Topography of the brain - physiology Flashcards
4 topographical land marks of the brain
Brainstem Cerebellum Diencephalon Cerebral hemispheres
All CNs( cranial nerves) emerge from the brainstem apart form which 2
CN I & II
Medulla is divided in 2 regions: + what distinguishes between the 2
- open medulla
- closed medulla
4th ventricle is surrounded by the open medulla
closed medulla is a continuation of the spinal cord hence ‘closed’
White matter of the medulla is made up of (4)
- pyramidal tract
- medial lemniscus
- inferior cerebellar peduncle
- other tracts
Grey matter of medulla made up of (4)
CN nucleii Inferior olivary nucleus Nuclei of reticular formation Sensory nuclei (gracile and cuneate)
Midbrain contains what grey matter (3) -one of these is part of basal ganglia
Periaqueductal grey matter Nuclei of CN III & IV Substantia nigra
White matter of pons made up of (3)
Middle cerebellar peduncle Medial lemniscus (sensory) Pyramidal tract (motor)
Grey matter of pons made up of (3)
CN nuclei Pontine nuclei Nuclei of reticular formation
Each hemisphere of the cerebellum consists of 3 lobes:
Anterior Posterior Flocculonodular
White matter of cerebellum made up of (2)
Arbor vitae Cerebellar peduncles
Surface of cerebellum has folds like brain surface called… (2)
sulci folia (instead of gyri)
Grey matter of cerebellum made up of (2)
Cerebral cortex on the surface of it Deep nuclei
Cerebellar hemispheres control ipsilateral or contralateral side of body
ipsilateral unlike cerebral hemispheres
Cerebellum sends its processed info to the cerebral cortex via what white matter structure
Superior cerebellar peduncle
What is the function is the cerebellum?
- posture maintenance
- fine tuning motor activity
Diencephalon consists of what 4 things
- thalamus,
- hypothalamus (and pituitary stalk),
- epithalamus (pineal gland),
- subthalamus
there is no white matter in the diencephalon, all is made up of grey matter
Diencephalon is mainly white or grey matter
Grey
What component makes up most of the diencephalon and what is its function?
Thalamus.
Function: all sensory information are synpsis at the thalamus and than it decides which information to important and to focus on.
The thalamus contains groups of nuclei (anterior, medial & lateral) - which one of these groups is the sensory relay station
Lateral group (processes sensory info entering the cerebral hemispheres)
Hypothalamus lies above or below thalamus + what is the groove that separates it
- below hypothalamic
- sulcus
What is the funtion os Hypothalamus?
visceral control centre and essential for homeostasis.
Name some the homeostatic functions of the hypothalamus?
Body temperature regulation Regulation of food intake Regulation of water balance & thirst Regulation of sleep-wake cycle Control of endocrine system
Surface features of the medulla (5)
- Anterior median fissure/groove
- Pyramids & their decussation
- Olives (lateral to pyramids)
- Inferior cerebellar peduncle which connects the medulla to the cerebellum and it also where CN IX, X, XI, XII (9,10,11,12) emerge
Pons- is connected to the cerebellum by the middle cerebeller peduncle
Mid-brain - is connected by the superior cerebeller peduncle.
Surface features of the midbrain (5)
Cerebral peduncle Superior cerebellar peduncle Superior colliculi Inferior colliculi CN III & IV
Which CN is the only one to emerge from the posterior brainstem
CN IV
Surface features of the pons (2)
Middle cerebellar peduncle CN V
2 paired arteries supplying the brain (that give important branches)
- R + L internatl carotid arteries (ICA)
- R + L vertebral arteries
How do the vertebral arteries enter the cranial cavity?
How do the ICA enter the cranial cavity?
- Pass through foramen transversarium then enter cranial cavity through foramen magnum. the vertebral arties join and form the Basal artery.
- Through the Foramen Lacerum (carotid canal)
ACA is a branch of
ICA
ACA supplies what surface of the cerebral hemispheres
Medial - but not the occipital lobes
MCA ( middle cerebral artery) supples what surface of the cerebral hemispheres
Lateral
PCA supples what parts of the cerebral hemispheres
Posterior and inferior
Describe the Circle of Willis? and its role?
- the two vertebral arteries join together to form Basilar artery.
- the Basilar artery branches into left and right Posterior arteries
- The ICA branches anteriorly into L & R Anterior cerebral arteries joined together by Anterior Communicating artery.
- The ICA also branches posteriorly into L & R Posterior communicating arteries.
- The L & R posterior communicating arteries join the Posterior cerebral arteries of the Basal artery
Role of Circle of Willis is protection against Vaso-occlusion.
Where does the brains venous drain into?
Drain into the venous sinuses between the two layers of the dura mater.
the dural venous sinuses finally join to drain into the Internal Jugula veins
identify the two venous sinuses which lie between the 2 layers of the dura matar?
