workbook part 1

Question 1

neuron types: Pseudounipolar, bipolar and multipolar

Answer 1

Pseudounipolar are sensory. Bipolar are retinal and olfactory. Multipolar are everywhere else

Question 2

Astrocytes

Answer 2

Main injury response, form gial scars. Part of glia limitans (BBB), numbers increase in inflammation enancing BBB protection

Question 3

Oligodendrocytes

Answer 3

form myelin sheaths around axons, NOT from neural crest cells

Question 4

Microglia

Answer 4

Phagocytes. Can be upregulated and causes damage in disease (e.g. Alzheimers)

Question 5

Ependymal cells

Answer 5

line ventricles (choroid plexus epithelium) to produce CSF. If damaged, can take on rosette morphology and become nodular with astrocyte infiltration (ependymal granulations)

Question 6

Which neurons are unmyelinated

Answer 6

Group C (slow pain transmission)

Question 7

Vestibular neuromas are…

Answer 7

schwannomas, therefore not neuromas and actually neural crest cell derived

Question 8

Commissural fibres

Answer 8

Connect the hemispheres (e.g. corpus callosum)

Question 9

Association fibres

Answer 9

Connect areas within the same hemosph

Question 10

Lateral horn (sympathetics) present in

Answer 10

T1-L2

Question 11

Projection fibres

Answer 11

connect superficial to deep structures

Question 12

Blood supply to basal ganglia

Answer 12

Anterior choroidal artery (branch of MCA), middle cerebral artery and posterior cerebral artery. Stroke to middle cerebral would particularly affect the internal capsule, restricting communication with the somatosensory and somatomotor areas.

Question 13

Difference between sensory and motor homunculi?

Answer 13

Sensory includes genitalia, motor has pharynx

Question 14

Middle meningel artery

Answer 14

Comes from external carotid. Enters skull through foramen spinosu. Vulnerable at pterion (join of temporal, parietal, sphenoid and frontal bones) and can cause epidural bleed. Supplies dural

Question 15

3 skull sutures

Answer 15

coronal, saggital and lamboid

Question 16

Bones that make up the orbit

Answer 16

Sphenoid, frontal, zygomatic, lacrimal, ethmoid, maxilla

Question 17

lacrimal gland location, innervation and drainage

Answer 17

superior lateral side of eye. Innervated by ophthalmic nerve. Drains to inferior meatus in nose.

Question 18

Muscle that opens eye

Answer 18

levator palpebrae
superioris (oculomotor nerve, CNIII). It also contains a smooth muscle, the superior
tarsal muscle innervated by the autonomic nervous system.

Question 19

Muscle that closes eye

Answer 19

orbicularis oculi

muscle (supplied by the facial nerve, CNVII)

Question 20

Superior oblique muscle

Answer 20

Innervated by CNIV. Makes eye go down and out and intorts. Lesions cause people to tilt head away from affected side. CNIV decussates prior to exit from midbrain.

Question 21

The reina and optic nerve are derficed from

Answer 21

diencephalon, therefore part of forebrain.

Question 22

Choroid layer (uvea) of the eyeball

Answer 22

Vascular layer

Question 23

optic disc -

Answer 23

entry point of optic nerve, blind spot

Question 24

fovea

Answer 24

area of high visual accuity, has high density of cones. Surrounded by macula

Question 25

cones and rods

Answer 25

rods do black and white, cones do colour and daylight.

Question 26

Blood supply to the eye

Answer 26

Ophthalmic artery, branch of ICA. No collateral circulation so blindness risk if compromised

Question 27

Flow of aqueous humour

Answer 27

The aqueous humour is secreted by the ciliary body into the posterior chamber. It flows the the pupillary aperture and into the anterior chamber where it is reabsorbed through trabecular network through Schlemm’s canal.

Question 28

Corneal blood supply

Answer 28

avasculure

Question 29

Corneal reflex

Answer 29

Afferent through CNVa, efferent through CNVII.

Question 30

pterygium

Answer 30

non cancerous growth of conjuctiva over the anterior of the eye (wing like structure)

Question 31

retinoblastoma

Answer 31

cancer at the back of the eye

Question 32

Eye movements: differentiate between IO/SR and SO/IR

Answer 32

Adduct and elevate for IO, adduct and depress for SO. Abduct and elevate for SR, abduct and depressfor IR

Question 33

cavernous sinus contents

Answer 33

anterior to posterior: Occulomotor, Trochlear, ophthalmic nerve, maxillary nerve. Then medial to lateral: ICA and abducens

Question 34

Abducens nuclei

Answer 34

anterior of the brainstem at the junction of the pons and medulla. The cell bodies (nuclei) lie on the posterior aspect of the pons (internally and pass through the body of the pons to emerge on the anterior surface).

