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Scanning Tunnelling microscope
A device which allows visualization of individual atoms. A fine needle tip is moved across a surface, separated from it by a tiny gap. Electrical changes are measured and the tip moved up or down to maintain a steady current. In this way the needle follows the contours of the surface, and a three-dimensional image of the atoms at the surface can be obtained.
The pouch of skin and smooth muscle that encloses the testes below the root of the penis. The muscle contracts in response to cold, exercise, and sexual arousal.
This consists of two main components: the spermatozoa produced by the testes and the seminal plasma secreted by structures forming the male reproductive tract (eg: prostate, seminal vesicles, and the system of ducts).
The tissue forming most of the outer surface of the body. It is composed of the outer epidermis and the layer deep to this called the dermis. The skin is part of the integumentary system which also includes hair, nails, sweat glands and sebaceous glands.
The part of the digestive tract that extends from the pyloric sphincter of the stomach to the beginning of the large intestine (caecum). A tube with a muscular wall, it propels food and liquids along its length, completing the process of chemical digestion and absorbing most of the usable products of digestion into the blood and lymph.
These are the male gametes: cells formed within the testes with the specific function of travelling through the female reproductive tract towards the ovulated egg. Sperm are haploid cells (23 chromosomes) formed by meiotic cell divisions.
The part of the nervous system lying within the spinal canal of the vertebral column. It extends from its continuity with the brainstem (above) to the level of the intervertebral disc between the first and second lumbar vertebrae (below).
Chemicals derived from cholesterol. The hormones secreted by the adrenal cortex and gonads are steroids, as are the bile acids and vitamin D.