Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neuro Exam I > Anatomic Basis of Hydrocephalus > Flashcards

Anatomic Basis of Hydrocephalus Flashcards

1
Q

what is the foramen of monroe?

where is it located?

A
  • the conduit between the lateral ventricles and 3rd ventricle
  • insertion onto lateral ventricle divides the anterior horn from the body
  • located in the frontal lobe
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the atrium?

where is it located?

A
  • the junction between the superior lateral ventricle (anterior horn, body and posterior horn) and the inferior lateral ventricle (inferior horn)
  • its insertion on the superior lateral ventricle divides in the anterior horn and the body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

the anterior horn of the ventricle is

  • located in what lobe
  • defined by what boundaries
A
  • frontal lobe
  • all of the temporal lobe rostral to the insertion of the foramen of monro
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

the body of the lateral ventricle is

  • located in what lobe
  • defined by what boundaries
A
  • located in?
  • defined as the lateral ventricle
    • caudal to the foramen of monroe
    • rostral to the atrium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

the posterior lobe is

  • located where
  • defined by what boundaries
A
  • in the occipital lobe
  • defined as the lateral ventricle caudal to the atrium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

the inferior horn of the lateral venticle is

  • located where?
  • defined by what boundaries?
A
  • in the temporal lobe
  • extends anteroinferioly from the atrium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

describe the continuity of the lateral ventricles to one another

A

they are separated medially by the septum pellucidum (& have no direct connections), except briefly at the foramen of monroe / interventricular foramen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

into what does the foramen of monroe empty?

A

the midline of the third ventricle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the most rostral midline ventricle?

A

the third ventricle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

the 3rd ventricle are

  • made of what components?
  • bordered rostrally by?
  • bordered caudally by?
  • bordered medially by?
A
  • components:
    • inferior expansion - in the hypothalamus
    • caudal extension - travels thru midbrain (between tectum & tegmentum) -> the pons -> dilates into 4th ventricle
  • bordered:
    • rostrally - by the anterior commissure
    • posteriorly - by the posterior commisure
    • medially - by the lateral walls of the thalami in the middle of the ventricle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

the cerebral aqueduct

  • travels how?
  • forms what?
A
  • in between the midbrain (separating tectum and tegmentum)
  • expands into the 4th ventricle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what borders the 4th ventricle is bordered by

  • ventrally?
  • dorsally?
  • superiorly?
  • inferiorly?
A
  • ventrally: caudal (superior) pons + rostral (superior) medulla
  • dorsally: ventral surface of the cerebellum
  • superiorly:dilation of cerebral aqueduct
  • inferiorly: the central canal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the obex?

where is it located?

A
  • triangular termination fo the 4th ventricle
  • in line with the rotral medulla
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is the fastigium?

where is it located?

A
  • the widest portion of the 4th aqueduct
  • in line with the caudal end of pons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are the aperatures of the brainstem?

where are they located?

what is their role?

A
  • perforations of the 4th ventricle
  • role: connects ventricular CSF to subarachnoid CSF
  • locations:
    • lateral aperature: just caudal to the end of the fastigium
    • medial aperature: just rostral to the end of the obex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

median aperature

  • other name
  • definition
  • role
  • location
A
  • name: foramen of magendie
  • definition: perforation of the 4th ventricle
  • role: connects ventricular CSF to subarachnoid CSF
  • location: just above to the end of the obex (termination of 4th ventricle in line with rostral medulla)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

lateral aperature

  • other name
  • definition
  • location
  • role
A
  • other name: foramen of luschka
  • definition: perforation of the 4th ventricle
  • connects ventricular CSF to subarachnoid CSF
  • locations: just caudal to the fastigium (widest section of 4th ventricle, in line with caudal pons)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

list & describe the layers that comprise the blood brain barrier

A
  1. endothelial cells:
    • ​​NON-FENESTRATED
    • connected by tight junctions
  2. basement membrane:
    • CONTINUOUS
    • EMBEDDED WITH PERICYTES
  3. perivascular tube feet of astrocytes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how does fluid move across the blood brain barrier?

A
  • there is minimal movement of fluid fom capillaries into blood
  • this is due to the tight nature of the barrier, largely from
    • non-fenestrated endothelium w/ tight junctions
    • continuous basement membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what attaches to the outer basement membrane forming the blood brain barrier?

A

pericytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

the choroid plexus

  • is derived from?
  • is located where?
  • has what role?
A
  • derived from: pia mater & ependymal cells
  • located: ventricles
  • role: primary site of secretion of cerebrospinal fluid (CSF) from blood -> ventricles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

in what direction does fluid move across the barrier surrounding the choroid plexus? why?

