week 4 Flashcards
1
Q
with regards to the central sulcus, where would you find the motor cortex and somaesthetic cortex
A
Motor cortex in front
somaesthetic cortex behind
2
Q
what is found on the left hemisphere beside the motor cortex
A
the motor speech area
3
Q
what is the path of the anterior cerebral artery
A
- goes forwards on the medial side near the frontal lobe
- and gives branches around the corner into the lateral side
4
Q
what does the posterior cerebral artery supply?
A
posterior part of hemisphere and much of the lower part of the hemisphere
5
Q
where does the middle cerebral artery come from
A
the main continuation from the internal carotid artery
6
Q
what is the path of the middle cerebral artery
A
Comes off the internal carotid artery and moves laterally and runs into the deep part of the lateral fissure
7
Q
if the patient has an embolus / blood clot which artery territory is most likely to be affected
A
If the patient had an embolus / blood clot it is quite likely to go into the territory of the middle cerebral artery
8
Q
what is the effect on the patient if there is damage to the left cerebral artery
A
patient likely to be paralysed in the face on the opposite side (in this patient it would be the right side that is affected), lower face and upper limb on right hand side
9
Q
what artery supplies the lower limn area of the hemisphere
A
anterior cerebral artery
10
Q
what artery supplies the area of the motor speech area
A
left middle cerebral artery
11
Q
how would a lesion in the left middle cerebral artery affect the motor speech area?
A
the patient cannot put a speech together and what comes out is unintelligible sounds
12
Q
what other cortex might be affected by a lesion in the left middle cerebral artery
A
auditory cortex
but hopefully the other side would be able to maintain some of the hearing
13
Q
where is the visual cortex found
A
posterior cerebral cortex
the visual cortex is in this territory on the medial side of the hemisphere
14
Q
what. is the cranial cavity lined by
A
dura mater - the outer most layer of the meninges
15
Q
what can be see around the outside of the floor of the cranial cavity
A
the cut edge of the vault
16
Q
what can be seen at the front within the vault
A
the frontal air sinus
one on each side of the midline
17
Q
where is bone marrow found
A
Bone marrow is found in between the inner and outer tables of the skull
18
Q
what is diploe
A
Diploe is the spongy cancellous bone separating the inner and outer layers of the cortical bone of the skull.
19
Q
what is the first cranial nerve
A
olfactory nerve
20
Q
how / where does the olfactory nerve appear on the floor of the cranial cavity
A
Lots of little nerves come from the olfactory epithelium
these little nerves come through the cribriform plate of the ethmoid bone
Soon join the olfactory bulb which has a long tract which leads to the rest of the forebrain
21
Q
what is the role of the olfactory nerve
A
Takes information about the sense of smell to the frontal lobe of the brain
22
Q
what is the bony projection in the anterior cranial fossa called
A
anterior clinoid process
23
Q
what is the anterior clinoid process a useful landmark for?
A
when looking for the optic nerve
24
Q
what is the second cranial nerve
A
the optic nerve
25
what is the path of the optic nerve
The optic nerve is passing from the cranial cavity into the orbit through the optic canal (a little round bony opening)
the optic nerve disappears out of the cranial cavity next to the anterior clinoid process
26
what can be see a little behind the optic nerve
pituitary stalk
27
what is the name of the thin layer of dura mater that covers the pituitary gland
diaphragma sellae
28
what artery can be seen next to the optic chiasm and the pituitary stalk
internal carotid artery
29
abnormal swellings / aneurysms of the internal carotid can cause what problem
Abnormal swellings / aneurysm (pathological swelling) of the artery can press on the optic chiasm and cause visual disturbances
30
what is the superior orbital fissure
large comma shaped opening which leads into the orbit)
31
what is the 3rd cranial nerve
oculomotor nerve
32
what is the 4th cranial nerve
trochlear nerve
33
what is the 5th cranial nerve
trigeminal nerve
34
what does the oculmotor nerve pass through to leave the cranial cavity
superior orbital fissure
runs forward underneath the dura but on top of the bone
35
where is the trochlear nerve in relation to the oculomotor nerve
Immediately behind the oculomotor, and slightly to the side
36
what does the trochlear supply
Supplies the superior oblique muscle / muscles in the orbit
37
what does the trochlear nerve pass through
superior orbital fissure
38
where is the territory of the middle cranial fossa between
