Neuro Exam 1

Front 1

Common dermatomal reference for back of head?

Back 1

C2

Front 2

Common dermatomal reference for nipples?

Back 2

T4

Front 3

Common dermatomal reference for thumb and index finger?

Back 3

C6

Front 4

Common dermatomal reference for umbilicus?

Back 4

T10

Front 5

Common dermatomal reference for kneecap?

Back 5

L3

Front 6

Common dermatomal reference for lateral foot?

Back 6

S1

Front 7

Through which openings do the vertebral arteries run?

Back 7

Transverse foramina of C6-C1

Front 8

What level of the CNS does this image represent?

Back 8

Sacral - note presence of spinal cord AND cauda equina.

Hint 8

Note presence of both spinal cord and cauda equina.

Front 9

What information does the dorsal/posterior horn carry?

Back 9

Sensory (GSA, GVA)

Front 10

What information does the intermediate horn carry?

Back 10

Both sensory and motor

Front 11

What information does the anterior (ventral) horn carry?

Back 11

Motor (GVE, GSE)

Front 12

Identify structure at arrow.

Back 12

Anterior/Ventral Commissure:
White matter connection b/t left and right spinal cord

Front 13

Identify structure at arrow.

Back 13

Anterior Funiculus

Front 14

Identify structure at arrow.

Back 14

Anterior Lateral Sulcus

Front 15

Identify structure at arrow.

Back 15

Anterior Median Fissure

Front 16

Identify structure at arrow and describe its significance.

Back 16

Dorsolateral Fasciculus (or Zone/Tract of Lissauer); contains axons originating in substancia gelatinosa, involved in sensory modulation

Hint 16

Zone of Lissauer

Front 17

Identify structure at arrow.

Back 17

Lateral funiculus

Front 18

Identify structure at arrow.

Back 18

Posterior funiculus

Front 19

Identify structure at arrow.

Back 19

Posterior Intermediate Sulcus

Front 20

Identify structure at arrow.

Back 20

Posterior Lateral Sulcus

Front 21

Identify structure at arrow.

Back 21

Posterior Median Sulcus

Front 22

Definition of nucleus?

Back 22

A group of neurons with a common function or modality. Ex: hypoglossal nucleus = motor to the tongue (GSE)

Front 23

GSA?

Back 23

General Somatic Afferent
*Innervates skin, muscle spindles, tendons, and joints
*Exteroception (touch, temp, pain, itch, vibration)
*Proprioception (limb position and movement)

Front 24

GSE?

Back 24

General Somatic Efferent; motor to "common" skeletal muscle.
-Innervates skeletal muscle derived from myotomes

Front 25

GVA?

Back 25

General Visceral Afferents
*From "guts"
*Innervates viscera (heart, GI tract, etc.)
*Interoception (GI tract and bladder stretch, pH in blood)

Front 26

GVE?

Back 26

General Visceral Efferents; preganglionic autonomic fibers to guts, glands, and blood vessels.
-Innervates smooth and cardiac muscle and glands

Front 27

SSA?

Back 27

Special Sensory Afferents
*From "external" special sense organs
*Teloception (vision, audition, balance)

Front 28

SVA?

Back 28

Special Visceral Afferents
*From "internal" special sense organs (taste, olfaction)

Front 29

SVE?

Back 29

Special Visceral Efferents; motor to "gill" muscles.
-Innervates skeletal muscle derived from branchial arches

Front 30

What level of the CNS does this image represent?

Back 30

C2

Front 31

What level of the CNS does this image represent?

Back 31

C8

Front 32

What level of the CNS does this image represent?

Back 32

L3

Front 33

What level of the CNS does this image represent?

Back 33

T10 (look for lateral horn)

Front 34

What level of the CNS does this image represent?

Back 34

Sacral (note very small amount of white matter)

Front 35

Rexed's Lamina I?

Back 35

Posteromarginal Nucleus
*Present at all cord levels
*Receives pain & temp inputs
*Forms part of spinothalamic tract

Hint 35

Posteromarginal Nucleus

Front 36

Rexed's Lamina II?

Back 36

Substantia Gelatinosa
*Present at all cord levels
*Receives dorsal root afferents
*Filters/modifies sensory information by synapsing on dendrites of neurons in nucleus proprius
*Axons ascend or descend 1-4 segments in Lissauer's Tract

Hint 36

Substantia Gelatinosa

Front 37

Rexed's Lamina III & IV?

Back 37

Nucleus Proprius ("Chief" or "Proper" Sensory Nucleus)
*Present at all cord levels
*Receives many sensory/afferent inputs
*Contains cells that project CONTRALATERALLY as part of spinothalamic tract

Front 38

Rexed's Lamina VII?

Back 38

Nucleus Dorsalis (Clark's Nucleus)
*ONLY from C8-L3
*Receives muscle spindle afferents
*Projects IPSILATERALLY to cerebellum as dorsal spinocerebellar tract

Intermediolateral Nucleus (IML)
*ONLY from T1-L3
*Origin of preganglionic cholinergic sympathetic efferents (GVE)

Intermediomedial Nucleus (IMM)
*All cord levels
*Receives visceral afferents (GVA)

Sacral Autonomic
*S2-4
*Origin of cholinergic preganglionic parasympathetic efferents

Front 39

Rexed's Lamina IX?

