CNS=brain and spinal cord

PNS=everything outside the CNS,including spinal nerves, cranial nerves, ganglia, and sensory receptors.

sensory(afferent)division

motor(efferent)division

somatic nervous system-(voluntary) contraction of skeletal muscle

autonomic nervous system-(involuntary) contains sympathetic and parasympathetic divisions

enteric nervous system-the nerves that innervate the digestive system.

List the two types of cells that compose nervous tissue

a.  Describe the general function of each

1) excitable cells= neuron(nerve cells) and muscle cells.  These conduct nerve impulses or action potientials. These secrete neurotransmitters.  They are amitotic, they don't divide after a certain point.

2) supporting cells= neuroglia(glia cells).  The glue that holds neurons together

a. sensory(afferent)neurons.  These are unipolar receptors.  The cell body is located in the ganglia close to the CNS. They always transmit toward the CNS. Examples are light and heat

b. interneurons=multipolar, between sensory and motor located in the CNS.  They integrate sensory information.  These make the decisions for everything.

c. motor(efferent)neurons=multipolar.  They transmit impulses within and away from the CNS. They elicit a response to an effector, either a muscle or gland

1.  soma(perikaryon, cell body)=contains all of the organelles.  Nissl bodies produce RER, required because a neuron has more protein synthesis. Lipofucin=pigment that is found in a neuron, the older the neuron, the more lipofuscin. In the CNS clusters=nuclei. In the PNS clusters=ganglia

2.  dendrites=processes off of the cell body, they are highly branched.  It gives a greater area to receive information.

3.  axon=one per neuron.  They conduct AP's.  They arise from the axon hillock or trigger zone

a. multipolar=most common, many dendrites, and one axon.

b.  bipolar=one axon and one dendrite.  In olfactory, mucosa, and inner ear.

c.  unipolar neurons=single process in ganglia

d.  anaxonic=many dendrites, no axon

1.  astrocytes=star shaped, most abundant. Form blood brain barrier. Maintain chemical environment and provide nutrients.  Form scar tissue.

2.  oligodendrocytes=Form myelin sheaths that wrap around several axons.  Myelin sheaths allow for faster propegation of AP's

3.  ependymal cells(epithelial)=ciliated, produce and circulate CSF.  These are part of the choroid plexus.

4.  microglia=phagocytic cells, clean up crews

List the neuroglia found in the PNS and give the function of each

1.  Schwann cells=produce myelin sheaths around one axon.  The nodes of Ranvier and internodes are the areas where there is no myelin.  They are important in the regeneration of nerve fibers

2.  Satellite cells=unknown function

1. neuron cell bodies and processes

2. unmyelinated axons

3. neuroglia

1. Define RMP

2. What is the RMP of a neuron?

3.  How is the RMP established?

4.  Describe the ion composition of the ICF and ECF

5.  How is RMP maintained?

1.  Voltage difference across a PM

2.  -70mV

3.  Unequal distribution of ions across a PM

4.  ICF due to A K+ more abundant

ECF due to Na+ ions in abundance

5.  By Na-K-ATP pump.  Protein that pumps Na+ and K+ against gradient.  It pumps 3 Na+ out and 2K+ back in.  Uses one ATP cycle

AP=an impulse propagated along an axon

TS=Voltage gated reversing polarity(-55mV)

1.  all or none

2.  self propagating, you only need one stimulus,a threshold stimulus

3.  not graded/same strength the entire time

4.  travel short and long distances without losing strength

5.  unidirectional

1.  TS

2.  Opening and closing of Na+ channels

3.  polarity is reversed

4.  more+ inside, more- outside

Describe the events that occur during the repolarization of an AP?

a.  How is RMP restored?

b.  What causes hyperpolarization?

1.Voltage gated K+ channels open as Na+ channels close.

2.K+ gates remain open longer

a.  RMP is restored by becoming more- inside and more+outside

b.  Very-inside causes hyperpolarization

Define absolute refractory period and relative refractory period

a.  When does each occur?

1.  absolute refractory period occurs during depolarization to repolarization.  Another AP can't be generated.  Na+ channels remain open

2.  relative refractory period hyperpolarization takes place here.  A stronger stimulus is needed to generat an AP

1.  TS

2.  depolarization

3.  absolute refractory

4.  relative refractory

5.  repolarization

6.  hyperpolarization

Describe saltatory conduction vs. cable conduction

a.  What effect does the myelin sheath have on conduction?

