Neuroanatomy

Front 1

Posterior column-medial lemniscal pathway

Back 1

Carries info about proprioception, vibration sense, and fine touch. Primary sensory neuron (dorsal root) --> ascends via ipsilateral white matter dorsal column --> synapse w/ dorsal column nuclei medulla --> secondary sensory neuron decussates --> synapse in the thalamus --> project to the primary somatosensory cortex in the postcentral gyrus

Front 2

Anterolateral pathway

Back 2

Carries info about pain, temperature sense, and crude touch. Primary sensory neuron (dorsal roots) --> synapse in gray matter of the spinal cord --> secondary sensory neuron decussates and ascends in anterolateral white matter (spinothalamic tract) --> synapse in thalamus --> project to the primary somatosensory cortex in the postcentral gyrus

Front 3

Which sensory input does not pass through the thalamus?

Back 3

Olfactory

Front 4

Components of the diencephalon

Back 4

Thalamus, hypothalamus, epithalamus

Front 5

Monosynaptic stretch reflex

Back 5

Reflex arc that begins with muscle spindles (sense stretch) --> transmission to sensory neurons --> dorsal root --> synapse in spinal gray matter with lower motor neurons (LMN's), causing contraction.

Front 6

Deep tendon reflex

Back 6

Muscle stretch reflex arc that begins with muscle spindles sensing stretch. Response can be routed via a monosynaptic stretch reflex (direct to LMN) and via interneurons (inhibitory). Tested clinically by tapping tendon with reflex hammer.

Front 7

CN I

Back 7

Olfactory nerve. Sensory.
Fxn: smell.

Front 8

CN II

Back 8

Optic nerve. Sensory.
Fxn: sight.

Front 9

CN III

Back 9

Oculomotor nerve. Motor.
Fxn: Eye movement (SR, IR, MR, IO), pupillary constriction (PS: E-W nucleus, muscarinic-R), accommodation, eyelid opening (levator palpebrae).

Front 10

CN IV

Back 10

Trochlear nerve. Superior oblique muscle; causes the eye to move downward and to rotate inward (depression and intorsion)

Front 11

CN V

Back 11

Trigeminal nerve. Sensations of touch, pain, temperature, vibration, and joint position for the face, mouth, nasal sinuses, and meninges; muscles of mastication; tensor tympani muscle.

Front 12

CN VI

Back 12

Abducens nerve. Lateral rectus muscle; causes abduction (outward movement) of the eye

Front 13

CN VII

Back 13

Facial nerve. Muscles of facial expression; also stapedius muscle and part of digastric; taste from anterior 2/3 of tongue; sensation from a region near the ear; parasympathetics causing lacrimation and supplying the submandibular and sublingual salivary glands

Front 14

CN VIII

Back 14

Vestibulocochlear nerve. Hearing; vestibular sensation.

Front 15

CN XI

Back 15

Glossopharyngeal nerve. Stylopharyngeus muscle; taste from posterior 1/3 of tongue; sensation from posterior pharynx, and from a region near the ear; chemo- and baroreceptors of the carotid body; parasympathetics to the parotid gland

Front 16

CN X

Back 16

Vagus nerve. Pharyngeal muscles (swallowing); laryngeal muscles (voicebox); parasympathetics to the heart, lungs, and digestive tract up to the splenic flexure; taste from epiglottis and pharynx; sensation from the pharynx, posterior meninges, and a region near the ear; aortic arch chemo- and baroreceptors

Front 17

CN XI

Back 17

Spinal Accessory nerve. Sternomastoid muscle; upper part of the trapezius muscle.

Front 18

CN XII

Back 18

Hypoglossal nerve. Intrinsic muscles of the tongue.

Front 19

From what does the CNS form?

Back 19

Wall of the neural tube

Front 20

Where does the ventricular system of the brain originate?

Back 20

The lumen of the embryonic neural tube

Front 21

Dorsal/ventral roots vs dorsal/ventral rami

Back 21

Roots are unimodal (they only carry information in one direction). Rami carry both afferent and efferent information.

Hint 21

Front 22

Major types of neuron interconnections

Back 22

Axoaxonic, axosomatic, axodendritic

Front 23

Embryologic origins of afferent cells, efferent cells, and association cells

Back 23

Afferent cells (bipolar and pseudounipolar) derive from neural crest cells. Efferent cells (multipolar) come from basal lamina. Association cells come from alar lamina.

Front 24

What kind of image is this?

Back 24

Myelin stained cross section.

Front 25

Describe the 3 primary brain vesicles and the 5 secondary brain vesicles.

Back 25

Front 26

Oligodendrocytes

Back 26

Glial cells that provide myelination to neurons in the CNS

Front 27

Nissl body

Back 27

Granules of RER with ribosomes attached that are located in neurons

Front 28

What kinds of things move by orthograde transport?

Back 28

Neurotransmitters, AA's, and membrane proteins. They travel via kinesin motor proteins.

Front 29

What kinds of things move by retrograde transport?

Back 29

Trophic factors/growth factors, viruses

Front 30

Axon hillock

Back 30

Junction between the cell body and the axon. Typically not covered by myelin or oligodendrocytes. More susceptible to changes in local ion concentrations. Site of departure of an action potential.

Front 31

How do you name the arms of pseudounipolar and bipolar neurons?

Back 31

Peripheral and central processes.

Hint 31

Front 32

Myelinated vs unmyelinated (structurally)?

Back 32

B. Unmyelinated axons are just "invaginations" into the Schwann cells (note they are not within the cytoplasm). i.e Remak Bundles

Front 33

Astrocyte functions

Back 33

Circumscribe the CNS (glia-pia membrane), induce blood brain barrier, buffer K+, regulated glutamate and glycogen in the brain, guide neurons during development, react to injury

Front 34

How do astrocytes buffer potassium?

Back 34

Astrocytes have many K+ channels and pick up the K+ ions that neurons release. There is also intra-astrocytic movement of K+ down its concentration gradient.

Hint 34

Bonus: when glial cells get sick and die, neurons can't survive.

Front 35

How do astrocytes regulate glutamate?

Back 35

Glutamatergic neurons release glutamate into the synaptic space. The glutamate is picked up by astrocytes, converted to glutamine, and given back to the presynaptic bouton.

Front 36

Excitotoxicity

Back 36

Path. by which neurons are damaged by excessive stimulation by NT's, e.g. glutamate.

