Nervous System (1/4) Flashcards

1
Q

Spinal Nerves

Thirty one pair of mixed nerves arise from the spinal cord and supply all parts of the body except the head

They are named according to their point of ______

___ Cervical (______)

___ Thoracic (______)

___ Lumbar (______)

___ Sacral (______)

___ Coccygeal (___)

A

Issue

8; C1-C8

12; T1-T12

5; L1-L5

5; S1-S5

1; C0

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2
Q

Nerve Plexuses

All ventral rami except T2-T12 form interlacing nerve networks called ______

Each muscle receives a nerve supply from more than one ______ ______

Damage to one spinal segment ______ completely _______ a muscle

A

Plexuses

Spinal Nerve

Cannot, Paralyze

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3
Q

Brachial Plexus

Formed by ______ and ____ (C4 and T2 may also contribute)

Brachial plexus gives rise to the nerves that innervate the _____ ______

A

C5-C8, T1

Upper Limb

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4
Q

Brachial Plexus

There are four major branches of this plexus

______ - Five ventral rami (______)

______ - Upper, middle, and lower, which form divisions

______ - Anterior and posterior serve the front and back of the limb

______ - Lateral, medical, and posterior fiber bundles

______

A

Roots; C5-T1

Trunks

Divisions

Cords

Branches

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5
Q

Brachial Nerves: Plexus

______ ______: second most common postop peripheral neuropathy

______: innervates the deltoid and teres minor

_______: sends fibers to coracobrachialis, biceps brachii, and brachialis (______ at elbow)

______: branches to most of the flexor muscles of forearm and opponens pollicis (______ of forearm, ______ of wrist, ______ of thumb, ______ of lateral three fingers)

A

Brachial Plexus

Axillary

Musculocutaneous; Flexion

Median, Prontation, Flexion, Opposition, Flexion

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6
Q

Brachial Nerves: Plexus

______: supplies the flexor carpi ulnaris and half of the flexor digitorum profundus (_____ of wrist, ______ of fingers, ______ of medial two fingers)

______: supplies ALL extensors of arm and forearm muscles (______ at elbow, ______ of forearm, ______ of wrist and fingers)

________ ______: can be blocked to reduce pain from tourniquet inflation during IV regional neural anesthesia

A

Ulnar, Flexion, Adduction, Flexion

Radial, Extension, Supination, Extension

Intercostobrachial Nerve

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7
Q

Neuron

Basic ______ ______ of CNS; around _____ billions of neurons

Responsible for _______ and _______ of nerve impulses

________ cells: produce myelin sheath which wraps around axon, providing insulation

_____ of ______: gaps in myelin sheath

_________ are synthesized in the _____ _____ and transported to synaptic knobs

A

Building Block, 100

Integration, Transmission

Schwann

Node of Ranvier

Neurotransmitters

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8
Q

Neuron

Neurons follow an ______ or _____ law in regard to action potentials

_______ _______: node to node jumping of depolarization

______ results slow or blocked conduction, such as seen with ______ ______ (nerve impulse conduction disorder)

A

All, Nothing

Saltatory Conduction

Demyelination, Multiple Sclerosis

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9
Q

Neurons

_______ neuron: short axon process arising from one side of the cell body, and a short dendritic process arising from the opposite site. Ex: ______ ______ neurons, including those found in the ____, _____, and ____

_______ neuron: has single large extension from its cell body. They are found in lower ______, but never in ______

________ neuron: present in _____ ______ ganglia

A

Bipolar, Special senses

Eyes, Ears, Nose

Unipolar, Invertebrae, Humans

Pseudounipolar, Dorsal Root

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10
Q

Neurons

_______ neuron: comprised of one axon and multiple dendritic processes; they are the most common type of neuron in the ______ and ______ ______

Other types of neurons include _______, ______, and ________

A

Multipolar

Brain, Spinal Cord

Sensory, Motor, Interneuron

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11
Q

Depolarization

Makes the cell membrane potential less ______ due to movement of positively charged ____ ions into the cell ( increased _______)

A

Negative, Na+

Excitability

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12
Q

Repolarization

The change that occurs after depolarization that returns membrane potential back to its ______ ______. Repolarization results from the movement of positively charged ____ ions out of the cells

