Review of neural anatomy

Question 1

what is meant by the epidural, subdural, and subarachnoid spaces

Answer 1

Epidural: a potential space above the dura mater Subdural: a potential space between the dura and arachnoid mater Subarachnoid: a potential space between the arachnoid and pia mater

Question 2

discuss the function of Cerebral Cortex (concentrating on pathology and presentation):

Answer 2

higher mental functions: behavior, memory, attention, perception, awareness, thought, language, and consciousness. integration of all the above

Question 3

discuss the function of LOBES

Answer 3

Frontal: motor function (motor cortex associated with voluntary skeletal movements and fine repetitive motor movements, eye movement), motor speech (Broca’s area); personality/emotional response; awareness of self -Parietal: Process sensory/tactile data (temp, pressure, pain, olfaction, gustatory); awareness of body position (proprioception); some compression of written word, communication between sensory and motor areas. - Temporal - perception and interpretation of sounds - reception and interpretation of speech, sensible speech (Wernicke’s area); - Occipital lobes - interpretation of visual data and primary visual center

Question 4

location and function of Broca’s area, pathology?

Answer 4

1.LEFT frontal lobe, posterior end of the the inferior frontal gyrus, adjacent t temporal lobe and primary motor cortex 2.motor speech area and controls movements of tongue, lips and vocal cords. 3. non-fluent aphasia

Question 5

location and function of Wernicke’s area, pathology?

Answer 5

1. DOMINANT Temporal lobe 2. sensible speech: recall, recognizes and interprets words and other sounds in the process of using language. 3. fluent aphasia

Question 6

function of Brain Stem, parts and their functions (and associated Cranial Nerves)

Answer 6

Brainstem: pathway b/n cerebral cortex and spinal cord, controls involuntary function, nuclei of 12 spinal nerves arise from here Midbrain: reflex center for eye and head movement; auditory relay pathway, corticospinal tract pathway; CN III, CN IV Pons: reflexes of pupillary action and eye movement; partially regulates respiration, controls voluntary mm action with corticospinal tract pathway; CN V, CN VI, CN VII, CN VIII Medulla: main respiratory center; circulatory and vasomotor activities, swallowing, coughing, sneezing, vomiting and hiccuping. RELAY CENTER for major descending and ascending spinal tracts that decussate( cross to the other side CN IX, CN X, CN XI, CN XII Diencephalon:relays impulses between cerebrum, cerebellum, pons and medulla; CN I and CN II

Question 7

Origin of cranial nerves

Answer 7

Diencephalon: CN I and CN II Midbrain: CN III and CN IV Pons: CN V - CN VIII Medulla: CN IX - CN XII

Question 8

function of Cerebellum

Answer 8

-integration of voluntary movement -uses sensory data to control mm tone, balance and posture to produce steady precise movements

Question 9

Function of Basal Ganglia

Answer 9

-processing station b/n the cerebral motor cortex and the upper brain stem -refines motor movements, especially slow stereotypical activities, such as walking

Question 10

Identify cranial nerves

Answer 10

Question 11

Describe the anterior & posterior arterial circulation of the brain, as well as the Circle of Willis
that connects them.

Question 12

what neurons in gray matter vs white matter

Answer 12

Gray: butterfly shape with anterior and posterior horns has nerves cell bodies associated with sensory pathways and autonomic ns

White: ascending a descending spinal tracts

Question 13

Ascending spinal tracts vs. descending spinal tracts

1. What mediate?

Answer 13

AST: various sensations, transmit precise information about stimulus and its location.

• Spinothalamic* (anterior and lateral): light and crude touch, temperature, pain, pressure
• Posterior(*dorsal column): fine touch, 2 point discrimination, proprioseption)

DST: convey impulses to various mm groups

• Vestibulospinal*
• Reticulospinal*
• Corticospinal* (anteriolateral): skilled , delicate and purposeful movement

Question 14

Dermatomes (check for accuracy by alternating dull and sharp objects)

C6:

C7:

C8:

T4:

T10:

T12:

L4:

L5:

S1:

Answer 14

C6: thumb pad

C7: middle finger pad

C8: little finger pad

T4: at level of nipples

T10: at level of umbilicus

T12: at inguinal ligament level

L4: medial foot

L5: dorsum of foot

S1: lateral foot

Question 15

Spinothalamic vs corticospinal tracts

1. Descending or ascending?
2. Location: anterio/posterior? medial/lateral?
3. functions?

Answer 15

Spinothalamic (anterior and lateral): sensations-oldest evolutionary; light and crude touch, temperature, pain, pressure)

Corticospinal (anteriolateral): skilled , delicate and purposeful movement

Question 16

Pyramidal tract decussation (in the medulla)