Front 37

How do astrocytes regulate glucose?

Back 37

Most transfer of glucose from blood to CNS happens through astrocytes (they virtually envelop all of endothelial cells).

Front 38

Two types of astrocytes

Back 38

Protoplasmic astrocytes --> grey matter, more numerous.

Fibrous astrocytes --> white matter.

Front 39

Two types of oligodendrocytes

Back 39

Fascicular --> white matter

Perineuronal --> grey matter

Front 40

Internodal segment

Back 40

A segment of myelinated axon between 2 nodes of Ranvier

Front 41

How do oligodendrocytes and Schwann cells differ in the number of internodal segments they can make?

Back 41

ODC's can make an internodal segment on many different axons in the CNS, but SC's can only wrap one axon (1 internodal segment) in the PNS

Front 42

What is the dark purple material?

Back 42

Lipofuscin granules are lipid-filled waste products that can collect around neurons (as well as other cell types).

Front 43

What is this?

Back 43

Longitudinal view of nerve, with two internodal segments shown with a node of Ranvier between them.

Front 44

From which pharyngeal arches does the viscerocranium develop?

Back 44

1st and 2nd

Front 45

What are the nerve supplies to the pharyngeal arches?

Back 45

1st = trigeminal (V), 2nd = facial (VII), 3rd = glossopharyngeal (IX), 4-6th = vagus (X).

Hint 45

Mnemonic: when you eat something bad, you 1) chew 2) make a face 3) swallow

Front 46

What are the 5 prominences that come together to form the nose?

Back 46

Frontonasal prominence, lateral nasal prominence, medial nasal prominence, maxillary prominence, mandibular prominence

Front 47

What are the skeletal derivatives of pharyngeal arch 1?

Back 47

Meckel's cartilage, malleus, incus

Front 48

What are the skeletal derivatives of pharyngeal arch 2?

Back 48

Lesser horn of hyoid bone, styloid process, stapes

Front 49

At what level in the brain does the directional naming convention change?

Back 49

Between the diencephalon and the midbrain.

Front 50

The lumen of the primitive mesencephalon becomes what adult structure?

Back 50

Cerebral aqueduct

Front 51

Where does the cervical flexure occur in the primitive brain?

Back 51

Between the caudal end of the myelencephalon and the rostral end of the spinal cord

Front 52

Name the layers of tissue that one would have to pass through to reach the arachnoid mater superiorly.

Back 52

SCALP + calvarium + dura mater

Front 53

Where does the middle meningeal artery enter the skull? Where does it travel? What does it supply?

Back 53

Enters through the foramen spinosum; runs in the epidural space; supplies the dura mater.

Front 54

Which arteries make up the circle of Willis?

Back 54

Anterior cerebral aa, anterior communicating, internal jugular aa, posterior communicating aa, posterior cerebral aa

Front 55

The dura mater is "glued" to the skull by what?

Back 55

Sharpey's fibers

Front 56

What is the most vulnerable part of the calvarium to fracture?

Back 56

Pterion - very thin, and also at risk for damaging the meningeal artery

Front 57

What part of the dura dissects due to injection of fluid or subdural hematoma?

Back 57

The deep layer of the meningeal dura because it has fibroblasts but not collagen. The more superficial layers of the dura have collagen and are very difficult to dissect.

Front 58

What is the tentorial notch?

Back 58

Also called the tentorial incisura, it is the opening between the right and left leaves of the tentorium cerebelli. The hindbrain passes through it. With increased ICP, structures may herniate through it, e.g. uncal herniation.

Front 59

Where are cerebral veins located?

Back 59

Subarachnoid space

Front 60

What cell-cell contact is made between the menginges and brain parenchyma?

Back 60

Pia mater - to - glial cell contacts. Pia mater does not contact neurons.

Front 61

What are the two layers of the pia mater?

Back 61

Epipia layer - collagen and fibroblasts.

Intima pia layer - reticular and elastic, in contact with glia

Front 62

Meningiomas are tumors of what layers of the meninges?

Back 62

Leptomeninges

Front 63

What is a dermatome?

Back 63

A peripheral region innervated by sensory nerve fibers from a single nerve root.

Front 64

Which of the two systems of ascending tracts is more primitive and of lower velocity?

Back 64

The anterolateral system, which transmits pain, temperature, and crude touch.

Front 65

GSE

Back 65

General somatic efferent. Cells that give rise to axons that innervate striated muscles.

Front 66

GVE

Back 66

General visceral efferent. Autonomic neurons that synapse with a postganglionic cell which eventually innervate smooth muscle and glands.

Front 67

SVE

Back 67

Special visceral efferent. Cells that give rises to axons that innervate structures of the branchial arches, e.g. facial muscles, mastication, pharyngeal muscle. These cells are only found in the brainstem.

Front 68

What are the two types of cells located in the dorsal root?

Back 68

Somatic afferents (from ectoderm and somatic mesoderm derived cells) and visceral afferents (from endoderm and splanchnic mesoderm derived cells).

Front 69

What is shown here (conceptually)?

Back 69

These are the columns of cells in the CNS that are derived from neural crest, alar lamina, and basal lamina. The basal lamina has 3 sub groups: GSE, GVE, and SVE. The alar lamina has 4 sub groups: general/visceral, somatic/special afferent association cells. Not all cell columns are present at each level of the spinal cord/brain stem.

Front 70

Dendritic spread

Back 70

The area where one nerve can communicate/synapse with another nerve is not just localized to the soma (axosomatic). It can be anywhere throughout the postsynaptic nerve's dendritic spread which may branch extensively throughout gray matter and even some white matter.

Front 71

Divergence

Back 71

The functional idea that a neuronal axon can branch and synapse with multiple cells.

Front 72

Convergence

Back 72

The functional idea that one neuron can receive synapses from multiple difference neuronal axons.

Front 73

Name the CT coverings of a nerve fiber and brief function.

Back 73

Endoneurium gives substance to surrounding nerve axons and capillaries. Perineurium sequesters groups of axons, is water tight, and forms the "blood-nerve barrier". Epineurium acts a protective layer around the nerve.

Front 74

What is the conduction speed of alpha motor neuron?

