The Medulla Oblongata

The Medulla Oblongata

• The medulla oblongata is the most inferior of the brain regions• It is directly superior to the

spinal cord• Its basic job is to relay

information to the rest of the brain stem and the thalamus• It also controls basic visceral

activities

The Medulla Oblongata

• The medulla oblongata is a busy place• It is the primary site where the

spinal cord relays information to the brain• It is a large task to coordinate

movements and function between the brain and body

The Medulla Oblongata

• The medulla oblongata looks like an enlarged section of the spinal cord with a central canal• However there is one main

difference with the organization of the white and grey matter• The arrangement of the white

and grey matter is much more complex with more avenues

The Cranial Nerves

• There are 31 spinal nerves • These relay information from the

sections of the body• The brain has a set of nerves

that relay information directly into the brain• These nerves are called the

crainial nerves

The Cranial Nerves

• The cranial nerves are named with the letter “N” and a roman numeral• The nerves are numbered NI

through NXII• NV through NXII attach to the

medulla oblongata• These nerves control a large

number of functions within the body

The Cranial NervesCranial Nerve Function Attachment Site

NINIINIIINIVNVNVINVIINVIIINIXNXNXINXII

Three Centers

• The medulla oblongata includes three groups of nuclei that will be encountered in later chapters• 1) Autonomic Nuclei Controlling

Visceral Activities• The reticular formation is loosely

organized cells that contain embedded nuclei• This part of the medulla oblongata

controls the vital autonomic functions and reflexes for those visceral functions

Three Centers

• 2) Sensory and Motor Nuclei of Cranial Nerves• The medulla oblongata contains

sensory and motor nuclei for five cranial nerves• It coordinates functions between

the back as well as the visceral organs

Three Centers

• 3) Relay Stations along Sensory and Motor Pathways• The nucleus gracillis and the nucleus

cuneatus pass somatic information to the thalamus• Information is interpreted and relayed

to higher functioning parts of the brain• The olivary nuclei relay commands as

they are issued by motor centers at higher levels of the brain through the medulla oblongata• These are small nodules that resemble

olives