Intro to the nervous system Slide Show Cards Flashcards Preview

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Flashcards in Intro to the nervous system Slide Show Cards Deck (72):
1

Somatic

What do these innervate?

Voluntary.

Innervate the bone, skin, muscles, and joints

2

Visceral - AKA Autonomic

What does it innervate?

Involuntary; autonomic Internal. Innervates the visceral tissues, smooth muscle, cardiac muscle, and glands.

3

Somatic efferent

Motor Supplies skeletal

4

Somatic afferent

Sensory Sensation from the skin, bone, joint

detecting temp, pain, burn

 

5

Visceral efferent - Autonomic Efferent 

Motor Sympathetic or Parasympathetic Smooth muscle cardiac muscle and glands

6

Visceral Afferent - Autonommic Afferent 

localized within organs and sending sensory information to the CNS

7

Cell body Where are they normally found?

Soma Usually found in collections (ganglia, nuclei, gray matter)

 

8

Dendrite What type of signal do they carry?

Multiple Carry Afferent impulses

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Axon What Type of signals do they carry?

single Carries Efferent impulses

10

Synapse

Point of communication between neurons or between neurons and effector cells (skin, muscle, gland)

11

Myelin...what does it do?

Insulates axons electrically Boosts nerve conduction

12

What are the cells that form the myelin sheath in the CNS?

Oligodendrocytes

13

What makes oligo dendrocytes unique to the CNS?

One oligo cell reaches out and mylinates many axons

14

Ehat are the cells that form the myelin sheath in the PNS?

Schwann Cells

15

What makes Scwann cells unique for the PNS?

One schwann cell mylinates a single axon

16

What is a collection of axons called?

A fascicle

17

What is the order and name of the connective tissue sheaths surrounding peripheral nerves?

1. Endoneurium (surrounds axon)

2. Perineurium (around fascicles)

3. Epineurium (around whole nerves)

18

Gray matter consists of 

Nerve cell bodies

Dendrites and short Axon segments

Glial Cells

Ganglion

19

White Matter Consists of

Axons. These primarily form the tracts

20

Where is white and gray matter on the spinal cord?

White = peripheral

Gray = central

21

Where is white and gray matter located in the cerebral cortex?

White = central 

Gray = peripheral

22

What are the three membranes that surround the spinal cord and roots? 

From Outermost to innermost

AKA Spinal Meninges

1. Dura Mater

2. Arachnoid mater

3 Pia mater

23

Dura Mater 

Dense Connective Tissue 

Forms Dural Root Sleeve

Blends with Epineurium (the outer connective tissue covering of the spinal nerves).

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Arachnoid Mater

Avascular

Encloses CSF-filled subarachnoid space

Held against the dura by CSF pressure

Arachnoid trabeculae connect the arachnoid and  the pia mater. 

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Pia Mater 

Adherent (like shrinkwrap) to brain, spinal cord, and nerve roots

Forms Denticulate ligament

Helps limit lateral movement of spinal cord

A image thumb
26

What are denticulate ligaments?

Lateral extension of pia mater

attach pia to arachnoid and dura

provides support for the spinal cord

27

What are the 3 main divisions of the gray matter in the spinal cord?

1. Dorsal horn

2. Lateral Horn - Intermediolateral column

3. Ventral horn

 

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Rootlets

Originate from one spinal cord segment and merge to form larger root

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Dorsal Root Ganglion

Swelling of the Dorsal root where the primary sensory neurons are locate

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Spinal nerve

Area where ventral and dorsal root merge

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Rami

Branching of the spinal nerve into dorsal and ventral rami

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Dorsal Rami innervate

synovial joints of vertebral column, intrinsic back muscles and overlying skin

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Ventral Rami innervate

anterior and lateral regions of the trunk and upper and lower limbs

34

What is the order of structures from the spinal cord that make a spinal nerve

dorsal and ventral rootlets -> merge to form dorsal and ventral roots -> form spinal nerve

35

Spinal roots have how many funstional fibers?

What are the two types of roots?

One single functional fiber type

A. Dorsal Root - afferent (sensory) -reception

B. Ventral Root - efferent (motor)- distribution

36

Spinal Nerves and Rami have how many functional fiber types?

Two (mixed)

Afferent (sensory) -reception

Efferent (motor) - distribution

37

Spinal Somatic reflex arc

What is the pathway?

Reaction to stimulus that does not involve the brain it's immediate.

 

Sensory input -> travels dorsal afferent signal -. dorsal horn -> Ventral horn -> signal transferred via efferent signal to muscle receptors.

38

Monosynaptic reflex

Mediated by receptors inside the muscle

Ex: biceps, triceps, patellar, achilles tendon, and deep tendon reflexes

39

Polysynaptic reflex 

Mediated by receptors outside muscle 

**Golgi tendon has a dysnaptic pathway

Ex: sensory receptors in the skin --touching a hot object

40

How many pairs of spinal nerves are there?

