Thoracic Cage Flashcards
Thoracic cage protects
Chief organs of circulation and respiration
Formation of thoracic cage
Anterior-sternum
Posterior-12 thoracic vertebrae and intervertebral disc in bw
Each side-ribs and their cartilage
Inlet of thorax
Kidney shaped
Anteroposterior diameter less than transverse diameter
Boundaries of inlet
Anterior-upper border of manubrium of sternum
Posterior-1st thoracic vertebrae
On each side-1st rib and its cartilage
Outlet
Broad end of thorax surrounds the user part of abdominal cavity separated by/excluding diaphragm
Costal margi formed by
Cartilage of 7-10 ribs and 11-12 ribs
Boundaries of outlet
Anterior-infrasternal angle bw the 2costal margins
Posterior-12th thoracic vertebrae on each side
Ribs
12 pairs
Greater part of thoracic skeleton
Flat,ribbon like,bony arches,one below another
Gap bw adjacent intercostal spaces
Classification
True or verteberosternal-1 to 7(cartilage to sterum
False or vertebrochondral-8 to 10(joins to higher cartilage next to them
Floating or vertebral-11th and 12th(free anterior ends
Typical-3 to9
Atypical-1,2,10,11,12
Typical ribs
Anterior end-concave depression
Shaft-flattened(inner and outer)
Posterior end-head ,neck and tubercle
First rib
Shortest,broadest,most curved
Shaft flattened
Anterior end - larger and thicker
Articulate with 1st costal cartilage
Small,round head
Sternum
Flat bone
Forming anterior median part of thoracic skeleton
T shaped vertical bone
Dagger or short sword
Parts of sternum
Manubrium-upper
Body
Xiphoid process-lowest tapering part
Leng-15 -17cm
Manubrium
Quadrilateral
Thickest and strongest part
2 surfaces-anterior and Posterior
4 borders -superior ,inferior, 2 lateral
Superior and inferior border of manubrium
Superior
Thick,round,concave
Suprasternal
and clavicular notch(articulate with medial end of clavicle to form sternoclavicular)
Inferior
2nd cartilaginous joint with body of sternum
Body of sternum
Longer,narrower and thinner than manubrium
Lateral borders form synovial joints with 2nd 6th costal cartilage and upper half of 7th costal cartilage
upper end articulate with manubrium
Lower end with xiphisternum
Xiphoid process
Smallest part
Varies greatly in size and shape
May show foramen
Vertebral column
Main part of axial skeleton
33 bones(intervertebral disc bw)
Function s of vertebral column
Support the body weight
Locomotion
Protection of nerve cordsandnerve roots
Transmit the body weight to ground
33vertebrae
C7 T12 L5 S5 C4
Cervical
Thoracic
Lumbar
Sacral-fused to form saccrum
Coccygeal-fused- coocyx
Length of thespine
Males-28inches
Females-24 inches
Contribution of the length of vertebrae
Vertebrae 4/5
Intervertebral disc1/5