Back 74

70-120 m/s

Front 75

Shoulder abduction

Back 75

*C5, C6 via the axillary neve

Front 76

Elbow flexion

Back 76

C5, *C6 via the musculocutaneous nerve

Front 77

Elbow extension

Back 77

C6, *C7 via the radial nerve

Front 78

Wrist extension

Back 78

*C6, C7 via the radial nerve

Front 79

Wrist flexion

Back 79

*C7, C8 via the median nerve

Front 80

Finger extension

Back 80

*C7, C8 via the radial nerve

Front 81

Finger flexion

Back 81

C8, T1 via the median/ulnar nerves

Front 82

Finger abduction

Back 82

*T1 via the ulnar nerve

Front 83

What are the two fiber bundles of the posterior columns, and from which regions of body do the nerves inside them come?

Back 83

Gracile fasciculus - sacral to T6.
Cuneate fasciculus - T6 up and cervical.

The lower extremity is represented medially (gracile) and the upper extremity is represented laterally (cuneate) within the posterior columns.

Front 84

Monoamines

Back 84

E.g. dopamine, NE, serotonin. NT's with an amino group and aromatic group--derived from aromatic amino acids.

Front 85

MAO

Back 85

Monoamine oxidase enzyme degrades monoamine NT's (DA, NE, S).

Front 86

COMT

Back 86

Catechol-O-methyl transferase enzymes degrades catecholamine NT's (NE, DA).

Front 87

AChE

Back 87

Acetylcholinesterase enzyme degrades acetylcholine.

Front 88

Benzodiazepines

Back 88

Sedative-hypnotic drug that binds to BZ receptor (part of GABA-A receptor). MOA: Increases GABA affinity and freq. of GABA-stimulated chloride channel opening. Leads to hyperpolarization. Rx orally for anxiety (short-term) and traditionally sleep disorders. Also, Rx for seizures, withdrawal states. Incr. lipid solublity, more rapid onset. Cleared by hepatic metab. SE: daytime drowsiness, sedation, ataxia, depressed respiration, *enhance CNS depression in combo with EtOH

Front 89

Diazepam

Back 89

Valium®. Benzodiazepine tranquilizer. Rx for anxiety, preanesthetic, seizures, withdrawal states, muscle relaxation. Long lasting, t1/2 > 24 hr.

Front 90

Alprazolam

Back 90

Xanax®. Benzodiazepine tranquilizer. Rx for anxiety, antidepression.

Front 91

Temazepam

Back 91

Restoril®. Benzodiazepine tranquilizer. Rx for insomnia.

Front 92

Phenobarbital

Back 92

Barbiturate, CNS depressant. Rx for anticonvulsant, sedative/hypnotic. MOA: acts allosterically on GABA-A receptors to potentiate and prolong effect of GABA. No real margin of safety. Very long acting (t1/2 ~ 2-7 days).

Front 93

Valproate semisodium

Back 93

Depakote®, divalproex sodium. Rx for manic episodes bipolar, epilepsy. MOA: possible GABA agonist. SE: teratogenic, liver disease.

Front 94

Zolpidem

Back 94

Ambien®. Nonbenzodiazepine sedative-hypnotic that acts on BZ receptor, potentiating GABA-A receptor. Rx for insomnia. In the class of "Z drugs" for insomnia.

Front 95

Eszopiclone

Back 95

Lunestra®. Nonbenzodiazepine hypnotic. Rx for insomnia. In the class of "Z drugs" for insomnia.

Front 96

Flumazenil

Back 96

Benzodiazepine antidote. Rx for BZ overdose.

Front 97

Inhibitory NT's bind to what kind of receptors to produce IPSP's?

Back 97

Ligand-gated K+ or Cl- channels. Both types push the local potential towards hyperpolarization, making it more difficult to achieve threshold.

Front 98

Nociception

Back 98

Experience of stimuli that damage tissue

Front 99

What's the function of the anterolateral pathway?

Back 99

To initiate the cells needed for protection and repair due to the stimulus of tissue damaging events. One thing is to make you aware, but the system actually developed to protect you from harm first.

Front 100

4 component operations of the ascending (sensory) system

Back 100

1. Transduction
2. Transmission
3. Perception/Localization
4. Interpretation

Front 101

Lissauer's tract

Back 101

Posterolateral tract. Contains Adelta and C fibers from dorsal rootlets entering spinal cord. Through this tract, these afferent fibers can ascend or descend 3 segments before entering gray matter.

Front 102

By the time afferent fibers from Adelta and C cross the midline, where in the spinal cord are they located relative to the segment it entered?

Back 102

They are about 2 segments upward when they have crossed the midline and entered the anterolateral column.

Front 103

How does encapsulation affect a sensory nerve ending?

Back 103

It lowers the threshold potential and allows for more sensitive nerve endings.

Front 104

What enters Lissauer's tract?

Back 104

A-delta and C fibers. NOT A-beta or Ia or Ib or II (muscle spindles)

Front 105

1) The central processes of afferent A-delta and C fibers synapse in which Rexed laminae?

2) And the cell bodies that provide the synapses (2nd order) are located in which laminae?

Back 105

1) I, II, V (A delta) and I, II (C fibers)

2) all but II and IX

Front 106

What is the somatotopic organization of the anterolateral column?

Back 106

Sacral is dorsolateral and cervical is ventromedial.
As the fibers enter the anterolateral column they enter laterally first.

Front 107

The medial part of VPL receives synaptic input from which dorsal fasciculus?

Back 107

Fasciculus cuneatus

Front 108

Stereognosis

Back 108

The faculty of perceiving and understanding the form and nature of objects by the sense of touch--via the lemniscal system. The absence of this ability is astereognosis or tactile object agnosia.

Front 109

Why is the tuning fork placed on bone?

Back 109

To entrap the Pacinian corpuscle against a hard surface so that the cutaneous tissue above it doesn't absorb all the vibration.

Front 110

What segment is this? Why?

Back 110

~ S1. The ventral horn is large (limb enlargement) and the dorsal columns are relatively small (not much of the lemniscal column has been added).

Front 111

What segment is this? Why?

Back 111

~T2 to T6 probably. The ventral horn is relatively small (so we are not looking at a limb region). The dorsal columns and anterolateral columns are relatively large so we are higher up the spinal cord. Also, we see a lateral horn (IML) which is sympathetic preganglionic cell bodies that are ONLY located between T1 and L2

Front 112

What region is this? Why?

