Topography of Brain Flashcards
What is the thalamus?
Relay centre for anything sensory
Parts of the cerebellum
Anterior lobe
Posterior lobe
Vermis
Flocculonodular lobe
The surface of the cerebellum has what?
Sulci
Folia
How is the cerebellum connected to the brainstem?
3 cerebellar peduncles
Function of the cerebellum
Posture maintenance
Fine tuning motor activity
What information is given to the cerebellum to help it carry out its function?
Information from pyramidal tracts (motor intention of brain)
Information from ipsilateral proprioceptors from periphery
Information from vestibular nuclei re balance and posture
How to test for ataxia?
Finger nose test
Knee heel test
Walking in a straight line
Parts of the brainstem
Midbrain
Pons
Medulla
What part of the brainstem can you not see from the posterior view?
Pons
Which cranial nerves are found in the brainstem?
III-IX
Function of the brainstem
Pathway for fibre tracts running between higher and lower centres
Brainstem nuclei are involved with 10 of the 12 CNs, so innervation of the head and neck
Brainstem centres produce the rigidly programmed automatic behaviours essential for survival
Where does the medulla continue and as what?
At spinal cord
At foramen magnum of cranium
Surface features of the medulla
Pyramids and their decussation (cross over)
Olives laterally
Cranial nerves IX, X, XI and XII
How is the medulla connected to the cerebellum
Inferior cerebellar peduncle
Two sections of the medulla
Caudal part
Cranial part
What is found in the caudal part of the medulla?
White matter
- pyramidal tract
- medial lemniscus
- inferior cerebellar peduncle
- other tracts
What is found in the cranial part of the medulla?
Grey matter
- cranial nerve nuclei and inferior olivary nucleus
- nuclei of the reticular formation (vital centres)
- sensory nuclei (gracile and cuneate)
What is posterior to the pons?
IV ventricle
Surface features of the pons
Middle cerebral peduncle
Cranial nerves V, VI, VII and VIII originate from its surface
What is found in the white matter of the pons?
Middle cerebellar peduncle Medial lemniscus (sensory) Pyramidal tract (motor)
What is found in the grey matter of the pons?
Cranial nerve nuclei
Pontine nuclei
Nucelii of reticular formation
What does the midbrain develop from?
Mesencephalon
What is found in the central cavity of the midbrain?
Cerebral aqueduct
Surface features of the midbrain
Cerebral peduncle
Superior cerebellar peduncle
Corpora quadrigemina (superior and inferior colliculus)
Origin of oculomotor (CN III) and trochlear (CN IV)
What is the only nerve to originate posteriorly from the midbrain?
IV nerve
Where is the diencephalon found?
Deep within the cerebral hemispheres, around the III ventricle
What is the diencephalon made up from?
Pineal gland (epithalamus)
Thalamus
Hypothalamus
Subthalamus
What are all of the diencephalon mainly?
Grey matter
How much of the diencephalon does the thalamus make up?
80%
The thalamus is found on either side of what?
III ventricle
Groups of nuclei of thalamus
Anterior group
Medial group
Lateral group
What is the lateral group of nuclei of the thalamus involved in?
Processing sensory information
What is the thalamus?
A sensory relay station
How is the hypothalamus separated from the thalamus?
By the hypothalamic sulcus
Where does the hypothalamus lie in relation to the thalamus?
Below it
Homeostatic roles of the hypothalamus
Autonomic control centre Body temp regulation Regulation of food intake Regulation of water balance and thirst Regulation of sleep wake cycle Control of endocrine system functioning
Anatomy of the internal carotid arteries
2 of them
Enter the skull through the carotid canal (foramen lacerum) to supply brain
How do the vertebral arteries enter the skull?
Through the foramen magnum to supply brain
What are the vertebral arteries branches of?
Subclavian artery
What are the branches of the ICA that supply the brain?
Anterior cerebral artery
Middle cerebral artery
Posterior communicating arteries
What do the 2 vertebral arteries join to make? Where does it do this?
Basilar artery
On the vertebral surface of the brainstem
What do branches of the vertebra-basilar system supply?
Brainstem
Cerebellum
Where does the basillar artery end?
The level of the midbrain by dividing into two posterior cerebral arterys (PCA)
What do the posterior cerebral arteries supply?
Posterior part of the cerebral hemispheres
What do the ACA and MCA supply?
Large part of the cerebral hemisphere
What arteries join to form the circle of willis?
Branches of ICA join with those of opposite side and with the PCA
Function of circle of willis
Protective feature against vaso occlusive arteries
What are end arteries?
Do not anastomose with anything else
What artery are strokes usually involved with?
Middle cerebral artery
What does the ACA supply?
Medial aspect of the cerebral hemispheres excluding the occipital lobe
What does the MCA supply?
Lateral aspect of cerebral hemispheres
What does the PCA supply?
Inferior aspect of cerebral hemispheres and occipital lobe
What is the venous drainage of the brain?
Superficial and deep veins of the brain drain into venous sinuses which lie between the two layers of the dura mater
The dura is joined everywhere apart from where?
The sinuses
The dural venous sinuses join together to drain ultimately into where?
Internal jugular veins
Veins of the brain
Superior sagittal sinus Inferior sagittal sinus Great cerebral vein Transverse sinuses Cavernous sinuses Superior and inferior petrosal sinuses Internal jugular veins
