5-alpha-redutase: Enzyme located in the capillary follicle that reacts with testosterone resulting in dihydrotestosterone, or DHT.

AGA: Acronym for Androgenic Alopecia, or simply baldness.

Albumin: A protein abundant in nature. It can also be found in egg’s white.

Androgenic Alopecia: Alopecia (gr. alopekia – naked, from alópex – fox) androgenic (gr. andro – man, gr. genica – transmission through genes) is the commonest form of alopecia, the pathology responsible for hair loss.

Androstenedione: Steroid that precedes the formation of testosterone and estrone. It comes from the ovaries and the supra-renal glands and is the most abundant sexual hormone in women.

Anterior Line: First rows of hair in the forehead. See front line.

Bald Area: Region on the head that is affected by baldness, usually located at the top of the head or crown.

Benign Prostatic Hyperplasia (BPH): Pathology characterized by the abnormal growth of the prostate, without any malign or cancerous traits.

Biological Modifier: Any chemical agent that can cause changes in the human body. Medicines are biological modifiers.

Circling Androgens: Active sexual hormones in the human body.

Cutaneous annex: skin annexes such as: hair, nails, sebaceous and sweat glands.

Densitometry: Is the measurement of follicular units per cm2 using an instrument called densitometer.

Dihydrotestosterone: Hormone resulting from the reaction between 5-alpha-reductase and testosterone.

DHT: Acronym for dihydrotestosterone.

Donating Area: in capillary megatransplant surgery is the area that will provide capillary follicles for the bald region.

Epidermis: Is the covering tissue of the human body.

Ethiopatogeny: Cause.

FDA: Food and Drug Administration, agency that regulates the use of medicine in the United States.

Follicular Unit: It is a set formed by one, two, three or even four hairs plus the sebaceous gland and hair erection muscle, all involved by a tissue called conjunctive. The hair in the scalp are disposed in follicular units of one ore more hairs (up to four) that we can also call Families. When we perform the capillary transplant surgery we try to “copy” the natural anatomy of the area. In the anterior line, we place follicular units of one hair and as we advance we put units of two, three and four hairs. In the graft cut we also maintain the anatomy and separate the grafts by follicular units.

Free Testosterone: Biologically active form of Testosterone in AGA. That is, the one which leads to androgenic stimulation, because it is the only one that can freely move from the blood vessels into the interior of the target cells.

Front Line: It is where the hair is located right above the forehead. In megatransplant surgery, special care must be taken with this area in particular in order to guarantee a natural appearance for the patient’s hair.

Frontoparietal Region: Corresponds to the anterior and superior part of the head. Both in male pattern baldness and in the female pattern, it is the area most afflicted by baldness. The follicles in this region possess a limited lifespan and are the one which suffer the most with the process of miniaturization of pilose follicles.

Hormonal Modifier: Any chemical agent that can change hormonal activity.

Ludwig Classification: Ludwig classification predicts three degrees for the evolution of female pattern baldness.

Mesoderm: Embryonic layer that will originate several structures of the human body.

Micro-punches and slot-punches: Surgical techniques that complement the capillary megatransplant.

Miniaturization: Process by which the hair thins and decreases in size until it reaches a microscopic standard.

Neural Crest: One of the complex structures that appear in the embryo to originate the definite structures of the human body.

Occipitotemporal Region: The sides and posterior part of the head. The follicles in these areas are genetically programmed to unceasingly produce hair. For this reason, it is not usually affected by baldness.

Pharmacological Therapy: Clinical treatment through medicines, without the necessity of a surgical intervention.

Pilose follicle: synonym for capillary follicle.

Pilose Density: Thickness, number and length of the hair. The greater the pilose density, the easier it is to cover the bald area.

Placebo: Is a pill that has no effect. The real medicine and the placebo are used in tests for comparison purposes.

Puberty: Period of great anatomical and physiological changes in the human body. In women, this period begins between the ages of 7 and 13. Great hormonal changes happen in this period and, for this reason, it is related to baldness.

Punch: Surgical technique used by Dr. Muricy (when necessary) together with capillary megatransplant.

Receiving Area: It is the area affected by baldness that will receive capillary follicles from the donating area.

Scar Alopecia: Type of alopecia caused by damage or lesion in the scalp.

Seborrhea: An illness that afflicts 2 to 5% of the population. Reddish spots with yellowish and thin scales appear in the scalp.

Sex Hormone Binding Globulin (SHBG): SHBG is one of the proteins synthesized by the liver. The levels are higher in women in reproductive age than in men, due to the higher ratio of estrogens to androgens in women.

Testosterone (T): Male hormone abundantly present in the human body, synthesized by the testicles and adrenal cortex.

Thyroid: Gland located in the neck. Its function is to regulate practically the entire metabolism of the human body.