skeletal system

 

HUMAN SKELETON - 206 bones

Axial-80                                                            Appendicular-126

APPENDICULAR SKELETON - 126 BONES

LIMB BONES - 120 GIRDLE BONES - 06

Fore limb Bones - 60 Hind limb Bones - 60 Pectoral Girdle - 4 Pelvic Girdle - 2

Humerus - 1× 2 Femur - 1× 2 Scapula - 1× 2

Radius - 1× 2 Patella - 1× 2 Clavicle - 1× 2

Ulna - 1× 2 Tibia - 1× 2 (is formed by 2 hip bones
and each hip bone is  formed by fusion of 3 hip
bones ilium, ischium and pubis)

Carpals - 8× 2 Fibula - 1× 2

Metacarpals - 5× 2 Tarsals - 7× 2

Phalanges - 14× 2 Metatarsals - 5× 2

Phalanges - 14× 2

AXIAL SKELETON - 80 BONES

 

SKULL SKELETON- 29

SKULL BONES - 22

Cranial - 8

Facial  

Frontal - 1

Maxilla - 2

Parietal - 2

Palatine -2

Temporal – 2

Zygomatic - 2

Occipital - 1

Nasal – 2

Ethmoid - 1

Lacrymal – 2

Sphenoid Inferior -1

Turbinals - 2

Mandible – 1

Vomer -1

STERNUM – 01

RIBS - 24

False – 10

True – 14

VERTEBRAL COLUMN - 26

Cervical – 7

Thoracic – 12

Lumbar – 5

Sacral - 5

Coccygeal – 4

ASSOCIATED SKULL BONES – 07

Hyoid Bone - 1        Ear ossicles - 2x3 (Malleus, Incus, Stapes)

Phalangeal formula is 23333
Bones formed by ossification of tendons are called sessamoid bones.
Longest and strongest bone of human body is femur.
Smallest bone of human body is stapes.
Rabbit - axial skeleton 132 bones , appendicular skeleton 128 bones 

Two types of skeleton are endoskeleton and exoskeleton.
Exoskeleton develops from epidermis e.g.nails, horns, hooves, feathers, scales, claws etc.
Exoskeleton is ectodermal in origin and nonliving.
Endoskeleton is mesodermal in origin and is living in nature

Axial skeleton comprises 80 bones distributed along the main axis of the body.
The skull, vertebral column, sternum and ribs constitute axial skeleton.

SKULL
The skull is composed of two sets of bones - cranial and facial, that totals to 22 bones.
Cranial bones are 8 in number (frontal-1, parietal-2, temporal-2, occipital-1, ethmoid-1 and
sphenoid-1). They form the hard protective outer covering, cranium for the brain.
Cavity of sphenoid bone is called sella turcica in which pituitary gland is present

 VERTEBRAL COLUMN
Our vertebral column is formed by 26 serially arranged units called vertebrae and is dorsally placed. It extends
from the base of the skull and constitutes the main framework of the trunk. Each vertebra has a central hollow
portion (neural canal) through which the spinal cord passes.
The vertebral column is differentiated into cervical (7), thoracic (12), lumbar (5), sacral (1-fused) and coccygeal
(1-fused) regions starting from the skull. The number of cervical vertebrae are seven in almost all mammals
including human beings.

JOINTS

1 BW. ACROMIAN PROCESS - CLAVICLE ACROMIOCLAVICULAR JOINT

2 BW. STERNUM - CLAVICLE STERNOCLAVICULAR JOINT

3 HEAD OF HUMERUS AND GLENOID BALL AND SOCKET JOINT

CAVITY OF SCAPULA

4 HUMERUS - RADIUS -ULNA HINGE JOINT

5 RADIUS - ULNA RADIOULNAR(PIVOT)(SYNDESMOSIS)

6 BW. CARPALS GLIDING JOINT

7 BW. CARPALS AND METACARPAL SADDLE JOINT

OF THUMB

8 BW. PHALANGES HINGE JOINTS

9 ACETABULUM OF HIP BONE AND BALL AND SOCKET JOINT

HEAD OF FEMUR

10 KNEE JOINT HINGE JOINT

11 TIBIA - FIBULA TIBIO FIBULAR

12 ANKLE JOINT HINGE JOINT

13 BW. PHALANGES HINGE JOINTS

14 BW. TARSALS GLIDING JOINTS

15 PUBIS - PUBIS PUBIS SYMPHYSIS

16 BW. CRANIAL BONES SUTURES

17 BW. ATLAS AND AXIS PIVOT JOINT

18 TEETH IN SOCKETS GOMPHOSIS

19 INTERVERTEBRAL DISCS CARTILAGENOUS

20 BW. STERNUM AND RIBS CARTILAGENOUS