C.S.F. Circulation

Question 1

csf is present in the

Answer 1

brain cavity subarachnoid space and central canal of spinal cord

Question 2

function of csf

Answer 2

• acts a cushion for cns
• csf creates buoyancy
• csf acts as a reservoir regulates contents of skull
• csf nourishes cns
• removes waste products
• moves hormones around

Question 3

healthy amount of csf present in the brain at one given time is

Answer 3

130ml

Question 4

csf pressure is

Answer 4

60-160 mm h2o

Question 5

csf is measured with a

Answer 5

manometer

Question 6

which structures are pierced in a lumbar puncture

Answer 6

• skin
• subcutaneous fascia
• ligaments supraspinous
• ligament interspinous
• ligament flavum
• space outside dura matter is epidural space dura matter subdural space arachnid matter
• subarachnoid space containing csf
• pia matter is not pierced XXX

Question 7

what happens if pia matter is pierced in a lumbar puncture

Answer 7

damage to spinal cord

Question 8

how much ml can be safely drawn during a lumbar puncture

Answer 8

30 ml

Question 9

signs of high intracranial pressure

Answer 9

1. history of unexplained constant headache if patient wakes up with headache high csf should always be considered
2. papilledema - optic nerve at the back of the eye becomes swollen. symptoms can include visual disturbances, headaches, and nausea papilldema
   - csf accumulates around optic disk margined blurred don’t do lumbar puncture
3. projectile vomiting
   - git regulating centres of medulla vagus nerve from medulla is disturbed vagus nerve controls motility of git causing projectile vomiting
4. progressively rising blood pressure and progressively falling pulse rate
   - because vagus is stimulated vagus is a cardio inhibitor heart rate is reduced heart rate goes down blood pressure goes up struggles to pump ischaemia develops in cns which triggers immense sympathetic overflow which constricts many vessels in body raising body up ischemic brain is important to save

Question 10

is optic nerve really a nerve or a tract of cns

Answer 10

optic nerve is technically not a nerve its a cns tract proof is that its covered in meninges and its myelinated by oligodendrocytes and not schwann cells

Question 11

csf lumbar puncture needle is pushed up towards

Answer 11

navel umbilicus

Question 12

circulation of csf

Answer 12

• csf circulates from the two lateral ventricles through the foramen of monro (inter ventricular foramen) to the third ventricle
• down the aqueduct of sylvius
• to the fourth ventricle
• and into subarachoiud space via median foramen magendie (most pass through this) but also foramen lusaka on either side of fourth ventricle

Question 13

spaces form openings in the subarachnoid space an anatomic space in the meninges of the brain the space separates two of the meninges the arachnoid mater and the pia mater and are filled with cerebrospinal fluid

Answer 13

cisterns

Question 14

how many cisterns are there in the cns and there names

Answer 14

1. chiasmatic
2. interpenduncular
3. pontine
4. superior
5. cerebellomedullary

Question 15

inter ventricular foramen

Answer 15

the foramen of monro

Question 16

how much csf is secreted per min and per day

Answer 16

0.5ml per min and 720 ml per day

Question 17

increases intracranial pressure

Answer 17

• coughing and crying increases the pressure by decreasing absorption of csf
• compression of internal jugular vein

Question 18

pressure is highest and lowest on csf when

Answer 18

siting and lateral recumbent

Question 19

weight if brain in and out of csf

Answer 19

• brain weighs: 1400 g

- but in csf it weighs: 50g

Question 20

csf collection happens at these two spots

Answer 20

• cisternal puncture : between occipital and atlas cistern magna
• lumbar : subarachnoid space in lumbar region between L3-4

Question 21

connects lateral ventricle to third ventricle

Answer 21

foramen monro

Question 22

what is the terminal ventricle

Answer 22

is located at the end of the spine it is a little dilated also a dead end

Question 23

ventricle that lies between the thalami is the

Answer 23

third ventricle

Question 24

the ventricle of the telencephalon

Answer 24

the lateral ventricles

Question 25

the ventricle of the diencephalon

Answer 25

third ventricle

Question 26

the ventricle of the midbrain aka mesencephalon

Answer 26

cerebral aqueduct

Question 27

the two expanded ends from the third ventricle and the central cavity make which ventricle

Answer 27

the fourth ventricle

Question 28

where is the fourth ventricle located

Answer 28

located on the posterior aspect of pons and upper medulla and anterior to cerebellum

