BONE IN HUMAN BODY

Bones in Human Body | Function of Bones |Classification bones

Bones in Human Body

Bones is 1/3 connective tissue. other 2/3 content have calcium salt.

HOW MANY BONES IN HUMAN BODY ?

In adult there are 206 bones and in children or new born baby have nearly 300 bones.

Largest bone in human body is

FUNCTION OF BONE :-

– Shape and support to body, & resist any form of stress.

– Provide surface for attachment of muscle’s ,tendon, ligament.

– Serve as lever for muscular action.

– The skull, vertebral column ,thoracic cage, are protect brain, Spinal cord ,thoracic visceral respectively.

– Bone marrow manufactures the blood cell’s.

– Bones store 97% of body calcium and phosphorous.

– Bone marrow contain reticulo endothelial system which are phagocytic in nature and take part in immune response.

– Larger paranasal air sinus affect the timber of the voice and make skull light in weight.

CLASSIFICATION OF BONES :-

A) ACCORDING TO SHAPE

B) DEVELOPMENTAL CLASSIFICATION

C) REGIONAL CLASSIFICATION

D) STRUCTURAL CLASSIFICATION

A) ACCORDING TO SHAPE :-

1. Long bone :

(a) typical long bones like humerus, radius, ulna, femur, tibia and fibula

(b) miniature long bones have only one epiphysis like metacarpals, metatarsals and phalanges.

2. Short bones :

Their shape is like cuboid, cuneiform, trapezoid, or scaphoid. Examples: tarsal and carpal bones

3. Flat bones :

Examples: bones in the vault of the skull, ribs, sternum and scapula

4. Irregular bones:

Examples: vertebra, hip bone, and bones in the base of the skull

5. Pneumatic bones:

Examples: maxilla, sphenoid, ethmoid, etc.

6. Sesamoid bones:

Examples: patella, pisiform, fabella, etc.

Functions of the sesamoid bones is

(a) resist pressure

(b) minimise friction
(c) alter direction of pull of the muscle
(d) maintain local circulation

7. Accessory (supernumerary) bones :-

Examples: sutural bones, lateral tubercle of talus, os vesalianum (tuberosity of 5th metatarsal), etc.

B) DEVELOPMENTAL CLASSIFICATION :-

1. Membrane (dermal) bones :-

This type of bone ossify in membrane (intramembranous or mesenchymal ossification)
Examples: bones of the vault of skull and facial bones.

2. Cartilaginous bones :-

This type of bone ossify in cartilage
Examples: bones of limbs, vertebral column and thoracic cage.

3. Membrano-cartilaginous bones :-

This type of bone ossify partly in membrane and partly in cartilage.
Examples: clavicle, mandible, occipital, temporal, sphenoid.

4. Somatic bones:

Most of the bones are somatic.

5. Visceral bones:

This type of bone develop from pharyngeal arches.
Examples are hyoid bones, part of mandible and ear ossicles

C) REGIONAL CLASSIFICATION or DIVISION OF BONE :-

There are Two Division of skeleton in body

1) axial and 2) Appendicular

Bones in Human Body

1) AXIAL SKELETON (80 bones) :-

A) Skull type(28)

I) Crenial bone :-

Parietal (2)
Temporal (2)
Frontal (1)
Occipital (1)
Ethmoid (1)
Sphenoid (1)

II) Facial Bones :-

Maxilla (2)
Zygomatic (2)
Mandible (1)
Nasal (2)
Platine (2)
Inferior nasal concha (2)
Lacrimal (2)
Vomer (1)

III) oditory ossical

Mallus
Incus
Steps

IV) Hyoid bone

B) Vertebral column :-

Cervical vertebrae
Thoracic vertebrae
Lumbar vertebrae
Sacral vertebrae
Coccxy vertebrae

C) Thoracic cage

Sternum
Ribs

2) APPENDICULAR SKELETON SYSTEM (126) :-

A) Pectoral region

clavical (2)
scapula (2)

B) upper limb/ extremity :-

humerus (2)
radius (2)
ulna (2)
carpal (16)
metacarpal (10)
phalanges (28)

C) Pelvic girdle :-

Hip bone

D) Lower limb/extrmity :-

Femur (2)
tibia (2)
fibula (2)
patella (2)
tarsal (14)
meta tarsal (10)
phalanges (28)

D. STRUCTURAL CLASSIFICATION :-

1. Macroscopically, bone may be compact or cancellous

a. Compact bone

b. Cancellous or spongy or trabecular bone

2. Microscopically, this have five types

a. Lamellar bone :- compact or cancellous it composed of thin plates of bony tissue called lamellae.

b. Woven Bone :- only in fetal bone

c. Fibrous bone :- it is found in young foetal bones

d. Dentine :-

e. Cement :- teeth

LONGEST BONE IN HUMAN BODY

Femur is longest bone of human body. It situated in thigh area of lower limb. Avarage size of femur length is 26.74% of person’s Height. There are two femur bone in human body, Right & Left and femur is strongest bone body

SHORTEST BONE OF HUMAN BODY

There are 3 bone in ear mallelus, incus, stapes. Stapes is shortest bone in human body. Size lf Staees is 3 × 5 mm. Stapes bone also called stirrup. It situated in middle ear. It helps to conduct vibration in inner ear. Shape of stapes is stirrup-shaped