A

Resting Potential

K+

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13
Q

Hyperpolarization

Makes the membrane potential more _______ due to movement of negatively charged ____ ions into the cell (reduced ______)

A

Negative, Cl, Excitability

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14
Q

Inward Current

The flow of _______ charge into the cell. Inward current ______ the membrane potential

A

Positive, Depolarizes

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15
Q

Outward Current

The flow of ______ charge out of the cell. Outward current ______ the membrane potential

A

Positive, Hyperpolarizes

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16
Q

Action Potential

Property of _____ cells (nerve and muscle) tha consists of a rapid _______ followed by ______ of the membrane potential

A

Excitable, Depolarization

Repolarization

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17
Q

Threshold

The membrane potential at which an action potential is _______

At threshold potential, net ______ current becomes larger than net ______ current

The resulting depolarization becomes self sustaining and gives rise to ______ of action potential

If net inward current is less than net outward current, no _____ _____ will occur

A

Inevitable

Inward, Outward

Upstroke

Action Potential

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18
Q

Resting Membrane Potential

Measured potential difference across the cell membrane (____ to ____ mV)

At rest, the nerve membrane is far more ______ to K+ than to ____

Leaky ___ channels are responsible for resting membrane potential

The ______ pump maintains resting membrane potential

A

-70 to -90 mV

Permeable, Na+

K+

Na+/K+

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19
Q

Action Potential

Action potential, or “______ ______” is a property of excitable cells that consists of a rapid depolarization (interior becomes less _______) followed by repolarization of membrane potential

Upstoke: Inward ___ movement; _______ blocks these voltage sensitive Na+ channels

Downstroke: Outward ___ movement; Outward flow of K+ _______ the membrane potential

Both ions flow by ______ _______

A

Nerve Impulse

Negative

Na+, Lidocaine

K+, Hyperpolarizes

Simple Diffusion

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20
Q

Absolute Refractory Period

Period during which another actional potential cannot be elicited, no matter how _____ the stimulus. This is due to closure of ______ gates of ____

A

Large, Inactivation, Na+

21
Q

Relative Refractory Period

Period during which an action potential can be elicited only if a ______ than usual stimulus is provided

Refractory period protects the cell from _____ ______, allowing a recovery period between the action potentials

A

Larger

Over-Excitation

22
Q

Signal Transmission (Myelination)

______ cells surround the nerve axon, forming a _____ ______

Sheath is interrupted every ____ mm

______ of _______ (Na+/K+ channels). Action potential can only occur at the _____

______ nerve fibers travel ______

A

Schwann, Myelin Sheath

1-3 mm

Node of Ranvier

Myelinated, Faster

23
Q

Multiple Sclerosis

Disease where _____ _____ is destroyed secondary to an _______ reaction

MS is an immune mediated inflammatory selective ______ of CNS

High incidence at higher _____; more common in women and those living in the _____ _____

1:1000 in US have this disease, female to male ratio is _____; with whites of ______ descent having highest incidence

A

Myelin sheath, Autoimmune

Demyelination

Latitudes, North Pole

2:1, European

24
Q

Multiple Sclerosis

Multiple foci of CNS demyelination of _____ _____

Characterized by ______ and ______

Signs and symptoms might include?

Diagnosed by?

Treatment: IV ______ to relieve acute symptoms. MS is _____ now

A

White Matter

Remissions and Relapses

Numbness, Transient sensory deficit, Pain, Fatigue, Optic Neuritis, Hemiparesis, Bladder & Bowel Incontinence, Loss of memory, Personality changes

MRI (Visible Plaques)

Steroids, Curable

25
Q

Multiple Sclerosis (Anesthetic Conditions)

Avoid ______ surgery during relapse

Any ______ may worsen the symptoms

______ ______ blocks with caution

Avoid ______ in paresis, will lead to ________

Avoid ______ in body temperature

A

Elective

Technique

Peripheral Nerve

Succinylcholine, Hyperkalemia

Increase

26
Q

Local Anesthetics

Procaine, Cocaine, Lidocaine, Bupivacaine

Blocks voltage sensitive ____ channels and inhibits conduction of _____ from periphery to CNS