Back 39

Motor neurons
*Large alpha motor neurons that innervate skeletal muscle
*Gamma motor neurons that innervate muscle spindle fibers
*Phrenic nucleus (innervates diaphragm)
*Spinal accessory nucleus (innervates SCM & trap)
*Origin of lower motor neuron pathway

Front 40

Caudal extent of spinal cord in newborn vs. adult?

Back 40

Newborn: L3
Adult: L1, L2

Front 41

Where is the lesion in a patient with a sensory loss corresponding to a dermatomal band just above the belly button?

Back 41

A sensory loss over a dermatomal area often indicates a DORSAL ROOT lesion. The described sensory loss corresponds to T9.

Front 42

Which meningeal layer continues as the epineurium surrounding peripheral nerves?

Back 42

The epineurium is continuous with the spinal dura, which is a continuation of the meningeal layer of the cranial dura.

Front 43

What nucleus is the upper limb equivalent of the nucleus dorsalis (of Clarke)?

Back 43

The lateral or accessory cuneate nucleus, which gives rise to the cuneocerebellar tract, is equivalent to Clarke's nucleus.

Front 44

What is the origin of sacral preganglionic parasympathetic efferents?

Back 44

Sacral preganglionic parasympathetic efferents originate for the sacral autonomic nucleus (S2-S4).

Front 45

Why is damage to high cervical spinal cord levels especially dangerous?

Back 45

Injury at high SC levels is especially dangerous b/c of the possibility of involvement of the phrenic nucleus, which could lead to respiratory paralysis.

Front 46

Identify the correct dermatomal level for the back of the head, the thumb, and the kneecap.

Back 46

C2 = back of head
C6 = thumb
L3 = kneecap

Front 47

Which vessels comprise the anterior circulation, and which regions of the cerebral cortex are supplied?

Back 47

Internal Carotids

Middle Cerebral
*lateral aspect of the cerebral hemisphere

Anterior Cerebral
*medial surface of the frontal and parietal lobes

Front 48

Which vessels comprise the posterior circulation, and which regions of the cerebral cortex are supplied?

Back 48

Vertebrals

Basilar

Post Cerebral
*Occipital lobe and inferior temporal lobe

Post Inf Cerebellar

Ant Inf Cerebellar

Sup Cerebellar

Front 49

Follow the pathway of CSF circulation from formation to return to bloodstream.

Back 49

1. Formation in choroid plexus of ventricles (mostly in laterals)
2. Through foramina of Monro (2) to 3rd ventricle
3. To 4th ventricle via cerebral aqueduct
4. Through foramina of Lushka (2 lateral) and foramen of Magendie (1 midline) into subarachnoid space
5. Through arachnoid villi into cerebral venous sinusus and returned to venous circulation

Front 50

What structures form the blood-brain barrier, and what determines whether substances cross it?

Back 50

The blood-brain barrier is formed by tight junctions between brain capillary endothelial cells. While astrocytic foot processes induce formation of tight junctions, it is the junctions themselves that form the barrier.

A substance's ability to cross the blood-brain barrier is usually determined by its lipid solubility. Some lipid insoluble substances (ie: glucose) are actively transported in, while some lipid soluble substances are actively transported out. Other substances may pass by endothelial cell pinocytosis.

Front 51

Name the three meninges and describe each.

Back 51

Dura mater:
*outermost layer
*comprised of outer endosteal layer and inner meningeal layer
*two layers separate to form dural venous sinuses, falx cerebri b/t hemispheres, and tentorium cerebelli b/t cerebrum and cerebellum

Arachnoid:
*intermediate layer
*lines dura with no space in between
*connects to pia via extensions called arachnoid trabeculae
*separated from pia by the subarachnoid space, which is filled with CSF

Pia mater:
*innermost layer
*adheres to brain surface, following gyri and sulci
*blood vessels on surface of the brain lie on top of pia

Front 52

What are arachnoid villi?

Back 52

One-way valves that penetrate the dural venous sinuses and allow CSF to pass from the subarachnoid space into venous circulation

Front 53

Which vessels comprise the Circle of Willis (as opposed to Ant/Post circulation)?

Back 53

Anterior Communicating a.
Posterior Communicating a.

Front 54

What vessels comprise the Circle of Willis?

Back 54

Anterior Communicating
Anterior Cerebral
Internal Carotid
Posterior Cerebral
Posterior Communicating

Front 55

What mechanisms are involved in maintaining stable cerebral blood flow?

Back 55

A constant cerebral blood flow is maintained by autoregulation: the ability of cerebral vessels to constrict or relax in response to changes in blood pressure, arterial CO2 levels, blood pH, and perivascular K+ concentration.

Front 56

Describe the encapsulation, adaptation, function, and distribution of free nerve endings (as receptors).

