Week 7 - Brainstem and blood supply to the brain Flashcards
What are the 3 components of the brainstem?
- midbrain
- pons
- medulla oblongata
Is the thalamus part of the midbrain?
no the thalamus and the pinaeal gland are not within the midbrain.
What 3 structures are within the Pons?
The 3 peduncles:
- the superior, middle and inferior cerebellar peduncle.
What 2 structures are within the Medulla of the brainstem?
The Gracile and the cuneate tubercle.
What is Parkinson’s disease?
It is a movement disorder, when substantia nigra are damaged.
–> leads to a depletion of dopamine, a tremor, jerking and is difficult to initiate voluntary movement.
What 2 structures are visible on the midbrain?
The superior and inferior colliculus.
What is the role of the descending (motor) pathway: the corticospinal tract?
controls muscles BELOW head and neck.
- involved in voluntary control over skeletal muscles.
- in the pyramidal tract.
What is the role of the descending (motor) pathway: Corticobulbar tract?
Controls the head and neck muscles.
- voluntary control over skeletal muscles.
What is the role of the ascending (sensory) pathway: DCML (Dorsal column medial lemniscus).
1) what signals from the lower limb?
2) What signals from the upper limb?
Carries sensory information from the peripheral nerves to cerebral cortex.
e.g.proprioception, fine touch and vibration.
1) Fasciculus gracilis (is at the medial part of the dorsal column)
2) Fasciculus cuneatus (is on the lateral part of the dorsal column).
What is the role of the ascending (sensory) pathway: Spinothalamic tract?
sends sensory information from the peripheral nerves to the cerebral cortex (such as pain, temperature, crude touch and pressure).
What is the role of the ascending (sensory) pathway: the Spinocerebellar tracts?
signals from muscles to cerebellum.
- carries unconscious proprioceptive information.
- co-ordinates and refines motor movement.
What is the cerebral arterial circle also known as?
- what is its function?
- What are the two systems called?
- The circle of Willis.
- It allows for the proper blood flow to the hemispheres of the brain.
The 2 systems are the…:
1) internal carotid system
2) Vertebral-basilar system
What are the 2 systems of the circle of Willis and where do they each enter the skull from?
1) The internal carotid system:
- enters skull through the carotid arteries.
2) The vertebral-basilar system:
- enters through the carotid canal .
- the vertebral artery arises from the subclavian artery.
These two systems are interconnected to form the cerebral arterial circle (circle of Willis)
What is a saccular (berry) aneurysm?
aka Cerebral berry aneurysm.
- occurs within the supply of the cerebral arterial circle.
= a rupture of the aneurysm –> blood accumulates in the subarachnoid space –> with a subseuquent increase in intracranial pressure.
Where do all the venous sinuses drain into?
ALL drain into the internal jugular vein.
Name the 4 tracts?
- 2 descendingg (motor) pathways and 2 ascending (sensory) pathways?
Descending (motor) pathways:
1. corticospinal tract
2. Corticobulbar tract
Ascending (sensory) pathways:
1. Spinothalamic tract
2. DCML - dorsal column medial lemniscus.
What 2 interconnected branches form the cerebral arterial circle?
The internal carotid system + verterbal-basilar system.
I+V
