The brain is a master organ for control and communication within the body and also with the surroundings. Amongst all, the human brain is the most complex and highly developed of all the brains. Larger and more complicated animals have a greater need for an organ to control activities of the body. Hence, more highly developed animals have more highly evolved brains.

Table of Contents

Basic Features of a Brain

Definition

[Medulla Oblongata – Highlights](#Medulla Oblongata - Highlights)

Location

Anatomy

Parts of Medulla Oblongata

[Medulla Oblongata Function](#Medulla Oblongata Function)

Pons and Medulla Oblongata

[Frequently Asked Questions](#Frequently Asked Questions)

Basic Features of a Brain:

• Ability to store and recall information
• Ability to process information
• Ability to make decisions
• Ability to create and understand language
• Ability to control movement

In spite of their great differences, all brains have some common features:

All brains are composed of neurons or nerve cells

All brains possess at least three major sections: a sensory section, an integrating section, and a motor section

The overall function of the brain, which is deemed as behaviour, is determined by two factors – the precise way in which these three divisions are connected and the presence of other special brain centres.

What is Medulla Oblongata?

The Medulla Oblongata is a part of the brainstem located in the hindbrain, and is responsible for controlling vital functions such as breathing, heart rate, and blood pressure.

The brain can be classified into three main parts: the forebrain, midbrain, and hindbrain. The hindbrain can be further divided into the Cerebellum, Medulla Oblongata, and Pons Varolii.

The Medulla Oblongata has its origins in Latin, where “medis” translates to “middle” and “oblongata” translates to “long”. This is why the medulla is a long, conical structure. It is located in the lower region of the brain and is responsible for controlling autonomic functions such as breathing, heartbeat, and digestion. It is also vital in connecting the spinal cord, pons, and cerebral cortex, as well as helping maintain body posture and reflexes.

The medulla oblongata is often referred to as the “spinal cord of the head” due to its importance in controlling head and facial musculature.

Medulla Oblongata - Highlights

The medulla oblongata is a small but important part of the brain. It is located in the brain stem and is responsible for controlling many vital functions, such as breathing, heart rate, and blood pressure. It also plays an important role in reflexes and movement. Here are some of the highlights of the medulla oblongata:

• Controls vital functions such as breathing, heart rate, and blood pressure
• Regulates reflexes and movement
• Relays information between the brain and spinal cord
• Processes sensory information from the body

The myelencephalon develops into the medulla oblongata

It is the most caudal brainstem structure situated in the posterior-most part of the brainstem, which merges with the spinal cord.

Dimensions - At its largest, the medulla is 3 cm long, 2 cm wide, and has a thickness of 1.25 cm.

It is the site of both ascending and descending tracts that transmit signals between the spinal cord and the brain.

The broad portions of the overlying pons join together, and the narrow section continues on with the spinal cord.

The intersection of the spinal cord and medulla is concurrent with the upper border of the first cervical vertebra (Atlas).

In addition to the other sections of the hindbrain, the medulla is situated in the infratentorial space.

The medulla is responsible for controlling a variety of autonomic functions.

The commissural fibres form the base of the medulla and cross over from the ipsilateral side of the spinal cord to the contralateral side of the brainstem, with the spinal cord underlying them.

It can be divided into:

The “open part of the medulla” is an upper posterior section connected to the lower part of the 4th ventricle.

The lower section with the central canal is the “closed part of the medulla”.

See also: Body fluids and circulation

Medulla Oblongata – Location: Located in the brain stem, the medulla oblongata is located between the pons and the spinal cord.

The medulla oblongata is located anterior to the cerebellum in the brain stem, inferior to the pons. It is the lowest section of the hindbrain. It is situated in the anterior section of the posterior cranial fossa, stretching down to the foramen magnum.

Posteriorly – Vallecula of the Cerebellum

Anteriorly – Meninges and Clivus

The fourth cerebral ventricle is formed by the topmost part of the medulla. This ventricle is a cavity that holds the cerebrospinal fluid and is connected to the cerebral aqueduct.

Medulla Oblongata Anatomy – Structure

The medulla oblongata is a portion of the brainstem linking the spinal cord and the pons. It extends through the foramen magnum to the levels of the atlas. It is embraced dorsally above the foramen magnum by the cerebral hemispheres.