A

from blood (choroid plexus) -> CSF

higher hydrostatic pressure of blood

23
Q

list & describe the layers that form the choroid plexus

A
  1. endothelial cells:
    • FENESTRATED
    • line with tight junctions
  2. basement membrane
    • DISCONTINUOUS
    • embedded within stroma: CT + immune cells
  3. epithelial cells (derived from ependymal cells)
    • simple cuboidal
    • have microvilli
    • connected w/ zonula occludens & desmosomes
24
Q

the ependyma

  • has what role?
  • is located where?
A
  • location: lines the ventricles & surface of central canal
  • role: provides a barrier against transfer between CSF and neural tissue
25
Q

list & describe the layers that form the ependyma

A
26
Q

list and describe the layers that form the ependyma

A
  • epithelium:
    • simple columnar
    • have microvilli
    • connected by zonula occludens & desmosomes
    • made of epyndmal cells + tanycytes:
      • ependymal cells: ciliated
      • tanycytes: send projections in neural tissue vasculature
  • basement membrane
  • perivascular tube feet of astrocytes
27
Q

what are tanycytes?

where are they found?

what is their role?

A
  • definition: a type of epithelial cell
  • location: found in the empyndema epithelium lining ventricles & central canal
  • role: extend small cellular processes through the basement membrane to vessels in the surrounding nueural tissue, to perform limited absorption / secretion of CSF
28
Q

the choroid plexus form what unique shape?

why is this important?

A

the form into villi

this allows for maximal surface area for CSF secetion

29
Q

compare & constrast the endothelial cells of the

  • BBB
  • choroid plexus
  • empendyma
A
  • BBB: non-fenestrated w/ tight junctions
  • choroid plexus: fenestrated w/ tight junctions
  • ependyma: n/a
30
Q

compare & contrast the basememt membranes of the

  • BBB
  • choroid plexus
  • ependymal cells
A
  • BBB:
    • continuous
    • contain pericytes
    • lind with perivascular tube feet of astrocytes
  • choroid plexus:
    • discontinuous
    • embedded in loose CT stroma
  • ependymal cells
    • pierced with tanycyte processes
    • lined with perivascular tube feet of astrocytes
31
Q

compare and contrast the epithelial linings of the

  • BBB
  • choroid plexus
  • ependyma
A
  • BBB - n/a
  • choroid plexus & ependyma
    • both:
      • columnar with microvilli
      • have demosomes & tight junctions
      • derived from ependymal cells
    • ependyma: ependymal cells (ciliated) + tanycytes (have foot processes)
32
Q

where is the subarachnoid space?

A

between the pia mater and arachnoid mater

33
Q

what determines the “depth” of the subarachnoid space?

why is this significant?

A
  • the length of the fine trabeculae that connect the
    • deep surface of subarabhnoid mater
    • superficial surface of the pia mater
  • this length throughout most of CNS is small - except at cisterns: deep subarachnoid spaces containing large amounts of CSF
34
Q

what are the cisterns of the CNS?

where are they each located?

A
  • chiasmatic cistern: surround the optic chiasms
  • interpeduncular cistern: between cerebral peduncles + ventral space
  • pontine cistern: around inferior pontine sulcus
  • cisterna magna (cerebellomedullary) cistern:
    • posterior (dorsal) medulla
    • inferior surface of cerebellum + inferior surface of occipital bone
  • quadrageminal (superior) cistern:
    • immediately posterior (dorsal) to tectum + pineal gland
    • along superior / inferior surfaces of tentorium cerebelli
  • lumbar cistern:
    • ​inferior to L2 (conus medullaris)
    • superior to S2 (end of dura mater)
35
Q

once the CSF reaches the 4th ventricles, it can go to which major locations?

A
  • through cantral canal of spinal cord -> pool in lumbar cistern.
  • through the lateral aperature (just below fastigium) to the
    • ventral surface
    • superior sagittal sinus
  • through the median aperature (just below opex)
    • cisterna magna: dorsal medulla + inf cerebellum / occipital bone
    • quadrigeminal cistern: dorsal to tectum & pineal gland + superior & inferior surface of tectorium cerebelli
    • superior sagittal sinus
36
Q

where is the pontine (pontomedullary cistern located?

A

around the inferior pontine sulcus

37
Q

the cisterna magna

  • has what other name?
  • is formed by what borders?
  • receives CSF how?
A
  • cerebellomedullary cisterna
  • borders:
    1. dorsal medulla
    2. inferior cerebellum
    3. inner occipital bone
  • receives CSF from: median aperature
38
Q

the quadrigminal cistern

  • has what other name?
  • is formed by what borders?
  • receives CSF how?
A
  • superior cistern
  • borders
    1. superior tetorium cerebelli
    2. dorsal pineal gland
    3. dorsal tectum
    4. superior cerebellum / inferior tentorium cerebelli
  • receives CSF via: cisterna magna
39
Q

how does CSF get from the 4th ventricle to the superior sagittal sinus?