Back 112

Pyramidal decussation is present, therefore we are in the caudal part of the caudal medulla. Also present are the nucleus gracilis and nucleus cuneatus.

Front 113

What region of is this? Why?

Back 113

Inferior olivary nucleus is present therefore we are at lower border of rostral medulla.

Front 114

Where is the distribution of the C5 dermatome?

Back 114

Lateral aspect of arm (e.g. superior aspect of abducted arm).

Front 115

Where is the distribution of the C6 dermatome?

Back 115

Lateral forearm and thumb

Front 116

Where is the distribution of the C7 dermatome?

Back 116

Middle and ring fingers (or middle three fingers) and the center of the posterior and anterior forearm.

Front 117

Where is the distribution of the C8 dermatome?

Back 117

Little finger, medial side of hand and forearm

Front 118

Where is the distribution of the T1 dermatome?

Back 118

Medial aspect of the forearm and inferior arm

Front 119

Where is the distribution of the L1 dermatome?

Back 119

Inguinal/suprapubic region

Front 120

Which spinal nerve innervates the lateral calf region

Back 120

L5

Front 121

Which spinal nerve innervates the lateral foot region?

Back 121

S1

Front 122

What are the nerve roots for the lateral cutaneous nerve of the thigh?

Back 122

L2-L3

Front 123

What are the 3 trunks of the brachial plexus and which nerves give rise to them?

Back 123

Superior is from C5, C6 ventral rami. Middle is from C7. Inferior is from C8, T1.

Front 124

What are the 3 cords of the brachial plexus and which nerve structures give rise to them?

Back 124

Lateral cord comes from 1 branch off the superior trunk and 1 branch off the middle trunk. Posterior cord comes from 1 branch off the superior, middle, and inferior trunks. Medial cord comes from the continuation of the anterior division of inferior trunk.

Front 125

Where is the lower body located in the motor homunculus?

Back 125

Medial to the arms, near the sagittal fissure.

Front 126

Describe the layout of the internal capsule and its bordering structures.

Back 126

V-shaped, "pointing medially". Anterior limb is bordered by globus pallidus and putamen laterally and the caudate nucleus medially. The genu is the knee or bend. The posterior limb is bordered by the globus and put laterally and the diencephalon medially.

Front 127

Describe the spatial relationships of the posterior columns fibers as they cross the midline in the medulla.

Back 127

In the posterior column, FGr is medial and FCu is lateral. After synapsing with their respective nuclei, Gr moves ventrally and Cu moves dorsally via the interarcuate fibers.

Front 128

Renshaw cells

Back 128

Inhibitory interneurons in the spinal cord that receive their afferent input from collateral branches of nearby efferent cells. These cells are "unique" because they are interneurons that are activated by efferent cells rather than afferent or descending neurons.

Front 129

Where are LMN cell bodies that innervate trunk flexors and extensors located?

Back 129

Medially inside the ventral horn

Front 130

All LMN's are located in which Rexed lamina? Where is it located?

Back 130

Lamina IX are "islands" within the ventral horn. There is somatotopic organization within the lamina IX islands in which axial innervation is medial and limb innervation is lateral.

Front 131

Which muscle fiber type (white/red) are more sensitive to disuse atrophy?

Back 131

Red fiber type

Front 132

Compare/contrast motor unit size

Back 132

Front 133

What type of nerve fiber innervates the periequatorial region of a muscle spindle?

Back 133

Type II fiber -- afferent fiber from secondary nerve endings (predominantly nuclear chain fibers) of the muscle spindle

Front 134

What does the "total convergence/total divergence" idea mean for Ia fibers?

Back 134

The Ia fibers from muscles spindles in a given muscle diverge and converge to monosynaptically "communicate" with all LMN's of that muscle.

Front 135

Which spinal nerves does the knee-jerk reflex test?

Back 135

L3 - L4 specifically, because this is the portion of the femoral nerve (L2 - L4) that innervates the quadriceps.

Front 136

Why is normal muscle tone maintained when passive muscle lengthening occurs?

Back 136

The alpha motor neuron activity stimulated by Ia afferents is counterbalanced by alpha motor inhibition from GTO's.

Front 137

Define muscle tone

Back 137

The level of activity (contraction) seen in resting skeletal muscle. "Resting" means some motor units are activity but not sufficient to produce movement. I.e. a muscle's resistance to passive stretch during a resting state

Front 138

UMN lesions are characterized by:

Back 138

Weakness, spasticity (clasped-knife phenomenon), hyperreflexia, primitive reflexes and the Babinski sign. Primitive reflexes include the grasp, suck and snout reflexes.

Front 139

LMN lesions are characterized by:

Back 139

Weakness, hypotonia, hyporeflexia, atrophy and fasciculations.

Front 140

Fasciculations

Back 140

Fine movements of the muscle under the skin; indicative of lower motor neuron disease. They are caused by denervation of whole motor units leading to ACh hypersensitivity at the denervated muscle. Atrophy of the affected muscle is usually concurrent with fasciculations.

Front 141

Eccentric contraction

Back 141

Sarcomeres get longer as you contract because the opposing force is greater than what the muscle is generating.

Front 142

Concentric contraction

Back 142

Sarcomeres get shorter as you contract because the force of muscle contraction is greater than the opposing load.

Front 143

Which type of afferent nerve fiber supplies secondary endings in the muscle spindle?

Back 143

Type II afferent

Front 144

If gamma neuron firing goes down, spindle sensitivity goes...?

Back 144

Down. By decreasing gamma motor neuron activity, the spindle is allowed to relax and become "less sensitive to stretch".

Front 145

What's the goal of alpha/gamma coactivation in maintaining muscle tone?

Back 145

To maintain a constant afferent Ia pulse in order to keep the same number of motor units active throughout a full range of passive motion.

Front 146

Why are the lower limb reflexes more brisk than upper limb reflexes?

Back 146

Lower limb reflexes (especially the extensors) are modified to be brisk, automatic reflexes because they are working on anti-gravity muscles.

Front 147

What are some characteristics of automatic behaviors (responses/reflexes)?

Back 147

relatively simple;
relatively predictable response to a specific stimulus;
relatively independent of "higher centers";
not typically or greatly affected by alterations in consciousness

Front 148

Pronator drift

Back 148

When holding arms outwards and supinated, the arm (contralateral to the lesion in the brain due to stroke) drifts to a mid-pronated position. This is due to spasticity in the pronator muscle.

