Anatomy - The Nervous System

Functions of the Nervous system

Gathering information

Monitoring changes inside and outside the body

Processing sensory input

Motor output

Generation of a response that acts on muscles or glands

The central nervous system is composed of…

The brain and spinal cord

The peripheral nervous system is composed of…

Cranial and spinal nerves

Functions of the central nervous system

Command center

Interprets incoming sensory information

Issues outgoing instructions

Functions of the peripheral nervous system

Contains nerves that extend from the brain and spinal cord

Serves as communication channels

Spinal nerves carry messages…

to and from the spine

cranial nerves carry messages…

to and from the brain

The function of sensory neurons are

Carries information TO the central nervous system

what are somatic sensory neurons

Afferent fibers that carry info from the skin, skeletal muscles and joints

what are visceral sensory neurons

afferent fibers that carry info from the visceral organs

What is the function of motor neurons

Carries info AWAY from the CNS to effector organs (muscles or glands)

What is the function of the somatic nervous system

Voluntary control of skeletal muscles

What is the function of the autonomic nervous system

involuntary control of smooth muscle, cardiac muscle and glands

What is the function of the sympathetic nervous system

Fight or flight response

What division of the nervous system is the sympathetic nervous system known as

‘E’ division

What does the ‘E’ division stand for

Exercise, Excitement, Emergency, Embarassment

What is the function of the parasympathetic nervous system

Rest and digest

Body conserves energy and maintains bodily functions

What division of the parasympathetic nervous system known as

‘D’ division

What is the ‘D’ division

Digestion, Defecation, Diuresis (urination)

what are the two types of cells in nervous tissue

Neurons and Neuroglia

What is the function of neuroglia

supports, insulates and protects neurons

What are astrocytes

Most abundant star shaped neuroglia

Braces/anchors neurons to blood capillaries

Protects neurons from harmful substances in the blood

Controls the chemical environment of the brain

What are microglia

Spider shaped neuroglia that monitors the health of neurons and disposes of debris

What are ependymal cells

neuroglia that Lines the cavities of the brain and spinal cord

Has cilia that assist with the circulation of cerebral spinal fluid

What are myelin sheath

neuroglia that protects and insulates neurons

increases the speed of nerve impulse transmission

What are satellite cells

neuroglia that protects and cushions nerve fibers

what are the functions of neurons

transmission of nerve impulses

what is the cell body of the neuron

contains the nucleus and is the metabolic center of the cell

What are processes on the neuron

fibers that extend from the cell body

What are nissl bodies/neurofibrils/rough ER in the neuron

important for maintaining cell shape

what is white matter

Myelinated fibers composed of axons that transmit signals to other regions of the brain, spinal cord and the rest of the body

what is gray matter

Unmyelinated fibers that receive messages and regulate outgoing information

What are interneurons

connect sensory neurons to motor neurons

What are the characteristics of neurons

Irritability, Conductivity

Reflexes occur via neural pathways called

reflex arcs

What are the two types of reflexes

Somatic and autonomic

What is a somatic reflex

A reflex that stimulates skeletal muscle

What is an autonomic reflex

Reflex that stimulates cardiac muscle, smooth muscle and glands

What are meninges

connective tissue membranes that protect the central nervous system

What are the 3 meninges layers called

Dura mater, Arachnoid mater, Pia mater

What is dura mater

the outermost layer that protects the CNS

What are the two layers of the dura mater

Periosteal layer and Meningeal layer

What is the periosteal layer of the dura mater

attaches to the inner surface of the skull

What is the meningeal layer of the dura mater

the outer covering of the brain

The dura mater folds inwards in several areas;

Falx cerebri and Tentorium cerebelli

what is the falx cerebri

a fold in the brain that separates the cerebral hemispheres

what is the tentorium cerebelli

a fold in the brain that separates the cerebellum and cerebrum

what is the arachnoid layer

the middle layer of the meninges, it spans the sub arachnoid space

what is pia mater

the internal layer of the meninges that clings to the surface of the brain and spinal cord

the subarachnoid space is filled with

cerebral spinal fluid

what produces cerebral spinal fluid

chordoid plexuses

what is multiple sclerosis

an autoimmune disease where the body attacks the myelin sheath. This leads to hardening and short circuited nerve impulses

What is hemiplegia

one sided paralysis as a result of a stroke

what is aphasia

damage to speech center as a result of a stroke

what is a transient ischemic attack

temporary restriction of blood flow to the brain resulting in numbness, temporary paralysis and impaired speech