THE SKELETAL AND MUSCULAR SYSTEM
• Despite its appearance, bone is a complex and
dynamic living tissue. The entire framework of
bones and their cartilages together constitute
the skeletal system. The study of bone
structure and the treatment of bone disorder
is called osteology.
Functions of the skeletal system (bones)
1) Support. Bones serve as the structural framework
for the body supporting soft tissues and providing
attachment points for the tendons of most skeletal
2) Protection. Bones protect internal organs from
injury. For example cranial bones protect the
brain, vertebrae protect the spinal cord, and the rib
cage protects the heart and lungs.
3) Assistance in movement. When skeletal muscles
contact, they pull on bones to produce movement.
4) Mineral homeostasis. Bone tissue stores several
minerals especially calcium and phosphorus, which
contribute to the strength of the bone. Bone can
release minerals into the blood stream to maintain
critical mineral balances and to distribute minerals
to other organs.
5) Blood cell production. Within certain parts of
bones a connective tissue called red bone marrow
produces red blood cells, white blood cells and
platelets by a process called hemopoiesis.
6) Triglyceride (human fat) storage. In the
newborn, all bone marrow is red and is
involved in hemopoiesis. However, with
increasing age, blood cell production
decreases, and most of the bone marrow
changes from red to yellow. Yellow bone
marrow consist primarily of adipocytes and a
few scattered blood cells.
Ligaments and Tendons
• Ligaments and tendons are soft collagenous
• Ligaments connect bone to bone and tendons
connect muscles to bone.
• Body movement
• Maintenance of posture
• Production of body heat
• Constriction of organs and vessels
• Heart beat