Front 149

Spasticity

Back 149

A motor disorder involving UMN's characterized by a velocity-dependent increase in tonic stretch reflexes (muscle tone) and exaggerated phasic muscle stretch reflexes.

Front 150

Muscle reflex latency

Back 150

How long after the stimulus does the reflex response occur? Not observable clinically, but can see it with nerve conduction studies. Demyelinating diseases can manifest this way.

Front 151

Muscle reflex amplitude

Back 151

How great is the response with a standardized stimulus? Compare bilaterally.

Front 152

Muscle reflex spread

Back 152

Does the stimulus cause alpha motor neuron activity in other muscles besides the one being tested? E.g. crossed-adductor reflex. By tapping the patellar tendon, the other leg adducts.

Front 153

Muscle reflex duration

Back 153

How long does the elicited reflex (contraction) occur? E.g. hanging reflexes.

Front 154

Plantar reflex

Back 154

Stroking of the lateral foot and across the plantar base of the toes. Normally, the toes should flex and curl inward. Abnormally, the Babinski sign is the extension and fanning of the toes in response to the plantar stimulus. This is due to a UMN lesion is adults, and can be normal in infants < 1 y/o.

Front 155

Which afferent fibers mediate the second, burning pain, warm, dull pain, itching, and sensual touch?

Back 155

C fibers

Front 156

Which afferent fibers mediate the first/fast pain, sharp pain, cold and pressure sensation?

Back 156

A delta fibers

Front 157

What is the midbrain tectum?

Back 157

Literally, the "roof" of the midbrain. Located in the dorsal mesencephalon (midbrain)-- it consists of superior and inferior colliculi (i.e. or the nuclei residing within these "bumps").

Front 158

Who talks to the magnocellular cells of the red nucleus?

Back 158

Cortex, globus pallidus, cerebellum.

Front 159

What's the general role of the cerebellum in communicating with motor neuron pathways?

Back 159

The cerebellum determines the sequences of events (EPSP's and IPSP's) in time to achieve a specific motor task.

Front 160

What's the general role of the basal ganglia in communicating with motor neuron pathways?

Back 160

The basal ganglia determine which LMN's you need to sends EPSP's and IPSP's to in order to achieve a specific motor task.

Front 161

Describe the pathway of the rubrospinal tract.

Back 161

The tract begins in the red nucleus (midbrain), crosses midline at ventral tegmental decussation, and descends contralaterally in the lateral funiculus (along with the lateral corticospinal tract). Note, some collateral branches terminate early in the pons and medulla.

Front 162

What is the major target of rubrospinal innervation?

Back 162

Upper limb proximal flexor muscles. Although it does go to flexors in the lower limb.

Front 163

Where do tectospinal fibers decussate?

Back 163

Dorsal tegmental decussation

Front 164

What's the boundary between the medulla and the spinal cord, and where is it located?

Back 164

Cervicomedullary junction, located at the foramen magnum

Front 165

Where do fibers in the anterior corticospinal fibers cross the midline?

Back 165

Mostly at the segmental level via interneurons rather than crossing at the pyramidal decussation.

Front 166

What are the 3 regions that UMN's can be found in the frontal cortex?

Back 166

Precentral gyrus, premotor cortex, supplementary cortex.

Front 167

For corticospinal UMN's, the most rostral decussating fibers come from where in the cortex?

Back 167

Upper limb (lateral cortex). The upper limb ends up medial in the lateral tract and the lower limb is lateral.

Front 168

Betz cells

Back 168

Very large neurons in the primary motor cortex, but only make up 4% of corticospinal cells. These tend to go to the distal musculature of the limb and synapse with alpha motors without interneurons.

Front 169

What is this diagram showing?

Back 169

Not everyone has a "textbook" pattern of pyramidal decussation. Most normal is 85% decuss/15% ipsilateral. However, 3% of people don't decussate at all, and 13% of people decussate completely (leaving no anterior pathway).

Front 170

Corticospinal UMN's are influenced by:

Back 170

1) cortical-cortical connections (e.g. frontal lobe, what's the goal?, write a program)
2) cortico-ponto, ponto-cerebellar, cerebellar-thalamic, thalamic-cortical (control WHEN in time that EPSP's and IPSP's need to fire to achieve a particular muscle movement)
3) cortico-strio, strio-pallido, pallido-thalamic, thalamocortico (WHICH muscles need to contract/relax)

Front 171

Back 171

Corticospinal fibers passing through the cerebral peduncle (midbrain)

Front 172

Back 172

Genu of the internal capsule.

Front 173

Back 173

VPL nuclei

Front 174

Back 174

Cerebral peduncles

Front 175

Back 175

Red nucleus

Front 176

Where are the corticospinal fibers located? What proportion of corticospinals make up this region?

Back 176

1 million out of 4 million in that "fifth" of the peduncle. In total, the peduncle has ~20 million axons.

Front 177

Back 177

Ventral tegmental decussation

Front 178

Back 178

MLF (medial longitudinal fasciculus). Interconnects the occulomotor, trochlear, and abducens nuclei so that we get conjugate eye movements.

Front 179

Back 179

Longitudinal pontine bundles. These are formed by axons of the tightly compacted cerebral peduncles being separated by the pontine nuclei into less compact bundles.

Front 180

Where is this slice from?

Back 180

Caudal pons. 4th ventricle, inferior cerebellar peduncle, pontine nuclei and longitudinal pontine bundles (some of which are coalescing to soon become pyramids)

Front 181

Back 181

Medial lemniscus

Front 182

Back 182

Tectospinal fibers

Front 183

Back 183

Medullary pyramid

Front 184

Erb's palsy

Back 184

Nerve injury to C5-C6 roots, with the suprascapular, musculocutaneous, and axillary being damaged most often. Loss of elbow flexion, supination, leads to "waiter's tip". Shoulder dystocia during childbirth is a common cause.

Front 185

Klumpke's palsy

Back 185

Primarily affects the lower roots of the brachial plexus (C8 - T1). Leads to weakness of the intrinsic hand muscles and flexors of the wrist and fingers. "Klumpke the monkey hung from a tree".

Front 186

Nerve branches of the posterior cord of the brachial plexus

Back 186

ARTS: axillary, radial, thoracodorsal, subscapular (upper and lower).

