1. AXIAL SKELETON ax·i·al ˈ aksēəl/ adjective 1.of, forming, or relating to an axis.

2. The Skeleton Consists of: Bones, cartilage, joints, and ligaments Joints—also called articulations Is composed of 206 named bones grouped into two divisions Axial skeleton (80 bones) Skull, vertebral column, and thoracic cage Appendicular skeleton (126 bones) Upper and lower limbs

3. Figure 7.1a The human skeleton. Skull (ribs and sternum) Thoracic cage Vertebral column Cranium Facial bones Clavicle Scapula Sternum Rib Humerus Vertebra Radius Ulna Sacrum Phalanges Metacarpals Femur Patella Tibia Fibula Tarsals Metatarsals Phalanges Anterior view Carpals Cranium Clavicle Scapula Rib Humerus Vertebra Radius Ulna Carpals Phalanges Metacarpals Femur Tibia Fibula Posterior view Lower limb Bones of pelvic girdle Bones of pectoral girdle Upper limb

4. The Skull Is the body’s most complex bony structure Is formed by cranial and facial bones Bones of the cranium Enclose and protect the brain Provide attachment sites for some muscles of the head and neck

5. The Skull Facial bones Form framework of the face Form cavities for sense organs of sight, taste, and smell Provide openings for passage of air and food Hold the teeth in place Anchor muscles of the face

6. Coronal suture Squamous suture Bones of cranium Lambdoid suture Facial bones CRANIUM AND FACE

7. Anterior cranial fossa Middle cranial fossa Posterior cranial fossa Superior view of the cranial fossae Fossa – shallow basinlike depression in a bone, often serving as an articular surface. Brain sits within the cranial fossae

8. Lateral view of cranial fossae Cranial fossae Middle Cerebellum Temporal lobe of cerebrum Frontal lobe of cerebrum showing the contained brain regions Posterior Anterior The brain, sitting within the cranial fossae, occupies cranial cavity

9. Overview of Skull Geography The skull contains smaller CAVITIES: Middle and inner ear cavities—in lateral aspect of cranial base Nasal cavity—lies in and posterior to the nose Orbits—house the eyeballs Air-filled sinuses— mucosal-lined air cavities that lead to nasal cavity. The skull contains approximately 85 named OPENINGS: These are called: foramina, canals, and fissures They provide openings for the: Spinal cord Blood vessels serving the brain 12 pairs of cranial nerves

10. The Cranium Contains 8 bones: Paired bones include Temporal bones Parietal bones Unpaired bones include Frontal bone Occipital bone Sphenoid bone Ethmoid bone Parietal bone Coronal suture Occipital bone Temporal bone Squamous suture Lambdoid suture Zygomatic process Occipitomastoid suture External acoustic meatus Mastoid process Styloid process Condylar process Mandibular notch Mandibular ramus Mandibular angle Coronoid process Mental foramen Mandible Alveolar processes Maxilla Zygomatic bone Nasal bone Lacrimal fossa Lacrimal bone Ethmoid bone (greater wing) Sphenoid bone Frontal bone External anatomy of the right side of the skull

11. The cranium contains 4 sutures: Coronal suture Squamous suture Sagittal suture Lambdoid suture Parietal bone Coronal suture Occipital bone Temporal bone Squamous suture Lambdoid suture Zygomatic process Occipitomastoid suture External acoustic meatus Mastoid process Styloid process Condylar process Mandibular notch Mandibular ramus Mandibular angle Coronoid process Mental foramen Mandible Alveolar processes Maxilla Zygomatic bone Nasal bone Lacrimal fossa Lacrimal bone Ethmoid bone (greater wing) Sphenoid bone Frontal bone External anatomy of the right side of the skull

12. Figure 7.4a Lateral aspect of the skull. Parietal bone Coronal suture Occipital bone Temporal bone Squamous suture Lambdoid suture Zygomatic process Occipitomastoid suture External acoustic meatus Mastoid process Styloid process Condylar process Mandibular notch Mandibular ramus Mandibular angle Coronoid process Mental foramen Mandible Alveolar processes Maxilla Zygomatic bone Nasal bone Lacrimal fossa Lacrimal bone Ethmoid bone (greater wing) Sphenoid bone Frontal bone External anatomy of the right side of the skull

