Anatomy & Organs

Corpus mamillare – structure, function & diseases

To breastfeed the body

The corpus mamillare is a structure in the midbrain (diencephalon) and forms part of the limbic system . It is also the origin of the mamillothalamic tract and the mamlotegmental tract. Damage to the corpus mamillare can lead to memory problems.

What is the mammary body?

In the midbrain (diencephalon) lies the corpus mamillare as part of the hypothalamus . Also known as the nipple body because of its shape, it is located between the two cerebral crura ( crura cerebri ).

These belong to the midbrain (mesencephalon) and can be found there in the front area. Due to its anatomical connections and functions, the corpus mamillare belongs to the limbic system. In its entirety, the limbic system is primarily responsible for emotions and memory processes, but its tasks are very complex overall. In addition to the mamillary body, it includes the cingulate gyrus , hippocampus , parahippocampal gyrus , amygdala , septum pellucidum , parts of the thalamus , and the fornix. The corpus mamillare is located in the brainfound once in most animals, but in humans and other primates the nipple body is paired.

Anatomy & Structure

The corpus mamillare has a rounded shape. Inside are two nuclei consisting of a dense mass of nerve cell bodies. The anatomy distinguishes between the lateral lateral mammary nucleus and the medial mammary nucleus, which is oriented towards the middle. These core areas play an important role in the processing of information in the corpus mamillare.The corpus mamillare is connected to the subiculum. The subiculum is the transition from the hippocampus to the parahippocampal gyrus. It is adjacent to the Horn of Ammon (Cornu ammonis ) and is part of the hippocampus. Nerve pathways run from the subiculum to the fornix, among other places, which they cross to end at the mamillary body.

Other nerve fibers begin in the two nuclei of the mammary body and proceed to two structures. One such nerve pathway is the mamillothalamic tract, which connects the mamillary body to the anterior nuclei of the thalamus . These anterior nuclei are the thalamic anteroventral nucleus, the anteromedial nucleus, and the anterodorsal nucleus. Another nerve pathway that begins at the mamillary body is the mamlotegmental tract. It establishes a direct connection to the midbrain hood ( tegmentum mesencephali).

Function & Tasks

The corpus mamillare represents a structure of the limbic system. Phylogenetically, the limbic system represents a relatively old part of the brain and deals with emotions and memory processes. Researchers continue to discover new functions and connections within the limbic system. However, the corpus mamillare seems to be involved primarily in processes that affect memory.

The mamillothalamic tract, which connects the mamillary body to the three anterior nuclei of the thalamus, is part of the Papez neuron circuit. James Papez concluded in 1937 that a network of anatomical structures and nerve tracts is responsible for processing emotions in the brain. Papez assumed that the circuit of neurons he discovered caused the development of emotions in the central nervous system . However, this assumption later turned out to be wrong. Today it is known that the activity of the corpus mamillare is primarily associated with memory processescorrelated. In the circle of Papez, the mamillary body is connected to the hippocampus via the fornix. The latter also has a connection to the entorhinal cortex on the other side. This connecting nerve pathway is the tractus perforans.

The mamillothalamic tract connects the mamillary body to the thalamus in the Papez neuron circuit. Nerve fibers then travel to the cingulate gyrus and on to the entorhinal cortex. The latter is located in the parahippocampal gyrus and plays an important role in connection with Alzheimer’s dementia .

Diseases

In the Papez neuron circuit, the corpus mamillare participates in memory processes. Damage to the mammary body itself or to structures that also belong to the circle of Papez is therefore typically associated with memory impairment.A well-known example is Alzheimer’s dementia. This is a neurodegenerative disease that usually begins in old age. The disease is characterized by a progressive loss of nerve cells , causing a variety of symptoms. Early signs include difficulty remembering, which typically only affects short -term memory at first . The exact development processes of Alzheimer’s dementia are still unknown, so that a causal treatment is currently not possible. Different therapies aim to slow the progression of the disease and focus on different symptoms.

The corpus mamillare can also be damaged by malformations, injuries, tumors , bleeding and inflammation. In this case, memory disorders are also possible. Damage to the mamillothalamic tract is associated with both short-term memory impairment and long-term memory impairment. In the case of long-term memory, the ability to move new memories from short-term memory to long-term memory suffers. The extent of the impairment is very individual.

A possible physical consequence of malnutrition is Wernicke encephalopathy , which medicine also knows as Wernicke-Korsakov syndrome. The disease is based on vitamin B1 (thiamine) deficiency and can affect the mammary corpus, geniculate body, thalamic nuclei, and other brain structures. Wernicke encephalopathy often occurs as a consequence of alcohol abuse. Eating disorders such as bulimia , purging-type anorexia and vomiting associated with other mental disorders can also lead to vitamin B1 deficiency and thus to Wernicke-Korsakov syndrome.

Those affected are often disoriented and suffer from impaired consciousness. Disorders of the eye muscles and unsafe walking (gait ataxia) are other core symptoms.

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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.