A
  • two major routes:
    • lateral aperature -> ventral space -> superior sagittal sinus
    • median aperature -> cistern manga -> quadrigeminal cistern -> superior cistern
40
Q

the lumbar cistern

  • what significance?
  • has what borders?
  • receives CSF how?
A
  • significance: contains the caunda equina
  • borders:
    • L2 - conus medullaris
    • S2 - end of dura mater
  • receives CSF via the central canal
41
Q

arachnoid granules

  • definition
  • location
  • makeup
  • role
A
  • definition: evaginations of arachnoid mater that protrude into dura matter
  • location: in between the periosteal & meningeal dural layers speciifcally, which is where the _superior sagittal sinu_s courses
  • makeup: only of thin arachnoid membrane
  • role: delivers CSF from the cisterns into the superior sagittal sinus: i.e., major site of CNS absorption in the blood
42
Q

how does CSF move across the CSF-blood barrier seen at the arachnoid granulations?

why?

A
  • blood moves into the sagittal sinus
  • pressure of the CSF > pressure of venous blood
43
Q

how much does the adult brain weigh?

how does the presence of CSF change this?

A

1300 g

with CSF, the “effective” weight comes down to 45 g

44
Q

what are the major sites of CSF production?

A
  • choroid plexus
  • pia matter arterioles
  • deep to ependymal
45
Q

how do changes in arterial and venous pressure alter CSF volume?

A
  • arteries (choroid plexus): site of CSF secretion
    • increased BP: increaes volume (increased secretion)
    • decreased BP: decreased volume (decreased secretion)
  • venous (sagittal venous sinus): site of CSF secretion
    • increased BP: increases volume (less absorption)
    • decreased BP: decreases volume (more absorption)
46
Q

how does hypoventilation affect CSF volume?

why?

A

increases CSF volume

decreases peripheral vasculature resistance

47
Q

what is the monro - killie hypothesis?

A
  • that the skull is an elastic chamber filled with 3 compartments, and an increase in pressure / volume of one compartment results in a compensatory decrease in another
    • blood
    • brain
    • CSF
48
Q

the brain can accomodate for what changes of in intracanial volume up to what point? how?

increases beyond this point value result in what?

A
  • can accomodate for changes up to 100 ml, via:
    1. decerasing CSF production (minor)
    2. shifting more CSF into the spinal cord -> lumbar cistern (major)
  • beyond 100 mL will result in one of three alterations:
    1. brain compression: decreased ventricles
    2. midline shift: brain out of line with falx cerebri
    3. herniation: midline shift + herniation of cerebellum thru foramen magnum
49
Q

what is hydrocephalus?

how does it generally present?

how is it treated?

A
  • a marked increase in the volume of the ventricles
  • generally, comes at the expense of the rest of the brain
  • tx: inserting a catheter in the lateral ventricles
50
Q

how does hydrocephalus present in newborns specifically?

A
  • compensetory decrease in brain volumes (like with adults), +
  • expansion of calvarial diameter
  • expansion of the frontaneles
51
Q

what are the two major classifications of hydrocephalus and what defines them?

A
  • based on whether or not the CSF can leave the 4th ventricle into subarachnoid space
    • communicating hydrocephalus: CSF can exit 4th ventricle
    • non-communicating hydrocephalus CSF cannot exit 4th ventricle
52
Q

what are the two major types of communicating hydrocephalus?

A

CSF movement from ventricle-subarachnoid space unimpeded

  • choroid plexus tumor: increase in CSF output
  • dural scarring / hematoma: decreased in CSF absorption
53
Q

what are the two major types of non-communicating hydrocephalus?

A

movement of CSF from 4th ventricle to subarachoid space impeded

  • aqueductal stenosis - congenital, tumor
  • 4th ventricle blockage - m/c cerebellar tumor
54
Q

normal pressure hydrocephaly

  • demographics
  • presentation
  • findigns
  • treatment
A
  • demographics: 60 yr +
  • presentation:
    1. gait impairment
    2. cognitive decline
    3. urinary incontinence
  • findings: increased volume yet normal pressure
    • imaging: ventricular increase + brain decrease
    • lumbar spinal tap: normal CSF pressure
  • treatment: nothing great; spinal tap = short term gait improvement

Neuro Exam I (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions