Chapter 7 - The Nervous System

Front 1

What are the functions of the Nervous System?

Back 1

1. Sensory Input 2. Integration 3. Motor Output

Front 2

What is Sensory Input?

Back 2

To monitor changes occurring inside and outside the body (changes = stimuli)

Front 3

What is Integration?

Back 3

To process and interpret sensory input and decide whether action is needed

Front 4

What is Motor Output?

Back 4

A response to integrated stimuli (the response activates muscles or glands)

Front 5

What is the Nervous System classified based on?

Back 5

1. Structures (structural classification - CNS - Brain and Spinal Cord) 2. Function (Integration: command center; interprets sensory info, and issues outgoing instructions)

Front 6

Facts about the Peripheral Nervous System (PNS)

Back 6

1. Nerves extending from the brain and spinal cord (spinal nerves carry impulses to and from the spinal cord, and cranial nerves carry impulses to and from the brain). 2. Functions serve as communication lines among sensory organs, the brain and spinal cord, and glands or muscles.

Front 7

What is the Sensory (afferent) Division of the PNS?

Back 7

1. Nerve fibers that carry information to the central nervous system. 2. Somatic Sensory fibers carry information from the skin, skeletal muscles, and joints. 3. Visceral sensory fibes carry information from the visceral organs.

Front 8

What is the Motor (efferent) Division of the PNS?

Back 8

1. Nerve fibers that carry impulses away from the central nervous system organs. 2. Two subdivisions - Somatic Nervous System (voluntary) and Autonomic (involuntary)

Front 9

What is Neurolgia?

Back 9

They're support cells in the CNS that are grouped together to support, insulate, and protect neurons.

Front 10

What are CNS Glial Cells called Astrocytes?

Back 10

They're star shaped cells that brace the neurons, and control chemical environment of the brain. Test note: They are the most abundant and versatile neuroglia.

Front 11

What are CNS Glial Cells called Microglia?

Back 11

They're a spider-like phagocyte that defend the CNS cells by engulfing bacteria or debris

Front 12

What are CNS Glial Cells called Ependymal Cells?

Back 12

They're ciliated cells that help circulate CSF. They line cavities of the brain and spinal cord.

Front 13

What are CNS Glial Cells called Oligondendrocytes?

Back 13

They're the cells that wrap around nerve fibers in the central nervous system. They're the ones that produce myelin sheaths.

Front 14

What are the PNS glial cells?

Back 14

Satellite cells (protect neuron cell bodies) and Schwann cells (form myelin sheath in the PNS)

Front 15

What are neurons?

Back 15

Neurons are nerve cells that are specialized to transmit messages.

Front 16

What are the major regions of the Neuron?

Back 16

Cell body (nucleus and metabolic center of the cell) and Processes (fibers that extend from the cell body (dendrites and axons))

Front 17

What do Dendrites and Axons do?

Back 17

Dendrites conduct impulses toward the cell body (input), and the Axon conducts imposes away from the cell body (output)

Front 18

What functions do the ends of the Axon do?

Back 18

They're the terminals that contain vesicles with neurotransmitters, and they're separated from the next neuron by a gap - the Synaptic Cleft.

Front 19

What's a Synapse?

Back 19

It's the junction between nerves.

Front 20

What are the parts of the Neuron Cell Body?

Back 20

Nissl Bodies (specialized rough endoplasmic reticulum), the Neurobrils (intermediate cytoskeleton that maintains cell shape), and Nucleus with a large nucleolus.

Front 21

What is a Cerebral Vascular Accident (CVA)?

Back 21

A stroke.

Front 22

What are the Nodes of Ranvier?

Back 22

They're gaps in myelin sheaths around axons of the CNS.

Front 23

What function do Myelin Sheath serve?

Back 23

They protect the neuron and speed the nerve impulse transmission.

Front 24

Where are most neuron cell bodies found?

Back 24

In the central nervous system

Front 25

What's the difference between white and gray matter?

Back 25

Gray Matter is cell bodies and unmyelinated fibers, and White Matter is clusters of cell bodies that are covered in myelin (tracts).

Front 26

What are Ganglia?

Back 26

Collections of cell bodies outside the CNS

Front 27

What are Tracts and Nerves?

Back 27

Tracts are bundles of nerve fibers in the CNS, and Nerves are bundles of nerve fibers in the PNS.

Front 28

What layer of skin are finger nerves located in?

Back 28

The Dermis

Front 29

What is Irritability and Conductivity?

Back 29

Irritability is the ability to respond to a stimulus and convert it to a nerve impulse; and Conductivity is the ability to transmit the impulse to other neurons, muscles, or glands.

Front 30

What is a Resting Neuron?

Back 30

The plasma membrane at rest is polarized. As long as inside is more negative than outside, the cell stays at rest. Fewer positive ions are inside the cell than outside the cell. K+ is the major positive ion inside the cell, and Na+ is the major positive ion outside the cell.

Front 31

Action potential initiation and generation:

Back 31

• A stimulus depolarizes the neuron’s membrane, which makes the membrane more permeable to sodium as sodium channels open • A stimulus leads to movement of ions, which initiates an action potential in the neuron

• A graded potential (localized depolarization) exists where the inside of a membrane is more positive and the outside is less positive.

• If stimulus is strong enough and sodium influx is great enough, local depolarization activates the neuron to conduct an action potential (nerve impulse)

Front 32

Propagation of the action potential

Back 32

• If enough sodium enters the cell, the action potential (nerve impulse) starts and is propagated over the entire axon

• All-or-none response means the nerve impulse either is propagated or is not

• Fibers with myelin sheaths conduct nerve impulses more quickly

Front 33

Repolarization:

Back 33

• Potassium ions rush out of the neuron after sodium ions rush in, repolarizing the membrane • Repolarization involves restoring the inside of the membrane to a negative charge and the outer surface to a positive charge

• Until repolarization is complete, a neuron cannot conduct another nerve impulse

• Initial ion conditions are restored using the sodium-potassium pump

• The pump, using ATP, restores the original configuration

• Three sodium ions are ejected from the cell while two potassium ions are returned to the cell

Front 34

Reflexes are:

Back 34

Rapid, Predictable, and an involuntary response to a stimulus. They occur over neural pathways called reflex arcs.

Front 35

Somatic Reflexes are:

Back 35

Reflectes that stimulate the skeletal muscle (conscious)

Front 36

Autonomic reflexes do what?

Back 36

They regulate the activity of smooth muscles, the heart, and glands. (on its own)

Front 37

What are the 5 elements of a reflex?

Back 37

1. Sensory receptor. 2. Sensory neuron. 3. Integration center (CNS) 4. Motor neuron. 5. Effector organ

Front 38

What is the Meninges of the brain?

Back 38

1. Dura Mater (tough outermost layer). 2. Arachnoid layer (middle layer). 4. Pia mater (internal layer)

Front 39

What makes cerebrospinal fluid (CSF)?

Back 39

Choroid plexuses - capillaries in the ventircles of the brain

Front 40

Where is CSF circulated?

Back 40

In arachnoid space, ventricles, and central canal of the spinal cord. (lower lumbar is the same fluid as in the brain)

Front 41

What are nervous system related diseases?

Back 41

Hydrocephalus, CVA (stroke), and Alzheimer's Disease

Front 42

What are the severe congenital brain diseases?

Back 42

Cerebral Palsa, Arencephaly, Hydrocephalus, and Spina Bifida