The middle cranial fossa is from the lesser wing of the sphenoid bone to the border of the petrous temporal bone
39
where is the trigeminal nerve found
Right at the back edge of the middle cranial fossa
40
where is the trigeminal nerve in relation to the 3rd and 4th cranial nerve
It is found a little bit lateral to where the 3rd and 4th cranial nerve is
41
what is the path of the trigeminal nerve
Comes from the pons, disappears into a tunnel / cave in the dura called the trigeminal cave
42
what are the divisions of the trigeminal nerve
- opthalmic
- maxillary
- mandibular
43
what happens after the trigeminal nerve enters the trigeminal cave
We will find that very soon after going into the trigeminal cave, we would find the trigeminal ganglion and the 3 divisions of the trigeminal nerve
44
what is the trigeminal ganglino
Flat lacey structure is the trigeminal ganglion and from that the branches come off
45
what is the path of the opthalmic division
The ophthalmic division goes forwards from the ganglion and disappears out of the cranial cavity into the orbit through the superior orbital fissure, going to supply the skin of the forehead and the front of the skull
46
what is the path of the maxillary division
quite close to the opthalmic division and running forwards [but not quite so far] is the maxillary division which is going to the foramen rotundum
47
what is the path of the mandibular division
Out to the side is the mandibular division which is going to the foramen ovale
48
what is found within the trigeminal ganglion
Cell bodies of many of the sensory neurons of the trigeminal lie within the trigeminal ganglion
49
what is teh french word for trigeminal neuralgia
Tic Doloreux
50
what is trigeminal neuralgia
Terrible condition, common enough
Presents as an extremely sharp pain in one of the sensory areas of the trigeminal nerve, quite often the maxillary division
patient experiences this extremely sharp pain on one side of their face
Very difficult to manage
Dental treatment can act as a trigger for it - might come across it
Very often treated medically with a drug called carbamazepine - suppressor drug, anti-epileptic
51
what is the foramen magnum
large hole in the base of the skull
52
what is the 6th cranial nerve
abducens
53
what is the clivus
that long slope down to the foramen magnum n the posterior cranial fossa
54
what is the path of the abducens nerve
Has a very long course
its going to run under the dura over the edge of the petrous temporal bone then forwards to get to the superior orbital fissure where it will leave the cranial cavities
(has a long way deep to the dura before it actually goes out through the bone)
55
what is the 7th cranial nerve
facial nerve
56
what is the 8th cranial nerve
vestibulocochlear nerve
57
where is the 8th cranial nerve found
the 8th is lateral to the 7th and a little bigger than the 7th
Important clinically but not so much as a dental significance
58
what is the passage way of the 7th and 8th cranial nerves
The passage way these nerves are going into is called the internal auditory / acoustic meatus (bony opening) on their way to an area where the middle ear is (middle ear inside the petrous temporal bone)
59
where does the 8th nerve go to
the ear
60
where does the 7th nerve go to
The 7th nerve is going to carry on past CN8, run close to the middle ear then comes out from the base of the skull to supply the muscles of facial expression
61
what is the 9th cranial nerve
glossopharyngeal
62
what is the 10th cranial nerve
vagus nerve
63
what is the 11th cranial nerve
accessory nerve
64
what is the 12th cranial nerve
hypoglossal nerve
65
where is the 10th and 11th (cranial root) cranial nerves found
Immediately behind the 9th nerve and lateral to this is the 10th nerve (quite big) and a little 11th nerve (cranial root)
66
what does the cranial root of CN11 do
the cranial root helps the vagus supply the muscles of the pharynx and larynx
67
what nerve comes up from the upper cervical cord
the spinal root of the accessory nerve
Spinal root comes from the first 5 cervical segments of the spinal cord
it comes up from the foramen magnum and joins CN9, CN10 and the cranial root of CN11
68
what does the spinal root of CN11 do
supply the sternocleidomastoid muscle and the trapezius
69
what do the vertebral arteries join to form
basilar artery
70
where does the basilar artery run up
the pons
71
where do the vertebral enter the cranial cavity
foramen magnum
72
where do the vertebral arteries join together to form the basilar artery
The vertebral arteries are coming through the dura themselves into the view, comes up from below and into the spinal canal, makes its way up through the foramen magnum, up alongside the medulla then when it gets to the pons it joins together to form the basilar artery
73
what is found in front of the foramen magnum
