Bb Neuroanatomy Lab 2

Front 1

Denticulate ligament

Back 1

Thickening of pia and glial elements that tethers spinal cord laterally
– Forms ribben along lateral surface of the spinal cord between dorsal and ventral rootlets
- attaches cord to and suspends it in dura/arachnoid tube

Front 2

Where the two spinal cord enlargement

Back 2

cervical enlargement C4-5 - T1
lumbosacral enlargement L2-S3

Front 3

Conus medullaris

Back 3

Tapered end of cord

Front 4

Filum terminale

Back 4

Extension of pia and supporting cells
Anchors spinal cord to dorsum of coccyx

Front 5

At which level does the spinal cord end

Back 5

L1-2
in children at L3

Front 6

Surface markings of cord

Back 6

– Anterior median fissure
– Anterior lateral sulcus
– Posterior median sulcus
– Posterolateral sulcus

Front 7

What is the ventral nerve roots exit

Back 7

Anterolateral sulcus

Front 8

Where does the dorsal nerve nerve root enter

Back 8

Posterolateral sulcus

Front 9

Which portion of the cord gives rise to the spinal nerve

Back 9

Segment
- posterior and anterior roots join to form spinal nerve
- 31 segments and human spinal cord giving rise to 31 pairs of spinal nerves
8C, 12T, 5L, 5S, 1C

Front 10

Which of the longest roots and why

Back 10

Lumbosacral roots because they have to travel the furthest before they exit

Front 11

What is the difference between epidural space in the spinal cord compared to the brain

Back 11

In the spinal cord it is a true space where the dura is not fused with vertebral bodies

Front 12

Which two arteries make up the posterior blood supply of the CNS

Back 12

Vertebral arteries
Basilar artery
Steer cerebral arteries

Front 13

The vertebral arteries give rise to

Back 13

Anterior and posterior spinal arteries
Posterior inferior cerebellar artery (PICA)

Front 14

Basilar arteries give rise to

Back 14

Anterior inferior cerebral arteries (AICA)
Pontine arteries
Superior cerebellar arteries

Front 15

Anterior blood supply is made up of

Back 15

Internal carotid arteries
Give rise to:
– Anterior cerebral arteries (ACA)
- Middle cerebral arteries (MCA)

Front 16

Are anterior and posterior circulation independent?

Back 16

No, they're connected by network of arteries on cortical surface and communicating arteries on ventral surface

Front 17

Circle of Willis

Back 17

Interconnections between anterior and posterior circulations on the ventral surface

Front 18

Spinal cord and brainstem are supplied by

Back 18

vertebral-basilar system (posterior supply)

Front 19

The cortex is supplied by

Back 19

Both vertebrobasilar system and internal carotid system (post and ant circulations)

Front 20

Artery of Adamkiewicz

Back 20

Branch from segmental spinal artery
- present at ~T12
- provide major supply for lumbosacral spinal cord
- a.k.a. great radicular artery

Front 21

The vertebral arteries originate from

Back 21

Subclavian artery

Front 22

Does the posterior or superior artery supply more of the spinal cord?

Back 22

anterior

Front 23

Anterior spinal artery (ASA)

Back 23

- only 1
- branches of each vertebral artery joined to form ASA
– runs in ant median fissure
- 5-9 sulcal branches to each spinal cord segment
- each brand supplies anterior two thirds of either right or left side [I.e. paramedian and lateral areas]

Front 24

Posterior spinal arteries (PCA)

Back 24

- X2
- arises from vertebral arteries or PICAs
– Run in posterolateral sulci
– Supply posterior 1/3 of cord [Dorsomedial and dorsolateral areas]

Front 25

Coronal arteries

Back 25

- Anterior and posterior spinal arteries give off coronal arteries that anastomosed with each other.
- Form Corona around cord.

