Neuro 2 Flashcards
What makes up the brainstem?
What type of information does the brainstem receive?
mibrain, pons and medulla oblongata (MPM)
connects cerebrum with spinal cord
cardiac and respiratory functions, controls heart rate and breathing
sensory and motor from the trunk and limbs travelling through the ascending and descending nerve tracts
What is another name of midbrain?
What are the important features of the midbrain?
What is the function of the midbrain?
mesencephalon
1.tectum = dorsal to cerebral aqueduct, made of 4 (2 superior and 2 inferior) colliculi: superior = visual
inferior = auditory
2. cerebral aqueduct: to connect 3rd and 4th ventricles of ventricular system
3. reticular formation, forms centre - contains nuclei for alertness, sleep and consciousness
4. tegmentum has red nucleus: motor coordination
5. cerebral peduncles, anterior and laterally: connect brain to brain stem
auditory and visual processing: eye movement motor response
maintaining consciousness
What is the reticular formation?
interconnected pathway of nuclei in the brainstem mediating the overall level of consciousness, sleep, alertness.
What is the tectum?
- roof of the midbrain
- corpora quadrigemina (2 superior and 2 inferior colliuculi)
superior = visual
inferior = auditory
What structure is the midbrain continuous with superiorly?
thalamus through the tentorial notch
What is the tegmentum?
ventral to cerebral aqueduct segmented into 2 regions: red nucleus and periaqueductal grey region - motor coordination
the pedicles are for connection
What is the red nucleus in charge of?
coordination of movement
What are cerebral peduncles?
two lobe (anterior and lateral) on either side of tegmentum separated by interpeduncular fossa
What information do the superior and inferior colliculi process?
superior = visual
inferior = auditory
What is the function of the pons?
What is the structure of the pons?
regulate breathing and sleep cycles
- cerebellar peduncles (superior: pons to cerebrum and middle: pons to cerebellum)
- basilar sulcus running down the middle of 2 halves allowing basilar artery to travel through
has:
- descending corticol spinal tract => motor tract to the contralateral side of body
- ascending spinothalamic tract => pass information about pain and temp
also called metencephalon
What are the cerebellar peduncles?
2 middle => connect pons to cerebrum
2 superior => connect pons to cerebellum
What travel on the middle of the pons?
- descending corticol spinal tract => motor tract to the contralateral side of body
- ascending spinothalamic tract => pass information about pain and temp
What is the structure of the medulla oblongata?
- 2 pyramids either side of anterior fissure (midline)
- 2 olive on either side of ventero-lateral sulcus and postero-lateral sulcus
What does the pyramid contain?
corticospinal tract
What is the path of the corticospinal tract?
upper motor neurones from brain to brainstem => decussate at level of pyramid and spinomedullary junction => travel down other side of spinal cord
What do the olives have and what does it do?
olivaric nucleus which are involved in perception of sound and motor control
What is the blood supply to the brainstem?
vertebrobasilar system
SPA (3 terminal branches of basilar artery) VP (arteries joining to form basilar artery)
What are the 12 cranial nerve pairs? And what type of nerve is it (sensory, motor or both)?
- Olfactory - S
- Optic - S
- Oculomotor - M
- Trochlear - M
- Trigeminal - B
- Abducens - M
- Facial - B
- Vestibulocochlear - S
- Glossopharyngeal - B
- Vagus - B
- Accessory - M
- Hypogloassal - M
Where do the 1st and 2nd cranial nerves come from?
cerebrum
Where do 3 - 12 cranial nerves come from?
brainstem
- midbrain => trochlear(4)
- midbrain-pontine junction =>oculomotor (3)
- pons => trigeminal (5)
- pontine-medulla junction => abducens, facial, vestibulocochlear (6, 7, 8)
- medulla oblongata => glossopharyngeal, vagus and accessory (9, 10, 11 - posterior to olive) and hypoglossal (12 - anterior to olive)
How does the olfactory nerve travel?
olfactory receptor in the upper part of nasal cavity => excited and signal travel to nerve fascicle originating in olfactory mucosa => through olfactory bulb => olfactory tract => cribriform plate with foramina
SMELL
How does the optic nerve travel through?
VISION
light enters eye and hits the retina => contains photoreceptors => carry signal and impulse to optic nerve => optic nerve exit through optic canal => enter cranial cavity => cross at optic chiasm which is level of sella turcica => both tracts project posterior on primary visual cortex
Where does the oculomotor travel through?
function of the oculomotor nerve?
EYE MOVEMENT, PUPIL SIZE and LENS
superior orbital fissure
involuntary movements of eye
- help extraocular muscle except superior oblique and lateral rectus muscle
- involuntary action of pupilae muscle during bright light / dim light
Where does the trochlear nerve travel through?
What is the function of the trochlear nerve?
superior orbital fissure
control superior oblique muscle = move your eyes towards your nose / away