Spinal Cord With Dr. Forbes

Front 1

Vertabrea are derived when and from?

Back 1

At the same time as the spinal cord

Sclerotome portion of somites

Front 2

Sclerotomes form what?

Back 2

Cartilaginous mesenchymal model of the vertabral column that during the 4 week migrates to surround the developping spinal cord and notochord. The mesenchymal model is later ossified to make bony vertabrae.

Front 3

The neural tube induces the development of?

Back 3

Vertebral arch (Spinous and transverse Process)

Front 4

The notochord is induces the development of?

Back 4

Vertebral body

Front 5

Sclerotome origin of vertabrae

Back 5

Sclerotome cells migrate to surround developing spinal cord (neural tube) and notochord.
They form a cartilaginous mesenchymal model of the vertebrae
Happens at each segment to make series of vertebrae

Front 6

Endochondral Ossifacation??

Back 6

Cartilaginous model that is latter ossified

Front 7

Intervertebral Disc

Back 7

Nucleus Pulposus+ Annulus Fibrosus

Pulposus--remnant of notochord
Annulus Fibrosus--remnant of mesenchyme

Front 8

Ribs develop as?

Back 8

Outgrowth of the costal processes of thoracic level vertebrae

Front 9

Spina Bifida Occulta

Back 9

Most common in low lumbar/upper sacral region. Common usually asymptomatic

Front 10

Defective fusion of vertebral arches??

Back 10

Spina Bifida occulta and spina bifida cyctica

Front 11

Defective formation of vertebral body??

Back 11

Hemivertebrae ((scoliosis))

Results from NOTOCHORD failur to induce formation of body

Front 12

Defective fusion of vertebral arches are the result of?

Back 12

Failure of the neural tubes to induce formation of the arch

Front 13

Spina bifida cystica

Back 13

Meninges and/or spinal cord protrude
Much more serious condition that spina bifida occulta since it it produced neurlogical conditions

Front 14

Hemivertebra--

Back 14

Failure of one half of the vertebrae to form

Front 15

Cervical, lumbar or forked ribs

Back 15

Lumbar ribs usually asymptomatic

Cervical ribs may produce neurovascual problems in upper limb by pressure on subclavian vessels

Front 16

Lumbar cistern==

Back 16

Expansion of subarchnoid space that goes from vertebra L2 to S2.

Front 17

Cauda Equina

Back 17

Collection of lumbar, sacral and coccygeal nerve roots within cistern as they travel to origion intervertebral foramen.

DO SPINAL TAP HERE

Front 18

Overview of Spinal cord

Back 18

45 cm long in men 43 in women. Continous with medulla of the caudal brainstem at the foramen magnum. Terminates at tapered conus medullaris at L2.

2 spindle shaped swellings (cervical and lumbar enlargement) <C4-T1 and L2-L3> respectively

SC is surrounded by menninges and CFS in the subarachnoid space.

Front 19

Overview of SC continues

Back 19

WHite and gray matter in SC denote its many functions, blood supply comes from vertebral arteries plus segmental and radicular arterila branches.

Segmental spinal nerves, nerve roots and ganglia are present along the length of the cord.

Front 20

Cervical Enlargement

Back 20

C4 to T1 comprises that portion of the cord from which the nerves of the brachial plexus arise

Front 21

Lumbar Enlargement

Back 21

L2-S3, corresponds to the origional nerves innervating the lower extremity

Front 22

Conus Medullaris

Back 22

Cone shaped caudal end of the spinal cord. Filum terminal, the thin non nervous extension of pia extends beyond the tip of conus medullaris

Front 23

Spinal cord segments and do not correspond with surrounding vertabrae!!! SUPER IMPORTANT FACT

Back 23

Know that the spinal nerves of 1-7 exit above cervical vertabrea while nerves C8 and below exit below the the thoracic, lumbar and sacral vertebrae

Front 24

Spinal Nerve C8 lies on which Vertebral body Level and Which vertebral spinous process?

