skeletal system includes both:

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings

• Axial skeleton

• Skull

• Auditory ossicles and hyoid bone

• Vertebral column

• Thoracic cage

• Appendicular skeleton

• Pectoral and pelvic girdles

• Upper and lower limbs

Skeletal system includes both:


Figure 7.1b The Axial Skeleton

Figure 7.1b


• Consists of the cranium and the bones of the face

• The cranium encloses cranial cavity

• Facial bones surround and protect the entrances to the respiratory and digestive tracts

• Superficial landmarks include the sutures

• Lambdoid

• Coronal

• Sagittal

• Squamous

The skull

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 7.2

Figure 7.2 Cranial and Facial Subdivisions of the Skull


Figure 7.3 The Adult Skull

Figure 7.3a, b



Figure 7.3c



Figure 7.3d



Figure 7.3e


• one occipital bone

• foramen magnum

• two parietal bones

• one frontal bone

• frontal sinuses

Focus: The Individual Bones of the Skull Cranial Bones

• two temporal bones

• auditory ossicles

• one sphenoid

• one ethmoid


Figure 7.4 The Sectional Anatomy of the Skull

Figure 7.4a


Figure 7.4 The Sectional Anatomy of the Skull

Figure 7.4b


Figure 7.5 The Occipital and Parietal Bones

Figure 7.5


Figure 7.6 The Frontal Bone

Figure 7.6


Figure 7.7 The Temporal Bones

Figure 7.7


Figure 7.8 The Sphenoid

Figure 7.8


Figure 7.9 The Ethmoid

Figure 7.9


• Maxillary bones

• Mandible

• Palatine bones

• Nasal bones

• Vomer

Facial bones

• Inferior nasal conchae

• Zygomatic bones

• Lacrimal bones

• Hyoid


• Largest facial bones

• Form the upper jaw and most of the hard palate

Maxillae


Figure 7.10 The Maxillary and Palatine Bones

Figure 7.10


• Palatine bones

• Small “L” shaped bones

• Form the posterior hard palate and floor of the nasal cavity

• Nasal bones

• Superior border of external nares

Palatine and Nasal Bones


• Vomer

• Inferior portion of the nasal septum

• Zygomatic bone

• Temporal process articulates with zygomatic process of temporal bone

• Lacrimal bones

• Smallest bones of the face

• Sit medially in orbit

Vomer, Zygomatic and Lacrimal bones


Figure 7.11 The Smaller Bones of the Face

Figure 7.11


• Mandible

• Bone of the lower jaw

• Hyoid

• Suspended by stylohyoid ligaments

• Supports the larynx

Mandible and Hyoid bones


Figure 7.12 The Mandible and Hyoid Bones

Figure 7.12a


Figure 7.12 The Mandible and Hyoid Bones

Figure 7.12b, c


• Seven bones in the orbital complex

• Nasal complex = bones that enclose the nasal cavities and paranasal sinuses

The orbital and nasal complexes


Figure 7.14 The Orbital Complex

Figure 7.14


• Fontanels permit skulls of infants and children to continue growing

Skulls of infants and children


• Vertebrae, sacrum, coccyx

• 7 cervical vertebrae

• 12 thoracic vertebrae

• 5 lumbar vertebrae

• Sacrum and coccyx are fused vertebrae

Vertebral column


Figure 7.16 The Vertebral Column

Figure 7.16


• Four spinal curves

• Primary (accommodation) curves = thoracic and sacral

• Secondary (compensation) curves = lumbar and cervical

Spinal curvature


• Typically has a body and vertebral arch

• Superior and inferior articular processes

• Separated by intervertebral discs

Vertebral anatomy


Figure 7.18 Vertebral Anatomy

Figure 7.18


• Cervical

• Has distinctive shape

• Large relative size of vertebral foramen

• Costal processes with transverse foramina

• Notched spinous processes

Vertebral regions


Figure 7.19 The Cervical Vertebrae

Figure 7.19


• Heart-shaped body

• Long slender spinous processes

• Articulations for ribs

Thoracic vertebrae


Figure 7.20 The Thoracic Vertebrae

Figure 7.20a


Figure 7.20 The Thoracic Vertebrae

Figure 7.20b, c

Animation: Axial DissectionsPLAY


• Most massive

• Least mobile

• Subjected to great stresses

Lumbar vertebrae


Figure 7.21 The Lumbar Vertebrae

Figure 7.21


• Protects reproductive, digestive and urinary organs

• Articulates with pelvic girdle and fused elements of coccyx

Sacrum


Figure 7.22 The Sacrum and Coccyx

Figure 7.22


• Thoracic vertebrae

• Ribs

• Sternum

• Ribs and sternum forms the rib cage

Thoracic cage


Figure 7.23 The Thoracic Cage

Figure 7.23a



Figure 7.23b


• Ribs 1-7 are attached to vertebrae

• 8-12 are vertebrochondral ribs

• 11-12 are floating ribs

The ribs


• Has a head, neck, tubercle and a body

• Costal groove marks pathway of blood returning to the heart

Typical rib


• Manubrium

• Body

• Xiphoid process

The Sternum consists of



Figure 7.23

Animation: Axial DissectionsPLAY

skeletal system includes both:

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