Back 56

Free nerve endings are:
*nonencapsulated
*slow adapting
*receptive to pain & temp
*found in deep skin and viscera

Front 57

Describe the encapsulation, adaptation, function, and distribution of Merkel's Disk.

Back 57

Merkel's Disks are:
*nonencapsulated
*slow-adapting
*sensitive to touch
*found in epidermis: feet, hands, genitalia, and lips

Front 58

Describe the encapsulation, adaptation, function, and distribution of hair follicles (as receptors).

Back 58

Hair follicles are:
*nonencapsulated
*fast adapting
*sensitive to touch
*found anywhere there is hair

Front 59

Describe the encapsulation, adaptation, function, and distribution of Meissner's Corpuscles.

Back 59

Meissner's Corpuscles are:
*encapsulated
*fast-adapting
*sensitive to 2-point discrimination
*found in hairless skin, fingertips, joints, and ligaments

Front 60

Describe the encapsulation, adaptation, function, and distribution of Pacinian Corpuscles.

Back 60

Pacinian Corpuscles are:
*encapsulated
*fast adapting
*sensitive to vibration, light pressure
*found in fingers, toes, palms, mesenteries, and peritoneum

Front 61

Describe the encapsulation, adaptation, function, and distribution of the neuromuscular spindle (as a receptor).

Back 61

Neuromuscular spindles are:
*encapsulated
*slow-adapting
*sensitive to muscle length (stretch)
*found in muscles

Front 62

Describe the encapsulation, adaptation, function, and distribution of golgi tendon organs.

Back 62

Golgi tendon organs are:
*encapsulated
*slow adapting
*sensitive to muscle tension
*found at the muscle tendon junction

Front 63

Which receptors are nonencapsulated?

Back 63

*Free nerve endings
*Hair follicle
*Merkel's Disk

Front 64

Which receptors are encapsulated?

Back 64

*Meissner's Corpuscle
*Pacinian Corpuscle
*Neuromuscular spindle
*Golgi tendon organs
*Ruffini ending
*Joint receptor

Front 65

With regards to the dorsal root afferents, how do the medial and lateral divisions differ?

Back 65

Medial:
*thick, heavily myelinated (m=medial=myelinated)
*2-point touch, limb position, muscle stretch
*sends collaterals to medulla

Lateral:
*thin, lightly myelinated (l=lateral=lightly myel.)
*pain, temp, light touch, visceral afferents
*asc/desc for 3-5 segments in dorslat. fasc. (Zone of Lissauer)

Front 66

What level of the CNS does this section represent?

Back 66

Medulla
*Note absence of "butterfly", thus not in spinal cord.
*Note "fused baby feet" look (per Dr. D)
*Note pyramids and inf. olivary nucleus
*Arrows point to Nuc. Gracilis, Nuc. Cuneatus, and medial lemniscus (from top to bottom)

Front 67

What information is conveyed via the dorsal column pathway?

Back 67

GSA:
*2 point discrimination (stereognosis)
*vibration sense (tuning fork)
*proprioception (position sense due to conscious perception of muscle spindle & golgi tendon receptors)

Front 68

Describe the Dorsal Column Pathway from start to finish.

Back 68

*Information sensed at receptor
*Info travels along afferent fiber through DRG
into Fasiculus Cuneatus (arm) or Gracilis (leg)
*Fiber shoots straight up,
synapsing in medulla at nucleus of same name (Nuc. Grac. or Cun.)
*In medulla --> crosses midline as internal arcuate fibers
*Travels upwards in medial lemniscus (white matter cord)
*Second synapse in thalamus (ventral posterolateral nucleus or VPL)
*Thalamus relays info to area 312 of cerebral cortex

Front 69

Which receptor types are involved in the dorsal column pathway?

Back 69

*Meissner’s corpuscle for 2 point touch
*Pacinian corpuscle for vibration
*Muscle spindle or golgi tendon for proprioception

Front 70

At what spinal cord level does fasiculus cuneatus begin?

Back 70

Fasiculus cuneatus begins at T6. Afferents below T6 travel along the fasiculus gracilis. Above T6, both the fasiculus gracilis and fasiculus cuneatus carry fibers to the medulla.

Front 71

Describe a positive Romberg sign and what it might indicate.

Back 71

Romberg's test is a neurological test that is used to assess the dorsal columns of the spinal cord, which are essential for joint position sense (proprioception).

A positive Romberg sign occurs when the patient is able to stand steadily with feet together, but sways and breaks stance when the eyes are closed. The essential feature is that the patient is unsteadier with closed eyes than with open eyes.

A positive Romberg sign indicates a problem with proprioception receptors or pathways, and could be due to a posterior column (or proprioceptive sensory nerve) lesion.

Front 72

A patient's MRI indicates that she has syringomyelia. If the cavity begins in the center of the cord and spreads laterally and to the right, what spinothalamic symptoms might she experience first?

Back 72

Contralateral (left-sided) loss of pain and temperature in the upper body.