The medulla extends from the pronto-medullary junction until the plane below the foramen magnum for close to 0.5 cm. It has a central canal that extends into its lower half to open in the four ventricles at its upper half. The cerebrospinal fluid surrounds the medulla from the inside (central canal) and outside (subarachnoid space). The medulla is situated between the two lobes of the cerebellum (anterior cerebellar notch).

Anatomy of the Medulla Oblongata: Key Components

Medulla is divided into two major parts -

Ventral Medulla - the front portion

The Dorsal Medulla is the rear portion of the brain, also known as the tegmentum.

Components:

1. Median Fissures

Along the posterior and anterior portions of the medulla, shallow grooves are found; these are the median fissures.

2. Pyramids

The medulla ventrally has a deeply grooved midline and a bold complexity on either side, which are known as the pyramids. This is due to the cortico-spinal fibres contained within, some of which overlap and obliterate the anterior median fissure, known as the decussation of the pyramids. The external arcuate fibers originate from the anterior median fissures above the decussation, running laterally across the surface of the pons.

They are the two round masses of white matter situated on either side of the anterior median fissure.

3. Olivary Bodies

A pair of oval structures known as the olivary bodies or olives are located in the upper part of the medulla, between the posterolateral and anterolateral sulcus. These structures contain nerve fibres which link the cerebellum, pons, and medulla. The olivary bodies are characterized by a swelling, which is caused by the large mass of gray matter known as the inferior olivary nucleus.

4. Fasciculus Gracilis

The posterolateral sulcus and posterior median of the medulla comprise tracts entering from the posterior funiculus of the spinal cord. Fasciculus gracilis is situated intermediate to the midline and laterally to the fasciculus cuneatus. These structures typically are the continuation of the bundle of nerve fiber tracts extending from the spinal cord to the medulla.

The terminal end of the fasciculi has round elevations known as the gracile and cuneate tubercles, which are caused by the nucleus cuneatus and nucleus gracilis. Above the tubercles, a triangular fossa is located on the posterior aspect of the medulla, and forms the floor of the 4th ventricle. This fossa is enclosed by the inferior cerebellar peduncle on either side.

Right laterally immediate to the fasciculus cuneatus is the tuberculum cinereum, which is a longitudinal elevation caused by the spinal nucleus of the trigeminal nerve.

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Parts of the Medulla Oblongata

The medulla is found between the spinal cord and the pons. Its ventral and dorsal surfaces of the medulla are distinguished by distinct fissures and protuberances constituted by different nuclei and related tracts.

Ventral Surface

The anterior median fissure is located along the midline of the ventral surface of the medulla. On either side of the fissure is a medullary pyramid, which is formed by fibres of the corticospinal tract. In between the medial fissure and the base of the pyramids is the fascicles of the corticospinal tract. This serves as the foundation for the pyramidal decussation in the midline.

There are two sulci on each section of the ventral medullary surface: the posterolateral sulcus and the anterolateral sulcus. An olive-shaped structure, located posterior and lateral to each of the pyramids, is found between these two sulci.

Dorsal Surface

The dorsal surface of the medulla oblongata is distinguished in the midline by the dorsal medial sulcus which is in continuation with its spinal counterpart.

The gracile fasciculus ascending from the spinal cord forms a lateral sulcus and its cranial part comprises the gracile nucleus, forming the gracile tubercle. Additionally, the cuneate fasciculus forms a lateral prominence on either side of the dorsal median sulcus, creating the cuneate tubercle.

The trigeminal tubercle is another prominence lateral to each of the cuneate nuclei formed by the spinal nucleus of the trigeminal nerve. The lateral funiculus of the medulla is present caudal to the trigeminal tubercle, in direct continuation with the lateral funiculus of the spinal cord.

Medulla Oblongata Function

The medulla oblongata, located in the brain stem, is responsible for autonomic functions such as breathing, heart rate, and blood pressure regulation. It also plays a role in relaying sensory information to the brain and controls reflexes such as coughing, sneezing, and swallowing.

The medulla is essential in carrying out some vital body functions related to the regulation of mental, motor and sensory processing. It is responsible for regulating the autonomic functions of the body while it links the higher levels of the brain to the spinal cord.

It transmits nerve impulses between the spinal cord and the brain.

Controls Autonomic Functions

Promotes Emotional Well-Being

Coordinates movement of the body

It is the reflex center for coughing, vomiting, sneezing, and swallowing.

