Thoracic Cage And Ribs Flashcards
What does the thorax consist of
External musculoskeletal cage
Thoracic wall
Internal cavity (contains hearts lungs etc)
What is inferior of the thorax
Separated from the diaphragm by the abdominal cavity
What does the thoracic wall also provide protection for
Some abdominal viscera -
Liver, stomach and spleen on the left and The kidneys
What are the boundaries of the thorax
Superior - thoracic inlet
Inferior - diaphragm
Anterior - sternum, ribs and costal cartilages
Posterior - 12 thoracic vertebra and posterior ribs
Laterally - outer parts of ribs
What are the two joints that make up the posterior articulations involving the ribs and thoracic vertebra
Costovertebral joint - synovial plane joint
Costotransverse joint - synovial plane joint
What is the structure/articulating surfaces of the costovertebral joints
Each ribs articulates with its nunmerically corresponding vertebra
Ribs 2-9 also articulate with the body of the vertebra above
Joint occurs between the head of the rib and vertebral bodies of 2 vertebra and the disc between them
What are the articulating surfaces of the costotransverse joints
Between facet on the tubercle on ribs 1-10 and the transverse processes of T1-10
What is the normal structure of a rib
Head that has 2 articular facets
Neck
Tubercle
Body that curves at costal angle
How do the first 1-6 rib facets differentiate with the lower ribs 7-10 on the posterior ribs
1-6 Attach independently to sternum
7-10 attach to costal cartilages superior to them
What are the functional properties of costal cartilages at the end of ribs
They provide a flexible attachment of the anterior end of ribs to the sternum which may undergo slight bending and twisting movements that facilitate widening of the thorcacic diameters in breathing
What are the anterior articulations involving the ribs
Vertebrosternal ribs 1-7
Vertebrochondral ribs 8-10
Vertberal floating ribs 11-12
Sternum
Describe the vertebrosternal ribs and their joints
These are true ribs
That attach via their costal cartilage
The 7 joints are sternocostal joints which are synovial plane joints capable of limited gliding movements only
Describe vertbrochondral ribs and their attachments
These ribs don’t attach directly to sternum but their costal cartilages attach to each other via the interchondral joints - synovial joints with limited gliding movements
Describe the vertebral floating ribs
Ribs 11,12
They end on costal cartilage which is not attached but free floating
Describe the sternum bone
What’s its 3 sections
A flat bone
Contains red bone marrow with
important haemopoietic function
Manubrium
Body
Xiphoid