Front 187

5 parts of the brachial plexus

Back 187

Roots, Trunks, Divisions, Cords, Branches. Mnemonic: Russell Trigonis Drinks Cold Beers.

Front 188

Nerve roots of lumbosacral plexus

Back 188

L1 - S4

Front 189

What are the motor actions and sensory innervations of the median nerve?

Back 189

Motor: Thumb flexion and opposition, flexion of digits 2 and 3, wrist flexion and abduction, forearm pronation.

Front 190

What are the motor actions and sensory innervations of the ulnar nerve?

Back 190

Motor: Finger adduction and abduction other than thumb; thumb adduction; flexion of digits 4 and 5; wrist flexion and adduction

Front 191

What are the motor actions and sensory innervations of the musculocutaneous nerve?

Back 191

Motor: Flexion of arm at elbow, supination of forearm

Front 192

3 nerves acting on the thumb movement

Back 192

Radial: abducts thumb (plane of palm)
Ulnar: adducts thumb (plane of palm)
Median: opposes thumb, and abducts thumb (perp. to plane of palm)

Front 193

What are the motor actions and sensory innervations of the femoral nerve?

Back 193

Motor: Leg flexion at the hip, leg extension at the knee

Front 194

What are the motor actions and sensory innervations of the obturator nerve?

Back 194

Motor: Adduction of the thigh

Front 195

What are the motor actions and sensory innervations of the tibial nerve?

Back 195

Motor: Foot plantar flexion and inversion, toe flexion

Front 196

What are the motor actions and sensory innervations of the superficial peroneal nerve?

Back 196

Motor: Foot eversion

Front 197

What are the motor actions and sensory innervations of the deep peroneal nerve?

Back 197

Motor: Foot dorsiflexion, toe extension

Front 198

What innervates the hamstring muscles (for knee flexion)?

Back 198

Sciatic nerve

Front 199

What are the conduction speeds for A-delta and C fibers?

Back 199

A-delta fibers: 15 - 30 m/s
C fibers: 0.5 - 2 m/s

Front 200

Back 200

Foramen Ovale:
Mandibular nerve (V3), Accessory Meningeal Artery, Lesser Petrosal nerve

Front 201

Back 201

Optic canal:
Optic nerve (CNII), opthalmic artery

Front 202

Back 202

Superior orbital fissure:
Oculomotor nerve (CNIII), trochlear nerve (CNIV), abducens nerve (CNVI), opthalmic nerve (V1), superior opthalmic vein

Front 203

Back 203

Foramen rotundum:
Maxillary nerve (V2)

Front 204

Back 204

Jugular foramen:
Glossopharyngeal nerve (IX), Vagus nerve (X), Accessory nerve (XI), Sigmoid sinus, Posterior meningeal artery, inferior petrosal sinus

Front 205

Back 205

Foramen lacerum:
Greater petrosal nerve, internal carotid (via the carotid canal)

Front 206

Back 206

Asterion

Front 207

Back 207

Glabella

Front 208

Back 208

Gonion

Front 209

Back 209

Greater wing of sphenoid

Front 210

Back 210

Rhinion

Front 211

Hoffman's reflex

Back 211

Test for UMN lesion - Flicking the middle finger to check for reflex contraction of the thumb or index finger. The positive response is abnormal if asymmetric and could be a normal finding if symmetric (e.g. hyperreflexia). Ex. testing for cervical myelopathy.

Front 212

Back 212

Frontal process of the zygomatic bone

Front 213

Back 213

Frontomaxillary suture

Front 214

Back 214

Zygomatic process of the temporal bone

Front 215

Back 215

Infraorbital foramen

Front 216

Back 216

Frontonasal suture

Front 217

Back 217

Middle nasal concha

Front 218

Back 218

Greater palatine foramen

Front 219

The anterior spinal artery supplies what portion of the spinal cord?

Back 219

ASA supplies anterior 2/3 and PSA's supply posterior 1/3.

Front 220

Artery of Adamkiewicz

Back 220

A branch off of the thoracic aorta (variable) that supplies the anterior spinal artery (as an "anterior segmental medullary artery). Provides blood supply to anterior cord below T11-T12.

Front 221

Back 221

CN VIII, Vestibulocochlear nerve passing through the internal acoustic meatus

Front 222

Back 222

CN VII, Facial nerve passing through the internal acoustic meatus

Front 223

Back 223

CN VI, Abducens nerve - will pass through the superior orbital fissure.

Front 224

Back 224

CN XI, Spinal accessory - will pass through the jugular foramen.

Front 225

Nerve roots of femoral nerve

Back 225

L2 - L4

Front 226

Nerve roots of common peroneal nerve

Back 226

L4 - S2

Front 227

Nerve roots of sciatic nerve

Back 227

L4 - S3

Front 228

Nerve roots of tibial nerve

Back 228

L4 - S3

Front 229

Nerve roots of superficial peroneal nerve

Back 229

L5 - S2

Front 230

Nerve roots of deep peroneal nerve

Back 230

L4 - L5

Front 231

Nerve roots of dorsiflexion

Back 231

L4*, L5

Front 232

Nerve roots of toe extension

Back 232

L4, L5*

Front 233

Nerve roots of plantar flexion

Back 233

L5, S1*, S2

Front 234

Nerve roots of toe flexion

Back 234

S2, S3

Front 235

Nerve roots of foot eversion

Back 235

L5*, S1*, S2

Front 236

Nerve roots of superior gluteal

Back 236

L4 - S1

Front 237

Nerve roots of inferior gluteal

Back 237

L5 - S2

Front 238

Nerve roots of obturator nerve

Back 238

L2 - L4

Front 239

Nerve roots of finger extension

Back 239

C7*, C8

Front 240

Thumb abduction in the plane of the palm

Back 240

Radial nerve (C7*, C8)

Front 241

Finger abduction

Back 241

Ulnar nerve (C8, T1*)

Front 242

Lumbricals: function and innervation

Back 242

Flexion of the metacarpophalangeal joints, extension of the interphalangeal joints.

Front 243

You suspect a C5 radiculopathy. Where do you suspect sensory abnormalities? Where do you suspect muscle weakness?