It is the Vasomotor Center: Baroreceptors

It is the cardiac centers: parasympathetic and sympathetic systems

The medulla is the primary control centre for respiratory and cardiovascular activities, responsible for regulating blood pressure, heart rate, respiratory rate, and other essential life-sustaining activities. It also coordinates involuntary reflexes such as gagging, sneezing and swallowing, as well as voluntary actions like eye movement.

The medulla is an important part of the brain, housing many cranial nerve nuclei that are essential for the head, speech, digestion of food and movement of the shoulder. It serves as a bridge between the peripheral and central nervous systems, sending sensory impulses between them. Furthermore, the medulla relays sensory information to the thalamus, which then reaches the cerebral cortex.

Pons and Medulla Oblongata

Pons is located near the base of the skull and is part of the brainstem, the lowest structure in the brain. It is situated just above the medulla oblongata and connects the spinal cord through the opening at the base of the skull. It is below the cerebellum and the cavity of the fourth ventricle, and is composed of a mass of nerve fibres connecting the medulla and the cerebellum. As a critical part of the autonomic nervous system, Pons serves as a pathway for nerve fibres connecting the cerebral cortex to the cerebellum. It also relays information related to sensation, motor function, eye movement, taste, hearing, etc.

The Pons not only regulates the activities of the cranial nerves, but also works in conjunction with the medulla oblongata to maintain the breathing rhythm. The steady regulation of the Pons is essential for a healthy REM (Rapid Eye Movement) sleep.

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Frequently Asked Questions

If the medulla is damaged, it could lead to a variety of symptoms, including paralysis, loss of sensation, difficulty breathing, and even death.

Damaging your medulla can lead to potentially fatal conditions, such as loss of sensation, paralysis, and disruption of respiratory processes.

Medulla

The medulla is the lower half of the brainstem and is responsible for autonomic functions such as breathing, digestion, and heart rate. It is also the origin of the cranial nerves, which control the head and neck muscles.

The Medulla forms the lowest part of the brain and the lowest section of the brainstem. It plays a pivotal role in passing signals between the spinal cord and the brain’s higher areas and is also involved in regulating autonomic activities.

No, the medulla oblongata is not used for thinking.

No, the medulla oblongata is not used for thinking. It regulates processes such as breathing, heartbeat and sneezing that do not require active thinking.

Is it possible to survive without a medulla oblongata?

Without a medulla oblongata, it is impossible to survive, as it is responsible for signal transmission between the brain and spinal cord, such as respiration and heart rate. The medulla oblongata is also continuous with the spinal cord.

The medulla oblongata is located in the brainstem.

The medulla is located at the base of the brain where the brain stem connects the brain to the spinal cord. It is connected to the midbrain by the pons and is posteriorly continuous with the spinal cord, with which it merges at the opening at the base of the skull.

What is the Role of the Blood Brain Barrier in Regard to the Medulla Oblongata?

The Area postrema is a paired structure located dorsally in the medulla oblongata. It is equipped with sensory neurons that are capable of detecting poisonous or harmful chemicals in the blood, which is why the medulla oblongata is not protected by a blood-brain barrier.

The Medulla Oblongata: An Overview of its External Features

The medulla oblongata is a vital part of the brain located at the base of the skull. It is responsible for controlling vital functions such as breathing, heart rate, and blood pressure. It is also involved in the regulation of consciousness, sleep, and digestion. The external features of the medulla oblongata include its shape, size, and location. It is roughly shaped like an oval and is about the size of a walnut. It is located at the base of the brainstem, just above the spinal cord.

The medulla can be categorized into 2 parts – ventral medulla and dorsal medulla. The ventral medulla comprises a pair of triangular structures – pyramids which in turn house the pyramidal tracts. The upper part of the dorsal medulla constitutes the lower part of the fourth ventricle. This region is the point of origin for the last 7 cranial nerves. Most of these ventrally exit the medulla.

The Medulla Oblongata is responsible for controlling many of the body’s involuntary functions, such as breathing, blood pressure, and heart rate.

The medulla oblongata is the lower part of the brainstem. It is connected to the higher parts of the brain and the spinal cord, and is responsible for regulating vital functions such as heartbeat and breathing, as well as different functions of the autonomic system.

The Brainstem connects the cerebrum to the cerebellum and the spinal cord. It comprises three sections – the pons, midbrain and the medulla oblongata.