13. Frontal Bone Forms the forehead and roofs of orbits Supraorbital margin — superior margin of orbits Supraorbital foramen — passage for supraorbital nerve and artery Glabella —smooth part of frontal bone between superciliary arches ( ridges on the frontal bone above the eye sockets ) Frontal sinuses within frontal bone Parietal bone Squamous part of frontal bone Nasal bone Sphenoid bone (greater wing) Temporal bone Ethmoid bone Lacrimal bone Zygomatic bone Infraorbital foramen Maxilla Mandible Mental foramen Mental protuberance Inferior orbital fissure Middle nasal concha Perpendicular plate Vomer Optic canal Inferior nasal concha Ethmoid bone Superior orbital fissure Supraorbital margin Supraorbital foramen (notch) Frontonasal suture Glabella Frontal bone Anterior view of skull

14. Occipital Bone Features and structures Foramen magnum Occipital condyles Hypoglossal foramen Opening for hypoglossal nerve, one of 12 cranial nerves External occipital protuberance Superior nuchal* lines Inferior nuchal lines * nuchal is pronounced “newkal” Nuchal - of or relating to the back (nape) of neck. Nuchal lines are ridges on the back of the occipital bone Parietal bone Occipital bone Sagittal suture Sutural bone Lambdoid suture Superior nuchal line External occipital protuberance Inferior nuchal line External occipital crest Occipital condyle Occipitomastoid suture -- condyle – a round prominence at the end of a bone

15. Incisive fossa Intermaxillary suture Median palatine suture Infraorbital foramen Maxilla Sphenoid bone (greater wing) Pterygoid process Foramen ovale Foramen spinosum Foramen lacerum Carotid canal External acoustic meatus Stylomastoid foramen Jugular foramen Occipital condyle Inferior nuchal line Superior nuchal line Foramen magnum (palatine process) (horizontal plate) Palatine bone Maxilla Hard palate Zygomatic bone Vomer Temporal bone (zygomatic process) Mandibular fossa Styloid process External occipital crest Temporal bone (petrous part) Basilar part of the occipital bone Occipital bone External occipital protuberance Inferior view of the skull (mandible removed) Mastoid process FORAMEN MAGNUM

16. The temporal bone: External acoustic meatus Squamous part Zygomatic process Mandibular fossa Tympanic part Petrous part Mastoid process Styloid process Petrous - the hard dense portion of the temporal bone, containing the internal auditory organs; petrosal.

17. Parietal bone Coronal suture Occipital bone Temporal bone Squamous suture Lambdoid suture Zygomatic process Occipitomastoid suture External acoustic meatus Mastoid process Styloid process Condylar process Mandibular angle Mandibular ramus Mental foramen Mandible Alveolar processes Maxilla Zygomatic bone Nasal bone Lacrimal fossa Lacrimal bone Ethmoid bone (greater wing) Sphenoid bone Frontal bone Coronoid process Mandibular notch Temporal Bone The mastoid process Site for neck muscle attachment Contains air sinuses

18. The Sphenoid Bone called the “keystone of the cranium” because it articulates with all the cranial bones. Spans the width of the cranial floor Resembles a bat with its wings spread Consists of a body and three pairs of processes Contains five important openings (SEE NEXT)

19. The Sphenoid Bone Important landmarks Body Sella turcica Sphenoidal sinuses Greater wings Lesser wings Pterygoid processes Figure 7.10a The sphenoid bone. Optic canal Lesser wing Greater wing Sella turcica Body of sphenoid Superior view Foramen rotundum Foramen ovale Foramen spinosum Body of sphenoid Superior orbital fissure Pterygoid process Greater wing Posterior view Lesser wing

20. The Ethmoid Bone – irregular-shaped bone anterior to the sphenoid bone Lies between nasal and sphenoid bones Forms most of the medial bony region between the nasal cavity and orbits