Local anesthetics slow the rate of ______ of the nerve action potential such that the ______ potential is not reached

As a result, an action potential cannot be ______ in the presence of local anesthetic, resulting in conduction _______

A

Na+, Impulses

Depolarization, Threshold

Propagated, Blockade

27
Q

The Motoneuron - Vesicle Formation

  1. ) ______ vesicles: formed from budding Golgi and are transported to the terminal by ______ “streaming”
  2. ) Acetylcholine is formed in the ______ and is transported into the vesicles
  3. ) Acetylcholine filled vesicles occasionally fuse with the post-synaptic membrane and release their contents, causing ____-_____ potentials in the post-synaptic membrane
A

Synaptic, Axoplasm

Cytoplasm

End-Plate

28
Q

The Motoneuron - Acetylcholine Release

  1. ) AP begins in the _____ _____ of the spinal cord
  2. ) Local _______ opens voltage gated ___ channels
  3. ) An increase in the ______ ___ triggers the fusion of synaptic vesicles with the pre-synaptic membrane and release of _______ (exocytosis)
A

Ventral Horn

Depolarization, Ca++

Cytosolic Ca++, Acetylcholine (Ach)

29
Q

Neuromuscular Junction

The NJ is the synapse between axons of ______ and ______ muscles

The neurotransmitter released from presynaptic terminal is ________, and the postsynaptic membrane is the ______ receptor

A

Motoneurons, Skeletal

Acetylcholine, Nicotinic

30
Q

Events at Neuromuscular Junction

  1. Synethesis and storage of Ach in the ______ terminal
    - Acetyl CoA + Choline = _____ _____
    - Catalyzed by ______ ________

Ach is stored in ______ ______

  1. Depolarization of the pre-synaptic teerminal opens ___ channels
  2. ____ uptake causes release of Ach into ______ ______
A

Pre-synaptic

Acetyl Choline

Choline Acetyltransferase

Synaptic Vesicles

Ca++

Ca++, Synaptic Cleft

31
Q

Events at Neuromuscular Junction

  1. Diffusion of Ach to _______ membrane (muscle end plate) and binding Ach to ______ receptor
    - The nicotinic receptor is also a ____ and ____ ion channel
    - Channels open up and increase ____ and ____ conductance
  2. Depolarization and AP occur in the muscle ____ ______
  3. Muscle ______ occurs
A

Postsynaptic, Nicotinic

Na+, K+

Na+, K+

End Plate

Contraction

32
Q

Events at Neuromuscular Junction

  1. _______ of Ach
    - Ach is degraded by ______ ________ (AchE) on the muscle end plate
    - Choline is reuptaked by presynaptic terminal for ______
    - AchE inhibitors, such as ______, block the ______ and increase the action of _______
    - _______ is also used to reverse neuromuscular blockade
A

Degradation

Acetyl Cholinesterase

Recycling

Neostigmine, Degradation, Ach

Physostigmine

33
Q

Events at Neuromuscular Junction

  1. Hypocalcemia _____ neurotransmitter release, while Hypercalcemia _____ neurotransmitter release
  2. Hypomagnesemia ______ neurotransmitter release, while Hypermagnesemia ______ neurotransmitter release (antagonistic actions)
A

Decreases, Increases

Increases, Decreases

34
Q

Chemical Synapses

  1. An AP causes _______ of presynaptic terminal
  2. ____ enters the presynaptic terminal, causing release of ________ into synaptic cleft
  3. Neurotransmitter diffuses across synaptic cleft and combines with receptors on the post synaptic membrane, causing change in membrane _______ and _______
A

Depolarization

Ca++, Neurotransmitter

Permeability, Potential

35
Q

Chemical Synapses

  1. Excitatory neurotransmitter _______ the post synaptic membrane by opening ____ channels (__ influx)
  2. Inhibitory neurotransmitter ______ the post synaptic membrane by opening ___ channels (___ efflux) or ____ channels (___ influx)
A

Depolarizes, Na+, Na+

Hyperpolarizes, K+, K+

Cl-, Cl-

36
Q

Botulinus Toxin

(Clostridium botulinum) - from bad bottle of _____ (like honey)