Back 24

C6-7 and C6

Front 25

Spinal Nerve T6 lies on which vertebral body and spinous process?

Back 25

T4-5 and T4

Front 26

Spinal Cord segement L1 lies on which vertebral process and body?

Back 26

Body Is T11, T10

Front 27

Meningeal Coverings??? 3 kinds

Back 27

Dura mater, arachnoid, and pia. DAP

Front 28

Dura mater

Back 28

Strong, continous with foramen magnum of the skull with the inner or meningeal layer of cranial dura. Extends caudally to S2 vertabrea where it terminantes in filum terminale and attaches to periosteum of coccyx. Dural tube forms sleeves around spinal nerve roots within intervertebral formainait then becomes continous with epineurium of peripheral nerve.

Front 29

Arachnoid mater

Back 29

Arachnoid membrane and arachnoid trabeculae. MEMBRANE lies near dura and forms the intner wall of the subdural space. Inner surface of membrane creates numerous trabeculae that pass across underlying CSF filled subarachnoids space to become continous with the pia. Continous to S2 level like dura.

Front 30

Pia mater

Back 30

Innermost menineal layer directly connects to the SC, Blood vessels supplying cord are associated with pia.

Front 31

Denticulate Ligaments-

Back 31

Twenty one pair of bi lateral extensions of pia, attached to lateral surface of cord between dorsal and ventral roots then penetrate thru subarachnoid space to inner wall of dura. They are used to suspend the cord in subarachnoid space and provide lateral stability.

Front 32

Filum terminale

Back 32

continuation of pia beyond the caudal end of the cord, serves as the anchor for the caudal end of the spinal cord to be incorporated to coccygeal ligament.

Front 33

Epidural Space

Back 33

Between dura and the inner wall of the vertebral canal. FAT FILLED.

Front 34

Subdural Space

Back 34

Small potential space between dura and arachnoid that can enlarge if infection is present

Front 35

Pachymeninx is another name for?

Back 35

Dura mater

Front 36

Spinal Ganglia are located where?

Back 36

Intervertebral foramina

Front 37

A stress fracture of the L5 vertabrae

Back 37

Spondylolisthesis

Front 38

For an injection into the subarachnoid space the most important land mark for determining where to insert the needle is the?

Back 38

Iliac Crest

Front 39

The Ligament flavum is located where?

Back 39

Between the laminae of adjacent vertebrae?

Front 40

What serves as the roof and floor of the intervertebral foramen?

Back 40

The pedicles.

Front 41

If there was a herniation of the L-4 and L-5 intervertebral disk which nerve would be compressed?

Back 41

L-5

Front 42

For a spinal block the drug is injected where?

Back 42

The subarachnoid space

Front 43

The cauda equina is located where?

Back 43

Lumbar cistern

Front 44

Denticulate Ligaments are made from what?

Back 44

Pia mater

Front 45

Conus Medullaris is what?

Back 45

The caudal end of the spinal cord

Front 46

Filum terminale is what?

Back 46

The caudal extension of the pia mater onto the conus medularius

Front 47

Subarachnoid Space

Back 47

Filled with CSF, has lumbar cistern-enlargement of the dura-arachnoid tube and thus subarachnoid space. SAMPLE CSF HERE. SAS is immediately adjacent to the pia mater that covers the surface of the spinal cord

Front 48

3 Things that create Longitudinal fissures and sulci of the spinal cord?

Back 48

Posterior median sulcus, posterior median septum, anterior median fissure

Front 49

Cauda equina

Back 49

bundles of caudally directed spinal nerve roots

Front 50

Posterolateral sulci

Back 50

Location of dorsal roots entry into the spinal cord

Front 51

Anterolateral sulci

Back 51

location of ventral roots exit from the spinal cord

Front 52

3 columns of longitudinally coursing nerve fibers?

Back 52

Posterial funiculi, anterial funiculi, lateral funiculi

Front 53

What are these structures?

Back 53

Front 54

Gray and white Rami communicantes do??

