Question

Heaviest vertebrae in man is
A. Atlas
B. Axis
C. Lumbar
D. Thoracic

Answer 1

Hint: Humans have five body part vertebrae. they're the largest, strongest vertebrae; custom-made for attachment of back muscles \[{L_1} - {L_5}\]. The body part vertebrae support back muscles; permit forward and backward bending of spine.

Complete Answer:
- The class rachis consists of 5 morphologically differentiated teams of vertebrae: cervical, thoracic, lumbar, sacral and bone.
- The spinal column, additionally called the vertebral column, is that the central axis of the skeleton all told vertebrates. The spinal column provides attachments to muscles, supports the trunk, protects the medulla spinalis and nerve roots and is a website for sanguification.
- In humans, the back sometimes consists of thirty three vertebrae, placed nonparallel and connected by ligaments and discs. However, the quantity of vertebrae will vary between thirty two and thirty five.
- Sometimes there are seven cervical, twelve pectoral, 5 lumbar, five sacral and four caudal (coccygeal) vertebrae. In humans, the length of the back is seventy one cm in males and sixty one cm in females.
- The atlas is that the initial cervical (neck) bone that is simply below the head; it's named for Atlas, the Greek god United Nations agency supported the globe on his shoulders. The axis is that of the second cervical vertebra; it's what's referred to as the outgrowth concerning that the atlas rotates. It permits the pinnacle flip from aspect to aspect.
- The pectoral vertebrae area unit a gaggle of twelve little bones that type the os spine within the higher trunk. pectoral vertebrae are unit distinctive among the bones of the spine therein they're the sole vertebrae that support ribs and have overlapping acanthoid processes.

Note: Usually their square measures seven cervical, twelve pectoral, 5 lumbar, five sacral and four caudal (coccygeal) vertebrae. In humans, the length of the rachis is seventy one cm in males and sixty one cm in females.