Answer 16

starts in the precentral gyrus

At the very caudal-most end of the medulla, right about at the point where you have to start calling it cervical spinal cord, the fibers in the pyramids cross. It explains why the cerebrum controls the opposite side of the body,

Question 17

CN 1:

Name, S/M/Both, opening, function, test

Answer 17

I.Olfactory

Through cribiform plate of ethmoid bone

Sensory—sense of smell; SVA

Sniff & identify aromatic substances such as cloves and vanillaI

Question 18

CN II

Name, M/S/Both, opening, function, test,

Answer 18

II. Optic

Optic canal

Sensory—vision; SSA

Eye charts, move object through visual field

Question 19

CN III

name, type, opening, function, test

Answer 19

III. Oculomotor

Superior orbital fissure

Primarily motor—GSE:move eyeball, open eye lid, GVE:reflexively respond to light

Use penlight to observe pupil constriction, open eyelid, follow objects with eye (cardinal positions of gaze)

Question 20

CN IV

name, type, opening, function, test

Answer 20

IV.Trochlear

Superior orbital fissure

Primarily motor—GSE: superior oblique mm

Track objects with eye-medially and down

Question 21

CN V

name, type, opening, function, test

Answer 21

V.Trigeminal-main sensory of head, motor mm of mastication

Both—Sensory and motor; GSA, SVE

V1 Ophthalmic division; Superior orbital fissure; SENSORY ONLY ant. Scalp, upper eyelid, nose, cornea; touch cornea with whisp of cotton to elicit blinking

V2 Maxillary division; SENSORY ONLY; Foramen rotundum; lower eyelid, nasal cavity mucosa, palate, upper teeth, upper lip; pain, touch, temperature test

V3 Mandibular division; Foramen ovale; ONLY MOTOR (mastication mm), but ALSO SENSORY(ant. Tongue, lower teeth, skin of chin, temporal scalp)

clench teeth, open mouth against resistance, move jaw side to side

Question 22

CN VI

name, type, opening, function, type

Answer 22

VI.

Abducens

Superior orbital fissure

Primarily motor—Lateral rectus EOM; convey proprioceptor impulses; GSE

As in III.; Track objects laterally with eye
(cardinal positions of gaze)

Question 23

CN VII

name, type, opening, function, test

Answer 23

VII.

Facial

Internal acoustic meatus

Both; SVA, SVE, GVE, GSA

Motor—SALIVARY AND LACRIMAL GLANDS; skeletal muscles facial expression:Temporal, Zygomatic, Buccal, Mandibular, Cervical branches;

Sensory—taste, ant. tongue

Check symmetry of face during movement—smile, whistle, close eyes, etc; tearing tested with ammonia fumes; taste tested with sweet, salty, sour, bitter substances

Question 24

CN VIII

name, type, opening, function, test

Answer 24

VIII.

Vestibulocochlear

Internal acoustic meatus

Sensory—equilibrium and hearing; SSA

Hearing check with tuning fork

Question 25

CN IX

name, type, opening, function, test

Answer 25

IX.

Glossopharyngeal

Jugular foramen

Both: SVA, SVE, GVA, GVE, GSA

Motor—pharyngeal muscles

Sensory—impulses from pharynx, tonsils, taste and sensory of posterior tongue; pressure from carotid artery

Check position of uvula; gag and swallow reflexes; speak, cough; test posterior tongue for taste

Question 26

CN X

name, type,opening, function, test

Answer 26

X.

Vagus

Jugular foramen

Both: SVA, SVE, GVA, GVE, GSA

Motor—pharynx, larynx, parasympathetic fibers to heart, smooth muscles of ab visceral organs

Sensory—impulses from organs

As for IX; test muscles of throat and mouth

Question 27

CNXI

name.type, opening, function, test

Answer 27

XI.

Accessory

Jugular foramen

Primarily motor—

sternocleidomastoid, trapezius, soxt palate, pharynx, larynx: GSE

Rotate head and shrug shoulders against resistance

Question 28

CN XII

name, type, opening, function, test

Answer 28

XII.

Hypoglossal

Hypoglossal canal

Primarily motor—muscle of the tongue: GSE

Protrude and retract tongue

Question 29

Question 30

Upper motor neuron vs lower Motor Neuron

Answer 30

UMN:originate and terminate within CNS, comprise descending pathways from brain to spinal cord; direct and modify spinal reflex arcs and curcuits. Can effect movement ONLY through LMN

LMN: cranial and spinal motor neurons, originate in the anterior horn of the spinal cord and extend into peripheral NS, transmit signals directly to mm

Question 31

List the five most commonly tested deep tendon reflexes (DTRs), begin to familiarize yourself

with the spinal nerves tested by each, describe how reflexes are graded and documented in the

medical record, and discuss maneuvers sometimes used to augment DTRs.

