangata

Cerebellum

Responsible for balance and coordination

Blood-Brain Barrier

Protects the brain from harmful substances but allows anesthetic gas and analgesics into the nervous tissues of the brain

Meninges

The three layers of connective tissue enclosing the central nervous system

Autonomic Nervous System

Contains sympathetic and parasympathetic nervous systems. Responsible for the stimulation of the visceral organs

Middle Ear

Consists of the tympanic cavity, the tympanic membrane (separates the external ear with the middle ear) and auditory ossicles

Vestibular Sense

Awareness of body balance and movement are monitored. So balance and head position are this sense. Head tilt, incoordination and nystagmus are possible symptoms of neurological disease. Proprioceptive is monitoring this sense.