Vertebral Column and bony thorax Vertebral Column and
Vertebral Column and bony thorax
Vertebral Column and bony thorax • Formed from 34 -56 bones in the different adult animals • Extends from skull to pelvis • Transmits weight of trunk to the lower limbs • Surrounds and protects the spinal cord
Vertebral Column 1 - Cervical Vertebrae 2 - Thoracic Vertebrae V 3 - Lumbar Vertebrae 4 - Sacrum 5 - Coccyx (Caudal)
Typical Vertebrae: Consists of: 1 - Body (1) 2 - A vertebral arch - right and left Pedicles and Lamiae 3 - Transverse process (7) 4 - Spinous process (9) 5 - Articular process (5)
Cervical Vertebrae n. Seven cervical vertebrae (C 1 – C 7) – smallest and lightest vertebrae • C 3 – C 7 are typical cervical vertebrae • Body is small, wider side to side • Spinous processes - short and bifid (except C 7) • Vertebral foramen - large and triangular • Transverse processes- contain transverse foramina
Atlas – C 1 • Lacks a body and spinous process • No intervertebral disc between C 1 and C 2 • Supports the skull –Cranial articular facets receive the occipital condyles (Atlanto-occipital Joint)
The Axis - C 2 -The most prominent feature is ridge like spinous process - Cranially the body project peg like eminence (the dens)
Vertebrae (T 1 – T 13) n. All articulate with ribs • Spinous process- long, sharp, projects caudally • The spine of 11 th vertebrae is perpendicular (anticlinal). • 12 th and 13 th process project cranially • Vertebral Foramen - circular • Each side of the body bears demifacets articulation with ribs for
Lumbar Vertebrae (L 1 – L 5) n. Body– large, kidney shaped • Transverse processes are thin and tapered • Spinous processes are short, thick, blunt, and point caudally
Sacrum (S 1 – S 3) • Formed from 3 fused vertebrae
Coccyx (Caudal): • Is the "tailbone" • Small, triangular bone • Formed from 15 -20 vertebrae • Offers only slight support to pelvic organs
• Cushion-like pads between vertebrae • Nucleus pulposus – gives the disc its elasticity and compressibility • Annulus fibrosis – strong outer ring of fibrocartilage which surrounds the nucleus pulposus and limits expansion
Bony Thorax n. Forms the framework of the chest • Components of the bony thorax • Thoracic vertebrae – dorsally • Ribs – laterally • Sternum and costal cartilage – ventrally • Functions • Protects thoracic organs • Supports shoulder girdle and upper limbs • Provides attachment sites for muscles
Sternum • Composed form eight unpaired segments, the sternbrae. • Joined by intersternebral cartilages –Manubrium – 1 st sternbra –Xiphoid process – last sternbra
Ribs • 13 pairs, form the sides of the thoracic cage • All ribs attach to vertebral column dorsally • True ribs - superior nine pairs of ribs which attach directly to sternum by costal cartilage • False ribs – remaining 3 pairs of ribs which attach indirectly to the sternum • Float ribs-rib#13
- Structure • Shaft –bulk of the rib • Head – dorsally most end • Neck – constricted portion of head beyond head • Tubercle – articulates with transverse process of the thoracic vertebrae
- Slides: 27