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Flashcards in Nervous System Deck (90):
0

What is the structural organization of the Nervous System?

It can be divided into the Central Nervous System (CNS) and the Peripheral Nervous System (PNS)

1

What structures make up the CNS?

Brain and spinal cord

2

What structures make up the PNS?

Spinal nerves (31) and cranial nerves (12)

3

What is the functional division of the Nervous System?

It can be divided into the Afferent Sensory division and the Efferent Motor division

4

What can the Afferent Sensory Division be divided into?

Somatic sensory- information from skin, joints, skeletal muscle, special senses, fascia
Visceral sensory- information from the viscera/organs

5

What can the Efferent Motor Division be divided into?

Somatic Motor- voluntary nervous system (skeletal muscles)
Autonomic Motor- involuntary nervous system (smooth muscle, cardiac muscle, and glands)

6

How does information travel via the Afferent Sensory CNS?

Information travels to the CNS from the body

7

How does information travel via the Efferent Motor CNS?

From the CNS to the rest of the body

8

What are the 3 cell types that make up the Nervous System?

1. Schwann Cells
2. Neuroglia Cells (Glial Cells)
3. Neurons

9

What are Glial cells (neuroglia)?

Non-excitable cells that are for support, insulation, and nourishment of neurons

10

What are Schwann Cells?

These are the glial cells the of the PNS

11

What do Schwann Cells produce?

Myelin protein for myelinated axons

12

What is the relationship between Schwann Cells and axons?

Schwann Cells will encase the axon- groups of up to 10unmyelinated axons can be encased by 1 Schwann cell

13

What is an oligodendrocyte?

It is the type of glial cell in the CNS and is the equivalent of the Schwann cell in the PNS

14

What is Myelin and what is its function?

Myelin is layers of protein and lipid that forms a sheath around some axons and increases the speed of the impulse transmission between neurons

15

What is the structural and functional unit of the nervous system?

Neuron

16

What is the function of the neuron?

Specialized for rapid communication

17

What are the components of a neuron?

Cell body (soma, Perikarya)
Dendrite
Axon- can be myelinated or unmyelinated

18

What does a dendrite do?

Carry impulses to the neuron cell body

19

What does an axon do?

Carry impulses away from the neuron cell body

20

What is a synapse?

The point at which one neuron communicates with one or more neurons

21

What facilitates the communication between neurons?

Neurotransmitters

22

What are some neurotransmitters?

Acetylcholine
Norepinephrine
Dopamine
GABA

23

What is the nucleus in the CNS?

It is a collection of neuron cell bodies

24

Where is gray matter located in the CNS?

Nucleus

25

What is a tract?

It is a collection of nerve fibers that connect nuclei and is found only in the CNS

26

What is a ganglion?

It is a collection of nerve cell bodies and is only present in the PNS (outside the CNS)

27

What are peripheral nerves?

A collection of nerve fibers that connect the CNS with peripheral structures, spinal nerves, or cranial nerves

28

Where does the spinal cord begin?

At the medulla of the brain stem

29

Where does the spinal cord end?

At the L1-L2 vertebrae in adults and L2-L3 vertebrae in children

30

What is the spinal cord?

A long and thin tube shaped bundle of nerve fibers

31

What is the primary function of the spinal cord?

Transmit signals to and from the brain to peripheral structures

32

What is the shape of the spinal cord in the cervical region?

It is large and oval shaped

33

Is there a large amount or a small amount of white matter in the cervical spinal cord and why?

There is a large amount of white matter because all motor information that needs to pass to the body needs to go through the cervical region

34

What is gray matter?

It is a component of the CNS made up of nerve cell bodies and few myelinated axons

35

What is white matter?

It is a component of the CNS that is made up of glial cells and myelinated axons and few cell bodies

36

Is there a large amount or a small amount gray matter in the cervical region and why?

There is a small amount of gray matter because the cervical region is mostly sensory and gray matter is mostly for motor information (descending (motor) tracts have not excited the spinal cord)

37

What is the shape of the thoracic spinal cord?

It is oval shaped but smaller than the cervical region

38

The thoracic region has which horn of gray matter?

Lateral horn which contains part of the autonomic NS

39

What cell bodies are located in the thoracic spinal cord?

Cell bodies of the sympathetic nervous system

40

What is the shape of the lumbar spinal cord?

Round in shape and large

41

Does the lumbar region contain a large amount or a small amount of gray matter and why?

