Anatomy Exam 4 - Thorax 1A

Front 1

Medial Cavity of Thorax

Back 1

-Mediastinum

Front 2

Lateral Cavity of Thorax

Back 2

-Lungs & Plurae

Front 3

Thoracic Inlet

Back 3

-Clinically called "outlet"
-Posterior --> 1st Thoracic Vertebrae
-Lateral --> medial border of rib 1
-Anterior --> superior border of manubrium

Front 4

Thoracic Outlet

Back 4

-covered by diaphragm
-Posterior --> 12th thoracic vertebra
-Lateral --> curve of costal margin
-Anterior --> Xiphosternal Joint

Front 5

Thoracic Portion of Vertebral Column

Back 5

-Concave forwarrd
-12 Vertebrae

Front 6

Typical Thoracic Vertebra

Back 6

-Body is medium sized & heart-shaped
-Vertebral foramen is small & circular
-Spines are long & point inferiorly
-Costal Facets on lateral aspects of body (for articulation with heads of ribs)
-Costal Facets on transverse processes (for articulation with tubercles of ribs)

Front 7

Sternum

Back 7

-Flat bone with 3 parts
1) Manubrium
2) Body
3) Xiphoid Process

Front 8

Manubrium

Back 8

-triangular
-articulates with clavicles & 1st and upper part of 2nd costal cartilage

Front 9

Sternum (Body)

Back 9

-Lateral border is notched for articulation with the lower part of the 2nd-7th costal cartilage

Front 10

Xiphoid Process

Back 10

-smallest part of sternum
-inferior portion

Front 11

Costal Cartilage

Back 11

-Bars of hyaline cartilage
-Connect upper 7 ribs directly to the lateral edge of the sternum = true ribs
-Connect ribs 8-10 to the 7th costal cartilage = false ribs
-Cartilage of ribs 11-12 end in abdominal musculature = floating ribs

Front 12

True Ribs

Back 12

-Ribs 1-7
-articulate directly with sternum through costal cartilage with same numbers

Front 13

False Ribs

Back 13

-Ribs 8-10
-Don't directly articulate with sternum

Front 14

Floating Ribs

Back 14

-Ribs 11-12
-Don't have costal cartilage

Front 15

Cervical Rib

Back 15

-An extra rib above Rib 1
-Found in 0.5% of the population unilaterally
-Found bilaterally in half of those that have cervical ribs

Front 16

Sternal Angle of Louis

Back 16

-Joint between manubirum & sternum
-Located at T4 level
-Correlates with 2nd rib

Front 17

Ribs

Back 17

-12 Pairs
-Each connected posteriorly to the thoracic vertebrae
-1-7 --> true ribs
-8-10 --> false ribs
-11-12 --> floating ribs

Front 18

Head of Rib (articulation)

Back 18

-head of rib articulates with Thoracic vertebrae of same number and one above it
-Ex. 6th rib articulates with T6 & T5

Front 19

Costal Groove

Back 19

-Vasculature & Nerves run in costal groove
-Veins, Arteries, Nerves (from superior to inferior)

Front 20

Intercostal Spaces

Back 20

-each space includes 3 muscles of respiration and a neurovascular bundle

Front 21

External Intercostal Muscle

Back 21

-Fibers pass inferior & anterior ("hands in pocket")
-Run from inferior border of a rib to superior border of rib below it
-Extend from vertebrae (posterior) to the costo-chondral junction (anterior)
-Muscle on posterior side --> turns into anterior (external) intercostal membrane anteriorly

Front 22

Internal Intercostal Muscle

Back 22

-fibers run perpendicular to external intercostal muscle fibers (perpendicular to "hands in pocket" orientation)
-Fibers pass inferior & posterior from the sternum to the angles of the ribs
-Muscle becomes posterior (internal) intercostal membrane posteriorly

Front 23

Innermost Intercostal Muscle

Back 23

-separated from the internal intercostal muscles by the intercostal nerves & vessels
-Veins arteries & nerves run between innermost intercostal & internal intercostal mm.

Front 24

Collateral Vessels

Back 24

-less important and smaller than vessels & nerves that run in costal grooves

Front 25

Subcostal Muscle

Back 25

-similar to innermost intercostal muscle, but traverses 2-3 ribs
-posterior rib cage

Front 26

Traversus Thoracis

Back 26

-crosses more than one intercostal space
-thin muscle arising from xiphoid process and inferior part of body of the sternum to insert on the 2nd to 6th costal cartilage

Front 27

Levatores Costarum Muscles

Back 27

-12 fan shaped muscles arising from the transverse processes of C7 to T11 vertebrae
-Insert inferiorly on ribs
-Raise ribs