Thorax Flashcards
what is the shape of the thoracic cavity?
cone that is narrow superiorly and increasing inferiorly with a thin wall
what is the thoracic cage supported by?
sternum + thoracic vertebrae
what are the 3 divisions of the thoracic cavity?
- mediastinum: houses thoracic viscera
- right pulmonary cavity
- left pulmonary cavity
Fx’s of the thoracic wall
- prtect organs
- resist pressure from respiration
- provide attachment + support for upper limbs, muscles, abdomen, neck
the thoracic skeleton consists of?
- 12 pairs of ribs + cartilages
- 12 thoracic vertebrae
- IV discs
features of ribs
lightweight, resilient, inner bone marrow is spongy (hempoietic) and forms blood cells
what are true ribs?
vertebrosternal, attach to sternum with own costal cartilages (ribs 1-7)
what are false ribs?
vertebrochondral, cartilages connected to rib above (ribs 8-10)
what are floating ribs?
vertebral, cartilage ends in abdominal musculature (ribs 10-12)
What are the 4 typical ribs parts?
Head: 2 crests to attach to superior vertebrae and one for corresponding vertebrae
Neck: connect head with body
Tubercle: found at junction of body and neck
Body: thin, flat, protects nerves and vessels
which ribs are the atypical ribs?
rib 1: broadest, shortest, facet on head for articulation with T1
rib 2: rough area on upper surface is tuberosity for serratus anterior
ribs 10-12: facet articulating with single vertebra
ribs 11-12: short with no neck or tubercle
what is the fx of costal cartilage?
prolong ribs, give elasticity to thoracic wall
what is the fx of intercostal spaces?
separate ribs + costal cartilages
what are thoracic vertebrae?
bilateral costal facets with inferior + superior pairs that articulate with head of ribs
have demifacets (T2-T9)
what do costal facets articulate with?
tubercle of rib
what are spinous processes?
long slanting process that prevents sharp objects from entering vertebral canal to injure spinal cord
they overlap lower vertebra
what limits movement btwn vertebra?
rib cage
what does the sternum protect?
mediastinal viscera + heart
what are the 3 parts of the sternum
- menubrium
- body
- xiphoid process
what happens to the sternum with age?
synchondroses: cartilaginous joints ossify in adulthood
what are the characteristics of the menubrium?
Jugular notch: concave center which is easily palpated
Clavicular notch create sternoclavicular joints
Synchondrosis of 1st rib
Manubrialsternal angle: different angle connecting manubrium to sternum
what are the characteristics of the body of sternum?
Costal notches creates joints for ribs
Transverse ridges: lines of fusion of sternums 4 original separate sternebrae
what are the characteristics of the xiphoid process?
Cartilaginous in young, ossified in adults over 40
what binds the superior aperture of thorax?
posterior: T1
lateral: 1st ribs + their costal cartilages
anterior: superior border of manubrium
what binds the inferior aperture of thorax?
posterior: T12
posterolateral: 11-12th ribs
anterolateral: 7-10th ribs costal cartilage
anterior: xiphisternal joint
what separates the inferior aperture from the abdomen?
the diaphragm