Back 243

The region of sensory abnormality would be in the shoulder and lateral arm. The main weaknesses associated with C5 would be deltoid (abduction), infraspinatus (lateral rot. of arm), and some biceps (elbow flexion).

Front 244

You suspect a C6 radiculopathy. Where do you suspect sensory abnormalities? Where do you suspect muscle weakness?

Back 244

The region of sensory abnormalities would be in the first and second fingers and the lateral forearm. The mains weaknesses associated with C6 would be biceps (elbow flexion) and wrist extensors.

Front 245

You suspect a C7 radiculopathy. Where do you expect sensory abnormalities? Where do you suspect muscle weakness?

Back 245

The region of sensory abnormalities would be in the third finger. The main weaknesses associated with C7 would be triceps (elbow extension).

Front 246

You suspect a L4 radiculopathy. Where do you expect sensory abnormalities? Where do you suspect muscle weakness?

Back 246

The region of sensory abnormalities would be on the knee and medial leg. The main weaknesses associated with L4 would be iliopsoas (hip flexion), quadriceps (knee flexion) and ankle dorsiflexion.

Front 247

Epidural hematoma

Back 247

Rupture of middle meningeal artery (branch of maxillary artery), often secondary to fracture of temporal bone. Lucid interval. Rapid expansion under systemic arterial pressure --> transtentorial herniation, CN III palsy. CT shows "biconvex disk" not crossing suture lines. Can cross falx, tentorium.

Front 248

Subdural hematoma

Back 248

Rupture of bridging veins. Slow venous bleeding (less pressure = hematoma develops over time). Seen in elderly individuals, alcoholics, blunt trauma, shaken baby (predisposing factors­ brain atrophy, shaking, whiplash). Crescent-shaped hemorrhage that crosses suture lines. Midline shift. Gyri are preserved, since pressure is distributed equally. Cannot cross falx, tentorium.

Front 249

Subarachnoid hemorrhage

Back 249

Rupture of an aneurysm (usually berry aneurysm in Marfan's, Ehlers-Danlos, ADPKD) or an AVM. Rapid time course. Patients complain of "worst headache of my life." Bloody or yellow (xanthochromic) spinal tap. 2-3 days afterward, risk of vasospasm due to blood breakdown (not visible on CT, treat with nimodipine) and rebleed (visible on
CT)

Front 250

Impaired function of multiple nerve roots below L1 or L2 is called _______.

Back 250

Cauda equina syndrome

Front 251

You suspect a L5 radiculopathy. Where do you expect sensory abnormalities? Where do you suspect muscle weakness?

Back 251

The region of sensory abnormalities is the lateral leg, dorsum of the foot and the big toe. The main weaknesses associated with L5 are gluteus medius (hip abduction), foot dorsiflexion, big toe extension, foot eversion and inversion.

Front 252

You suspect an S1 radiculopathy. Where do you expect sensory abnormalities? Where do you suspect muscle weakness?

Back 252

The region of sensory abnormalities is the lateral foot, small toe, and the plantar surface of the foot (except for big toe area). The main weaknesses associated with S1 are the posterior leg muscles (plantar flexion) and gluteus maximus (hip extension) .

Front 253

Pinprick of the big toe tests which spinal nerve root?

Back 253

L5

Front 254

The superolateral thigh contains which spinal nerve's autonomous zone?

Back 254

S2

Front 255

Where is the L3 autonomous zone?

Back 255

Medial thigh superior to the knee

Front 256

Where is the L4 autonomous zone?

Back 256

Medial leg, midway between knee and ankle

Front 257

The lateral border of the foot contains which spinal nerve's autonomous zone?

Back 257

S1

Front 258

Hemiplegia

Back 258

Total paralysis of the arm, trunk, and leg on one side of the body. Most common cause is stroke.

Front 259

Absent pin prick sensation on the skin of the palmer surface of the left long finger?

Back 259

Left side C7 radiculopathy

Front 260

At what level of the brainstem do the axons of the gracile nuclei and cuneate nuclei cross the midline?

Back 260

Rostral part of the caudal half of medulla

Front 261

Topesthesia

Back 261

The ability to localize light touch

Front 262

Graphesthesia

Back 262

Tactual ability to recognize writing on the skin

Front 263

Sensory extinction

Back 263

Extinction to simultaneous sensory stimulation (ESS) is a clinical phenomenon in which a patient perceives a unilateral sensory stimulus presented in isolation but fails to perceive the same stimulus when presented simultaneously with a second stimulus

Front 264

Describe the 5 muscle strength grades

Back 264

5/5: full ROM against gravity w/ max resistance
4/5: full ROM against gravity w/ some resistance
3/5: full ROM against gravity w/ no resistance
2/5: full ROM w/o gravity
1/5: palpable or visible contraction w/ little or no movement
0/5: no palpable or visible muscle contraction

Front 265

Components of striatum

Back 265

Putamen and caudate nucleus

Front 266

Components of corpus striatum

Back 266

Putamen, caudate nucleus, globus pallidus

Front 267

Components of lenticular nucleus

Back 267

Putamen and globus pallidus

Front 268

Back 268

Caudate nucleus from a coronal slice that is relatively rostral because the caudate nucleus is fairly thick here.

Front 269

Back 269

Putamen

Front 270

Back 270

Internal medullary lamina of the globus pallidus. This is a coronal slice at the level of the optic chiasm.

Front 271

Back 271

Thalamus. This is a coronal slice at a level posterior to the optic chiasm. The internal capsule (posterior limb) is seen. Also seen superficially and inferior are the mammilary bodies, hypothalamus, and 3rd ventricle.

Front 272

Back 272

Internal medullary lamina of the thalamus

Front 273

Back 273

External medullary lamina of the thalamus

Front 274

What does the internal medullary lamina of the thalamus separate?

Back 274

Medial nuclear group and the lateral nuclear group

Front 275

Describe the major functions of the cerebellum vs. basal ganglia.

Back 275

Cerebellum - plays major roles in the timing of motor activities and in rapid, smooth progression from one muscle movement to the next. Also helps control the intensity of muscle contraction when the muscle load changes and controls the necessary instantaneous interplay between agonist and antagonist muscle groups.

Basal ganglia - help to plan and control complex patterns of muscle movement, controlling relative intensities of the separate movements, directions of movements, and sequencing of multiple successive and parallel movements for achieving specific complicated motor goals.

