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A Handbook of Biology

B. VËRTËBRÅL ÇØLÜMÑ



Formed

of

26

vertebrae:

Includes Cervical vertebrae

(7),

Thoracic

vertebrae

(12), Lumbar vertebrae (5),

Sacral

vertebrae

(1-fused)

and

Coccygeal

vertebrae

(1-fused).



Skull

articulates

with

first

vertebra

(atlas)

with

the

help of 2 occipital condyles

(dicondylic skull).



Vertebra has a central hollow

portion (neural canal) through

which the spinal cord passes.



The vertebral column protects the spinal cord, supports the head and

serves as the point of attachment for the ribs and musculature of the

back.

Ç. STËRÑÜM ØR BRËÅST BØÑË (1)



Flat bone on the ventral midline of thorax.

D. RÏBS (12 PÅÏRS)



True ribs (first 7 pairs):

They are attached to

thoracic vertebrae and

ventrally connected to

sternum with the help

of

hyaline

cartilage.

(AIPMT 2000)



V e r t e b r o c h o n d r a l

(false) ribs (8th, 9th &

10th pairs): They do not

articulate directly with

the sternum but join the 7th rib with the help of hyaline cartilage.



Floating ribs (11th & 12th pairs): They are not connected ventrally (no

connection with sternum or other ribs).



Each rib has 2 articulation surfaces on its dorsal end and is hence called

bicephalic.

Cervical Vertebra

Thoracic Vertebra

Lumbar Vertebra

Sacral Vertebra

Coccygeal Vertebra

Clavicle

True ribs

(1-7)

False ribs

(8-10)

Floating ribs

(11 and 12)

Lumbar vertebra

Costal cartilage

Sternum

Manubrium

Body

Xiphoid process

Jugular notch

Thoracic vertebra