little rootlets of the hypoglossal nerve
74
what does the hypoglossal nerve supply
muscles of the tongue
75
what does the hypoglossal nerve pass into
hypoglossal canal
76
where is the hypoglossal canal found
sits just in front of the foramen magnum, slightly to the side of the midline
Imagine it is disappearing under the dura
77
what is found immediately inside the vault of the skull
dura mater
78
is the dura mater attached to the vault
Slightly attached to the vault but its not firmly attached to the vault
we can take the vault off and push the dura away
79
what is can be seen in the midline of a coronal section of the head
falx cerebri ~ a large sickle shaped fold
80
what is inside the falx cerebri
superior sagittal sinus
81
what is in the superior sagittal sinus
venous blood
82
what are the 3 layers of meninges
- Dura mater
- Arachnoid mater
- Pia mater
83
where is the pia mater dound
On the surface of the brain
also found down around the spinal cord (covers the CNS)
84
describe the pia mater layer
Quite a vascular area - many fine blood vessels in it
Very thin
Follows the surface of the brain everywhere - where there is a gyrus it follows it down into the depths of the sulci
85
what is the arachnoid layer
middle layer of meninges
86
where is the arachnoid layer found
Lies immediately deep to the dura
not really attached to the dura, just pushed up against the dura
87
what is the difference between the meninges layers
Arachnoid and pia are quite soft, flimsy layers
whereas the dura is a very tough layer of collagen
88
where is cerebral spinal fluid made
inside the ventricles
89
what is the space between teh arachnoid and pia layer called
sub-arachnoid space
90
where is the 4th ventricle found
Down at the hind brain, where there is the 4th ventricle, the space between the cerebellum on one side and the pons and the medulla on the othe
91
how does the CSF escape the brain
escapes from the 4th ventricle at the hind brain
92
where is CSF found outside the brain
in the sub-arachnoid space
| also goes down around the spinal cord as well through the foramen magnum
93
what is the function of CSF
CSF has biochemical functions
also helps to cushion the brain if someone was to fall and the brain was to move slightly
94
what gives off the thin cob web like strands found within the sub-arachnoid space
little extensions from the arachnoid mater
95
where else can these little projections of arachnoid be found
Up at the sinuses, the superior sagittal sinus for example, there are little projections of arachnoid through the wall of the sinus that absorb the CSF - these are arachnoid vili
96
what are arachnoid villi
The arachnoid villi are little specialisations of the arachnoid that pass through the dura and into the lumen of the superior sagittal sinus
97
what happens to the CSF around the brain
the CSF around the brain is gradually absorbed into the blood stream of the sinuses by the arachnoid villi
98
what happens to the CSF around the spinal cord
it is taken away by local lymphatics down in the vertebral region
99
what else drains the brain
Also get veins draining the brain and heading through the dura as well and opening into the sinus
cerebral vein coming over from the brain into the sinus
100
what does the middle meningeal artery supply
the vault and to some extent the meninges
101
where does the middle meningeal artery run
running up between the dura and the bone
the artery is running in a groove at this site of the pterion
102
what happens if fracture occurs at the pterion
the middle meningeal artery is likely to burst and the blood starts to come out of the vessel between the dura and the bone
enlarges the blood clot / haematoma which then starts to press on the underlying brain
This build up of blood would probably happen over a few hours - patient's conscious level would start to deteriorate and they might become confused
extra dural haemorrhage
103
what are the 3 types of haemorrhages you get around the brain (extracerebral)
- extradural haemorrhage
- subdural haemorrhage
- subarachnoid haemorrhage
104
what is an extradural haemorrhage
○ Rupture of the middle meningeal artery
○ Between the dura and the bone
○ Occurs over a few hours with the patient's conscious level deteriorating
○Happen to anyone at any age if they get a fracture to the skull
105
what is a subdural haemorrhage
○ Involves the cerebral veins
○ Tends to happen in the elderly with a small blow to the head - tissues aren't quite as resilient as they were before so even a little bump of the head could be enough to move the brain
○ Cerebral vein is going from the brain through the dura to the superior sagittal sinus
§ The soft vein is attached to the firm dura - movement is likely to damage this site, can actually pull the vein off just as it is going into the dura
