Skeleton and Movements
Disorders related to muscles
1) Muscular dystrophy :
*It is a gradual wasting disease affecting various groups of muscles.
* It is genetically inherited problem running in families.
* usually voluntary skeletal muscles are weak and where as internal muscles search as diaphragm are not affected .
*Duchenne type usually occurs in boys due to it's inheritance affecting lower limb.
*limb girdle muscular dystrophy affects the muscles of shoulders for hips. This is usually among adults of 20 to 35 years.
*No treatment appears to cure the disease.
2) Myasthenia gravis:
* It is a weakness of skeletal muscles.
*It is caused by an abnormality at the neuromuscular junction that partially blocks contraction.
*It is an autoimmune disorder caused by an excess of certain antibodies in the blood stream.
*That antibodies bind to acctylecholine receptors of neuromuscular junction .
*Thus transmission of nerve impulses to the muscle fibres is blocked.
*This causes progressive and extensive muscle weakness.
* It may affect the eye and eyelid movements , facial expressions and solving the degree of muscles weakness vary from local to general.
*Symptoms:
*Ptosis also known as diplopia double vision.
*Difficulty in swallowing ,chewing and speech.
Disorders related to bones:
1) Arthritis:
An inflammation of joints
*Painful disorder of bones, ligaments, tendons etc .
* Joints become swollen ,stiff cand painful.
*Leads to disability.
*Three types of arthritis, as below:
(a) Osteoarthritis:
*Joint cartilage is degenerated due to various factors such as aging, obesity,muscle weakness. etc.
*Most common type of arthritis affecting hands, knees and spine.
(b) Gouty arthritis (Gout):
*Joint pain due to deposition of uric acid in joints.
*Excess production of uric acid or it's accumulation without excretion
causes painful joints.
*Uric acid is stored as sodium urate
which degenerates cartilage, causing Inflammation and pain .
*Joints of feet are affected .
(c) Rheumatoid arthritis:
*It is autoimmune disorder where body 's immune system attacks it's own tissues.
*Synovial membrane swells up and secrets extra synovial fluid.
*Excess fluid exerts pressure on joint making it painful.
*Abnormal granulation tissue called pannus may develop.
* Pannus erodes cartilage.
*Fibrous tissue may be ossified leading to stiffness in joints.
2) Osteoporosis:
*Bones become porous and brittle.
*Primary age-related ,more common in women than men.
* With advancing age , bone resorption is faster than the bone formation.
*Bones does loose mass and become brittle.
*Calcium is lost in urine,sweat to the greater extent as compare to that which is gained through diet.
*Consuming adequate amount of calcium and exercise at young age does becomes preventive measure to osteoporosis.
*Decreasing estrogen secretion after menopause is also a cause of osteoporosis in middle aged women.
*Deficiency of vitamin D ,low calcium diet ,decrease secretion of sex hormones and thyrocalcitonin are some of the causative factors of osteoporosis.
*Osteoporosis cause fractures lead to shrinkage of vertebrae, height loss ,hunched back and bone pain .
