6 - Gross Brain Meninges, Sinuses Flashcards
1
Q
Recall the neurocranium =
A
cranial vault
2
Q
Folium (folia)
A
– tiny fold of brain (cerebellum
3
Q
Sulcus (sulci)
A
shallow groove between folds
4
Q
Fissure (fissures)
A
deep grooves between folds
5
Q
Lateral fissure/sulcus
A
between temporal & frontal lobes
6
Q
Longitudinal fissure
A
between 2 cerebral hemispheres
7
Q
Central sulcus
A
– between frontal & parietal lobes
8
Q
Frontal lobe
A
1°motor & personality area
9
Q
Parietal lobe
A
1° sensory & integration area
10
Q
Temporal lobe
A
auditory, speech, olfactory & memory areas
11
Q
Pons
A
CN nuclei & tracts between cerebrum & cerebellum
12
Q
Medulla oblongata
A
BP and respiration
13
Q
Hypothalamus
A
center for autonomic & endocrine functions
14
Q
Pituitary gland
A
“master” gland for homeostasis
15
Q
Pineal gland
A
center for sleep-wake cycles
16
Q
Mammillary bodies
A
nuclei related to emotions
17
Q
Interpeduncular fossa posterior to the
A
optic chiasm
18
Q
Interpeduncular fossa holds
A
infundibulum
mamilary bodies
19
Q
cerebral peduncle is medial to the
A
uncus
20
Q
2 Main sources of blood to brain:
A
Internal Carotid arterial system
Vertebrobasilar arterial system
These anastamose at circle of willis
21
Q
Internal Carotid Artery ascends neck to
A
base of skull
22
Q
ICA Enters
A
carotid canal & makes 90° turn
23
Q
ICA Ascends
A
supr. Foramen lacerum
24
Q
ICA enters
A
Enters cavernous sinus
25
ICA supplies
Supplies: anterior & middle brain
26
Vertebral Artery ascends through
transverse foramina of C6 & above
27
VA Makes a
90° turn
28
VA enters
Enters Foramen Magnum
29
VA joins this after entering foramen magnum
Joins opposite vertebral a.
30
Upon joining the two VAs, the ------ is formed
Basilar a.
31
VA supplies
Supplies: posterior brain
32
Internal Carotid Artery Brs.
Ophthalmic aa.
Anastomoses with post. communicating aa.
Terminates as middle & ant. cerbral aa.
33
Vertebrobasilar System
Vertebral aa. gives off ant. & post. Spinal aa.; post. inferior cerebellar aa.
34
Basilar artery gives off
Vertebrobasilar system
ant. Inferior cerebellar aa.; labyrinthine aa & pontine aa., then superior cerebellar aa.
35
Basilar artery splits to form
Splits to form posterior cerebral aa.
36
PCA branches supply
medial & inferior surfaces of temporal and occipital lobes
Branches also go to rostral midbrain and posterior diencephalon
37
Vertebral arteries run along
lateral medulla, fuse into basilar artery at pons
38
VA gives off - 1
Posterior spinal artery: supplies posterior 1/3 of spinal cord
39
VA gives off - 2
Anterior spinal artery: join together in midline, resulting single artery supplies anterior 2/3 of cord
(Note these arteries get help caudal to cervical cord)
40
PICA: supplies
inferior cerebellum and lateral medulla
41
Anterior Cerebral artery arches
posteriorly and follows corpus callosum
42
ACA supplies
medial parts of frontal and parietal lobes, note some branches extend over the dorsolateral surface
43
Anterior cerebral aa. – supply
ant./med. cerebrum
44
Middle cerebral aa. – supply
ant./lat. cerebrum
45
Posterior cerebral aa. – supply
post./infr. cerebrum
46
AICA supplies
supplies anterior portions of the inferior surface of cerebellum (flocculus) and caudal pons
47
SCA: supplies
superior cerebellum, caudal midbrain and rostral pons
48
Post. Infr. cerebellar aa. – supply
post./infr. cerebellum
49
most superior portions of the ethmoid bone,
that is the cribriform plate and crista galli
50
In the cribriform plate are the
foramina of the cribriform plate which transmit the olfactory nerves or CN I
51
Anterior fossa
| bones
Frontal
Ethmoid
Sphenoid
52
Middle fossa
| bones
Sphenoid
Parietal
Temporal – petrous portion
53
Posterior fossa bones
Temporal
Parietal
Occipital
54
Foramen cecum
Emissary vein from nasal cavity to superior sagittal sinus
55
Anterior ethmoidal foramen
Anterior ethmoidal nerve, artery & vein
56
Posterior ethmoidal foramen
Posterior ethmoidal nerve, artery & vein
57
Foramen Ovale
CN V3 & accessorymeningeal a.