Front 276

3 anatomical lobes of the cerebellum

Back 276

Anterior, posterior, and flocculonodular

Front 277

Striatum efferents use which neurotransmitter?

Back 277

GABA

Front 278

GPe and GPi efferents use which neurotransmitter?

Back 278

GABA

Front 279

The primary fissure of the cerebellum separates which 2 lobes?

Back 279

Anterior and posterior

Front 280

Which fissure separates the posterior lobe of the cerebellum from the flocculonodular?

Back 280

Posterolateral fissure

Front 281

5 cell types of the cerebellar cortex?

Back 281

Stellate cells, basket cells, purkinje cells, golgi cells, and granule cells

Front 282

Name the layers of the cerebellar cortex (from superficial to deep).

Back 282

Molecular layer (few cells) --> Purkinje cells --> Granular layer (many cells)

Front 283

Types of cells in the granular layer of the cerebellum

Back 283

Golgi cells and granule cells

Front 284

Types of cells in the molecular layer of the cerebellum

Back 284

Stellate cells (tend to be more superficial), and basket cells (closer to purkinje cells)

Front 285

Rigidity

Back 285

Increased resistance throughout the range of movement, in both directions, which is not rate-dependent.

Front 286

Lead pipe vs. cogwheel rigidity

Back 286

Cogwheel (gamma) rigidity: Rachety pattern of resistance and relaxation as the examiner moves the limb through its full range of motion

Lead-pipe rigidity: State of stiffness & inflexibility that when an increase in muscle tone causes a sustained resistance to passive movement throughout the whole range of motion, with no fluctuations.

Front 287

Hypomimia

Back 287

Reduced degree of, or a "masked" facial expression. Often seen in PD

Front 288

Indirect pathway of basal ganglia

Back 288

Putamen to GPe (inhibitory), GPe to subthalmic nucleus (inhibitory), STN to GPi (excitatory), GPi to thalamus (inhibitory), thalamus to cortex (excitatory). A normally stimulated indirect pathway inhibits motor activity. Normal DA input on indirect pathway stimulates motor activity.

Front 289

Direct pathway of basal ganglia

Back 289

Putamen to GPi (inhibitory), GPi to thalamus (inhibitory), thalamus to cortex (stimulatory). A normally stimulated direct pathway stimulates motor activity. Normal DA input on direct pathway stimulates motor activity.

Front 290

The subthalmic nucleus projects what kind of neurons to the GPi?

Back 290

Glutamatergic (stimulatory)

Front 291

Back 291

Nucleus accumbens

Front 292

Back 292

Septal nuclei

Front 293

Back 293

Claustrum

Front 294

Back 294

Ventral pallidum. Contains the cells of Meynert.

Front 295

Back 295

Caudate nucleus

Front 296

Back 296

Substantia nigra

Front 297

Back 297

Septum pellucidum. The lateral side is ependymal lined and the medial side is pia.

Front 298

Back 298

Middle cerebral artery lying in the Sylvian fissure (between the frontal and temporal lobes).

Front 299

Back 299

Anterior commissure

Front 300

Back 300

Ventral anterior nuclei of the thalamus

Front 301

Where are the cell bodies whose axons terminate here?

Back 301

Predominantly in the frontal lobe

Front 302

If you destroy this structure, signs and symptoms will occur on which side?

Back 302

Ipsilateral (right)

Front 303

Not being able to smell after head injury?

Back 303

Damage to the olfactory filia (being sheared off at the cribiform plate) due to inertia.

Front 304

What do Bowman's glands do in the olfactory epithelium?

Back 304

They secrete mucous so that olfactory molecules can be dissolved in order to activate chemoreceptors on the cilia.

Front 305

Which cell in the olfactory bulb has the predominant task of sending olfactory information back to the brain?

Back 305

Mitral cells

Front 306

Primary olfactory cortex

Back 306

Located in the lateral olfactory gyrus which surrounds the lateral olfactory stria. Only perceive odorants when they activate cells here.

Front 307

"Double inhibitory" system of olfaction?

Back 307

There are inhibitory neurons in the olfactory bulb AND in the olfactory tract that project back to the bulb that inhibit olfaction sense.

Front 308

Scotopic vision

Back 308

The vision of the eye under low light (monochromatic, low acuity). Mediated by rod cells. Most sensitive around 498 nm (blue-green).

Front 309

Photopic vision

Back 309

The vision of the eye under well-lit conditions (color perception, high acuity). Mediated by cone cells.

Front 310

Back 310

Anisocoria (unequal pupil size)

Front 311

Back 311

Scotoma - a circumscribed region of visual loss

Front 312

Homonymous defect

Back 312

See 4, 5, 6, 7.
Homonymous - same visual defect in both eyes.

Front 313

Corneoscleral tunic

Back 313

Outer "housing", principally collagenous. Route by which blood vessels get in/out and form choroid. Cornea is the chief refractory structure (60-70%). External ocular muscles attach to this tunic.
See 3rd side...

Hint 313

Front 314

Uveal tunic

Back 314

Supportive tunic: focusing mechanism (lens), light adjustment (iris), reflection dampening, nourishment of retina (choroid), production and removal of aqueous (ciliary body/processes)

Front 315

Back 315

Front 316

Bowman's membrane

Back 316

Located between superficial epithelium and stroma. Strong collagen fibers help the cornea keep its shape.

Front 317

Drainage of aqueous humor

Back 317

AH is removed via the canal of Schlemm. Blockage of this can lead to glaucoma.

Front 318

Back 318

Front 319

9 layers of the retina

Back 319

Also, see 3rd side...

Hint 319

Front 320

Back 320

Fundus of right eye: blind spot is also nasal to macula.

Front 321

Optic disc

Back 321

aka (optic papilla)
-disc diameter – 1.5 mm
-nasal half – thicker and pinker
-temporal half – lighter and sharper
-physiologic cup – < 30-40% disc diameter
-cup/disc ratio – 3-4/10

Retinal Vessels
veins – slightly larger than arteries and may pulsate
arteries – “silver wire” appearance

Front 322

How does an increase in intracranial pressure affect the physiological cup of the eye?

Back 322

The increased CSF pressure pushes the optic nerve back towards the optic cup causing optic papilladema. It may elevate the physiologic cup (flattening the concavity).

Front 323

What are the variations of the optic chiasm as it relates to the hypophysis?

Back 323