Railway Science (Biology – Skeleton System)

Spines or quills are found in four major groups of living mammals: hedgehogs, tenrecs, echidnas, and rodents.

Rheumatic diseases are autoimmune and inflammatory diseases. Rheumatoid arthritis is a long-term condition that usually affects joints in the hands, feet and wrists. That means the body's immune system (which usually fights infection) attacks the cells that line body joints by mistake, making the joints swollen, stiff and painful.

Scapula - A large triangular flat bone situated in the dorsal part of the thorax between the second and the seventh ribs. Femur (thigh bone – the longest bone), tibia and fibula, tarsals (ankle bones – 7 in number), metatarsals (5 in number) and phalanges (14 in number) are the bones of the legs (hind limb).

Stapedius - Smallest skeletal muscle present within the middle ear and attaches to the stapes bone. Pectoralis - divided into two: Pectoralis Major - superior most and largest muscle of anterior chest wall and Pectoralis Minor - triangular muscle, located on anterior thoracic wall, beneath the Pectoralis Major. Tibialis - largest muscle in the anterior compartment of leg and acts as the strongest dorsiflexor of the foot.

Biceps (biceps brachii) is a large muscle that lies on the front of the upper arm between the shoulder and the elbow. Other Arm Muscles - Bracialis, Anconeus, Triceps brachii, Teres, Infraspinatus, Supraspinatus, Deltoid, Subscapularies, Coracobrachialis. Other Important Muscles: Cardiac - Present only in the heart. Visceral - Present in Intestines, blood vessels and stomach.

Periodontics is a branch of dentistry that focuses on gum disease that destroys the gums and other supporting structures around the teeth. Other branch of Medical science : Gastroenterology - The branch that deals with disease of the stomach and intestines. Syndesmology - The branch of anatomy that deals with ligaments. Orthopedics - The branch of surgery deals with the musculoskeletal system.

Connective tissue supports, protects, and gives structure to other tissues and organs in the body. Types of connective tissue: loose connective tissue, adipose tissue, dense fibrous connective tissue, elastic connective tissue, cartilage, osseous tissue (bone) and blood.

Normal human skeleton has two main types of bones: cortical or compact bone which is hard, solid and very strong and forms shafts of long bones i.e. the femur and tibia etc; and spongy or trabecular/ cancellous bone is found in the marrow cavities and is a mesh of bone strands which is almost ideal weight bearing structure particularly in the femoral head and vertebrae.

It is a type of connective tissue. It is produced by Chondroblasts. Cartilage is also present in the nose, ear, trachea and larynx. Areolar tissue acts as a filler tissue between skin and muscles. Tendons are a type of connective tissue which connect muscles to bones.

Voluntary muscles - It is composed of cylindrical fibers and are usually attached to bones and the skin. These muscles are under the control of our will. It includes Skeletal Muscles. Example - Diaphragm, pharynx, abdominal wall, tongue.
Involuntary Muscles - It is uninucleated, Spindle-shaped, small muscles and is controlled by the autonomic nervous system in the body (Not on our will). It includes Smooth muscles (intestines, stomach, uterus, and blood vessels) and Cardiac muscles (Heart).