Answer 31

Biceps (C5)

Brachioradialis (C6)

Triceps (C7)

Patellar (L2,3,4)

Achilles (S1)

0 = no response; always abnormal

1+ = a slight but definitely present response; may or may not be normal

2+ = a brisk response; normal

3+ = a very brisk response; may or may not be normal

4+ = a tap elicits a repeating reflex (clonus); always abnormal

Whether the 1 + and 3 + responses are normal depends on what they were previously, that is, the patient’s reflex history; what the other reflexes are; and analysis of associated findings such as muscle tone, muscle strength, or other evidence of disease. Asymmetry of reflexes suggests abnormality. Response of other muscles that were not tested. When a reflex is hyperactive, that muscle often will respond to the testing of a nearby muscle. A good example is reflex activity of a hyperactive biceps or finger reflex when the brachioradialis tendon is tapped. This is termed “overflowing” of a reflex.

After obtaining the reflex on one side, always go immediately to the opposite side for the same reflex so that you can compare them.

Question 32

DTR abnormalities

Answer 32

Absence, hypoactive: neuropathy or LMN disorder; ipsilateral body part affected

Hyperactive: UMN disorder, damage above brainstem-contraleteral body part, below-ipsilateral, damage above reflex arc

Clonus (muscular spasm involving repeated, often rhythmic, contractions)-UMN disease

Assymetry:Asymmetry suggests abnormality either on the ipsilateral side of the spinal cord or on the contralateral side if the problem/lesion is higher as in the cortex(after crossing over)

Question 33

Babinsky

Answer 33

superficial reflex performed by stroking the lateral edge of the foot.

A negative test is normal and involves the toes curling down. A positive test is abnormal and involves dorsiflexion of big toe and other toes may be fanning upward (!!!! unless the patient is <1 year old, then a positive babinski test is normal).

an abnormal response indicates an pyramidal disease (UMN).

Question 34

Cerebellar function

Answer 34

finger to nose testing, romberg testing for proprioception (close eyes and stay standing, imbalance=abnormal=positive finding = possible dysfunction), gait observation

Question 35

Distinguish between the clinical findings associated with upper motor neuron disorders and

lower motor neuron disorders.

Answer 35

Distinguish between the clinical findings associated with upper motor neuron disorders and

lower motor neuron disorders.

Upper MOTOR NEURONE SIGNS

Indicate that the lesion is above the anterior horn cell (i.e. spinal cord, brain stem, motor cortex).

Are characterised by increased muscle tone (spasticity), weakness (generally flexors weaker than extensors in the legs and the reverse in the arms - pyramidal pattern of weakness), increased reflexes, an up-going plantar response and sustained clonus (a few beats is normal).

LOWER MOTOR NEURONE SIGNS

Indicate that the lesion is either in the anterior horn cell or distal to the anterior horn cell (i.e. anterior horn cell, root, plexus, peripheral nerve).

Characterised by decreased muscle tone, weakness and wasting (atrophy) in the muscle(s) supplied by that motor nerve, arreflexia (absence of the relevant reflex - the motor nerve is the efferent arm of the reflex arc), muscle fasciculations.

Question 36

Myelogram

Answer 36

A myelogram is a diagnostic imaging procedure done by a radiologist. It uses a contrast dye and X-rays or computed tomography (CT) to look for problems in the spinal canal, including the spinal cord, nerve roots, and other tissues. It is also known as myelography.

The contrast dye is injected into the spinal column before the procedure. The contrast dye appears on an X-ray screen, allowing the radiologist to see the spinal cord, subarachnoid space, and other nearby structures more clearly than with standard X-rays of the spine.

Question 37

X-rays

Answer 37

X-rays: X-rays use invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs on film or digital media. Standard X-rays are performed for many reasons, including diagnosing tumors or bone injuries.X-rays are made by using external radiation to produce images of the body, its organs, and other internal structures for diagnostic purposes. X-rays pass through body structures onto specially-treated plates (similar to camera film) or digital media and a “negative” type picture is made (the more solid a structure is, the whiter it appears on the film).When the body undergoes X-rays, different parts of the body allow varying amounts of the X-ray beams to pass through. The soft tissues in the body (such as blood, skin, fat, and muscle) allow most of the X-ray to pass through and appear dark gray on the film or digital media. A bone or a tumor, which is more dense than soft tissue, allows few of the X-rays to pass through and appears white on the X-ray. When a break in a bone has occurred, the X-ray beam passes through the broken area and appears as a dark line in the white bone

