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Flashcards in Ch. 12 Deck (109)
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1

Types of neuroglia aka glial cells (found in CNS): 

Bank: Microglia, Ependymal cells, Oligodendrocytes, Schwann Cells, Astrocytes, Satellite Cells

 

Description:

  • Star-shaped cells with many processes
  • Metabolize NT’s, maintain [K+] balance for CNS neurons
  • Help form the blood-brain barrier (BBB)
  • Serve as link between neurons & blood vessels

Nutshell: Maintains environemnt for neurons, which involves balancing POTASSIUM

Astrocytes

2

_______ = two or more graded potentials added together creates a greater change in membrane potential

Summation

3

Types of Neurotransmitters associated with CNS & PNS:

 

Acetylcholine is the most ______ of the neurotransmitters. It exists in both the somatic and autonomic nervous systems. It's also excitatory (i.e. moves muscles) and inhibitory (i.e. slows heart rate)

 

 

versatile

4

Graded potential is

• Generated on _______ (axons/membrane of dendrites and cell body)

• Remains localized; _____ (short/long)-distance communication only

membrane of dendrites and cell body

 

short

5

Quiz: Which items fit "Graded Potential" vs "Action Potential"

6

____________ - small deviation from RMP caused by a certain stimulus

 

_______________ GP – inner membrane more negatively charged than normal RMP

 

_______________ GP – inner membrane less negatively charged than normal RMP

Graded Potential

 

 

Hyperpolarized

 

Depolarized

 

NOTE: Occurs due to the opening/closing of mechanically or chemically gated channels (not voltage gated)

 

When ions move thru these gated channels, the membrane either depolarizes OR hyperpolarizes (relative to RMP); depends on ion charge & flow direction

7

Faulty neurotransmitters are treated in 2 ways:


1) With drugs that _____ a NT

2) Drugs that ______ a transmission

 

mimic

block

 

8

Types of Neurotransmitters associated with CNS & PNS:

 

_____ Acids
• Excitatory CNS: Glutamate & Aspartate
• Inhibitory CNS: GABA (brain) & Glycine (spinal cord)

 

Amino

9

Types of Ion Channels:  Chemically-Gated, Voltage-Gated, Mechanically-Gated, Leak Channels

 

  • Not gated
  • Randomly Open/Close
  • Membrane more permeable to K+ than Na+
  • More K+ leak channels and are leakier than sodium
  • Found in nearly all areas & types of neurons

Leak Channels

10

Nervous system serves 3 basic functions that relate to maintenance of an internal balance called ___________

 

What are those 3? 

homeostasis


1. Sensing changes, both inside & outside the body (sensory function)


2. Interpreting these changes (integrative function)


3. Reacting to these changes by causing muscle contractions or glandular secretions (motor function) 

11

Neurotransmitters are _____ (slowly/quickly) removed from the synaptic cleft by:

 

  1. ______ out of (away from) the synaptic cleft
  2. Enzymatic degradation (e.g. acetylcholinesterase)
  3. Uptake into cells – ______ transported back into neurons (reuptake) or into neuroglia (uptake)

quickly

 

1. Diffusion

3. actively

12

Branch of medical science that deals with nervous system is ___

neurology

13

Types of Ion Channels:  Chemically-Gated, Voltage-Gated, Mechanically-Gated, Leak Channels

 

  • Gate opens in response to neurotransmitters, hormones, and some ions
  • • Found in dendrites of some sensory (pain) neurons, interneurons, & motor neurons

Chemically-Gated

14

What are nerve cells called?

Neurons

15

Other factors that can modify of membrane potential:


1. Increased excitability - reduce the threshold; easier to depolarize membrane

  • Alkalosis (pH > 7.45) - lightheadedness, tingling, numbness spasms, etc.
  • Caffeine & nicotine


2. Decreased excitability – increases threshold; more difficult to depolarize

  • Acidosis (pH < 7.35) - weakness, lethargy, coma
  • Hypnotics, tranquilizers, anesthetics

just look at this a few times

16

The PNS is divided into 3 "subdivisions":

 

The _____ nervous system (SNS) is voluntary. It's basically your muscles.

