Chapter 12 Axial Skeleton.pptx

AHS 101 Anatomy and Physiology Chapter 12: Axial Skeleton The Skeletal System - Introduction Skeletal tissues form bones Bones are the organs of the skeletal system There are 206 (+)...

AHS 101 Anatomy and Physiology Chapter 12: Axial Skeleton The Skeletal System - Introduction Skeletal tissues form bones Bones are the organs of the skeletal system There are 206 (+) bones in the human skeletal system See Figure in Textbook Divisions of the Skeleton – See Figure in Textbook Axial skeleton  Skull  Hyoid  Spine  Thorax Appendicular skeleton  Upper extremities, including shoulder girdle  Lower extremities, including hip girdle Divisions of the Skeleton – Axial - Skull The skull is made up of 28 bones. Most are categorized as either cranial bones or facial bones: Cranial bones (8) – note location and sutures 1. Frontal (1) 2. Parietal (2) 3. Temporal (2) 4. Occipital (1) – forms a moveable joint with C1 5. Sphenoid (1) 6. Ethmoid (1) Please refer to related pages in textbook Divisions of the Skeleton – Axial - Skullbones (14) – note location and sutures Facial 1. Maxilla (2) 2. Mandible (1) – largest/strongest facial bone; forms only moveable joint of the skull (w/temporal) 3. Zygomatic (2) – shapes cheeks 4. Nasal (2) 5. Lacrimal (2) – contains groove for tear duct 6. Palantine (2) 7. Inferior nasal conchae (2) 8. Vomer (1) Please refer to the tables and diagrams in textbook Divisions of the Skeleton – Axial - Skull The remaining 6 bones are ear bones: Malleus/hammer (2 – one in each ear) Incus/anvil (2 – one in each ear) Stapes/stirrup (2 – one in each ear) Summary: 8 Cranial + 14 Facial + 6 Ear = 28 skull bones total Please refer to the tables and diagrams in textbook Divisions of the Skeleton – Axial - Skull spaces/cavities/caverns in the bones of the Numerous skull = sinuses; named for the bones that contain them (See Figure in textbook) Divisions of the Skeleton – Axial - Skull The fetal skull – See Figure in textbook Has unique anatomical features that aren’t seen in the adult skull 4 soft spots, referred to as fontanels – Allow skull to be ‘flexible’ during Divisions of the Skeleton – Axial- Hyoid Hyoid bone See Figure in textbook U-shaped bone located just above the larynx and below the mandible Suspended from the styloid processes of the temporal bone Only bone in the body that doesn’t articulate with any other bones Tongue movement & swallowing Attached to muscles of the tongue & floor of the mouth Divisions of the Skeleton – 24 vertebrae Axial - Spine  Cervical (7)  Thoracic (12)  Lumbar (5) + Sacrum + Coccyx (tail bone) Curvature gives strength to support body allowing us to stand and walk (See Figure in textbook) Divisions of the Skeleton – Axial - Spine Vertebrae (see Figure in textbook)  Stacked in such a way to give spine flexibility and strength  The various parts of the vertebrae play an important role in controlling the movement of the spine See Figures in Textbook Divisions of the Skeleton – Axial - Spine – some characteristics (See Figure in Vertebrae textbook)  All have similar features, except C1  All have a foramen  C2 has an upward projection (dens) to allow rotation of the head  C7 has a long, blunt spinous process (find it!)  Vertebrae articulate with each other  Thoracic vertebrae articulate with the ribs  As a whole, the vertebral column articulates with the head, ribs, iliac bones Divisions of the Skeleton–Axial - Thorax Thorax = vertebral column + sternum + ribs See Figure in Textbook Divisions of Skeleton – Axial - Thorax Thorax -Sternum See Figure in Textbook  ‘dagger’ shaped  middle of chest  3 parts: 1. Manubrium 2. Body 3. Xiphoid process  Manubrium articulates with clavicle & 1st rib  Next 9 ribs joined to its body directly or indirectly via costal cartilage Divisions of the Skeleton - Axial - Thorax– Ribs (12 pairs) Thorax  each pair attach posteriorly to a thoracic vertebrae  all except the lower 2 pairs also attach anteriorly to sternum by costal cartilage  8th, 9th & 10th pairs attach to the cartilage of the 7th ribs (‘false ribs’)  11th & 12th pairs don’t attach to any costal cartilage (‘floating ribs’)