spinal anatomy

Question 1

how many vertebra are in the spine

Answer 1

33

Question 2

portion of the spinal cord that allows for passage of the spinal cord

Answer 2

• vertebral foramen

Question 3

what are lateral notches

Answer 3

• know as intervertebral foramina
• allows for passage of the nerves
• if discs become damaged pressure is exerted on them

Question 4

what is the sacral cornu

Answer 4

• the bony process used to identify the sacral hiatus
• good for caudal block

Question 5

scoliosis

Answer 5

• lateral curvature

Question 6

kyphosis

Answer 6

• posterior curvature

Question 7

lordosis

Answer 7

• anterior curvature

Question 8

what are the 3 ligaments of the spine

Answer 8

• supraspinous
• intraspinous
• ligamentum flavum

Question 9

where is the epidural space

Answer 9

• between the ligamentum flavum and dura mater
• runs from base of cranium to sacral sulcus
• average depth is 5 cm (2.5 - 8cm)

Question 10

where does the spinal cord stop in adults and peds

Answer 10

• starts at medulla oblongata
• L2 in adults
• L3 in peds

Question 11

what are the 3 layers of the meninges

Answer 11

• dura mater
• arachnoid mater
• pia mater

Question 12

which meninge layer holds CSF

Answer 12

• arachnoid mater

Question 13

how many spinal nerves are there

Answer 13

• 31 pairs
• 8 cervical
• 12 thoracic
• 5 lumbar
• 5 sacral
• 1 coccygeal

Question 14

where in the spine are the nerves located

Answer 14

• 1st is between base of skull and atlas
• cervical correlate with vertebra below
• after T1 they correlate with vertebra above

Question 15

where is the cord enlarged

Answer 15

C5 - C7 and L2 - S3

Question 16

where is the brachial plexus located

Answer 16

C4 - T1

Question 17

where is the lumbar and sacral plexus

Answer 17

L2 - S3

Question 18

where is the cauda equina

Answer 18

L1 - S5

Question 19

what is the dorsal root

Answer 19

• sensory neurons, incoming
• laminae 1-6

Question 20

what is the ventral root

Answer 20

• motor neurons, outgoing
• laminae 7-9

Question 21

what regions make up the spinal cord

Answer 21

• dorsal
• lateral
• ventral

Question 22

what is the grey matter subdivided into

Answer 22

10 laminae of Rexed

Question 23

what is laminae 2 called

Answer 23

• substancia gelatinosa

Question 24

what is the substancia gelatinosa

Answer 24

• is where first order neurons of the spinothalamic tract synapse
• mu and k opioid receptors, presynaptic and post synaptic are found of these nerve cells
• are targets to manage pain

Question 25

what does the dorsal white matter consist of

Answer 25

- ascending sensory fibers tracts

Question 26

what do the lateral and ventral white matter consist of

Answer 26

- descending motor tracts - can ascend to the brain or - association tracts originate and terminate entirely within the spinal cord (reflexes)

Question 27

what do sensory/ afferent fibers do

Answer 27

- ascend - transmit pain, temp, pressure, touch, vibration, and proprioception

Question 28

where are sensory/ afferent fibers located

Answer 28

- in the epidermis and dermis

Question 29

what are the 2 classifications of sensory fibers and where are they

Answer 29

- exteroceptors (near surface of skin and oral mucosa) - proprioceptors (deep in skin, joints, ligaments, tendons, muscles, periostium)

Question 30

what are the two main sensory tracts

Answer 30

- dorsal column - medial lemniscus - anterolateral pathway

Question 31

dorsal column - medial lemniscus pathway

Answer 31

- sensory signal enters dorsal root - ascends through dorsal column on same side - arrives at medulla and crosses over (1st order to 2nd order synapse) - ascends via medial lemniscus tract through brainstem (2nd order neuron) - arrives at thalamus (2nd to 3rd order neuron)

Question 32

anterolateral pathway

Answer 32

- sensory enters through dorsal horn (1st order) - immediately crosses, synapses in the dorsal horn of grey matter (rexed laminae)(1st to 2nd order) - ascends to thalamus (2nd order) - synapses in brainstem or thalamus (2nd to 3rd) - interpreted in brain (3rd order)

Question 33

fiber and details of dorsal column medial lemniscus

Answer 33

- large myelinated fibers - discrete types of mechanoreceptive sensations - very specific - vibration, movement against skin, position of joints, fine touch

Question 34

fibers, sensations and details of anterolateral system

Answer 34

- small myelinated - slower speeds - broad spectrum of sensory modalities (pain, touch, warm, cold) - non-specific - sexual sensations

Question 35

SNS preganglionic fibers

Answer 35

- b fibers - originate in the intermediolateral gray horn between T1-L2 - exit the spinal cord via ventral nerve root (white rami) - paired segmental paravertebral ganglia form sympathetic trunk

Question 36

what are the cervical ganglia divided into

Answer 36

- superior ganglia - medial ganglia - inferior ganglia

Question 37

stimulation of the SNS superior ganglia causes

Answer 37

- mydriasis (dilation, contraction of radial muscle) - constriction of ciliary muscles of the head

Question 38

damage to the cervical paravertebral ganglia causes what

Answer 38

- horner syndrome

Question 39

what are the signs of horner syndrome

Answer 39

- miosis (pupil constriction) - ptosis (drooping eyelid) - anhydrosis (lack of sweating)

Question 40

inferior ganglia forms what

Answer 40

- fuses with first thoracic to form the stellate ganglia - located C5-C6

Question 41

what are the 4 stages of pain

Answer 41

- transduction - transmission - modulation - perception

Question 42

T-4 correlates with what

Answer 42

- nipple line

Question 43

T6/7 correlates with what

Answer 43

- xiphoid process

Question 44

T- 10 correlates with what

Answer 44

- umbilicus

Question 45

corticospinal tract

Answer 45

- supplies voluntary muscles of the trunk and extremities - originates in the large, upper motor neurons in the precentral gyrus - most neuromuscular disorders originate here (cerebral palsy and ALS)