Question 38

CT scan

Answer 38

CT or CAT scan is a diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce horizontal, or axial, images (often called slices) of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, organs, and blood vessels. CT scans are more detailed than standard X-rays.In standard X-rays, a beam of energy is aimed at the body part being studied. A plate behind the body part captures the variations of the energy beam after it passes through skin, bone, muscle, and other tissue. While much information can be obtained from a regular X-ray, a lot of detail about internal organs and other structures is not available.In computed tomography, the X-ray beam moves in a circle around the body. This allows many different views of the same organ or structure, and provides much greater detail. The X-ray information is sent to a computer that interprets the X-ray data and displays it in two-dimensional form on a monitor. Newer technology and computer software makes three-dimensional (3-D) images possible.CT scans may be done with or without contrast. “Contrast” refers to a substance taken by mouth or injected into an intravenous (IV) line that causes the particular organ or tissue under study to be seen more clearly..CT scans may be performed to help diagnose tumors, investigate internal bleeding, or check for other internal injuries or damage.

A CT scan of the brain may be performed to assess the brain for tumors and other lesions, injuries, intracranial bleeding, structural anomalies such as hydrocephalus, infections, brain function or other conditions, particularly when another type of examination such as X-rays or physical examination are not conclusive.A CT scan of the brain may also be used to evaluate the effects of treatment on brain tumors and to detect clots in the brain that may be responsible for strokes. Another use of brain CT is to provide guidance for brain surgery or biopsies of brain tissue.

Question 39

MRI

Answer 39

MRI: creates a strong magnetic field around the patient and sends pulses of radio waves from a scanner. The strong magnetic field causes the hydrogen atoms in the body to align along the same axis. The radio waves knock the nuclei of the atoms out of this aligned position. As the nuclei realign back into proper position, they send out radio signals. Magnetic resonance imaging (MRI) may be used instead of computed tomography (CT) in situations where organs or soft tissue are being studied, because MRI is better at telling the difference between different types of soft tissues, as well as the difference between normal and abnormal soft tissues.Because ionizing radiation is not used, there is no risk of exposure to ionizing radiation during an MRI procedure.Functional magnetic resonance imaging of the brain (fMRI) is used to determine the specific location within the brain where a certain function, such as speech or memory, occurs. The general areas of the brain in which such functions occur are known, but the exact location may vary from person to person. By pinpointing the exact location of the functional center in the brain, doctors can plan surgery or other treatments for a particular disorder of the brain. MRI is faster than CT and is preferred in case of emergiencies

Question 40

Angiogram

Answer 40

Angiogram: Angiography is a minimally invasive medical test that uses x-rays and an iodine-containing contrast material to produce pictures of blood vessels in the brain.In cerebral angiography, a catheter is inserted into an artery in the leg or arm through a small incision in the skin. Using x-ray guidance, the catheter is navigated to the area being examined. Once there, contrast material is injected through the tube and images are captured using ionizing radiation (x-rays). Cerebral angiography is also called intra-arterial digital subtraction angiography (IADSA). This phrase refers to acquiring the images electronically, rather than with x-ray film. The images are electronically manipulated so that the overlying bone of the skull, normally obscuring the vessels, is removed from the image resulting in the remaining vessels being clearly seen.

Question 41

PET

Answer 41

PET: PET is a type of nuclear medicine procedure. PET studies evaluate the metabolism of a particular organ or tissue, so that information about the physiology (functionality) and anatomy (structure) of the organ or tissue is evaluated, as well as its biochemical properties. Thus, PET may detect biochemical changes in an organ or tissue that can identify the onset of a disease process before anatomical changes related to the disease can be seen with other imaging processes, such (CT scan) or (MRI).

To diagnose dementias, Alzheimer’s disease, as well as other neurological conditions such as Parkinson’s disease , Huntington’s disease, epilepsy.To evaluate the brain after trauma to detect hematoma (blood clot), bleeding, and/or perfusion (blood and oxygen flow) of the brain tissu; To detect the spread of cancer to other parts of the body from the original cancer site

Question 42

Discogram

Answer 42

Discogram: is a test used to evaluate back pain. A discogram may help determine if an abnormal disk is causing back pain. During a discogram, dye is injected into the soft center of the disk. The injection itself sometimes reproduces back pain. The dye also moves into any cracks in the disk’s exterior, which can then be seen on an X-ray or CT scan. However, disks that show signs of wear and tear don’t always cause symptoms, so the usefulness of a discogram is controversial.

Question 43

sutures vs fractures on x-rays

Answer 43