21. The Ethmoid Bone Cribriform plate Where olfactory fibers pass from nasal cavity to brain through cribriform foramina Crista galli Attachment for dura mater Perpendicular plate Forms superior part of nasal septum Anterior view

22. Facial Bones Unpaired bones Mandible and vomer Paired bones Maxillae Zygomatic bones Nasal bones Lacrimal bones Palatine bones Inferior nasal conchae Parietal bone Squamous part of frontal bone Nasal bone Sphenoid bone (greater wing) Temporal bone Ethmoid bone Lacrimal bone Zygomatic bone Infraorbital foramen Maxilla Mandible Mental foramen Mental protuberance Inferior orbital fissure Middle nasal concha Perpendicular plate Vomer Optic canal Inferior nasal concha Ethmoid bone Superior orbital fissure Supraorbital margin Supraorbital foramen (notch) Frontonasal suture Glabella Frontal bone Anterior view of skull

23. Mandible: Lower jaw bone, the largest and strongest facial bone the only movable bone of the skull Composed of two main parts Horizontal body Two upright rami [ rami – an arm or branch of a bone] Major landmarks are shown in the figure: Coronoid process Mandibular foramen Alveolar process Mental foramen Body of mandible Mandibular fossa of temporal bone Temporomandibular joint Mandibular notch Condylar process Ramus of mandible Mandibular angle Mandible, right lateral view Coronoid process – site of muscle attachment Mental foramen transmits nerve to lower jaw Alveolar process: the thickened Ridge of bone that contains the tooth sockets mandibular foramen ( permits passage of the nerve involved in tooth sensation, cranial nerve V

24. Maxillary Bones Articulate with all other facial bones except the mandible Forms part of the inferior orbital fissure Are the “keystone” bones of the face Orbital surface Zygomatic process (cut) Alveolar process Anterior nasal spine Infraorbital foramen Frontal process Articulates with frontal bone Maxilla, right lateral view

25. Other Bones of the Face (Identify these during lab) Zygomatic bones Form lateral wall of orbits Nasal bones Form bridge of nose Lacrimal bones Located in the medial orbital walls Palatine bones Complete the posterior part of the hard palate Vomer Forms the inferior part of the nasal septum Inferior nasal conchae Thin, curved bones that project medially form the lateral walls of the nasal cavity

26. Paranasal Sinuses Air-filled sinuses are located within: Frontal bone Ethmoid bone Sphenoid bone Maxillary bones Lined with mucous membrane Lighten the skull Frontal sinus Ethmoidal air cells (sinus) Sphenoidal sinus Maxillary sinus Anterior aspect

27. The Hyoid Bone Lies inferior to the mandible The only bone with no direct articulation with any other bone Acts as a movable base for the tongue Greater horn Lesser horn Body

28. Regions The vertebral column has five major regions 7 cervical vertebrae of the neck region 12 thoracic vertebrae 5 lumbar vertebrae Sacrum—five fused bones Inferior to lumbar vertebrae Coccyx—inferior to sacrum Right lateral view Anterior view 4 fused vertebrae Coccyx Sacral curvature (convex) 5 fused vertebrae sacrum (concave) 5 vertebrae, L 1  L 5 Lumbar curvature 4 5 2 12 11 10 9 8 7 L1L1 Intervertebral foramen Intervertebral discs 3 (convex) 12 vertebrae, T 1  T 12 Thoracic curvature Transverse processes Spinous process 6 5 4 2 5 4 3 3 7 6 7 vertebrae, C 1  C 7 Cervical curvature (concave) 2 C1C1 T1T1 Surrounds and protects the spinal cord Serves as attachment sites for muscles of the neck and back The Vertebral Column

29. Normal Curvatures Curvatures of the spine- increase resilience of spine Cervical and lumbar curvatures (secondary curvature) Concave posteriorly Thoracic and sacral curvatures (primary curvature) Convex posteriority

