Cells organize to form tissue. According to Ayurveda there are seven basic tissues: plasma, blood, muscle, fat, bone, marrow (the brain is known as the "sea of marrow" and this suggests that marrow is also related to the nervous systems) and reproductive tissue. Plasma tissue contains nutrients from digested food, which nourishes all of the other tissues, organs and body systems. Blood supplies oxygen to the body tissues.
Muscle tissue covers the organs, performs the movement of joints and lends strength. Fat tissue lubricates the tissues. Bone tissue supports the body structure. Marrow and nerve tissue carry motor and sensory impulses. Reproductive tissue contains the ingredients of all tissues. Each tissue depends on the energy of the less complex tissue in this chain of life.
Each tissue is nourished in a serial manifestation, according to Ayurveda as taught by Dr. Lad in his books Ayurveda, the Science of Self- Healing and Textbook of Ayurveda. Each of the seven tissue types are transformed sequentially from plasma to the reproductive tissue. Any weakness in one tissue type affects the formation of subsequent tissue. For example, a weakness in the muscle tissue will affect the fat tissue. Tissue transformation results from three processes that occur simultaneously: irrigation - nutrients are supplied to the tissues through the blood vessels; selectivity - each tissue extracts the nutrients it needs; and direct transformation - as nutritional substances pass through each tissue the food for the subsequent tissue is produced.
Each of the seven tissues is subtler than the previous one and takes longer to form. Reproductive tissue takes the longest to produce. It is said that it takes 28 days to form a drop of semen, whereas plasma can be formed in a few hours.
In standard anatomy and physiology, cell formation progresses to tissue to formation of the organs. The seven tissues, as taught in Ayurveda, each relate to the structure and function of various organs.
Besides the nourishment and production of the tissue itself, each tissue develops a related by-product. And, as with any manufacturing process, there is also production of something similar to a base or waste by-product, which is called a mala.
Plasma is rooted in the right chamber of the heart, where all the venous blood returns, and in the large vessels. Plasma passes through the venous and lymphatic systems and opens into the arteriole-venous junction. The by-products of plasma are the outer (epidermis) layer of the skin, breast milk and menstrual fluids. The base by-product (mala) of plasma is mucus.
Blood, as defined in Ayurveda, is only the red blood cells, not ‘blood plasma’, which includes white blood cells and blood platelets. Red blood cells only make up 45% of a blood sample. The remaining 55% is ‘blood plasma’.
Blood is rooted in the liver and spleen, passes through the arteriole circulatory system and opens into the arteriole/venous junction. The by-products of blood are blood vessels, granulations (which are formed as a part of the healing process in large open wounds) and small tendons. The base by-product is bile.
Muscle tissue is rooted in the fascia and tendons, mesodermal cells, and the layers of the skin below the dermis (outer layer of the skin). Muscle tissue opens to the pores of the skin. Muscle tissue by-products are the inner (dermis) layers of the skin and the subcutaneous layer made of fat and connective tissue. The base by-product is earwax, nasal crust, sebaceous secretions and tartar.
Fat tissue is rooted in the omentum, which is an apron-like double fold of fatty membrane that hangs down in front of the intestines, and the adrenal glands. Fat tissue opens to the pores of the skin. The by-products of fat tissue are tendons or sinews, ligaments and flat muscles. The base by-product of fat is sweat.
Bone tissue is rooted in the pelvic girdle and sacrum. It opens to the nails and head hair. Bone tissue has a by-product of teeth and cartilage. The base by- products are head hair and nails.
Marrow and nerve tissue is rooted in the brain, spinal cord, joints and junctions between the tissues. It passes through the central, sympathetic and parasympathetic nervous systems. Marrow and nerve tissue opens to the synapses and neuromuscular junctions. The by-products of nerve tissue and bone marrow are tears. The base by-product is the crusty secretion in the eyes.
Reproductive tissue is rooted in the testicles and nipples on a man, and in the ovaries and areola of the nipples on a woman. Its passage is by way of the ejaculatory duct, prostate, urethra and urinogenital tract on a man and fallopian tubes, uterus, cervical canal and vaginal passage in a woman. It opens to the urethral termination on a man and labia on a woman. Reproductive tissue has a superior by-product of ojas, the subtle essence of properly nourished bodily tissues. It has a base by-product of pubic and axillary hair.
The tissues are woven from the five elements. They are enlivened by the life energy, prana and the biological affects of vatta, pitta, and kapha. Bodily tissues are the biological representation of the subtle energy currents in the body. If they are in a healthy condition, the tissues maintain normal physiological functions and promote proper working of the more subtle energetic forms of the doshas - prana related to vatta, tejas related to pitta, and ojas related to kapha.