It has the largest amount of gray matter because it is more for the motor function of the lower limbs

42

What is the shape of the sacral spinal cord?

Similar to the lumbar spinal cord but smaller

43

Descending and ascending tracts of the sacral spinal cord

Most Descending tracts have excited the spinal cord
Many Ascending tracts have not yet entered the spinal cord

44

What are the 3 meninges of the spinal cord?

Dura mater
Arachnoid mater
Pia mater

45

What is dura mater?

It is the thick and fibrous outermost layer of the spinal cord

46

What separates the dura mater and the spinal cord?

Epidural space

47

What does the dura mater form?

The spinal dural sac

48

What pierces the dural sac?

Spinal nerves

49

At which region of the vertebral column does the dura mater end?

S1/S2

50

What anchors the dural sac to the coccyx?

Film terminale

51

What is arachnoid mater?

The delicate and vascular middle layer of the spinal cord

52

What is the subarachnoid space?

The space between the arachnoid mater and the pia mater

53

What is in the subarachnoid space?

CSF

54

What is CSF?

Cerebrospinal fluid
It is a clear and odorless fluid that is low in protein and cellular content and it is a cushion for the cord

55

What is pia mater?

It is the inner most layer of the spinal cord and is also the most delicate layer- it closely follows the surface of the cord

56

Pia mater

This layer directly covers the spinal nerve roots and blood vessels and it continues as the filum terminale

57

What is filum terminale?

It is a continuation of pia mater coming off of the conus medullaris after the spinal cord has ended- it pushes through the dural sac taking pia and arachnoid matter with it

58

What does the filum terminale do?

It anchors the spinal cord to the coccyx

59

What is the denticulate ligament?

Sheets of pia mater that runs longitudinal to the cord

60

What is the function of the denticulate ligament?

It anchors the spinal cord to the dural sac and it separates the posterior and anterior roots

61

How many total spinal nerves are there?

31

62

Where do the cervical spinal nerves exit?

From the intervertebral foramina above the named segment and C8 exits above T1

63

Where do the thoracic spinal nerves exit?

The intervertebral foremen below the named segment

64

Where do the lumbar spinal nerves exit?

The intervertebral foremen below the named segment

65

What do spinal nerves do?

They carry posterior (Afferent/sensory) and anterior (efferent/motor) information from 1 spinal segment

66

Where do the dorsal and ventral root run?

In the subarachnoid space

67

What meningeal layer covers the spinal nerves?

Pia mater

68

What meningeal layer do the spinal nerves pierce?

Dura mater

69

What are the 3 connective tissue coverings of the peripheral nerves?

Epineurium
Perineurium
Endoneurium

70

What does the epineurium enclose?

It encloses the bundle of fascicles including fat, blood vessels, amd lymphatics- this is the outermost covering

71

What does the perineurium enclose?

Dense tissue around one fascicles to protect it against foreign substances- this is the middle layer

72

What does the endoneurium enclose?

It is a delicate sheath that encloses a neurolemma and cells- this is the inner most layer

73

What forms the brachial plexus

C5-T1

74

What does the brachial plexus innervate?

The upper extremities

75

What forms the lumbosacral plexus?

It is formed by the lumbar and sacral nerve roots of L1-S5

76

What does the lumbosacral plexus innervate?

The lower extremities

77

What is the lumbar cistern?

An enlargement of the subarachnoid space to accommodate the cauda equina

78

What is a dermatome?

An area of skin innervate by a single spinal nerve

79

What is a myotome?

Muscle receiving Innervation from a single spinal level

80

What are the 3 longitudinal arteries that run from the brain stem to the conus medullaris and supply the superior spinal cord?

The 1 anterior spinal artery and 2 posterior spinal arteries

81

Where is the anterior spinal artery from?

Branches of the vertebral artery

82

Where are the posterior spinal arteries from?

Vertebral or posterior inferior cerebellar artery

83

What arteries supply most of the spinal cord?

Segmental medullary and radicular artery

84

Which artery reinforces circulation to 2/3 of the cord?

Greater anterior segmental medullary artery

85

Which artery supplies the nerve roots?

Anterior/posterior radicular arteries

86

How many spinal veins are there?

3 anterior spinal veins and 3 posterior spinal veins

87

How do the spinal vein run?

They run longitudinally and communicate freely with each other

88

What drains the spinal veins?

The 12 anterior and posterior medullary and radicular veins

89

What do the spinal veins form?

Internal vertebral venous plexus in the epidural space which communicates with dural venous sinuses and veins of the cranium