cavities; it may be red or yellow. Red bone marrow is present in all bones at birth and is the factory for most of the blood cells. During the teens, red bone marrow is gradually replaced in some bones by less active yellow marrow. In adults, red marrow is confined chiefly to the spine, sternum, (breastbone), ribs, pelvis (hip-bones), scapulae (shoulderblades), clavicles (collarbones), and bones of the skull.
Stem cells within the red marrow are stimulated to form blood cells by the hormone erythropoietin.
Yellow marrow is composed mainly of connective tissue and fat.
If the body needs to increase its rate of blood formation, some of the yellow marrow will be replaced by red.
Sometimes marrow fails to produce sufficient numbers of normal blood cells, as occurs in aplastic anaemia (see anaemia, aplastic) or when marrow has been displaced by tumour cells.
In other cases, marrow may overproduce certain blood cells, as occurs in polycythaemia and leukaemia.... bone imaging
The neck contains many important structures: the spinal cord (which carries nerve impulses to and from the brain); the trachea (windpipe); the larynx (voice box); the oesophagus; the thyroid and parathyroid glands; lymph nodes; and several major blood vessels. The upper 7 vertebrae of the spine are in the neck; a complex system of muscles is connected to these vertebrae, the clavicles (collarbones), the upper ribs, and lower jaw.
Neck disorders include torticollis (wry neck) in which the head is twisted to one side. Fractures and dislocations of vertebrae in the neck and whiplash injury can injure the spinal cord causing paralysis or even death (see spinal injury). Any condition causing swelling in the neck may interfere with breathing or swallowing.
Degeneration of the joints between the neck vertebrae may occur due to cervical osteoarthritis, causing similar symptoms to those of disc prolapse. In ankylosing spondylitis, fusion of the vertebrae may result in permanent neck rigidity. Cervical rib is a rare congenital defect in which there is a small extra rib in the neck.Neck pain of unknown origin is very common.
As long as neurological symptoms (such as loss of sensation or muscle power) are absent, the condition is unlikely to be serious and usually disappears within a few weeks.... neck
There are often no symptoms, but if symptoms do occur, the most common ones are bone pain and deformity, especially bowing of the legs. Affected bones are prone to fracture. Skull changes may lead to leontiasis (distortion of the facial bones producing a lion-like appearance) and to damage to the inner ear, sometimes causing deafness, tinnitus, vertigo, or headaches.
The disorder is diagnosed by X-rays and blood tests. Most people do not need treatment, or only need analgesic drugs. In more severe cases, treatment with drugs such as calcitonin may be prescribed or surgery may be needed.... paget’s disease
It is attached to the top and back of the shoulderblade and to the outermost part of the collarbone.
The trapezius helps support the neck and spine and is involved in moving the arm.... trapezius muscle