Trachea synthetic windpipes; however, a successful method for this method of transplant does not currently exist and development of such a method remains theoretically daunting. The word "trachea" is used to define a very different organ in invertebrates than in vertebrates. Insects have an open respiratory system made up of spiracles, tracheae, and tracheoles to transport metabolic gases to and from tissues. An adult's trachea has an inner diameter of about and a length of about 10 to 11 centimetres (4 in.). It begins at the bottom of the larynx, and ends at the carina, the point where the trachea branches
Human body neurotransmitters. At the same time, the endocrine system releases hormones, such as to help regulate blood pressure and volume. Together, these systems regulate the internal environment of the body, maintaining blood flow, posture, energy supply, temperature, and acid balance (pH). Development of the human body is the process of growth to maturity. The process begins with fertilisation, where an egg released from the ovary of a female is penetrated by sperm. The egg then lodges in the uterus, where an embryo and later fetus develop until birth. Growth and development occur after birth, and include both physical and psychological development,