TEST 3 Neurons

Question 1

Function of Nervous System (3)

Answer 1

1) Receive and collect Information(Dendrites) 2)process received information (soma/body) 3) Respond to information (axon)

Question 2

Structure of the Nervous System 2

Answer 2

1) CNS Central nervous system (Only Brain/Spinal Cord) 2) PNS Peripheral Nervous system (other nervous tissue; cranial and spinal nerves

Question 3

Two Functions of Nervous system

Answer 3

1) Sensory (afferent) 2) Motor Efferent)

Question 4

Sensory (afferent) Function

Answer 4

Toward CNC from periphery

Question 5

Motor (efferent)

Answer 5

Toward periphery from CNS 1) Somatic (to skeletal muscle 2) Autonomic ( anywhere else : smooth/cardiac muscle and glands

Question 6

Neuron chars

Answer 6

Respond to stimuli and send nerve impulses (action potential)

Question 7

Different Parts of Neuron

Answer 7

1) Soma 2) Dendrites 3) Axon 4) Axon Hillock (begin AP) 5) Axon collaterals(branches) 6) Axon terminals(telodendria) 7) Synaptic Knobs 8) Synaptic vesicles 9) Myelin sheath 10 Nodes of Ranvier

Question 8

Axon Hillock

Answer 8

Triangular region connecting axon to cell body where the AP(action potential) Begins

Question 9

Axon collaterals

Answer 9

Side branches of an axon

Question 10

Axon terminals (telodendria)

Answer 10

Fine terminal branches of an axon or axon collateral

Question 11

Synaptic knobs

Answer 11

Slightly expanded regions at the tips of Axon terminals (telodendria)

Question 12

Synaptic vesicles

Answer 12

Contain Neurotransmitters (i.e.. acetylcholine (ACh)

Question 13

myelin sheath

Answer 13

White covering that speed up an action potential

Question 14

Nodes of Ranvier

Answer 14

Gap/spaces between myelin sheath( sausages)

Question 15

What are supporting cells Called in the nervous system

Answer 15

Glial Cells

Question 16

Characteristics of Glial cells(6)

Answer 16

1) Supporting cells 2) No AP 3) Can divide 4) Outnumber neutrons 5) smaller then neurons 6) 6 main types

Question 17

6 types of Glial Cells and Location

Answer 17

1) Astrocytes (CNS) 2) Ependymal Cells (CNS) 3) Microglia (CNS) 4) Oligodendrocytes 5) Satellite Cell (PNS) 6) Schwann cells (PNS)

Question 18

Astrocytes Char

Answer 18

BLOOD BRAIN barrier 2) Most Common 3) Star shaped 4) Provide structural support

Question 19

Ependymal Cells

Answer 19

1)PRODUCE CEREBROSPINAL Fluid (CSF) 2) Cilia to circulate fluid 3) Form choroid plexus(network) 4) Line Ventricle of BRAIN and CENTRAL canal of spinal canal (CNS)

Question 20

Microglia Char

Answer 20

1) Phagocytize dead/damaged nervous tissue 2) <5% of neuroglia

Question 21

Oligodendrocytes

Answer 21

1) COVER AXON forming MYELIN Sheath (IN CNS) 2) Large 3) Cytoplasmic processes

Question 22

Satellite Cells

Answer 22

1) Regulate exchange of nutrients / waste products 2)separate cell soma of neutron interstitial fluid

Question 23

Schwann Cells(neurolemmocytes)

Answer 23

Form Myelin sheath in the (PNS)

Question 24

Myelin Sheath CNN vs PNS

Answer 24

Oligodendrocytes (multi) in CNS and Schwann cells (portion of an axon) in PNS

Question 25

Whats a Neurons neutral state?

Answer 25

Starts at a resting membrane potential (-70mv) (more negative on the INSIDE)

Question 26

How does a membrane maintain is membrane potential(-70mv)

Answer 26

1) Ion concentration (K+ Phosphate -; - protein all inside and NA+ Cl- outside) 2) Relative permeability of cell membrane to ions (m more permeable to K+ than anything else) 3) Na+/K+ pumps (2K+ IN & 3 NA+ out

Question 27

Action Potentials

Answer 27

1) Neuron send electrical impulses call action potentials (AP) 2) AP occurs when a stimulus CAUSES the NEURON to DEPOLARIZE. 3) If the neuron I depolarized to a CRITCAL Threshold (55mv) an Ap is generated(wave of depolarization)

Question 28

Depolarization is due to

Answer 28

NA+ ions rush IN inward(voltage -gate NA+ channel open)

Question 29

Repolarization Follows due to

Answer 29

K+ Flowing out (Voltage - gate K+ Channels Open

Question 30

Refractory Period and Types

Answer 30

Period after AP when it is difficult or impossible to generate other AP 1)Absolute (no AP can be generated regardless of stimulus 2) Relative: An AP can be generates but requires a larger then normal stimulus

Question 31

Myelinated AP Conduction

Answer 31

Ion flow can only at nodes of Ranvier; Saltatory Conduction( Skips sections Pass electrical current Faster)

Question 32

Unmyelinated AP conduction

Answer 32

No Node has continuous conduction (slower)

Question 33

All or None Law

Answer 33

If an AP is generated it will trail the ENTIRE length of the axon without losing strength(like shooting a gun)

Question 34

What happen in Axon Terminals

Answer 34

When AP reaches end of axon; cause voltage gated Ca+ channels to open and then neurotransmitter(chemical) is released. The Neurotransmitter cross synapse (synaptic cleft and bind receptor on another cell ( muscle gland or another neuron) causing a response.

Question 35

What are the TWO main neurotransmitters

Answer 35

1) Norepinephrine(NE) and Acetylcholine (ACh)

Question 36

Presynaptic neuron vs. post-synaptic neuron

Answer 36

Presynaptic neuron is the one simulating or inhibiting the other neuron while the Postsynaptic is getting acted on.

Question 37

Stimulus to the Post-synaptic neuron 2 TYPES

Answer 37

Excitatory postsynaptic potential(EPSP) - depolarize the postsynaptic neuron 2) Inhibitory postsynaptic potential (IPSP) Hyperpolarize the postsynaptic neuron

Question 38

Nerve fiber

Answer 38

Axon

Question 39

Nerve

Answer 39

Bundle of axons in Peripheral NS

Question 40

Ganglion

Answer 40

Cluster of neuron cell bodies in PNS

Question 41

Nucleus

Answer 41

Cluster of cell bodies in CNS

Question 42

Tract

Answer 42

Bundle of axons in Central NS

Question 43

Endoneurium

Answer 43

Cover individual axons

Question 44

Perineurium

Answer 44

Cover fascicles of axons

Question 45

Epineurium

Answer 45

Covers entire nerve

Question 46

White VS Gray Matter in CNS

Answer 46

White : mylinated axons Gray: no myelin(somas dendrites; unmylelinated axons; neuroglia) IN SC the white surrounds the gray while in the brain gray surrounds white with grey in the middle

Question 47

Multipolar Neurons(2)

Answer 47

1) 1 axon; several dendrites 2)Motor neurons; interneurons

Question 48

Bipolar Neurons (2)

Answer 48

1) 1 axon & 1 main dendrite 2) RARE (retina of eye; olfactory neurons)

Question 49

Unipolar Neurons (5)

Answer 49

1) 1 process divides into 2 branches 2) Branches resemble axons 3) Dendrites at tip of axon 5) Sensory neurons