Back 54

Associated with sympathetic (autonomic) ganglia

Front 55

Spinal Cord variations occur because and how?

Back 55

The cord is smaller caudally and differs at each level there is less white matter at each level. due to nerve fibers decreasing caudally as descending tracts terminate and ascending tracts aren't yet complete.

cervical segments are larger and oval while lumbar and sacral segments are smaller and rounder.

Front 56

Spinal Enlargements that have more gray matter at these points?

Back 56

Cervical C4-T1
Lumbosacral L2-S3
Lateral Horn T1-L2

Front 57

Segmental Spinal nerves fuse where?
Branch?
How many spinal nerves?

Back 57

Dorsal (sensory) and ventral (motor) roots fuse laterally outside the spinal cord.

The spinal nerves branch into the dorsal and ventral rami and then into peripheral nerves

31 pairs of spinal nerves
8 cervical
12 thoracic
5 lumbar and 5 sacral and 1 coccygeal

Front 58

Dorsal roots Do what?

Back 58

They carry sensory (primary afferent) input to the cord from the somatic and visceral structures. NO SYNAPSIS FOR DORSAL ROOT GANGLIA. Cell bodies of all sensory neurons that send their axons via the dorsal roots are all located in the dorsal root ganglia and are made of PSEUDIOUNIPOLAR neurons that have only 2 processes.

Front 59

Dorsal roots are made up of only??

The peripheral process of a primary afferent neuron extends?

The central process of the PAN goes where?

Back 59

Pseudiounipolar neurons

Peripheral processes extend to receptors in the skin, joints, viscera

Passes thru the dorsal root and then Branches multiple times before coming to rest in the CNS

Front 60

Ventral roots carry what?

Their cell bodies are located where

Back 60

Motor (efferent) output from the cord to the somatic and viscera structures.

The cell bodies are located in the anterior and lateral horns of the gray matter of the spinal cord

Front 61

Motor neurons in the ventral horn innervate ????

Motor neurons in lateral horn are ????

Back 61

Skeletal Muscles

pre-ganglionic autonomic neurons

Front 62

Gray and white rami communicas??

Back 62

Extend to and from the Spinal nerve

Front 63

Pre ganglionic fibers are ?? and travel in ?? to ??

Post ganglionic ??? fibers travel in the ??? from the ????

Back 63

Pre ganglionic fibers are mylenated fibers that travel in the white ramus to the automic ganglia

Post ganglionic (unmylenated) fibers travel in the GRAY RAMUS from the autonomic ganglia.

There are synapses in the autonomic ganglia between pre and post ganglionic nerves

Front 64

The Central canal develops from??

Back 64

The neural canal of the neural tube.

Front 65

Central canal details

Back 65

Very small canal opening that is continuous rostrally with the central canal and fourth ventricle of medulla (brain stem) it ends caudally within the conus medullaris. Very little CSF present in it even though there should be.

Primary circulation of CSF is associated with the subarachnoid space

Front 66

Gray Matter contains?

Back 66

Nerve cell bodies and synapses

Front 67

White matter consists of?

Back 67

AXONS!! that form Tracts.

Front 68

Posterior funiculus divided into??

Back 68

2 Fasciculi

Fasciculi Gracilis and fasciculi cuneatus

Front 69

All sensory and motor activity associated with the body involves the spinal cord. What are the 4 functional components of the spinal cord

Back 69

1 General Somatic Afferent (GSA)
2. General Visceral Afferent (GVA)
3. General Somatic Efferent (GSE)
4. General Visceral Efferent (GVE)

Front 70

Each Spinal nerve retains its relationship with its respective??? this allows what?

Back 70

Respective somite during development, this allows for spinal cord segments to be related in a systematic fashion to the structures that they innervate such as skin or muscle.

Front 71

Sensory Innervation involves 2 aspects what are they and what do they do?