Action: Blocks release of ___ from presynaptic terminals

Effect on neuromuscular transmission: Total _____, ______ paralysis “floppy baby” syndrome

A

Food

Ach

Blockade, Flaccid

37
Q

Curare

(Arrow Poison)

Action: Competes with ___ for receptor on _____ end plate

Effect on neuromuscular transmission: Decreases ___, paralysis of ______ muscles and death

A

Ach, Motor

EPP, Respiratory

38
Q

Neostigmine

Action: Inhibits ______ ______ (enzyme)

Effect on neuromuscular transmission:

______ and ______ action of ___ at muscle end plate

A

Acetyl Cholinesterase

Prolongs, Enhances, Ach

39
Q

Hemicholinium

Action: Blocks ______ of ______ into presynaptic terminal

Effect on neuromuscular transmission: ____ Ach stores from presynaptic terminals

A

Re-uptake, Choline

Depletes

40
Q

Amioglycosides

(Lambort Eaton Syndrome)

Action: Antibodies block ___ channels

Effect of neuromuscular transmission: No _____ of Ach, secondary to a lack of ____ release

A major sign and symptom of this antibiotic might include _____ _____

A

Ca++

Release, Ca++

Muscle Weakness

41
Q

Black Widow Spider

Action: ______ release of Ach

Effect on neuromuscular transmission: ________

A

Excessive

Convulsions

42
Q

Myasthenia Gravis “Grave muscle weakness”

  1. Antibodies bind to ____ receptors. This is an ______ reaction
  2. This _____ the number of Ach receptors (Ach cannot _____, therefore there is no _____ contraction)
  3. Signs ans symptoms: Double ______, difficulty _______ and ______, ______ muscle weakness and fatigue, _____ speech, _______ eyelids
  4. IV _______; a short acting ________ inhibitor, causes temporary improvement
A

Ach, Autoimmune

Reduces, Attach, Muscle

Vision, Swallowing, Speaking, Skeletal, Slurred, Droopy

Edrophonium, Cholinesterase

43
Q

Myasthenia Gravis “Grave muscle weakness”

  1. Treatment: _____ inhibitors, such as _______ will prevent the degradation of ____ and prolong the action of ____ at the muscle end plate, partially compensating for the reduced number of ______
  2. Thymectomy: tumor in ______ may be the actual cause of the ______ production; it will need to be removed
A

AchE, Physostigmine

Ach, Ach, Receptors

Thymus, Antobody

44
Q

Lambert Eaton Myasthenic Disease

Antibodies against ______ channels markedly reduce release of ____

Associated with underlying ______, such as ____ ____ lung cancer

A

Calcium, Ach

Malignancy, Small Cell

45
Q

Lambert Eaton Myasthenic Disease

Repetitive nerve stimulation demonstrates and increase in the motor action potential (contrasted with the decrease response in patient with true myasthenia gravis) Why?

A
46
Q

Acetylcholine released at the nerve ending by the nerve impulse normally binds with acetylcholine ______

This evokes ______ ______ in the muscle

In Myasthenia Gravis, ______ ______ ______ binds to the acetylcholine receptor and ______ the action of ____

Bound antibody evokes _____-_____ destruction of muscle ____ _____

A

Receptors

Action Potential

Anti-Acetylcholine Receptor Antibody, Inhibits, Ach

Immune-Mediated, End Plate

47
Q

Neuromuscular Function (Recap)

Normal transmission involves depolarized-induced influx of ___ through voltage gated channels. This stimulates the release of ____ from synaptic ______ at the active zone, and into the synaptic cleft.

Ach binds to Ach receptors and ______ the postsynaptic muscle membrane

A

Ca++, Ach, Vesicles

Depolarizes

48
Q

Neuromuscular Disorder (Recap)

Disorders of neuromuscular transmission result from:

Blockage of ____ channels. Examples of these are? (List 2)

Impairment of ___ mediated ____ release (List 1)

Antibody induced degradation of ____ receptors (List 1)

A

Ca++; Lambert-Eaton Syndrome, Aminoglycoside ABX

Ca++, Ach; Botulinum Toxin

Ach; Myasthenia Gravis