The Nervous System

Front 1

Central Nervous System

Back 1

complex of nerve tissues controlling the activities of the body; cns, specifically, brain and spinal cord

Front 2

Peripheral Nervous System

Back 2

the nervous system outside the brain and spinal cord

Front 3

neuron

Back 3

specialized cells for the conduction of information

Front 4

cell body

Back 4

contains the nucleus and most organelles

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axons

Back 5

conduct impulses away from cell body toward other neurons or effectors

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dendrites

Back 6

extensions leading toward the cell body; brings signals to cell bodies from other neurons

Front 7

myelin sheath

Back 7

a fatty white substance that surrounds the axon of some nerve cells, protecting them and speeding messages along

Front 8

sensory neuron

Back 8

take information to the CNS, have sensory receptors

Front 9

interneuron

Back 9

completely embedded w/in the CNS; receives input from sensory and other interneurons and sends feedback back through motor neurons

Front 10

motor neuron

Back 10

takes messages from CNS t effector organs (muscles, glands or organs)

Front 11

Describe the transmission of a nerve impulse along a neuron.

Back 11

Sensory receptor transmits impulse to cord. Synapses with interneurons in cord (integration) and up to the brain. Transmitted to motor neuron. Motor neuron carries impulse to effector muscle.

Front 12

What is resting potential? How is it maintained?

Back 12

the amount of energy waiting to be used within a neuron; maintained by sodium potassium pumps which actively transport Na out of and K into a synapse

Front 13

What is action potential?

Back 13

a rapid change in polarity across an axonal membrane as a nerve impulse occurs; "all or nothing" phenomenon

Front 14

List the membrane structures involved in an action potential and the role of each.

Back 14

1. Sodium Gates- open first, Na flows down concentration gradient into an axon. Axon changes from negative to positive, "depolarize"

2. Potassium Gates- open 2nd, K flows down concentration gradient to outside axon. AP inside post synapse resumes negative charge.

Front 15

refractory period

Back 15

time during which sodium gates in a presynapse are unable to open, preventing backflow of synapses

Front 16

Name 2 neurotransmitters.

Back 16

ACl (acetycholine) and norepinepherine

Front 17

synaptic cleft

Back 17

a junction between 2 nerve cells through which neurotransmitters jump from synapse to synapse

Front 18

Explain the transmission that takes place within a synapse.

Back 18

one way transmission, from presynaptic to post synaptic; neurotransmitters are chemical messengers that cross from synapse through synaptic cleft and into the next neuron

Front 19

Describe spinal nerves.

Back 19

the spine extends from the base of the brain. White matter, myelinated, surrounds grey matter; takes messages to the brain. Grey matter, unmyelinated, takes messages back from the brain. Dorsal root and ganglion (sensory) stem from back of spine; ventral (motor) from in front.

Front 20

Relate the following parts of the spinal cord: central canal, grey matter, and white matter.

Back 20

the spinal cord has 3 layers. the innermost part is the central canal, center of "H" grey matter (unmyelinated cell bodies of neurons). the outer most part is called white matter, myelinated neurons.

Front 21

Describe the reflex arc.

Back 21

automatic responses to a stimulus

Receptor neurons ---> Sensory neurons ---> interneurons (integrate) ----> motor neuron ---> effector

Front 22

Function of: ventricles

Back 22

hollow interconnecting cavities in the brain that connect with the hollow central canal of the spinal cord; produce and hold cerebrospinal fluid, the substance that cushions and protects the CNS

Front 23

Function of: brain stem

Back 23

contains midbrain, pons and medulla oblongata

Front 24

Function of: cerebrum

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the largest portion of the brain in humans that receives sensory input, processes it, and commands voluntary motor responses

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Function of: grey matter

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contains brain's cell bodies of neurons; includes regions of the brain involved in muscle control and sensory perception

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Function of: white matter (fibers)

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connects grey matter through axons

Front 27

Function of: cerebellum

Back 27

receives sensory input from joints, muscles and other sensory pathways about position of body parts; maintains body posture

Front 28

Function of: medulla oblongata

Back 28

regulates vital functions (heartbeat, breathing, blood pressure) and contains the reflex centers (vomiting, coughing, sneezing, hiccuping, and swallowing)omit "limbic system and higher mental functions"

Front 29

Explain the autonomic nervous system.

Back 29

a part of the PNS subdivided categorically between the sympathetic "fight of flight" and the parsympethetic "rest and digest"; automatic and involuntary impulses

Front 30

Name the 2 divisions of the autonomic nervous system and what they are responsible for.

Back 30

*Sympathetic, "fight or flight"

*Parasympathetic, "rest and digest"