○ Arachnoid is immediately internal to the dura so blood starts to build up between the arachnoid and the dura
○ Blood tends to ooze out slowly and you get an enlarging blood clot between the dura and the arachnoid
§ Because it is venous blood it is not coming out as quickly as arterial blood does in an extradural haemorrhage
○ Tends to occur over a few days / weeks
106
what is a subarachnoid haemorrhage
○ Bleeding of the cerebral arteries still at base of brain
○ Around the area of the circle of Willis you might get a little aneurysm which is known as a Berry aneurysm
○ sometimes in middle life people get a little pathological swelling somewhere on the arteries in this area (often where there is a bifurcation of an artery)
Can burst and give a subarachnoid haemorrhage
○ Can either be caused by trauma or can occur spontaneously
○ Massive bleed into the subarachnoid space, only on the underside of the brain
§ Arterial blood
○ Patients often have a very severe headache in the moments before they go unconscious or sometimes people go unconscious immediately - well recognised cause of sudden death
○ Caused by the pathological process that causes a localised weakness of the artery (aneurysm)
107
what part of the brain overlies the foramen magnum
cerebellum
108
what is the layer of dura that covers the cerebellum called
tentorium cerebelli
has a gap in it for brainstem to pass down
109
where does the superior sagittal sinus comes down
where the falks meets the tentorium cerebelli
check diagram lol cos i think ive taken this down wrong
but i think the superior sagittal sinus runs within the falks to the back of the skull?
110
what happens to the blood in the superior sagittal sinus when it gets to the tentorium cerebelli
the blood in it swings to the right and the name of the sinus changes to the right transverse sinus
111
where does the right transverse sinus run
Right transverse sinus runs from the place where the tentorium is meeting the side wall
makes a groove on the inside of the bone of the skull
112
what happens to the right transverse sinus once it reaches the front of the postrerior cranial fossa
it changes direction again and forms an 'S' shaped bend
it is now called the sigmoid sinus
113
where is the sigmoid sinus found
Deep to the dura of the floor of the posterior cranial fossa, down under the cerebellum
114
where does the sigmoid sinus exit the skull
at the jugular foramen
115
what else leaves the skull at the jugular foramen
CN9
CN10
CN11
116
what does the blood run into runs it leaves the skull at the jugular foramen
once the blood leaves the skull at the right jugular foramen it becomes the right internal jugular vein
117
where does the straight sinus run
the straight sinus which is running in the place where the falks is meeting the tentorium
118
where does the straight sinus go
it comes round and swings to the left and becomes the left transverse sinus
119
what happens to the left transverse sinus
The left transverse sinus then forms an 'S' shaped bend (sigmoid sinus) and goes down to the jugular foramen as well
120
what is the little connection between the straight sinus and the superior sagittal sinus called
the confluence of sinuses
121
where does the transverse sinus run
Transverse sinus runs fairly horizontally where the tentorium is meeting the side wall
122
in the middle cranial fossa, what sinus is formed when 2 opthalmic veins join together
cavernous sinus
123
how is the cavernous sinus drained
drained by little sinuses which run along the edge and down
these are called the superior and inferior petrosal sinuses
124
where does the cavernous sinus receive blood from
Cavernous sinus is receiving lots and lots of blood from the orbit, has connections to the face through the orbit so there is lots of venous blood coming in the ophthalmic veins in the orbit which drains into the cavernous sinus
125
is the cavernous sinus a single lumen
There are lots of spaces within the cavernous sinus,
it is not a single lumen, instead
there are lots of little lumens within
126
how fast is the blood flow within the cavernous sinus
there is a very slow blood flow through the cavernous sinus
127
what sinus travels to the sigmoid sinus from the middle cranial fossa
The petrosal sinuses go down to the sigmoid sinuses and so goes out into the internal jugular vein
(superior and inferior petrosal sinuses)
128
what is the vein that comes out the side of the cavernous sinus
sphenoidal emissary vein
129
where does the sphenoidal emissary vein go
goes through the base of the skull
often goes through the foramen ovale but sometimes it has its own hole
130
what problems can patients get in the cavernous sinus
thrombosis of the cavernous sinus (the blood inside it clots)
131