58
Foramen Lacerum
fibrocartilage (IC passes over)
59
Dura Mater
| 2 layers
periosteal layer
| meningeal layer
60
periosteal layer (Dura mater)
rough outer layer adherent to the skull : forming the endocranium or inner periosteum
61
Meningeal layer (dura mater)
smooth inner layer covers arachnoid mater
62
layers of dura separate to form
venous sinuses
63
Anterior meningeal supply from
ethmoidal aa. branches
64
Posterior meningeal supply from
ascending pharyngeal a.
65
Branches from Vertebral A. around the
foramen magnum
66
Posterior Occipital branches from
Occipital a.
67
Middle Meningeal A. branches
Frontal br. (ant.)
Parietal br. (post.)
68
Middle Meningeal A. tearing quickly leads to
epidural (extradural) hematoma (arterial bleeding between dura mater & skull)
69
Middle meningeal a. Expanding hematoma can exert
fatal pressure on brain
Must be promptly recognized & surgically treated
70
middle meningeal a. Fractures thru pterion of skull commonly produce
tearing of ant. branch of a. (Frontal br.) crossing area of pterion
71
Falx cerebri is found between
cerebral hemispheres
72
Falx cerebelli is found between
between cerebelli hemispheres
73
Tentorium cerebelli found between
cerebrum & cerebellum
74
Diaphragma sellae found
between brain & pituitary gland
75
2 dural layers split to form
venous sinuses
76
Sinuses receive venous drainage from
brain & skull (via cerebral, cerebellar, & emissary vv.)
77
Blood entering sinuses flows
posterior & inferior
78
Dural Venous Sinuses
```
Superior & Inferior sagittal sinuses
Sigmoid sinuses
Straight sinus (sinus rectus)
Sphenoparietal sinuses
Carvernous sinuses
Superior & Inferior petrosal sinuses
```
79
Sphenoparietal sinuses
connects to the caverous sinuses (from along the ridge between the anterior and middle cranial fossae)
80
Superficial sinuses
on cerebral surface, most empty into superior sagittal sinus
81
Deep sinuses
drain internal structures, empties into straight sinus
82
Facial vv. anastomose with
ophthalmic vv.
83
Infections (boils) of face can spread into the
ophthalmic vv.
84
Infections can travel to
cavernous sinuses
May result in cavernous sinus thrombosis (clot formation)
85
Cavernous Sinus contents; vasculature
Internal Carotid a. & CN VI pass thru sinus
86
Cavernous sinus contents: nerves
CN III, IV, V1, & V2 are sheathed in its lateral wall
87
Cavernous sinus: Injuries or infections of sinus can affect
ICA or CNs
88
Clinical Note: ICA may rupture with
skull base fractures; results in arteriovenous fistula
89
arteriovenous fistula produces
This produces abnormal reflux of blood into ophthalmic vv.
Eye engorges, protrudes & pulsates in sync with radial pulse
Referred to as pulsating exophthalmos
Pulse can be seen in eyelids
90
Dura
contains vessels and sinuses
91
Pia covers
vasculature and brain
92
Subdural hematoma
Rupture of cerebral v. produces subdural hematoma (venous bleeding into subdural space)
Hemorrhage may spread widely over hemisphere
Limited by falx cerebri & tentorum cerebelli
Blows which jerk the brain inside the skull cause this injury
93
arachnoid mater covers
Covers all fissures and sulci of brain
94
arachnoid matter web like processes extend
Web-like processes extend downward to pia mater
95
Deep to the arachnoid mater is
subarachnoid space
96
SubArachnoid Space
| contains
cerebrospinal fluid (CSF) & acts as shock absorber by forming a fluid cushion over gyri & sulci
Cerebral & cerebellar blood vessels also in this space
97
Cerebral & cerebellar blood vessels also in this space
These cover and penetrate surfaces of brain
98
Drainage occurs via
Projections of arachnoid & subarachnoid space into superior sagittal sinus
passive pressure gradient
99
Some of the arachnoid granulations become so large that they actually create
depressions in the internal surface of the calvaria (skull), = lateral venous lacunea
100
CSF absorbed in the
venous system at the SAG in the SSS.
101
The subarachnoid space contains CSF and acts as a
shock absorber by forming a fluid cushion over the gyri and sulci.
102
Pia Mater
Delicate membrane surrounding brain
Covers surface of all fissures and sulci of brain
Closely adherent to the surface of the brain
Pierced by vessels that supply the brain
103
Falx cerebri in
longitudinal fissure
104
CN 3 located between
SCA and PCA
105
Lateral to bulb is
9, 10, 11
106
6 found between
anterior cerebellar, labarynthian
107
Separation of periosteal and meningeal layer of dura makes
sinus
108
V1 supplies
anterior meninges
109
V2 supplies rest of
anterior cranial fossa
110
V3 supplies
middle cranial fossa
111
V1 supplies
posterior cranila fossa (lateral)
112
C2, C3 from XII and X supply
supply medial posterior cranial fossa
113
Diploic veins –
from spongy part of skull, drain to sinus.
114
SSS at top of
falx cerebri
115
Arachnoid granulations –
outpocketings of arachnoid mater, venous drainage goes here (choroid plexus)
