Vertebral column means spine. The spine is formed by 33 vertebrae along the midline on the human surface. Vertebrae are joined by cartilage called symphysis to form the spine. Intervertebral foramen is on either side of the junction of two vertebrae. The average length of the spine is 70 cm in males and 60 cm in females. There are 5 types of vertebrae in the spine.

Vertebral column means spine. The spine is formed by 33 vertebrae along the midline on the human surface. Vertebrae are joined by cartilage called symphysis to form the spine. Intervertebral foramen is on either side of the junction of two vertebrae. The average length of the spine is 70 cm in males and 60 cm in females. There are 5 types of vertebrae in the spine.
1. Cervical vertebrae: its number is 7. The first vertebra is called the atlas and the second vertebra is called the axis. The remaining 5 are ideal vertebrae.
2. Thoracic vertebrae: Its number is 12. Each vertebra has facets called capitulum and tuberculum
3. Lumber vertebrae: 5 in number. Their transverse processes are massive.
4. Sacral vertebrae: their number is 5. They join at 26 to form the sacrum. It has 4 pairs of 8 pairs of sacrum holes.
5. Coccygeal vertebrae: Their number is 4. It has 2 articulated cornua on its surface.

The U-shaped bone between the lower jaw and the larynx is called the hyoid. It consists of a body stem and 4 cornua. Its middle part is called body or hyoid body. There are two small cornua on either side of the body and two large cornua on the back.

Stepis looks triangular or like a horse’s stirrup. It is the smallest bone in the human body. One end is attached to the incus and the other end to the fenestra ovalis.

It looks like anvil. One end is attached to the malleus and the other end to the stapes.

It looks like a hammer. One end is attached to the tympanic membrane and the other end to the incus.

There are 3 small bones in the middle ear. These are-
(i) Malleus: It looks like a hammer. One end is attached to the tympanic membrane and the other end to the incus.
(ii) Incus : It looks like anvil. One end is attached to the malleus and the other end to the stapes.
(iii) Stepis: Stepis looks triangular or like a horse’s stirrup. It is the smallest bone in the human body. One end is attached to the incus and the other end to the fenestra ovalis.

Mandible is the lower jaw. It looks U shaped. It consists of a trunk and 2 branches. It has two amplifiers. Coronoid and condyloid.

The upper jaw consists of two equal maxillae. Right and left maxilla. It has four amplifiers. These are – zygomatic, palatine, frontal and alveolar.

It is a quadrangular bone. It consists of an elevated part called the zygomatic arch.