why can bacteria multiply from infection within the cavernous sinus
because the blood flow is slow
132
what happens if there is bacteria multiplying within the cavernous sinus
blood cannot get back from the orbit
133
what are features of cavernous sinus thrombosis
swollen eye and fever
134
what is the name of the little plexus of veins from behind the upper jaw
pterygoid venous plexus
135
can dental sepsis cause cavernous sinus thrombosis
yes
The bacteria from an abscess of a tooth might get into the blood of the pterygoid venous plexus
this plexus connects through the little sphenoidal emissary vein into the cavernous sinus
It is possible that bacteria from the upper jaw area to make their way through the veins into the cavernous sinus and allow bacteria to multiply and the blood to clot
Thrombosis stops the blood flowing back from the eye so the patient again has a fever and a swollen eye
136
what colour do bones appear in an MRI scan
white
| they are radiopaque
137
what is periosteum
thin membrane immediately on surface of bone
138
what would you expect to see in the cut surface of the vault
- Part in middle = diploe (spongy bone, rich in bone marrow)
- Outer zone = outer table of the skull (cortical bone)
- Inner zone = inner table of the skull (cortical bone)
139
what happens in paget's disease
bone remodelling is out of control
skull can look more bulging in this disease
can affect any part of the skeleton
140
what is the tentorium cerebelli
fold of dura mater between the cerebrum and the cerebellum
141
what bony projection does the falx cerebri attach to
crista galli
142
where does the great cerebral vein go into
straight sinus
143
what is the middle crania fossae
depression formed by sphenoid and temporal bones
144
what is the central part of the middle cranial fossae occupied by
pituitary gland
145
what do the lateral parts of the middle cranial fossae contain
temporal lobes of the cerebral hemispheres of the brain
146
where do the transverse sinuses begin
at the confluences of sinuses
147
where do the transverse sinuses pass
passes laterally across occipital bone in the attached margin of the tentorium cerebelli
148
where do the transverse sinuses drain into
sigmoid sinus
149
where does the transverse sinuses receive from
- inferior cerebellar veins
- inferior cerebral veins
- posterior temporal
- occipital diploic veins
- superior petrosal sinus (into sigmoid sinus)
150
where is the straight sinus found
site of attachment between falx cerebri and tentorium cerebelli
151
where does the straight sinus pass
passes down and back to enter confluence of sinuses then continues as left transverse sinus
152
where does the straight sinus receive from
superior cerebellar veins
153
where does the superior petrosal sinuses run
over the groove of the upper border of petrous parts of temporal bonea
passes back and out from cavernius sinus to transverse sinus at junction with sigmoid sinus
154
where is the inferior petrosal sinuses found
at lower border of petrous bone, groove on petro-occipital suture
155
where does the inferior petrosal sinuses pass
passes from postero-inferior side of cavernous sinus and terminates at sigmoid sinus / jugular foramen
156
where does the tentorium cerebelli lie
between cerebellum and occipital lobes of cerebral hemispheres
157
where does the lateral edges of the tentorium cerebelli attach
attach to occipital bone
| encloses the transverse sinuses
158
where are the anterior lateral edges of the tentorium cerebelli attached to
attached to the upper borders of the petrous parts of temporal bones and contain the superior petrosal sinuses
159
where is the free margin of the tentorium cerebelli found
continues anteriorly to get attachment to anterior clinoid processes
160
what is the falx cerebri
sickle shaped fold of dura that lies along the median sagittal plane in the longitudinal cerebral fissure between 2 cerebral hemispheres
161
what does the falx cerebri separate
separates 2 lobes of cerebellum
162
where does the falx cerebri attach anteriorly
the crista galli of the ethmoid bone
163
where else does the falx cerebri attach to the skull
attachment to the skull continues supero-posteriorly along the margins of the superior sagittal sinus to the internal occipital protuberance
164
what happens to the falx cerebri at the posterior and inferior limits
it is continuous with the tentorium cerebelli
165
where does the inferior sagittal venous sinus run
in the free border of the falx cerebri
166
where does the straight sinus run
runs along the falx cerebri's junction with the tentorium cerebelli
167
what is teh anterior cranial fossae
depression fromed by frontal, ethmoid and sphenoid bones
168
what is the anterior cranial fossae occupied by
frontal lobes of the cerebral hemispheres of brain
