Majja Dhatu

Majja dhatu is the sixth tissue element in Ayurveda. The word purana means "to fill space," and a major function of this dhatu is to fill the spaces within the innermost tissue of the body — the bones. Majja dhatu encompasses both nerve tissue and bone marrow. Bone marrow is a soft, jelly-like tissue within the bone cavity. Every bone has a small foramen (opening) through which nerves and blood vessels enter, giving bone tissue a sense of pain, pressure, and joint position.

There are two kinds of bone marrow: red and yellow. Red bone marrow is found in spongy bone, is rich in pitta, and produces red blood cells and hemoglobin. As a person ages, some red marrow converts to yellow. Yellow bone marrow resides in the medullary canal of long bones, consisting primarily of fat cells and connective tissue — it does not produce red blood cells but supports the bone structure.

Majja dhatu also serves a critical communication function. It is present in the brain, hypothalamus, spinal cord, and all interspinal and cranial nerves, including subcutaneous nerves. Sensory stimuli are carried to the brain by prana, while motor responses are carried by apana. Unresolved emotions stuck in the bone marrow matrix can alter marrow properties, and radiation or broad-spectrum antibiotics like tetracycline and chloramphenicol can depress bone marrow and create blood dyscrasia.

The main function of majja dhatu (nerve tissue and bone marrow) is communication. It brings all organs together through conscious awareness, creating the physical sense of embodied identity — the awareness that "this is my finger, this is my hand." Through motor nerves, majja dhatu responds to stimuli; through sensory nerves, it carries stimuli from the periphery to the brain center where each of the five sensations (seeing, hearing, smelling, touching, tasting) is interpreted.

Majja dhatu governs both the voluntary actions of skeletal muscles and the involuntary actions of smooth muscles. The cardiac muscle and the muscles of the gastrointestinal tract are governed by majja dhatu via prana. Sthayi majja dhatu is formed from asthayi majja dhatu via majja agni, which is composed of enzymes, amino acids, and neurotransmitters necessary for the nourishment and metabolism of nerve cells.

Understanding itself is described as subtle neurological digestion — a process of assimilation governed by majja agni. Every experience and sensation carried to the brain arrives unprocessed and unmetabolized. In the brain, these raw sensations are processed and transformed into understanding.

At the deepest level, the core function of majja dhatu is to create the feeling of "I am" — self-identity. Thought expresses as a material process (neurotransmitter secretion) that flows through the medium of majja dhatu. The ego is a bundle of material processes crystallized within majja dhatu. Through recognition and identity, majja dhatu nourishes the ego. Intense thoughts of anger, fear, or grief can damage the neuronal pathways shaped by thought within majja dhatu.

When there is too much ama in majja dhatu, or when majja dhatu is raw and unprocessed, the result is misunderstanding, misconception, confusion, delusion, and even hallucination. All these are unhealthy states of majja dhatu. Scanty lacrimal secretions in the eyes indicates inferior majja dhatu quality.