Front 26

Radicular arteries

Back 26

Reinforce circulation to cord

– Branches from cervical, intercostal, lumbar and sacral arteries that arise segmentally --> enter vertebral canal at intravertebral foramina --> anastamose with coronal arteries and from lower cervical area down, with anterior and posterior spinal arteries

Front 27

Which arteries provide most supplied to upper cervical cord

Back 27

Anterior and posterior spinal arteries

Front 28

Majority of blood supply beginning with lower cervical segments comes from

Back 28

Radicular arteries

Front 29

Which artery provides most of supplies for lumbosacral spinal cord

Back 29

Artery of Adamkiewcz

Front 30

The Gray matter consists of

Back 30

– Nerve cell bodies
– Processes
– neuroglia

Front 31

The anterior horn contains

Back 31

- cell bodies of lower motor neuron
- innervate skeletal muscles

Front 32

Lateral/intermediate horn

Back 32

- T1-L2/3 : preganglionic sympathetic cell bodies
- S2-S4 : preganglionic parasympathetic cell bodies

Front 33

Clarks nucleus

Back 33

Located in lateral horn within lamina 7
- relay center for unconscious proprioception
– Extends only to C6

Front 34

Rexed's laminae

Back 34

Layers that gray matter is divided into

Front 35

Major tracks and dorsal column

Back 35

Fasciculus gracialis [present at all levels]
Fasciculus cuneatus [present above T6]

Front 36

Major tracks in lateral column

Back 36

Lateral corticospinal tract
Rubrospinal tract [from red nucleus]
Spinocerebellar tracts
– Dorsal spinocerebellar tract
– Central spinocerebellar tract

Front 37

Which tracks are most lateral and lateral column

Back 37

Spinocerebellar tracts

Front 38

Major tracts in anterior column

Back 38

Spinothalamic tract
Vestibulospinal tracts
Reticulospinal tracts
Anterior corticospinal tract

Front 39

Lissauer's tract

Back 39

- Sensory fibers carrying pain and temperature will ascend and descend several spinal cord levels here before synapsing in the dorsal horn.
- Associated with spinothalamic tract.

Front 40

Substantia gelatinosa

Back 40

lamina 2 of the gray matter, first processing for pain and temperature

Front 41

Anterior White commissure

Back 41

Pain and temperature fibers cross
Anterior corticospinal tract fibers cross

Front 42

Six sulci of the spinal cord

Back 42

– Posterior median sulcus
– Posterolateral sulcus X 2
- Anterolateral sulcus X2
- anterior median fissure

Front 43

Where is the entry point of the dorsal root

Back 43

Posterolateral sulcus

Front 44

Where is the exit point for the ventral root

Back 44

Anterolateral sulcus

Front 45

Which is larger the anterior median sulcus or the anterior median fissure

Back 45

Anterior median fissure is much larger

Front 46

Anterior corticospinal tract

Back 46

- Motor to ipsi- and contra- lateral ventral horn
- Mostly axial musculature

Front 47

Spinothalamic tract

Back 47

Pain and temperature from contralateral side of the body

Front 48

Lateral corticospinal tract

Back 48

Motor to ipsilateral ventral horn
- mostly limb musculature

Front 49

Spinocerebellar tract

Back 49

Proprioception from limbs to the cerebellum

Front 50

Fasciculus cuneatus

Back 50

Sensory [fine touch, proprioception] from ipsilateral upper limb

Front 51

Fasciculus Gracialis

Back 51

Sensory [find touch, proprioception] from ipsilateral lower limb

Front 52

Summary: which tracks are ipsilateral

Back 52

– Lateral corticospinal tract
– Anterior corticospinal tract
– Fasciculus gracialis and cuneatus

Front 53

Summary: which tracks are contralateral

Back 53

– Spinothalamic tract
– Anterior corticospinal tract

Front 54

Somatotopic arrangement of fibers

Back 54

– Head [cervical region] fibers are always closest to the Gray matter

Front 55

What is the primary neurons synapse in the spinothalamic tract

Back 55

Primary Axons enter the spinal cord from the spinal ganglion, travel up or down 1 to 2 segments in the Lissauer's track and synapse in the posterior horn