30. Major supporting ligaments: Anterior longitudinal ligament Attaches to bony vertebrae and intervertebral discs Intervertebral disks - cushions found in between vertebrae Prevents hyperextension Posterior longitudinal ligament Narrow and relatively weak Attaches to intervertebral discs Ligaments of the Spine Posterior longitudinal ligament Anterior longitudinal ligament Body of a vertebra Intervertebral disc Anterior view of part of the spinal column

32. Structure of a typical vertebra. Vertebral arch Spinous process Posterior Lamina Transverse process Superior articular process and facet Pedicle Body Vertebral foramen Anterior Common structures to all vertebrae: Body Vertebral arch Vertebral foramen Spinous process Transverse process Superior and inferior articular processes Intervertebral foramina Facet = surface Pedicle – a small, stalk-like structure

33. LOCATION OF Atlas and Axis Dens of axis Transverse ligament of atlas C 1 (atlas) C 2 (axis) C3C3 Inferior articular process Bifid spinous process Transverse processes C 7 (vertebra prominens) Cervical vertebrae

34. The Atlas C 1 is the atlas C 1 lacks a body and spinous process Allows flexion and extension of neck Nodding the head “yes” Posterior Posterior tubercle Posterior arch C1C1 Transverse foramen Superior articular facet Anterior tubercle Lateral masses Anterior arch Superior view of atlas (C 1 )

35. The Axis Has a body and spinous process Dens (odontoid process) projects superiorly Is formed from fusion of the body of the atlas with the axis Acts as a pivot for rotation of the atlas and skull Participates in rotating the head from side to side Figure 7.22c The first and second cervical vertebrae. Posterior C2C2 Inferior articular process Spinous process Transverse process Dens Lamina Pedicle Superior articular facet Body Superior view of axis (C 2 )

36. Thoracic Vertebrae Spinous processes are long and point inferiorly Vertebral foramen are circular Transverse processes articulate with tubercles of ribs Superior articular facets point posteriorly Inferior articular processes point anteriorly Allows rotation and prevents flexion and extension SuperiorLateral CHARACTERISTICS

37. Lumbar Vertebrae (L 1 –L 5 ) Bodies are thick and robust Transverse processes are thin and tapered Spinous processes are thick and blunt and point posteriorly Vertebral foramina are triangular Superior and inferior articular facets point medially Allows flexion and extension— rotation prevented

38. Sacrum (S 1 –S 5 ) Formed from 5 fused vertebrae Superior surface articulates with L 5 Inferiorly articulates with coccyx Sacral promontory Where the first sacral vertebrae bulges into pelvic cavity Sacral promontory Ala Median sacral crest Body of first sacral vertebra Transverse ridges (sites of vertebral fusion) Apex Anterior sacral foramina Posterior sacral foramina Coccyx Anterior view Posterior view Coccyx Sacral canal Body Facet of superior articular process Auricular surface Lateral sacral crest Sacral hiatus The coccyx is Formed from 3–5 fused vertebrae The coccyx is the tail bone

39. The Thoracic Cage (Rib Cage) Components Thoracic vertebrae— posteriorly Ribs—laterally Sternum and costal cartilage— anteriorly Protects thoracic organs Supports shoulder girdle and upper limbs Provides attachment sites for many muscles of the back Jugular notch Clavicular notch Manubrium Body Sternal angle Xiphisternal joint Xiphoid process Sternum Intercostal spaces Costal cartilage Costal margin L 1 Vertebra Floating ribs (11, 12) Skeleton of the thoracic cage, anterior view False ribs (8  12) True ribs (1  7)

40. Shaft Articular facet on tubercle of rib Ligaments Spinous process Transverse costal facet (for tubercle of rib) Body of thoracic vertebra Neck of rib Head of rib Superior costal facet (for head of rib) Superior view of the articulation between a rib and a thoracic vertebra

41. Sternum Formed from three sections Manubrium—superior section Clavicular notches articulate with medial end of clavicles Body—bulk of sternum Sides are notched at articulations for costal cartilage of ribs 2–7 Xiphoid process—inferior end of sternum Ossifies around age 40 Other characteristics: Jugular notch Central indentation at superior border of the manubrium Sternal angle A horizontal ridge where the manubrium joins the body