How does the skin age? The skin is a barrier between our body and the outside world, protecting us from aggressors, retaining water and controlling our temperature. The skin has three layers: the epidermis, the dermis and the subcutaneous tissue. As the skin ages, these three components undergo changes. Some changes are obvious: wrinkles appear […]
Parts and functions of the brain The brain works like a big computer. It processes the information it receives through the 5 senses, and sends back messages, conscious and unconscious, to the body. However, the functions of the brain go much further with the ability to think, make decisions and feel emotions.The size of the […]
Oxidation, how does it work? Oxidation is a chemical reaction that takes place in the presence of oxygen. You can see it when you cut an apple: once cut, the apple tends to turn brown because one of its enzymes reacts with oxygen and transforms a molecule (called phenol) into another molecule (called quinone) which […]
A short introduction to the function of our immune system What is a pathogen ? Bacteria are organisms constituted of one cell (size in µm: one millionth of a meter) and are able to grow and reproduce. Viruses are smaller (size in nm: one billionth of a meter) and are constituted of an envelope with […]
570 skeletal striated muscles Skeletal striated muscles bind bone through tendons. By contracting, they allow the voluntary movement of the skeleton in a specific direction. These contractions are controlled by motor neurons which connect the spinal cord and the muscles. Their activation leads to the release of calcium, which will bind to contractile proteins. Each […]
The tissues of cartilage, tendons, ligaments and skin have strong common features. In scientific language they are part of the “extra cellular matrix” and in everyday life they are known as “connective tissue”. The building blocks of connective tissue are the same for cartilage, tendons, ligaments and skin (especially in the subcutaneous layers, the hypodermis): […]
A joint is the point of connection between two (or more) bones. There are different types of joints, which have varying degrees of mobility. The knee, shoulder, hip and fingers are very movable joints, while the vertebrae are less movable, and the joints of the skull are immovable. The tolerated movements of the skeleton […]