My Lifestyle content choices: Tutorial | The Skeleton | by @gwillchrist

Skeleton can be defined as the structural frame which supports the body. There are several types of configurations, including the exoskeleton, which is the stable external shell of an organism, the endoskeleton, which forms the support structure inside the body, and the hydroskeleton, a flexible internal shell supported by fluid pressure. Invertebrates are creatures with a vertebral column, and their configurations are generally composed of bone and cartilage. Pets are creatures that warrant a vertebral column. The configurations of pets vary, including hard exoskeleton shells, plated endoskeletons, or spicules. Cartilage is a rigid connective towel that’s set up in the cadaverous systems of invertebrates and pets.

FUNCTIONS OF THE SKELETON

• Protection: It protect some vitals organs in the body e.g the skull protect, the brain, thoracic cage protect lungs and heart.

• Support: It provides support to some internal organs. It also gives forms and shape to the body.

• Locomotion: Skeleton provides points of attachment for muscles whose contractions bring about movement of the limbs.

• Production of red blood cells: This take place in the bone marrow of skeleton thus it serves as a reserve house for the supply of mineral salts for the body e.g calcium and phosphorus.

THE VERTEBRATE SKELETON

The endoskeleton of mammal consist of two parts.
Axial skeleton and appendicular skeleton:
The axial skeleton consist of the skull and the vertebral column (backbone).
The appendicular skeleton is made up of pectoral and pelvic girdles, the fore and hind limb bones. There are about two hundred and six bones in the human skeleton.

THE AXIAL SKELETON

The skull, which is one of the bones of the axial skeleton consist of three main regions:

• The cranium: The cranium (brain box) protects the brain.

• The facial skeletons: It supports the eyes, nose and muscles of cheek.

• The jaw: It is divided into upper jaw and lower jaw (mandible) and contain the teeth.

THE VERTEBRAL COLUMN

The vertebral column forms the backbone and protects the spinal cord. The vertebrate are held one to the other with ligament (in vertebral disc) between consecutives vertebrae. There are five different types of vertebrae in mammals: these are cervical, thoracic, lumbar, sacral and caudal vertebrae.

DISTINGUISHING FEATURES OF VERTEBRAE

1. Cervical vertebrae
   I. Short neural spine
   II. Two vertebral canals through which blood vessels of the neck pass
   III. Large neural canal
   IV. Small centrum

2. Atlas: (First cervical vertebrae)
   I. Large neural spine
   II. No centrum
   III. Strong, flat and broad transverse processes
   IV. Reduced neural spine

3. Axis: (second vertical vertebrae)
   I. Broad flat centrum
   II. Large and flattened neural spine
   III. Odontoid process fits into the neural canal
   IV. Small transverse process
   V. Flat cervical ribs

4. Thoracic vertebrae
   I. Large neural canal
   II. Neural spine is long slender pointing backwardly
   III. Well-developed transverse process
   IV. Small cylindrical centrum
   V. The tuberculum of the ribs articulates with the transverse process

5. Lumbar vertebrae
   I. Large thick (short) centrum
   II. Short and flat neural spine
   III. Long and short transverse process which points forwards and downwards
   IV. High neural arch with several projections

6. Sacral vertebrae
   I. Large centrum
   II. Reduced neural spine
   III. Narrow neural canal
   IV. Large fused vertebrae called sacrum

7. Caudal vertebrae
   I. Few processes and most have only a centrum
   II. In man, these bones are four vertebrae forming the coccyx

I invite @bela90 @oasiskp to join this interesting contest.