1.  Continuous(cable)conduction occurs in unmyelinated fibers or axons.  Voltage gated ion channels are across the entire PM.  Each adjacent segment of the PM is stimulated.  Slower conduction takes place here

2.  Saltatory conduction occurs in myelinated axons.  Voltage-gated ion channels are located at the nodes.  Faster conduction takes place here.  The myelin sheath makes conduction faster

1. Graded potentials occur in the dendrites and soma

2.AP's are impulses that are propagated along an axon

3.  Graded potientials are stimulated by the opening or closing of ligand or mechanically gated channels

4.  There are two types of graded potiential receptor and post-synaptic

5.  Graded potientials vary in size with stimulus strength

6.  AP's are the same strength the entire time

7.  Graded potientials are localized, they travel short distances and lose strength

8.  AP's travel short and long distances without losing strength

9.  Graded potentials are reversible RMP is restored if stimulus ceases

10.  AP's are not reversible they are all or none

11.  Graded potentials are excitatory(depolarizing) or inhibitory(hyperpolarizing)

12.  AP's travel in one direction

13.  AP's are self propagating

2 types

1.  Electrical=AP conducted across a gap junction.  Faster transmission.  AP's can be synchronized.  Examples are cardiac and smooth mnuscle.

2.  Chemical=Post and pre synaptic neurons separated by a synaptic cleft. One way transmission

synapse=Site of communication between presynaptic and postsynaptic neurons

Describe the sequence of events that occur during synaptic transmission at a chemical synapse

a. calcium

b. neurotransmitters

c. receptors

d.  acetylcholinesterase

synaptic transmission=chemical synapse

1.  Ca2+ channels open

2.  Ca2+ enters synaptic bulb

3.  synaptic vessicles release neurotransmitters

4.  Nt diffuses across synaptic cleft

5.  Nt binds to receptors or post synaptic neurons.  Ligand gated ion channels open

6.  Generates a PSP or graded potential

Describe a PSP

a.  How are EPSP's generated?

b.  How are IPSP"S generated?

a.  Graded.  When Na+ enters the cell to threshold to depolarization

b.  Graded.  When K+ leaves or Cl- enters to hyperpolarization

Define temporal and spatial summation

Define summation

a.  Nt released by one presynaptic neuron

b.  Nt released by many presynaptic neurons

summation=integration of neural input

List the different classes of nt's and give examples of each

a.  ACh

b.  EAA

c.  IAA

d.  catecholamines

e.  indolamines

f.  neuropeptides

a.  A class by itself, which skeletal muscle which contracts when binds.  Cardiac muscle which slows when binds

b.  glutamate=brain opens Ca++ channels, learning and memory

aspartate=spinal cord main EAA here

c.  glycine=spinal cord, strychnine blocks glycine receptors

GABA=inhibitory here, valium enhances the GABA action.  Alcohol affects GABA inhibition

d.  NE=dreaming, arousal and mood

E=same as above

Dopamine=elevation of mood, addictive behavior, pleasurable experiences.  Skeletal muscle tone and contraction

e.  serotonin=sleep, alertness, mood, thermoregulation, blocked by LSD, and enhanced by ecstasy

histamine=vasodilator

f.  CCK=Suppresses appetite and affects hypothalmus

substance P=Pain

endorphins=Natural pain killers our bodies produces.  Pain killers block substance P, effects mimicked by morphine and heroine

1.  cerebrum(83% of volume)

2.  diencephalon=central part of the brain, the thalamus, and hypothalamus

3.  cerebellum(10%)=little brain

4.  brain stem=medulla oblongata, pons, midbrain continuous with the spinal cord

Which blood vessels supply the brain with blood?

astrocytes/connection between endothelial cells of capillaries.  Tight junctions between

1.  a. glucose b. ions c. H2O d. O2 e. CO2 f. alcohol g. caffeine h. nicotine i. anesthetics

a. dura mater=tough membrane

b.  arachnoid mater=middle layer a lot of blood vessels with spidery appearance

c.  pia mater=dips into groove of brain

Describe the compositon of the CSF.

a.  Where does it circulate in the brain and sc

b.  Where is it produce?

c.  Where is it reabsorbed?

