Chapter 11 - Functional Organization Of The Nervous System

Front 1

List the five main functions of the nervous system

Back 1

1) Sensory input
2) Integration
3) Homeostasis
4) Mental Activity
5) Control of muscles and glands

Front 2

Sensory receptors

Back 2

the endings of nerve cells or separate, specialized cells that detect temperature, pain, touch, pressure, light, sound, odors, and other stimuli; located in various locations throughout the body

Front 3

Nerve tract

Back 3

bundles of parallel axons with their associated sheaths in the CNS

Front 4

Ganglion

Back 4

any group of nerve cell bodies in the PNS

Front 5

Plexus

Back 5

intertwining of nerves or blood vessels

Front 6

Afferent division

Back 6

nerve fibers that send impulses from the periphery to the CNS

Front 7

Efferent division

Back 7

nerve fibers that send impulses from the CNS to the periphery

Front 8

Somatic nervous system

Back 8

composed of nerve fibers that send impulses from the CNS to skeletal muscle

Front 9

Autonomic nervous system

Back 9

composed of nerve fibers that send impulses from the CNS to smooth muscle, cardiac muscle, and glands

Front 10

Sympathetic division

Back 10

subdivision of the autonomic nervous system characterized by having the cell bodies of its preganglionic neurons located in the thoracic and upper lumbar regions of the spinal cord (thoracolumbar division); usually involved in preparing the body for physical activity

Front 11

Parasympathetic division

Back 11

subdivision of the autonomic nervous system; characterized by having the cell bodies of its preganglionic neurons located in the brainstem and the sacral region of the spinal cord (craniosacral division); usually involved in activating vegitative functions such as digestion, defecation, and urination

Front 12

Enteric nervous system

Back 12

consists of plexuses within the wall of the of the digestive tract; considered part of the ANS

Front 13

Astrocytes

Back 13

neuroglia that are star-shaped due to cellular processes that extend out toward other cells; play a role in regulating the extracellular composition of brian fluid; release chemicals that promote the formation of tight junctions between the endothelial cells of capillaries, helping to form the blood-brain barrier

Front 14

Blood-brain barrier

Back 14

a barrier that forms between the blood vessels and nervous tissue; determines what substances can pass from the blood into the nevous tissue of the brain and spinal cord; protects brain from toxic substances in the blood, allows the exchange of nutrients and waste products, and prevents fluctuations of in the composition of the blood from affecting the functions of the brain

Front 15

Ependymal cells

Back 15

cells that line the ventricles of the brain and central canal of the spinal cord

Front 16

Choroid plexuses

Back 16

specialized plexus located within the ventricles of the brain the secretes CSF

Front 17

Microglia

Back 17

small neuroglial cells that become phagocytic and mobile in response to inflammation; considered to be macrophages within the CNS

Front 18

Oligodendrocytes

Back 18

neuroglial cells that have cytoplasmic extensions that form myelin sheaths around axons in the CNS; one cell can myelinate multiple neurons

Front 19

Schwann cells (neurolemmocytes)

Back 19

neuroglial cells that wrap around axons in the PNS; each only wraps around one axon

Front 20

Satellite cells

Back 20

neuroglial cells that surround neuron cell bodies in ganglia, provide support, and can provide nutrients to the neuron cell bodies

Front 21

Myelinated axons

Back 21

neuron axons that are surrounded by extensions of oligodendrocytes or Schwann cells wrapped many times; gives the axon a white appearance due to high lipid concentrations

Front 22

Nodes of Ranvier

Back 22

2-3um interruptions in the myelin sheath that permit quicker electrical conductance up the axon

Front 23

Internodes

Back 23

the myelinated areas located between the nodes of Ranvier

Front 24

White matter

Back 24

bundles of parallel axons with their associated myelin sheaths; whitish in color

Front 25

Gray matter

Back 25

collections of neuron cell bodies and unmyelinated axons; grayish in color

Front 26

Nerve tracts

Back 26

bundles of axons in the CNS that serve to "connect" different areas of the nervous system by propogating action potentials from one area to another

Front 27

Cortex

Back 27

area in the periphery of the brain that is composed of gray matter

Front 28

Nuclei

Back 28

areas within the brain that are composed of collections of gray matter

Front 29

Action Potential

Back 29

change in membrane potential in an excitable tissue that acts as an electric signal and is propagated in an all-or-none fashion

Front 30

Na+/K+ pump

Back 30

biochemical mechanism that uses energy derived from ATP to achieve the active transport of potassiumions opposite to that of sodium ions

Front 31

Nongated ion channels

Back 31

also called leak channels; channels that are always open and are responsible for the permeability of the plasma membrane to ions when the plasma membrane is unstimulated, or at rest; plasma membrane is more permeable to K+ and Cl- and much less permeable to Na+

Front 32

Gated ion channels

Back 32

channels that open and close in response to stimuli;
can change the permeability characteristics of the plasma membrane;
there are three types: ligand-gated, voltage-gated, and other-gated ion channels

Front 33

Ligand

Back 33

a molecule that binds to a receptor

Front 34

Receptor

Back 34

a protein or glycoprotein that has a receptor site to which a ligand can bind; most are located within the plasma membrane

Front 35

Ligand-gated ion channel

Back 35

ion channels that open or close in response to a ligand binding to a receptor; exist for Na+, K+, Ca2+, and Cl-

Front 36

Voltage-gated channel

Back 36

ion channels that open and close in response to small changes across the plasma membrane;