The Brainstem and blood supply to the brain Flashcards
What are the 3 main arteries that Supply the brain ?
- Anterior cerebral artery - supplies the middle part (medial branch)
- middle cerebral artery - supplies the majority of brain and outer bits
- Posterior cerebral artery - supplies the bottom part of the brain, important for vision
Important for classifying strokes
What is the Homunculus ?
Shows the tomography of the parts of the brain are being activated by.
How does the ACA get to the middle of the brain?
It wraps around the corpus callous
What is the Corpus Callosum ?
Corpus callous is in middle part of the brain. Linked with memory and houses the Singlet of Gyrus. 4 parts. The Genu, splenium, Rostrum and Body
Low yield, used to connect the 2 sides of the brain together
What are the 3 main parts of the brainstem ?
- Medulla oblongata - bottom part
- Pons - Middle part
- Midbrain - Top part
What does the medulla do/ include ?
The opening just before spinal cord.
Main features -
Olives
Corticospinal tract
Inferior cerebellar peduncles
Anterior and posterior median
What does the pons do/ include ?
Middle cerebellar peduncles - connects the pons to the cerebellum
What does the midbrain do/ include ?
Superior cerebelar peduncles - connects the midbrain to the cerebellum
Includes the substantia nigra.
Tectum and Tegmentum - protrusions that hold inferior and superior colliculi. They make up the rectum
Superior - eye movement in one direction
Inferior - houses all descending fibres for hearing
They are linked because when you hear something need to be able to look in the direction
What is the Rubrospinal tract ?
Only intervals upper limbs and doesn’t go to the finger tips, it changes sides similar to the corticospinal tract
Includes red nucleus which is found in the midbrain.
Ends at the C5 level (cervical spine )
what is somatosensory ?
Genreal sensory is going from the muscle to the brainstem.
Motor innervation goes from the brainstem down towards the mUSCLE
What are the different types of sensation ?
General sensory - touch (crude touch and discriminative touch), temperature, vibration, pain (C fibres) and Proprioception. They are split into different tracts
Primary afferent nerones- takes info from the surroundings
Secondary order neutron takes info from spinal cord up to thalamus and also desiccates onto opposite side where they synapse.
Thalamic neutron takes info from thalamus to cerebral cortex.
What are the 2 main types of tracts ?
- Spiniothalamic tract - for detecting info like temperature, pain, crude touch. It decisates at eh same point of its innervation
- Dorsal column/ Medial lemiscus when in brainstem - Travels up dorsal side of Proprioception, vibration, discriminative touch.
What is the main difference of the Spinothalamic tract and Dorsal column ?
STT - desiccates at same level of spinal cord (its second order neurone )
DC - First order neurone continues travelling up and only desiccates at the medulla, at medulla it synapses
What is the blood supply of the spinal cord ?
Spinal cord has an anterior and posterior artery
Anterior - supplies majorly of spinal cord, supplies everything apart from dorsal column meniscus.
What is the journey of the CSF
Goes from lateral ventricle to 3rd ventricle to 4th ventricle.
Choriod plexus is in the lateral ventricle which makes the CSF
Lv -> 3rd Interventricular foramen
3rd -> 4th Cerebral aqueduct
What is Syringomyelia ?
This is damage to the spinal cord
A syrinx - a fluid filled. cavity in the central canal of the spinal cord that can appear. Will affect the spinothalamic tract
What does the cerebral aqueduct connect ?
Cerbral aqueduct connects 3rd and 4th ventricle. Can be blocked and cause hydrocephalus, can cause enlargement of ventricles.
What is the Corticospinal tract?
Corticospinal tract - main descending tract of the brain, allows intricate movement, goes all the way to your fingertips and such. At the open medulla it desiccates to contralateral side to become the lateral corticospinal tract (happens at lowest part of medulla). Originates from cerebral cortex
What are the Inferiror cerebellular penduncles?
Inferior cerebellar peduncles - connects the medulla to the cerebellum
What are the anterior and posterior median sulcus?
Anterior and posterior median sulcus - the line that goes through the brainstem
What is the substantia nigra?
Includes the substantia nigra - It is where Parkinsons takes place. The degradation of substance nigra. It is where the main nuclei that produces dopamine for the pathway is produced.
What are the Olives of the Medulla?
Olives (inferior olivary nuclei) - send information via climbing fibres towards the cerebellum, important for recorrecting movement Sends info to inf cerebellar peduncle in order to get to the cerebellum
