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Sternum Bone Anatomy

Introduction to Sternum Bone Anatomy

  • image descriptionThe sternum (pronounced ˈstər-nəm) is located in the center of the anterior thoracic wall and is also known as the breastbone.
  • It consists of three segments, the manubrium, body, and xiphoid process. The segments fuse to form a long, flat bone. The sternum articulates with the clavicles and costal cartilages of the ribs. It also covers and protects the heart.
Sternum Bone - Overview
Sternum Bone - Labeled
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Markings of the Sternum:

Anterior view:

  1. image descriptionManubrium (\mə-ˈn(y)ü-brē-əm\ L., handle) – triangular-shaped, superior portion of the sternum.
Sternum Bone - Anterior View
Manubrium - Sternum Bone - Anterior View
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  1. image descriptionClavicular notches – depressions on the superolateral borders of the manubrium. They serve as articulation points for the clavicles.
Sternum Bone - Anterior View
Clavicular notch - Sternum Bone - Anterior View
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  1. image descriptionJugular (suprasternal) notch –  depression between the two clavicular notches.
Sternum Bone - Anterior View
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  1.  image descriptionBody or gladiolu (L. gladiolus, little sword) – middle segment of the sternum.
Sternum Bone - Anterior View
Body or gladiolus - Sternum Bone - Anterior View
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  1. image descriptionCostal notches – 7 small depressions located on each side of the sternum.  They serve as areas of attachment for the costal cartilages of the first 7 ribs.
Sternum Bone - Anterior View
Costal notches - Sternum Bone - Anterior View
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  1. image descriptionXiphoid process (\ˈzī-ˌfoid\ Gr., xiphous sword + eidos, form) – inferior segment of the sternum. The xiphoid process is composed of cartilage early in life and typically converts to bone by age 30-40. It serves as an area of attachment for the rectus abdominis muscle.
Sternum Bone - Anterior View
Xiphoid process - Sternum Bone - Anterior View
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Lateral view:

  1. image descriptionManubrium – triangular-shaped, superior portion of the sternum.
Sternal angle - Sternum Bone - Lateral View
Manubrium - Sternum Bone - Lateral View
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  1. image descriptionClavicular notches – depressions on the superolateral borders of the manubrium. They serve as an articulation points for the clavicle.
Sternal angle - Sternum Bone - Lateral View
Clavicular notch - Sternum Bone - Lateral View
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  1. image descriptionSternal angle – slight, anterior protrusion formed at the junction of the manubrium and body. Palpation of this bony landmark indicates the relative position of the second ribs.
Sternal angle - Sternum Bone - Lateral View
Sternal angle - Sternum Bone - Lateral View
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  1. image descriptionBody or gladiolus (L. gladiolus, little sword) – middle segment of the sternum.
Sternal angle - Sternum Bone - Lateral View
Body or gladioulus - Sternum Bone - Lateral View
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  1. image descriptionCostal notches – 7 small depressions located on each side of the sternum.  They serve as areas of attachment for the costal cartilages of the first 7 ribs.
Sternal angle - Sternum Bone - Lateral View
Costal notches - Sternum Bone - Lateral View
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  1. image descriptionXiphoid process (\ˈzī-ˌfoid\ Gr., xiphous sword + eidos, form) – inferior segment of the sternum. The xiphoid process is composed of cartilage early in life and typically converts to bone by age 30-40. It serves as an area of attachment for the rectus abdominis muscle.
Sternal angle - Sternum Bone - Lateral View
Xiphoid process - Sternum Bone - Lateral View
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Test yourself:

Anterior view: [image descriptionShow/image descriptionHide]

Sternum Bone - Anterior View - Test yourself
Sternum Bone - Anterior View - Test yourself - Answers
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Lateral view: [image descriptionShow/image descriptionHide]

Sternum Bone - Lateral View - Test yourself
Sternum Bone - Lateral View - Test yourself - Answers
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