Question 35

paramedian pontine reticular formation (PPRF)

Answer 35

Lies near CNVI in pons. contralateral eye fields and vestibular nuclei give input to PPRF, PPRF synapses with ipsilateral CNVI AND CNIII nucleus in midbrain (pathway to CNIII is medial longitudinal fasciculus). Therefore, left frontal eye field stimulation means right PPRF is stimulated to stimulate right CNVI and left CNIII (therefore MR) to produce right gaze

Question 36

Eye lesions: 1) on left optic nerve 2) on decussations 3) on left optic tract 4) left meyers loop 5) input to left occiptal lobe

Answer 36

1) monoocular anopia (left) 2) bitemporal heminanopia 3) right homonymous hemianopia (both right side visual fields gone from both eyes) 4) contralateral superiorquadropia (upper right quadrant gone in both eyes on right visual field) 5) right homonymous hemianopia

Question 37

Muscles controlling pupil size

Answer 37

``` The diameter of the iris is controlled by dilator pupillae (radial muscle fibres, innervated by sympathetic innervation(through superior cervical ganglion) which allow dilation) and sphincter pupillae (circular muscle fibres, parasympathetic innervation (oculomotor nerve) and they constrict the pupil) ```

Question 38

myopia

Answer 38

short sitedness, can't focus on far away objects (focuses before retina). Use concave lens

Question 39

hhyperopia

Answer 39

long sites, can't focus on close objects - focuses beyond retina. Use convex lens. In presbo[ia, lens becomes rigid through age and can't be as rounded, so convex lenses are used.

Question 40

CNS meningeal spaces

Answer 40

Epidural space: PotentialSpace between periosteal and meningeal dura. It contains lymphatics, nerves, small arteries and dural venous sinuses. Subdural space: Potential space Sub-arachnoid space: Actual space with CSF

Question 41

Meningeal reflections

Answer 41

Falx cerebri runs along longitudinal fissure. Tentorium cerebelli sits between cerebrum and cerebellum. Tentorial notch allows passage of brainstem. Diaphram sellae covers pituitary, with gap for infundibulum. These are all dural reflections

Question 42

Dural innervation

Answer 42

Anterior: CNVa and CNVb branches Middle: CNVa, CNVb and CNVc branches 59 Posterior: CNX and CN IX

Question 43

Vein that receives drainage from the IC veins?

Answer 43

Internal jugular vein

Question 44

emissary, meningeal, cerebral and diploic veins

Answer 44

Emissary run through the skull, meningeal run with the meningeal arteries, diploic run in the skull and cerebral run in the subarachnoid space

Question 45

Pterygoid venous plexus

Answer 45

Palate, nasal cavity, paranasal sinuses, nasopharynx, auditory tube, deep parts of the scalp in the temporal region. Drains into maxillary vein, but anastamoses with facial vein, which also anastamoses with ophthalmic vein, therefore route to cavernous sinus.

Question 46

Flow of CSF in ventricles

Answer 46

Lateral horn of lateral ventricles, then posterior horn of lateral ventricles, then body of lateral ventricles, then anterior of lateral ventricles. Then through interventricular foramen to 3rd ventricle (with interthalamic adhesion), and then cerebral aqueduct to forth ventricle and central canal to spinal cord. Median and lateral apertures in 4th ventricle allow reabsorption. CSF leaves by superior sagital sinus through arachnoid villi (protrude into the subarachnoid space). Valves are one-way, so blood will not flow through (Even if CSF pressure < venous pressure).

Question 47

CSF function

Answer 47

protects brain, removes waste, provides nutrients, maintains ICP

Question 48

Occipital bone has groves

Answer 48

For transverse sinus

Question 49

Inferior orbital fissure

Answer 49

inferior orbital fissure which transmits the zygomatic branch of the maxillary nerve and the ascending branches from the pterygopalatine ganglion.

Question 50

Skull foramina

Answer 50

The superior orbital fissure is formed inferiorly by the sphenoid bone. CNIII, CNIV, CNVa and CNVI run through this fissure. The following foramen all run in the sphenoid bone The foramen rotundum is where CNVb passes The foramen ovale is where CNVc runs. The formanen spinosum is where the middle meningeal artery and vein pass. These foramina all lie posterior lateral to each other, but medially is the foramen lacerum. The foramen lacerum is where the ICA enters into the skull (ICA runs over lacerum) then into the carotid canal. Above the jugular foramen is the internal acoustic meatus (CNVIII and CNVII pass through here). 75 The styo-mastoid forman is between the styloid and mastoid processes, and CNVII exits the skull here. The confluence of sinuses in CNIX, X and XI (and IJV) all exit via jugular foramen CNXI enters through foramen magnum CNXII exits through hypoglossal canal (medial to foramen magnum)