d.  Describe the functions of the CSF

Made from plasma

a.  ventricles of brain and central canal of sc around the brain and sc in subarachnoid space

b.  in the chorid plexus of ventricles

c.  by arachnoid villi

d.  1.  protection and buoyancy

2.  chemical stability

3.  exchange of wastes and nutrients

inflammation of the meninges caused by a bacteria or virus.  A spinal tap is needed to diagnose(L3-4 orL4-5)

Excess CSF in ventricles in babies, many have developmental disabilities as a result.  cure=drainage tube

main=transmits impulses

a.  nerve impulse propagation

b.  information integration

c.  sensory reflexes-skeletal/voluntary muscles

Describe the external anatomy of the spinal cord

a.  conus medularis,filum terminale, and cauda equina

45 cm long, extends from the medulla oblongata thru L1, conus medullaris and filum terminale-cord tapers to coccyx

cauda equina-L2-S5 horses tail

What type of nerve fibers are carried by the dorsal root?

What is found in the dorsal root ganglion?

sensory afferent axons

sensory neuronal cell bodies

In general describe th difference between ascending and descening tracts of the spinal cord?

a.  What direction is the nerve impulse traveling?

b.  Where soes each tract begin and end?

c.  What type of information is carried by these tracts?

ascending carry somatic sensory impulses toward the brain.  3 neuron pathways, descending carry motor impulses from brain down sc

a.  up or down the sc

b.  sc and brain

c.  somatic sensory or motor impulses

1.  xing over to the opposite side of the thalamus/ occurs in the medulla oblongata

2.  opposite side

3.  same side

What type of sensory information is carried by the following ascending tracts?

a.  anterior and posterior spinothalmic tracts

b.  posterior columns

c.  spinocerebellar tracts

d.  Do any of these tracts decussate? If so where?

somatic sensory

a.  anterior=touch, pressure, tickle, and itch

b.  destination is the brain, relay proprioception, position/movement. Light, pressure, vibrational sensations

c.  start spinal cord/end cerebellum.  Proprioceptors relayed ipsilaterally coordinated muscle movements, balance and posture

Yes, the spinothalmic in the opposite side of the brain

What type of motor information is carried by the following descending tracts of the spinal cord?

a.  corticospinal and corticobulbar

1.  Why are these considered pyramidal pathways?

b.  rubrospinal, tectospinal, vestibulospinal,recticulospinal

1.  Why are these extrapyramidal pathways?

c.  Do any of these decussate?

a.  cause precise muscle movement

1.  They originate with the pyramidal neurons

b.  start in cortex/red nucleus/reticular formation/midbrain/coordinate with vision/inner ear/maintain posture and equilibrium

1.  Includes all pathways except motor pathways

Describe the following conditions

a.  spina bifida

b.  poliomyelitis

c.  ALS

a.  occults/cystica=occulta is a develepmental abnormality that a person might not even realize they have.  The cystica is more serious, it occurs because of an infection

b.  poliovirus destroys mototneurons in the anterior horn of the sc and nuclei of cranial nerves.  It targetsmotor neurons, muscle weakness, to paralysis

c.  affects lateral tract and neurons.  Muscle weakness begins in the hands and arms

para=transection between T1 and L1 both lower limbs are affected

quadri=cervical region, all four limbs are affected

Nissl bodies are found

a.  in the neuroglia

b.  in the neuronal axons

c.  in the neuronal cell bodies

d.  in the neuronal dendrites

All of the following are found in the PNS except:

a.  spinal nerves

b.  cranial nerves

c.  myelinated axons

d.  microglia

The nodes of Ranvier are found

a.  in the CNS only

b.  on dendrited

c.  on the neuroglia

d.  on myelinated axons

A membrane maintains its RMP mainly due to

a.  the Na+-K+_pump

b.  chemically gated Na+ channels

c.K+ channels

d.  Ca+ channels

The velocity of nerve impulse conduction is greatest in

a.  heavily myelinated, large diameter fibers

b.  myelinated small diameter fibers

c.  unmyelinated, small diameter fibers

d.  unmyelinated large diameter fibers

The anatomical region of a multipolar neuron that has the lowest threshold for generating an AP is the

a.  soma

b.  dendrites

c.  axon

d.  distal axon

Neuroglial cells that line the cavities of the brain are the

a.  astrocytes

b.  ependymal cells

c.  microglia

d.  schwann cells

In a neuron the RER is referred to as

a.  soma

b.  lipofuscin

c.  nissl bodies

d.  neurofibrils

During membrane repolarization, there is a decrese in the membrane permeability to which ion?

