| Ja Jz |  |
| Jejunum | Part of the small intestine that connects the duodenum with the ileum. |
| Joint | The place where two bones meet. Most joints are moveable, i.e., the bones can move with respect to each other. Different types of joints allow different types of movement – the joint between the shoulder and the arm allows movement in three dimensions, while the elbow allows movement in only two dimensions. |
| Ka Kz | |
| Kidney | One of a pair of organs in the abdomen. They filter waste products and excess water from the blood to produce urine. |
| Kidney failure | Describes when the kidney stops working properly, so that it can not filter enough waste or excess water from the blood. It can lead to the person becoming seriously ill. |
| Kidney stones | Hard, stone-like structures formed within the kidney. |
| La - Lz | |
| Labia | The two sets of ‘lips’ around the entrance to the vagina. |
| Laxative | A drug used to encourage the passage of stools, or to make stools softer or more bulky. |
| Lesion | Damage to an area of the body, as a result of an injury or disease. |
| Ligaments | Bands of tough, fibrous supporting tissue that strengthen joints. Ligaments are important in supporting the bones in the spinal column. |
| Lithotripsy | A technique for destroying kidney stones without surgery – it uses sound waves to painlessly break up the stones. |
| Long bones | Name given to bones that may be of any length, but which contain bone marrow and have two ends and a central shaft. Long bones provide strength, structure and mobility. Examples include bones of the legs, arms and fingers. |
| Lower digestive system | The lower parts of the digestive tract – called the bowel. The bowel can be divided into the small bowel (small intestine) and the large bowel (large intestine). The small intestine is arranged in coils and loops and divided into three parts: the duodenum, jejunum and ileum. Food enters the small intestine after leaving the stomach, and it continues to be digested, and starts to be absorbed into the body. The small intestine joins the large intestine, which is divided into the caecum, colon and rectum. The undigested food residue is stored as stools (faeces) in the large intestine, before being expelled to the outside through the anus. |
| Lower motor neurone | Nerve cells (neurones) that start in the spinal cord (where they receive messages from nerve cells called upper motor neurones). They then branch out from the spinal cord and travel to different parts of the body, where they deliver their final message to muscles or other body tissues. |
| Lubricant | An oily or slippery substance that reduces friction. For example, a lubricant may be used to ease the insertion of a gloved finger into the rectum (bowel) during manual evacuation of stools. |
| Lubricated | Something onto which lubricant has been applied. |
| Lumbar | Describes the area around the lower back. Lumbar vertebrae are the bones of the spine in this region. A lumbar fracture is a break in the lumbar vertebrae. |
| Lymph vessels | Enclosed network of tubes (the lymphatic system) that transports a fluid known as lymph around the body. Lymph consists of the fluid that bathes the tissues, protein, fat, and white blood cells. The lymphatic system filters this fluid and returns it to the blood stream, and also plays an important role in the immune system. |