Question 29

tube connecting third and fourth ventricle is called

Answer 29

cerebral aqueduct

Question 30

the ventricle for pons medulla and cerebellum aka rhombencephalon

Answer 30

fourth ventricle

Question 31

where is csf formed

Answer 31

within the ventricles by chorid plexuses

Question 32

all cavities within cns are lined with which type of cells

Answer 32

ependymal cells

Question 33

glucose ratio from cns to blood is

Answer 33

cns glucose level is 2/3 of the blood

Question 34

epithelial cells covering choroid plexuses have a specialised pump for

Answer 34

sodium (they actively secret sodium attracting chlorine)

Question 35

in csf how are sodium and chlorine exchanged

Answer 35

sodium is actively pushed by sodium pumps whilst chloride is passively pushed

Question 36

transported in reverse from csf to blood is

Answer 36

potassium (naturally low in csf)

Question 37

foramen between fourth ventricle and the subarachnoid space at the cerebellopontine angle (pontine cistern/ cerebellopontine cistern)

Answer 37

foramen of luschka

Question 38

foramen located on posterior aspect of the fourth ventricle creates cerebellomedullary cistern

Answer 38

foramen magendie (median foramen median aperture)

Question 39

drains csf

Answer 39

dural venous sinuses lined with epithelial cells

Question 40

cavity where the arachnoid extends across between the two temporal lobes it encloses the cerebral peduncles and the structures contained in the interpeduncular fossa, and contains the arterial circle of Willis.

Answer 40

interpeduncular cistern

Question 41

cavity subarachnoid cistern of the subarachnoid space between the splenium of the corpus callosum and the superior surface of the cerebellum it extends between the layers of the tela choroidea of the third ventricle and contains the great cerebral vein and the pineal gland

Answer 41

superior cistern

Question 42

is formed as the interpeduncular cistern extends forward across the optic chiasm and onto the upper surface of the corpus callosum

Answer 42

chiasmatic cistern

Question 43

large area in subarachnoid space between medulla and cerebellum

Answer 43

cistern magna

Question 44

pressure of csf is at 10-18 cm H20

Answer 44

lateral recumbent position

Question 45

pressure of csf is at 13 cm H20

Answer 45

lying position

Question 46

pressure of csf is at 30 cm H20

Answer 46

sitting position

Question 47

ph of csf

Answer 47

7.28 -7.32

Question 48

noncommunicating (internal) hydrocephalus

Answer 48

obstruction of any foramen

Question 49

communicating (external) hydrocephalus

Answer 49

blockage of arachnoid villi

Question 50

gait instability urinary incontinence dementia symptoms of

Answer 50

normal pressure hydrocephalus

Question 51

hydrocephalous ex vacuo is due to

Answer 51

brain atrophy

Question 52

congenital hydrocephalus includes

Answer 52

- aqueduct stenosis narrowing of aqueduct - brain extends to spinal cord - dandy walker malformation no cerebellar vermis

Question 53

tapping on the skull near the junction of the frontal temporal and parietal bones yielding resonant sound

Answer 53

macewan sign a result of hydrocephalus in children

Question 54

sign hydrocephalus in children

Answer 54

- failure of upward gaze: due to pressure on the tectal plate through the supra pineal recess imitation of upward gaze is of supranuclear origin - macewen sign - unsteady gait - large head: sutures are closed, but chronic increased icp will lead to progressive macrocephaly. - unilateral or bilateral sixth nerve palsy is secondary to increased icp

Question 55

ophthalmologic sign in young children resulting from upward-gaze paresis eyes appear driven downward, the sclera may be seen between the upper eyelid and the iris, and part of the lower pupil may be covered by the lower eyelid

Answer 55

setting-sun sign of hydrocephalus

Question 56

visual impairment seen in adults with hydrocephalus

Answer 56

- Parinaud's syndrome inability to move the eyes up and down caused by compression of the vertical gaze center at the rostral interstitial nucleus of medial longitudinal fasciculus (riMLF)

Question 57

drug of choice for hydrocephalus

Answer 57

acetazolamide and frusemide

Question 58

foramen monro blocked

Answer 58

leads to asymmetrical enlargement

Question 59

cerebral aqueduct blocked

Answer 59

symmetrical enlargement

Question 60

symptoms of hydrocephalus ex vacu where the brain shrinks

Answer 60

urinary incontinuence - wet gait - wobbly dementia - whacky

Question 61

queckenstedt sign

Answer 61

pressing on internal jugular vein test