a.  K+

b.  Na+

c.  Ca+

d.  both K+ and Na+

Whiach channels open during the absolute refractory period?

a.  K+

b.  Na+

c.  Ca+

d.  all of the above

Myelin sheaths in the CNS are produced by

a.  astrocytes

b.  microglia

c.  oligodendrocytes

d.  schwann dells

During membrane repolarization there is a decrease in the permeability to which ion?

a.  K+

b.  Na+

c. Ca+

d.  both a and b 

What type of current flowa through the axolemma during the steep phase of repolarization?

a. chiefly Na+ current

b.  chiefly a K+ current

c.  Na+ and K+ at about the same magnitude

In order for Na+ to pass thru a voltage gated channel

a.  the activation channel is opened and the inactivation channel is closed

b.  both channel are open

c.  both channels must be closed

d. the activation channel is open and the inactivation channel is closed 

Spatial summation occurs when

a.  an EPSP from one terminal

b.  multiple local potientials occur at different places on the same cell at the same time

c.  mutiple potientials occur at the same synapse on a cell

d.  multiple potientials occur at different times in the cell

During which phase of an AP are voltage-gated K+channels open, while voltage Na+ channels are closed

a.  repolarizing phase

b.  regeneration

c.  resting state

d.  depolarizing phase

Which of the following is characteristic of an IPSP but Not an EPSP?

a.  direct flow of ions from one neuron to the next

b.  refractory period absent

c.  hyperpolarization spreads across an axon hillock

d.  short distance signaling

e.  chemical nt's open K+ and Na+ channels

What is the most common neuron type in humans?a.  tripolar

b.  unipolar

c.  multipolar

d.  bipolar

All of the following describe an AP except

a.  They can be generated by muscle and nerve cells

b.  Generation of an AP in a muscle is very different from that of a neuron

c.  An AP is aka a nerve impulse

d.  An AP is the principle way neurons signal over long distances

Which of the following is unique to the axon hillock membrane?

It is the site where AP's enter and leave a neuron

b.  It contains a large # of excitatory synapses

c.  It contains a large # of inhibitory synapses

d.  The AP of this membrane reflects the sum of all incoming neuronal information

Organelle degradation in the axon are moved by

a.  the synaptic cleft into the extracellular space

b.  anterograde movement

c.  retrograde movement

d.  saltatory movement

Tracts in the CNS correspond to ______ in the PNS

a.  myelin sheaths

b.  nerves

c.  dendrites

d.  ganglia

Generation of an AP can be inhibited by all of the following except

a.  IPSP's

b.  presynaptic inhibition

c.  depolarization

d.  hyperpolarization

These are natural opiates in our bodies

a.  biogenic amines

b.  GABA

c.  endorphins

d.  histamines

IPSP's cause the post synaptic membrane to become more permeable to____

a.  Ca+

b.  Na+

c.  K+

d.  Cl-

The presynaptic neuron releases nt's in response to an influx to____ ions

a.  Na+

b.  K+

c.  Ca+

d.  Na+ and K+

synaptic knobs are found _____

a.  in the neuroglia

b.  in the neuronal axons

c.  in the neuronal cell bodies

d.  in the dendrites

All of the following are neuroglial cells except

a.  schwann cells

b.  ependymal cells

c.  microglia

d.  perikaryons

Which of the following neuroglia is most responsible for the blood brain barrier?

a.  schwann cells

b.  ependymal

c.  microglia

d.  astrocytes

e.  oligodendrocytes

Somatic sensory afferents transmit impulses from the______ to the CNS

a.  kidney

b.  the skin

c.  heart

d.  sweat glands

e.  stomach

The neurolemma is found on the____

a.  dendrites of the CNS

b.  dendrites of the PNS

c.  axons of the CNS

d.  axons of the PNS

At rest a cell membrane will have more ____ ions on the cytoplasmis surface

a.  Na+

b.  Cl-

c.  K+

d.  Ca+

Which of the folowing structures is not part of the CNS?