How many are cervical?

How many thoracic?

How many Lumbar?

How many Sacral?

How many coccygeal?

31

8

5

5

1

41

How many cervical spinal nerves are there?

How many cervical vertebrae are there?

8

7

One nerve exits above C1

C8 exits between C7 and T1

All other nerves exit just below the vertebrae with the same number

42

Where does a spinal nerve exit the spinal column?

Where are the intervertebral discs located in proximity to the IV foramen

The intervertebral (IV) foramen

Adjacent to the lower half of the IV foramen

43

Where would a herniated disc have its impact?

L4/L5 herniation affects what spinal nerve?

C5/C6 herniation affects which spinal nerve?

Affects the spinal nerve directly below it. 

L5

C6

44

What about the cervical region C5/C6 and C6/C7 disks are most commonly herniated?

The presence of the extra cervical spianl nerve C8 results in cervical nerves contacting the disk of the next higher number.

45

Where on the spinal cord are there enlargements?

C4-T1 because need more ventral rami to form the brachial plexus that supplies the upper limb

 

T11-S1 more ventral rami are need to form the lumbrosacral plexus that supplies the lower limb

46

Which spinal cord level is found at the L2 vertebral level?

What area can this spinal cord actually occur in real patients?

Conus Medullaris

 

high as T12 or as low as L3

47

Cauda Equina 

Spinal nerve roots form lumbosacral (lumbar) enlargement

48

Filum Terminale 

Anchors inferior end of spinal cord (Tip of the conus medullaris) to the coccyx 

 

49

What are the two parts of the Filum Terminale?

1. Filum terminale internum (pia mater)

 

2. Filum terminale externum (dura mater)

50

What is the Lumbar Cistern?

Where is it located?

What does it contain?

Enlargement of the subarachnoid space

Inferior end of spinal cord (conus medullaris at L2)

Inferior end of dura mater and subarachnoid space at S2

Cauda Equina, Filum Terminale, CSF

51

why does spinal cord end higher than the vertebral (spinal) canal?

What is a practical application of this?

During development, the vertebral column grows more than the spinal cord.

Spinal cords in children end at lower vertebral level than in adults. This is important when performing a lumbar puncture.

52

Where is the tip of the spinal typically found in an adult?

Where is the tip found in a newborn

L1/L2 IV disc

L3/L4

53

What creates and is occupied by the cauda equina?

Which way are lumbar and sacral spinal nerve roots in the cauda equina?

Lumbar cistern

Inferiorly

54

What is a lumbar puncture

What anatomical features allows this procedure to be performed safely?

Extraction of CSF from the lumbar cistern

The lumbar cistern is filled with fluid with the spinal nerves directed inferiorly in CSF. When you puncture a fluid filled space it gives greater chance that the nerve will be pushed out of the way instead of being punctured by the needle

55

Which space contains CSF?

Subarachnoid space

56

what are the two spaces lumbar anesthesia is typically placed?

1. epidural space - area before the dura mater (no spinal cord puncture)

 

2. Subarachnoid space - more risky because you are puncturing the spinal cord

57

What do most ventral rami form?

A peripheral nerve plexus

58

Cervical plexus is made up of which ventral rami?

The Brachial Plexus?

The lumbar plexus?

The Sacral plexus?

Why is there no thoracic plexus?

C1-C4

C5-T1

L1-L4

S1-S4

Thoracic ventral rami form individual parallel intercostal nerves (next to ribs)

59

Where does the brachial plexus begin?

What ventral rami form it?

What is it?

Where does the plexus extend into?

What is it's purpose?

Intervertbral Foramina

C5-T1

Branching network of intersecting nerves 

Into the Axilla (armpit)

It's branches supply the upper limb

60

What are the 3 Regions of the brachial plexus?

1. Supraclavicular

Roots

Trunks

2. Posterior to clavicle 

Divisions

3. Infraclavicular

Cords

Terminal Branches

61

Mnuemonic to remember parts of the brachial plexus

Rugby Team Drinks Cold Beer

Roots

Trunks

Divisions

Cords

Terminal Branches

62

What are the 5 terminal branches?

1. Axillary

2. Radial

3. Musculocutaneous

4. Median

5. Ulnar

63

All spinal nerves transmit sensory information from where? What is the single exception?

 

The skin

C1 nerve does not

64

What is a Dermatome?

Dermatomes on the trunk, neck, and posterior head form what?

Skin of the face and scalp are suppplied by what nerve?

A region of skin innervated by a single spinal nerve. 

Consecutive bands

The trigeminal nerve (CN V)

65

What is a Myotome?

 

Portion of skeletal muscle innervated by a single spinal nerve

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