Front 56

Which structures do the secondary neuron's of the spinothalamic tract pass

Back 56

Travels in the anterior lateral system:
– Caudal Medulla
– Rostral Medulla [between the inferior olivary nucleus and the nucleus of the spinothalamic tract of the trigeminal nerve]
- through pons and midbrain lateral to the medial lemniscas

Front 57

What is the spinothalamic tract terminate

Back 57

In the VPL of the thalamus
– From the thalamus fiber project through the internal capsule and Corona radiata to terminate in the primary somatosensory cortex [postcentral gyrus]

Front 58

What are the three Antero lateral pathways

Back 58

– Spinothalamic
– Spinalreticular
– Spinal mesencephalic

Front 59

Where do the primary axons of the dorsal columns synapse

Back 59

Axons enter the spinal cord from the spinal ganglion and passed directly to ipsilateral dorsal column and synapse
– Caudal fibers [below T6] enter FG [medial]
– Rostral Fidlers [above T6] enter FC to ascend

Front 60

Where do the secondary neuron of the dorsal columns travel

Back 60

Primary neurons terminate in NG and NC
- secondary neuron's cross the midline of internal arcuate fibers [Forming the medial lemniscus]
- they travel medial lemniscus adjacent to the midline thru the roster medulla
- through the caudal ponds, the media lemniscus flattens horizontal

Front 61

Where does the media lemniscus terminate

Back 61

In the VPL of the thalamus
– From the thalamus fiber project through the internal capsule and Corona radiata to terminate in the primary somatosensory cortex [postcentral gyrus] <-- same as SpT tract

Front 62

Where do the primary neurons of the corticospinal tract originate

Back 62

Primary motor cortex

Front 63

What is the path of the primary neurons of the lateral corticospinal tract

Back 63

- descending fibers from corona radiata converge to passes the posterior limb of the internal capsule
- fibers then descend through the middle 3/5 of the crus cerebri in the anterior part of the midbrain
- fibers a broken up into many bundles in the pons
- fibers descend as the pyramids in the anterior part of the medulla
-

Front 64

Where does crossover of the corticospinal fibers occur

Back 64

At the junction of the Meduna in the spinal cord, most of fibers cross the midline in the deposition of the planets.
– Cross fibers going to form the lateral corticospinal tract
– Uncrossed fibers descend as the anterior corticospinal tract

Front 65

What percentage of fibers cross over and what percentage of fibers descend in the anterior corticospinal tract

Back 65

– 85-90% of fibers crossover
- 10-15% descend in anterior corticospinal tract

Front 66

Where does the lateral corticospinal tract terminate

Back 66

On the lower motor neurons in the ant horn of the spinal cord
- anterior corticospinal tract fibers cross the midline at the level where they terminate on the LMN

Front 67

Corona radiata becomes the internal capsule when

Back 67

… It reaches striatum [caudate + putamen]

Front 68

Which cranial nerves are part of the parasympathetic nervous system

Back 68

3, 7, 9, 10

Front 69

Pain and temperature sensation from the bladder is carried by

Back 69

Somatic afferents

Front 70

Sensory fibers supplying the mucus and fundus of the bladder

Back 70

- travel with sympathetic
– reach spinal cord at T 12/L1
--> via spinothalamic tract to CNS

Front 71

Sensory from neck of the bladder

Back 71

– travel with parasympathetic's
– Reach spinal cord at S2/3/4
--> via spinothalamic tract to CNS

Front 72

Fullness of bladder

Back 72

– Carried by visceral afferents (PSNS)
– bladder wall mechanoreceptors --> sarcral parasympathetic's 2/3/4

Front 73

Voiding

Back 73

– Parasympathetic visceral motor
– Ditchers or muscle innervated by parasympathetic's from as 2/3/4 in the spinal cord --> hypogastric plexus --> synapse in vesical plexus --> detrusor muscle

Front 74

Internal urethral sphincter

Back 74

– Sympathetic visceromotor
- t11 – L2
- lumbar splanchnic nerves --> inferior mesenteric ganglion --> internal urethral spincter