a.  the brain

b.  a nerve

c.  the spinal cord

d.  a tract

If a membrane has a RMP of 90mV it is said to be____

a.  depolarized

b.  polarized

c.  hyperpolarized

d.  unresponsive

Astrocytes carry out all of the following functions except

a. maintaing the chemical environment

b.  guiding the migration of young neurons

c.  forming synapses

d.  enhancing the movement of CSF in the CNS

Nt's are removed from the synaptic cleft by all of the following except

a.  reuptake by presynaptic neurons

b. simple diffusion

c.  enzymatic degradation

d.  presynaptic inhibition

All of the following are true of AP's except

a.  all or none response is exhibited

b.  they are inhibited by IPSP's

c.  they need a ts

d.  they travel more slowly on myelinated fibers

___has occured when a neuron is stimulated by more than one terminal

a.  temporal summation

b.  spatial summation

c.  synaptic delay

d.  synaptic potentiation

When of the following electrical events occurs when a certain threshold is reached

a.  RMP

b.  EPSP

c.  AP

d.  IPSP

Which of the following line the central cavities of the brain and sc and provides a barrier between the CSF and nervous tissue?

a.  astrocytes

b.  schwann cells

c.  microglia

d.  ependymal cells

e.  oligodendrocytes

Which of the following defines integration?

a.  monitoring changes inside and outside the body

b.  processing and interpretation of sensory input and making decisions about it

c.  increasing the level of one substance in response to a decrease in the level of another

d.  activitating effector organs

Which of the following statements about nervous tissue is incorrect

a.  it is composed of excitable cells and neurons

b.  only 20% of nervous tissue is composed of cells therefore can be considered relatively a cellular

c.  there are many types of supportive cells

Which of the following divisions of the nervous system is aka the involuntary system?

a.  sns

b.  PNS

c.  ANS

The innermost layer of the meninges, delicate and closely opposed to the brain tissue is

a.  dura mater

b.  corpus callosum

c.  arachnoid

d.  pia mater

CSF is formed by

a.  arachnoid villi

b.  dura mater

c.  choroid plexus

d.  all

spastic=damage to cortical neurons or cerebral cortex, too much muscle tone

flaccid=damage to ventral root or anterior horn nuclei, loss of muscle tone

1.  alter membrane permeability

2.  alter cell physiology

They don't mimic nt's and act on reuptake

Haldol(anti-psychotic)=dopamine

PCP=blocks NMDA receptors(glutamate receptor)

glycine=spinal cord

GABA=brain and sc, inhibitory here.  Valium enhances GABA

mimic nt's

nicotine=enhances dopamine

amphetamine=dopamine enhancement and NE

MAOI=antidepressant

prozac=seratonin reuptake inhibitor

cocaine=blocks reuptake of dopamine

t or f

A neuron becomes depolarized during IPSP?

Voltage gated Na+ ion channels are completely open during

a.  repolarization

b.  depolarization

c.  hyperpolarization

d.  both a and c

Which of the following statements is false?

a.  The Na-K pump maintains the RMP by pumping Na out of the cell and K+ into the cell

b.  The plasma membrane of a neuron is polarized

c.  In a resting neuron, the ICF  is more+ charged than the ECF

d.  none

This nt is classified as an e aa:

a.  GABA

b.  NE

c.  Glutamate

d.  ACh

Nerve impulses travel faster:

a.  by continuous(cable)conduction

b.  by saltatory conduction

c.  in myelinated fibers

d.  b and c

Which of the following statements is true?

a.  Interneurons are located in the PNS

b.  Efferent neurons are typically unipolar

c.  Afferent neurons transmit sensory information toward the CNS

d.  none

These supporting cells help form the BBB

a.  oligodendrocytes

b.  astrocytes

c.  microglia

d.  Schwann cells

Which neuroglia is not correctly paired with its function?

a.  oligodendrocytes; produce the myelin sheath

b.  microglia; phagocytic

c.  astrocytes; produce and release ACh

d.  ependymal cells; produce CSF

Which of the following statement is true?

a.  AP"s can vary with stimulus strength

b.  Graded potentials can travel long distances w/o losing strength

c.  Graded potentials are reversible

d.  AP's are generated w/i the dendrites

What is white matter primarily composed of?

a.  neuroglia

b.  myelinated axons

c.  neuron cell bodies

d.  all