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Flashcards in Topography of the brain Deck (43)
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1
Q

Identify the labels

Which foramen do some of these arteries go through?

A

Internal Carotid Arteries:

  • enter the skull through the carotid canal (Foramen Lacerum) to supply the brain

Vertebral arteries:

  • branches of the subclavian artery
  • enter the skull through the foramen magnum to supply the brain
2
Q

The ‘Circle of ______’ is the vascular structure that plays a central role in cerebral blood supply

Identify the arteries that make up the circle

A

Circle of Willis

3
Q

Complete the statement about the Circle of Willis

Branches of the Internal carotid artery join with ____________ and with the ____________ (branch of the basilar artery) to form a continuous circle at the base of the brain.

A

Branches of the ICA join with those of the opposite side and with the Posterior Cerebral Artery (branch of the basilar artery) via the PComA to form a continuous circle at the base of the brain.

4
Q

Why is the circle of willis an important protective structure of the brain?

A

Protects against vaso-occlusion of large arteries

As it provides alternative routes

5
Q

Heres a lovely diagram of the bottom of the brain

Identify the arteries of the COW

A
6
Q

Which branches of the ICA are important in supplying the brain?

A

The ICA gives branches – the anterior (ACA), middle cerebral (MCA) and posterior communicating arteries (PComA).

The ACA and the MCA supply a large part of the cerebral hemispheres

7
Q

The 2 vertebral arteries join together to form a basilar artery on the ventral surface of the brainstem

The system that is formed supplies what areas of the brain?

What is the fate of this basilar artery?

A

The vertebro-basilar system gives branches that supply the brainstem and cerebellum

The basilar artery finally ends at the level of the midbrain by dividing into two Posterior cerebral arteries (PCA) which supplies the posterior part of the cerebral hemispheres

8
Q

Cerebral blood supply can be split into 3 territories

What are these?

Identify the areas below

A

Anterior cerebral:

  • Medial aspect of cerebral hemispheres excluding Occipital lobe.

Middle cerebral:

  • Lateral aspect of cerebral hemispheres

Posterior cerebral:

  • Inferior aspect of cerebral hemispheres and Occipital lobe
9
Q

Give an overview of the venous drainage of the brain

A

Superficial & deep veins of the brain drain into venous sinuses which lie between 2 layers of dura mater

The dural venous sinuses join together to ultimately drain into the Internal Jugular Veins

10
Q

Bit aids but identify the veins n stuff

A
11
Q

Shown below is the cavernous sinus.

What structures pass through/near it?

Identify the labels

A

CN III

CN IV

CN V1

CN V2

CN VI

Internal jugular

Pituitary gland

12
Q

From what embryonic layer does the neural tube develop?

A

(dorsal) surface ectoderm

13
Q

What is the fate of the cranial end of the neural tube (embryology)?

A

Cranial end of the tube forms vesicles each of which develops into different parts of the brain

14
Q

Describe the formation of the primary and secondary vesicles in embryology

A

As soon as the neural tube forms, it divides into 3 primary vesicles - the prosencephalon (forebrain), mesencephalon (midbrain) and rhombencephalon (hindbrain)

From these - the secondary vesicles develop

These develop into the adult brain

15
Q

What are the parts of the brainstem

A

Midbrain

Pons

Medulla

16
Q

What nervey stuff is in the brainstem?

A
  • Cranial nerves III – XII
  • Tracts from spinal cord
  • Vital centres - eg: cardiorespiratory centre
17
Q

You know the drill

Yellow = nerves

Red = areas n stuff

A
18
Q

What are the functions of the brainstem?

A

Pathway for fibre tracts running between higher & lower centres.

Brainstem nucleii are involved with 10 of the 12 cranial nerves, so innervation of head & neck.

Brainstem centres produce the rigidly programmed automatic behaviours essential for survival.

19
Q

Which cranial nerves leave from each part of the brainstem?

A

Midbrain:

  • III to IV

Pons:

  • V to VIII

Medulla:

  • IX to XII
20
Q

What is the relation between the brainstem and the cerebellum?

A

Cerebellum and brainstem are connected by Cerebellar peduncles of which there are 3 pairs (6)

Superior, Middle & Inferior cerebellar peduncles leaving from the Midbrain, Pons & medulla respectively

Each level joins and they leave as one big daddy peduncle. You can not differentiate them on a cadaver

21
Q

Identify the labels on the medulla’s surface

A

The arrow without the label is pointing at the daddy peduncle (you can see the individual peduncles)

22
Q

What is the cavity within the medulla?

A

The 4th (IV) ventricle

(located in the Superior medulla)

23
Q

Why are the pyramids of the medulla an important feature?

A

Decussation of pyramids

There is a crossing over of motor fibres from each hemisphere of the brain as they enter the medulla

24
Q

What are the olives of the medulla?

A

The olives contain the inferior olivary nucleus

The superior olivary nucleus is in the pons

25
Q

Identify the nerves leaving the Pons

A
26
Q

What cavity lies posterior to the Pons?

A

IV ventricle

27
Q

Which peduncle originates on the pons’ surface?

A

The middle cerebellar peduncle

28
Q

Identify the parts of the posterior midbrain

What function is associated with each?

A

Corpora quadrigemina:

  • superior (visual) & inferior (auditory) colliculus
29
Q

Identify the parts of the anterior midbrain

A

Note that CN IV originates on the posterior surface but kinda comes round

30
Q

What embryological structure develops into the midbrain?

A

Mesencephalon

31
Q

What cavity is located within the midbrain?

A

Cerebral aqueduct

(connects III & IV ventricles)

32
Q

Describe the structure of the cerebellum

A
  • Right and left hemispheres separated by Vermis
  • Each hemisphere has an anterior, posterior and flocculonodular lobe
  • Surface has sulci and folia
  • Three cerebellar peduncles connect it to brainstem
33
Q

Identify the parts of the diagram of the cerebellum

A

Arborvitae - tree like white matter structure

34
Q

Where is the diencephalon?

What does it develop from?

A

Deep within the cerebral hemispheres - around the III ventricle

Diencephalon develops from the diencephalic vesicle (part of the forebrain vesicle)

35
Q

What structures make up the diencephalon?

A

Thalamus

Hypothalamus

Infundibulum (stalk of the pituitary)

Epithalamus (pineal gland)

36
Q

What tissue makes up most of the diencephalon?

A

Mainly grey matter

37
Q

Identify the parts of the diencephalon

A
38
Q

What is the purpose of the thalamus?

A

It is basically the relay centre for all sensory information that is going to the cerebral hemispheres

(The only exception to this is SMELL)

In the thalamus, sensory triage takes place - so it decides how important/relevant it is

39
Q

Identify the labels

A
40
Q

Describe the functional structure of the thalamus and how it works

A

Contains groups of nuclei - Anterior, Medial and lateral

The lateral group is the sensory relay bit - it has different areas for different sensory info from different parts

There is also the Lateral geniculate body, which sticks out the lateral group - this is where the optic tract synapses in the visual pathway

41
Q

Do the thing

A
42
Q

What does the hypothalamus do?

A

Main visceral control centre & is essential for control of homeostasis

Controls:

  • Autonomic control
  • Body temp
  • Food intake
  • Water balance & thirst
  • Sleep-wake cycle
  • Endocrine system function
43
Q
A