Medulla Oblongata - Neuroanatomy Lab Spring 2025

1) pyramids

2) olive

3) lateral funiculus

What are the 3 main parts of the medulla oblongata?

inferior olivary nucleus

What is the government name of the olive of the medulla oblongata?

anterior (ventral) median fissure

What sulci runs down the midline of the medulla between the pyramids?

until the bottom of the medulla oblongata, motor neuron decusation at this point

The anterior median fissure is continuous until when?

CN XII and its 10 rootlets

What CNs come off the anterior lateral sulcus of the medulla oblongata?

IX, X, XI

What CNs come off the posterolateral sulcus of the medulla oblongata?

no -- only about 1/2 way

Does the olive run the entire length of the medulla?

vital centers of the body

What does the medulla contain in the olive?

cannot breathe on own, heart cannot beat on its own

What happens if you compress the cranial side of the medulla?

no -- that is where cardiac and respiratory centers are

Do you want a descending coma to reach the medulla?

pupillary response ---> mesencephalon

What is the easiest place to see where the coma is in the brainstem?

the medulla wraps around and encompasses it

What does the medulla oblongata do to the 4th ventricle?

XII (and its roots)

What CNs exit the medulla at the anterior lateral sulcus?

IX, X, XI

What CNs exit the medulla at the posterolateral sulcus?

larger

The inferior cerebellar peduncles will appear (smaller/larger) as we move inferior in the medulla?

inferior olivary nucleus

What is a distinct structure in the medulla that looks like a worm?

smaller

The 4th ventricle will appear (larger/smaller) as we move inferior in the medulla?

CN XII

The GSE nucleus of what cranial nerve will be present in the olivary section of the medulla?

smaller

The inferior olivary nucleus will appear (smaller/larger) as we move inferior in the medulla?

it will become wrapped by the medulla

As we move inferior in the medulla, what will happen to the 4th ventricle?

sends fibers into the contralateral cerebellar hemisphere via the inferior cerebellar peduncles

Where does the inferior olivary nucleus send its fibers? via what?

Purkinje fibers

What do the fibers from the olivary nucleus of the medulla synapse on in the cerebellum?

Error detection

Synapsing on Purkinje Fibers in the cerebellum creates an ________ system for motor movements

left

Right inferior olivary nucleus projects into the _____ inferior cerebellar peduncle

the mesencephalon

The superior cerebellar peduncles connect the cerebellum to what?

fibers out of cerebellum to the red nucleus

The superior cerebellar peduncles contain what fibers?

pontine nuclei (pons)

The middle cerebellar peduncles connect the cerebellum to what?

fibers go INTO the cerebellum

The middle cerebellar peduncles contain what fibers?

cerebellum to the medulla

The inferior cerebellar peduncles connect the cerebellum to what?

fibers going INTO the cerebellum

The inferior cerebellar peduncles contain what fibers?

sensory fibers/conscious proprioception for the upper limbs

What does the nucleus cuneatus do?

sensory fibers/conscious proprioception for the lower limbs

What does the nucleus gracilus do?

unconscious proprioception to the cerebellum

What does the cuneocerebellar nucleus do?

Motor nerve fibers decussate in the caudal portion of the medulla pyramids

What is important about the corticospinal tract in relation to the medulla?