Module 7: The ASEAN World of Medicine

Table of Contents

Reading Text & Presentation

7.1 The human body

7.1.2 The structure of bones

As stated already, the bones of our skeleton are the body’s storehouse for iron, calcium, and a lot more besides. It is made up of nonliving bone matrix and many tiny bone cells. Approximately half of the bone matrix’s mass is water, and the other half is collagen protein and solid crystals of calcium carbonate and calcium phosphate. The skeleton makes up about 30-40% of an adult’s body mass.


The only living bone cells are on their edges and in small cavities inside the matrix. These cells have several important roles in the skeletal system’s functions. They allow bones to grow and develop, to repair injury or daily wear, and to be broken down to release stored minerals.

The bones of the body are classed into five types: long, short, flat, irregular, and sesamoid. The long bones grow more than the other classes of bone throughout childhood, and so are the storage areas for bone marrow. Short bones are about as long as they are wide and are often cubed or round in shape. Flat bones vary in size and shape, and do not have a medullary cavity like the long bones. Irregular bones do not fit the pattern of the long, short, or flat bones. The sesamoid bones are formed after birth inside of tendons that run across joints to protect them from stresses and strains. The patella and the pisiform bone of the carpals are the only sesamoid bones that are counted as part of the 206 bones of the body. Other sesamoids can form in the hands and feet, but are not present in all people.


The human skeleton (Front view) The human skeleton (Rear view)

1. Skull
2. Maxilla
3. Mandible
4. Clavicle
5. Humerus
6. Radius
7. Ulna
8. Sternum
9. Scapula (hidden)
10. Ribs
11. Vertebral column
12. Ilium
13. Sacrum
14. Coccyx
15. Femur
16. Fibula
17. Tibia
18. Hand bones
19. Foot bones
20. Patella (arrow)

 

 

 

1. Scapula (shoulder blade)
2. Cervical (neck) vertebrae
3. Thoracic (chest) vertebrae
4. Floating rib
5. Lumbar (lower back) vertebrae
6. Thumb phalanges
7. Carpals
8. Metacarpals
9. Finger phalanges
10. Tarsals and metatarsals
(Source: http://www.google.co.th/imgres?imgurl=http://upload.wikimedia.org/wikipedia/commons/7/7b/Human_skeleton_back_no-text_no-color.svg&imgrefurl=http://commons.wikimedia.org/wiki/File:Human_skeleton_back_no-text_no-color.svg&h=806&w=343&sz=509&tbnid=gzbQQhYAQG4EGM:&tbnh=90&tbnw=38&
zoom=1&usg=__Y7xgGnBV4RWW_jgmX_mbyJBXTds%3D&docid=ex25uvFx74LdVM&sa=X&ei=ZqwWU-zvC-20iQeFpoG4CA&ved=0CD4Q9QEwBA retrieved 05/03/2014)

 

7.1.3 The integumentary system