Neuro 4: Anatomy of blood flow in CNS + Consequences of disruption Flashcards

1
Q

The brain uses up _____% of cardiac output

A

10-20%

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

What are the 2 sources of blood supply to the brain?

A
  • internal carotid arteries (front)

- vertebral arteries (back)

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

The 2 sources of blood supply to brain gives rise to network of cerebral arteries called _________

cerebral arteries come off the circle

A

Circle of Willis.

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

External carotid supplies the ______

Internal carotid supplies the _______

A

External carotid supplies the face

Internal carotid supplies the cerebral hemispheres

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

Vertebral arteries branch off the ________

and make their way through the _______ ________ (in the cervical vertebrae)

and through the ______ _____ into the brain

A

Vertebral arteries branch off the subclavian arteries

and make their way through the TRANSVERSE FORAMINA

and through the ________ _______ into the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the ventral view of the brain?

A
  • from underneath
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

the two vertebral arteries at the bottom join together to form the _______ _____

A

the two vertebral arteries at the bottom join together to form the Basilar Artery

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

The basilar artery bifurcates –> to form the ____ ______ _____

A

The basilar artery bifurcates –> to form the posterior cerebral arteries

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

The internal carotid arteries travel superiorly, then heads laterally —> forming the ______ _____ ______

and
they also branch to form the ______ ______ _____

A

The internal carotid arteries travel superiorly, then heads laterally —> forming the middle cerebral arteries

((They emerge through the fissure btw frontal, parietal + temporal lobes))

and they also branch to form the anterior cerebral arteries

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

Why is the arrangement of arteries circular?

A
  • if one side gets occluded, there is still another route for blood to travel.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the 4 main veins that drain the cerebral hemispheres via the jugular system?

A
  • cerebral veins
  • venous sinuses
  • dura mater
  • internal jugular vein
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Dural Venous sinuses:

Running along the top, housed between the 2 folds of dura –>

at bottom of dural fold –>

A

Dural Venous sinuses:

Running along the top, housed between the 2 folds of dura –> Superior Sagittal Sinus

at bottom of dural fold –> Inferior Sagittal Sinus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The superior + inferior sagittal sinus runs backwards to form a large blood filled space called –>

A

The superior + inferior sagittal sinus runs backwards to form a large blood filled space called –> CONFLUENCE OF THE SINUSES

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

DEFINE stroke:

A

DEFINE stroke:

  • rapidly developing focal disturbance of brain function of presumed vascular origin, lasting more than 24 hours

(85% due to infarction, 15% due to hemorrhage)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Define Transient Ischemic Attack (TIA)

A

Define Transient Ischemic Attack (TIA):

  • rapidly developing focal disturbance of brain function of presumed vascular origin that resolves completely within 24 hrs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is an infarction?

A
  • degenerative changes that occur in tissues following occlusion of an artery
17
Q

What is Cerebral Ischaemia ?

A
  • lack of sufficient blood supply to the nervous tissue
  • -> resulting in permanent damage if blood flow is not restored quickly.

–> due to hypoxia/anoxia

18
Q

What are 2 major causes of Occlusions?

A
  • Thrombosis

- Embolism

19
Q

What are 5 main risk factors for stroke?

A
  • age
  • hypertension
  • cardiac disease
  • smoking
  • diabetes mellitus
20
Q

Middle cerebral artery extends laterally

–> supplies __ of the lateral hemisphere

A

Middle cerebral artery extends laterally

–> supplies 2/3 of the lateral hemisphere

21
Q

The posterior cerebral artery supplies the ____ and ____ parts of the posterior part of the hemisphere.

A

The posterior cerebral artery supplies the MEDIAL and LATERAL parts of the posterior part of the hemisphere.

22
Q

The anterior cerebral artery supplies the _____ part of the hemisphere

A

The anterior cerebral artery supplies the medial part of the hemisphere

23
Q

What might happen in disturbance of the anterior cerebral artery?

A
  • paralysis of contralateral leg more common than arms
  • disturbance of intellect, executive function + judgement
  • loss of appropriate social behavior
24
Q

What might happen in disturbance of the middle cerebral artery?

A
  • “classic stroke”
  • contralateral hemiplegia (arm >leg)
  • contralateral hemisensory deficits
  • hemianopia
  • aphasia (L-sided)
  • -> can’t speak
25
What might happen in disturbance of the posterior cerebral artery?
PCA supplies the occipital lobe (which has the primary visual cortex) - this leads to visual defects - -> homonymous hemianopia - -> visual agnosia - -> can't recognize things you see
26
What is a lacunar infarct?
- stroke causes small holes (lacunae) as brain tissue dies - occurs due to small vessel occlusion. - may also occur due to hypertension - symptoms = dependent on anatomical location of vessel that has been occluded
27
What are the different classifications of haemorrhagic stroke?
- extradural - subdural - subarachnoid - intercerebral
28
How do the different subtypes of hemorrhagic stroke differ? - extradural - subdural - subarachnoid - intercerebral
EXTRADURAL - from trauma - immediate effects SUBDURAL - from trauma - has delayed effects SUBARACHNOID - due to ruptured aneurysms INTRACEREBRAL - due to spontaneous hypertensive rupture of small vessels
29
What is the difference between dura in the skull and in the vertebral column.
in the VERTEBRAL COLUMN: - single layer of dura with fat btw bone + the dura in the SKULL: - 2 layers of dura
30
What are the 2 layers of dura ?
- periosteal | - meningeal
31
What is the Falx Cerebri
- fold of dura extends between the medial surfaces of the 2 hemisphere.
32
peeling apart of the 2 layers of 2 layers of dura at the top forms the ______ ______ ______
peeling apart of the 2 layers of 2 layers of dura at the top forms the superior sagittal sinus
33
in the superior sagittal sinus, you find the arachnoid granulation which are:
in the superior sagittal sinus, you find the arachnoid granulation which are: - bursts of subarachnoid space - that protrudes into the superior sagittal sinus - CSF leakes through the holes in the arachnoid memb - and enters the superior sagittal sinus
34
Extradural hemorrhages have a rapid onset due to the rupture of a _____ artery.
Extradural hemorrhages have a rapid onset due to the rupture of a meningeal artery.
35
What is an extradural haematoma?
- high pressure arterial supply to the brain --> leads to splitting of arteries in the meninges themselves - leads to compression of the skull underneath - potential space in periosteal dura --> can be filled with blood in extradural hemorrhage
36
Why is subdural hemorrhagic stroke delayed?
- has slower development because: | - it is a lower pressure venous bleed
37
skull isn't completely closed they might have veins through them e.g
- emissary vein
38
why is antibiotics given in scalp laceration?
there is a chance of infection passing into brain via the emissary vein