Front 75

External urethral sphincter

Back 75

– Somatic motor, pudendal nerve
- S2/3/4 with pudendal nerve
- conscious and voluntary

Front 76

Onuf nucleus

Back 76

Origin of the pudendal nerve

Front 77

Micturition centers in cortex

Back 77

superior frontal gyrus

Front 78

Micturition centers in pons

Back 78

Pontine micturition center
Pontine storage center
Periaqueductal gray

Front 79

What needs to be inhibited or excited for voiding to occur

Back 79

– Inhibition of sympathetics (T12 L1) (to relax int sphincter)
- inhibit Onuf ( to relax ext sphincter)
- excitation of parasympathetic S2/3/4 (to contract detrusor)

Front 80

Why did infants have poor bladder control

Back 80

- their sacral reflex causes reflex contraction of the detrusor
- no control of external sphincter

Front 81

Sacral reflex pathway

Back 81

– Stretch receptors and bladder wall are activated
– Stretch receptor output is transmitted via afferet fibers of the pelvic nerve to the sacral cord
– Parasympathetic nerves bodies activated
– ACH released by parasympathetic cause contraction of the detrusor muscle
- in infants there is no control over the external center
- in adults the ext sphincter is under somatic control thru the pudendal nerve

Front 82

Voiding in adults

Back 82

– Under central control
– bladder feels full --> info is relayed to the cortex and PAG
- if socially susceptible to avoid, the Pontine micturition center is activated for both the cortex and the PAG
- excitation of parasympathetic as 2/3/4 --> contraction of detrusor muscle
- simultaneous inhibition of T12, L1 and internal sphincter relaxes
– inhibition of onuf (S2/3/4) --> somatic control of external sphincter is inhibited --> relaxation of ext sphincter

Front 83

Overflow Incontinence

Back 83

a form of urinary incontinence, characterized by the involuntary release of urine from an overly full urinary bladder, often in the absence of any urge to urinate. This condition occurs in people who have a blockage of the bladder outlet (benign prostatic hyperplasia, prostate cancer, or narrowing of the urethra), or when the muscle that expels urine from the bladder is too weak to empty the bladder normally.

Front 84

Reflex Bladder
Overflow bladder
Spastic bladder
Small volume bladder

Back 84

?

Front 85

BROWN SEQUARD SYNDROME:

Back 85

loss of pain & temperature on contralateral side of body
loss of discriminative touch, vibration & proprioception on ipsilateral side of body
UMN lesion on ipsilateral side of body
LMN for C8 myotome

Front 86

The spinal tap where's the needle extracting fluid from

Back 86

Subarachnoid space [CSF extraction]

Front 87

Spinal tap: at which level is a needle inserted

Back 87

L3 – L4

Front 88

Spinal tap: how is it performed in a newborn or a two-year-old

Back 88

At L4 or below
- posterior superior iliac spine [as L4 landmark]

Front 89

What is an epidural? How does it result in pain control?

Back 89

The form of local anesthetic
- blocks fast Na channels (washes over spinal nerves)

Front 90

Epidural: at which level do you insert the catheter? Which space is a needle inserted into?

Back 90

- Insertion at L3-L4
– Epidural space [outside sack]

Front 91

Spastic paralysis of the leg and Babinski signs are both indicators of

Back 91

Upper motor neuron lesion

Front 92

Loss of discriminative touch, vibration and joint position sense from approximately the level of the nipples down on the left side only. Where is the lesion?

Back 92

Dorsal column
– Nipples located at approximately T4
– At T4 fibres uncrossed --> Cross at medulla

Front 93

Lots of pain and temperature sensation from the mid abdomen downward on the right side. Where is the lesion?

Back 93

Spinothalamic tract
– Cross at spinal quite level
– At approximately T10

Front 94

What consequence will a severe lesion at the level of T8 have on bladder function?

Back 94

Lesion above T11 lose conscious control of bladder
– retain ANS reflex