 

  • Sensory (afferent) neurons conduct impulses from cutaneous & special sensory receptors to the CNS
  • Motor (efferent) neurons send impulses from CNS to __________

 

 

 

Somatic

 

 

 

skeletal muscles

17

Saltatory Conduction:
• Myelin sheath = electrical insulator; blocks membrane depolarization
• Nodes of Ranvier = contains many voltagegated channels (e.g. Na+)
• Membrane depolarizes/repolarizes very _______ (slowly/quickly) at nodes
• Stops at myelin sheath
• Nerve impulse “leaps” from node to node; travels very FAST
• Also uses ______ (less/more) ATP, since only small portions of the membrane gets depolarized

 

Quickly

 

 

less

18

The word _____ means = the capability to change based on experience.

 

Repeat to yourself: Learning new things means making new connections! Expending the dendrites to connect to other neurons (and using your neurons!). i.e, repitition is the best way to learn).

Plasticity

 

Repeat to yourself: Learning new things means making new connections! Expending the dendrites to connect to other neurons (and using your neurons!). i.e, repitition is the best way to learn).

19

 In the CNS, there is no connective tissue between nerve fiber bundles; therefore, bundle of nerve fibers (axons) are called a _____ instead of a nerve.

tract 

20

Two basic types of synapses:

1. Electrical synapse - found in smooth muscle, cardiac muscle, CNS (between neurons)

  • _____ (one-way/two-way) communication between cells:
    • • Ionic current spreads directly from cell to cell thru ____ junctions
    • • Electrical synapses are ____(faster/slower) than chemical synapses
    • • Quickly coordinates (synchronizes) activity of a group of
    • neurons or muscle fibers (e.g. in heart, bladder, etc.)

 

two-way

gap junctions

faster

21

Myelination ________(decreases/increases) from birth to maturity (e.g. better coordination with time)

increases

22

Excitatory & Inhibitory Postsynaptic Potential:


Excitatory NT - __________ (hyperolarizes/depolarizes) the postsynaptic neuron membrane

  • Inner membrane less negative; Cations IN or anions OUT
  • Generates _______ (excitatory/inhibitory) postsynaptic potential (EPSP) – closer to threshold potential
  • A single EPSP is not enough to start a nerve impulse. However, it is more excitable (closer to its threshold). The next EPSP may be enough to start a nerve impulse (summation).

depolarizes

 

excitatory

23

A bundle of nerve fibers in the PNS is called a nerve.

 

A bunde in the CNS is called a tract because it doesn't have __________ surrounding it

nerve

 

connective tissue

24

Which cell produces the lipids and mylinates the axon?

Schwann cell

25

Node of __________ = Gaps in the myelin sheath; neurofibral nodes 

Ranvier 

26

Types of neurons based on transmission:

Bank: Presynaptic neuron, Postsynaptic neuron


_________________ - Sends the signal toward synapse
_________________- Receives the signal and carries message away from synapse

 

 

Prestsynaptic neuron

Postsynaptic neuron

27

2. Chemical synapse (“slower”) - e.g. neuromuscular junction


________ (two-way/one-way) transfer of information (presynaptic to postsynaptic neuron or effector)


___________ neuron has end bulbs to release neurotransmitter
___________ neuron has receptor to recognize neurotransmitter
____________ - gap between pre-postsynaptic neurons

 

Bank: Postsynaptic, Presynaptic, Synaptic cleft

 

 

one-way

 

Presynaptic

Postsynaptic

Synaptic cleft

28

___________ (association neurons)

 

Connects sensory & motor neurons inside CNS

 

Most are multipolar

Interneurons

29

Review this "nuclei in the brain" image several times to get familiar with it

30

Regeneration of Nervous Tissue:


In CNS, injury ____ (can/can't) be repaired. Learning DOES frequently stimulate production of NEW neurons in the hippocampus of the brain; but no repair of injured neurons.

Example: A spinal cord injury makes you paralyzed for good! 

 

 

can't