Back 71

Sensory (or primary afferent) input arrives via spinal nerves to the dorsal roots (GSA and GVA) primary afferent or first order cell bodies are in the dorsal root ganglia

Dermatomes: spinal nerve associated primarily with one dermatome

Front 72

Motor Innervation invovles?

Back 72

Motor output that leaves the spinal nerve via the ventral roots and spinal nerves to innervate skeltetal muscles GSE and to supply preganglionic neurons GVE that will terminate on postganglionic autonomic neurons. Skeletal muscles are innervated in a systematic fashion by spinal nerves.

Front 73

Reflex Activity details

Back 73

Ranges from simple or monosynaptic (knee jerk) to polysynaptic (flexor)

Maybe confined to spinal cord *one or more levels or involve brain stem connections.
INFLUENCED BY DESCENDING TRACTS and local inputs

ALTERED if either afferent or efferent neuron is damaged or there is a change in the influence of descending tracts.

Front 74

Gray Matter of the Dorsal Horn

Back 74

SENSORY!!
Contains neurons (that send axons up the white matter of SC to form tracts that terminate in the brain) and interneurons which create synaptic connections with nearby neurons.

Primary afferent of dorsal root GSA and GVA. Descending tracts that also travel in the white matter of spinal cord

Nuclie-specialized for diff. functions t

Front 75

Nuclie

Back 75

areas specialized for different functions, it is a collection of nerve cell bodies with similar functions and connections

Front 76

Gray Matter of the lateral horn

Back 76

Aka: Intermediolateral cell column. (Present in the rostral-caudal extent from T1 to L1/L2 cord segments)
PREGANGLIONIC SYPATHETIC NEURON CELL BODIES.

Front 77

Preganglionic Sypathetic cell bodies

Back 77

Axons exit spinal cord via ventral roots, parasympathetic preganglionic cell bodies are also located in the lateral region o fthe spinal gray at S2-S4

Front 78

Gray matter of ventral horn contains???/

Back 78

MOTOR NEURONS: contains alpha neurons that innervate extra fusial skeletal fibers. Aka lower motor neurons or anterior horn cells.

Gama motor neurons that innervate the intrafusal muscle fibers of the muscle spindle receptors, interneurons that are similar to the dorsal horn

Front 79

Alpha motor neurons

Back 79

Innervate the exrafusal muscle fibers that make up the bulk of the body

Front 80

Gamma motor neurons

Back 80

Innervate the small intrafusal muscle fbers of the muscle spindles which are found within the muscles

Front 81

Muscle spindles??

Back 81

Are sensory receptors that influence the contraction of the extrafusal muscle fibers

Front 82

Phrenic nucleus

Back 82

Medial position of the ventral horn at c3 to c5
reflects origin of the diaghrgm from cervical myotomes

Front 83

Accessory Nucleus

Back 83

lateral position in ventral horn at c1 to c5/c6
Nerve rootlets exit spinal cord dorsal to the denticulate ligament and pass rostrally alon the cord to enter the skull thru foramen magnem. Gives ride to Cranial NERVE XI (ACCESSORY NERVE)

Front 84

Anterior Spinal Artery

Posterior Spinal Artery

Back 84

Supplies Ventral and lateral horns, base of dorsal horn central gray and anteraior and lateral funiculi

Dorsal horn, dorsal funiculi and possible dorsal part of lateral funiculus

Front 85

Fasciculus Gracillus

Back 85

Portion of the lateral column that is most medial and brings input to the lower extremity

Front 86

Fascicous Cuneatus

Back 86

Portion of the lateral column that feeds the upper extremities is located laterally to the f. gracillus and stops at t6

Front 87

Dorsal columns are responsible for??

Back 87

Touch, vibration

Front 88

Dorsal lateral fasciculi are responisble for?

Back 88

Pain and temperature but they must travel ventally and pass thru the ventral white commissue

Front 89

Ventral white commissue

Back 89

Portion of SC that pain and temp. input must pass thrue

Front 90

The lateral colums are responsible for?

Back 90

Cortocspinal and Spinalthalmic tract