© 2012 Pearson Education, Inc. PowerPoint ® Lecture Slides Prepared by Patty Bostwick-Taylor, Florence-Darlington Technical College C H A P T E R 5 The Skeletal System

© 2012 Pearson Education, Inc. The Axial Skeleton Forms the longitudinal axis of the body Divided into three parts Skull Vertebral column Bony thorax

© 2012 Pearson Education, Inc. Figure 5.8a (a) Anterior view Phalanges Metatarsals Tarsals Fibula Tibia Patella Femur Metacarpals Phalanges Carpals Ulna Radius Vertebra Humerus Rib Sternum Scapula Clavicle Facial bones Cranium Skull Thoracic cage (ribs and sternum) Vertebral column Sacrum

© 2012 Pearson Education, Inc. Figure 5.8b (b) Posterior view Fibula Tibia Femur Metacarpals Phalanges Carpals Radius Ulna Vertebra Humerus Rib Scapula Clavicle Cranium Bones of pectoral girdle Upper limb Bones of pelvic girdle Lower limb

© 2012 Pearson Education, Inc. The Skull Two sets of bones Cranium Facial bones Bones are joined by sutures Only the mandible is attached by a freely movable joint

© 2012 Pearson Education, Inc. Figure 5.9 Coronal suture Parietal bone Lambdoid suture Temporal bone Squamous suture Occipital bone Zygomatic process External acoustic meatus Mastoid process Styloid process Mandibular ramus Frontal bone Sphenoid bone Ethmoid bone Lacrimal bone Nasal bone Zygomatic bone Maxilla Alveolar processes Mandible (body) Mental foramen

© 2012 Pearson Education, Inc. Figure 5.10 Sphenoid bone Temporal bone Internal acoustic meatus Parietal bone Occipital bone Foramen magnum Jugular foramen Foramen ovale Sella turcica Optic canal Frontal bone Cribriform plate Crista galli Ethmoid bone

© 2012 Pearson Education, Inc. Figure 5.11 Maxilla (palatine process) Hard palate Palatine bone Zygomatic bone Temporal bone (zygomatic process) Vomer Mandibular fossa Styloid process Mastoid process Temporal bone Parietal bone Occipital bone Foramen magnum Occipital condyle Jugular foramen Carotid canal Foramen ovale Sphenoid bone (greater wing) Maxilla

© 2012 Pearson Education, Inc. Figure 5.12 Coronal suture Parietal bone Nasal bone Sphenoid bone Ethmoid bone Lacrimal bone Zygomatic bone Maxilla Mandible Alveolar processes Vomer Inferior nasal concha Middle nasal concha of ethmoid bone Temporal bone Optic canal Superior orbital fissure Frontal bone

© 2012 Pearson Education, Inc. Paranasal Sinuses Hollow portions of bones surrounding the nasal cavity Functions of paranasal sinuses Lighten the skull Give resonance and amplification to voice

© 2012 Pearson Education, Inc. Figure 5.13a Frontal sinus Ethmoid sinus Sphenoidal sinus Maxillary sinus (a) Anterior view

© 2012 Pearson Education, Inc. Figure 5.13b Frontal sinus Ethmoid sinus Sphenoidal sinus Maxillary sinus (b) Medial view

© 2012 Pearson Education, Inc. The Hyoid Bone The only bone that does not articulate with another bone Serves as a moveable base for the tongue Aids in swallowing and speech

© 2012 Pearson Education, Inc. Figure 5.14 Greater horn Lesser horn Body

© 2012 Pearson Education, Inc. The Fetal Skull Comparisons between fetal skull & adult: Fetal/infant skull is 1/4 body length adult skull is 1/8 body length Fetal/infant skull is made of cartilage, bone, and a fibrous membrane (Fontanels) Adults only bones Fontanels vs. Sutures

© 2012 Pearson Education, Inc. The Fetal Skull The largest fontanel is located between the 2 parietal bones and the frontal bone). Diamond shaped Anterior fontanel Posterior fontanel

© 2012 Pearson Education, Inc. Fetal Skull fibrous membranes connecting the cranial bones Purpose of fontanels: Allow skull compression during birth Allow the brain to grow during later pregnancy and infancy Convert to bone (ossification) within months after birth

© 2012 Pearson Education, Inc. Figure 5.15b Anterior fontanel Frontal bone Sphenoidal fontanel Parietal bone Posterior fontanel Occipital bone Mastoid fontanel Temporal bone (b)

© 2012 Pearson Education, Inc. The Vertebral Column aka spine Extends from the skull to the pelvis Not rigid but flexible Comprised of 26 irregular bones connected & reinforced by ligaments  creates a flexible & curved structure 24 vertebrae + 2 additional composite bones = 26 total bones

© 2012 Pearson Education, Inc. Vertebral Column aka spine Before birth the spine is actually 33 vertebrae long (not 24). 9 of them fuse together to form 2 composite (bones made up of the combination of more than one bone originally—fused together) Form the sacrum & coccyx.

© 2012 Pearson Education, Inc. The Vertebral Column Each vertebrae is given a name according to its location There are 24 single vertebral bones separated by intervertebral discs Seven cervical vertebrae are in the neck Twelve thoracic vertebrae are in the chest region; attachment for ribs; protect thoracic cavity. Five lumbar vertebrae are associated with the lower back = 24

© 2012 Pearson Education, Inc. The Vertebral Column Intervertebral foramen: openings between vertebrae that allow spinal nerves to pass through. Vertebrae are separated by flexible pads of fibrocartilage called intervertebral discs. They cushion the vertebrae They absorb shocks They allow the spine flexibility

© 2012 Pearson Education, Inc. The Vertebral Column Disc composition: As a young person  90% water; they are spongy & compressible As you age  water decreases; so the discs become harder & less compressible DISC

© 2012 Pearson Education, Inc. The Vertebral Column As an adult the spinal column has an S-shaped curve. These curves help prevent shock to our head when we walk or run

© 2012 Pearson Education, Inc. The Vertebral Column Newborns do NOT have an S -shaped curve. Instead, it is C -shaped. Found in 1.thoracic vertebra 2.Sacral region These are primary curvatures because they are present at birth

© 2012 Pearson Education, Inc. The Vertebral Column The curvatures in the cervical & lumbar regions are secondary curvatures. Cervical curve forms as babies lift their heads Lumbar curve forms as babies begin to walk.

© 2012 Pearson Education, Inc. Figure 5.18

© 2012 Pearson Education, Inc. A Typical Vertebrae Body Aka centrum Disc-like Weight-bearing part of the vertebra Faces anteriorly (front) in the vertebral column

© 2012 Pearson Education, Inc. Figure 5.19 Posterior Body Anterior

© 2012 Pearson Education, Inc. A Typical Vertebrae Vertebral arch Arch formed from the joining of all posterior (back) extensions from the body Formed from the lamina & pedicles Contains the spinal cord

© 2012 Pearson Education, Inc. Figure 5.19 Posterior Lamina Vertebral arch Pedicle Body Anterior

© 2012 Pearson Education, Inc. A Typical Vertebrae Vertebral foramen Formed in part by the vertebral arch Canal through which the spinal cord passes

© 2012 Pearson Education, Inc. Figure 5.19 Posterior Lamina Vertebral arch Pedicle Vertebral foramen Body Anterior

© 2012 Pearson Education, Inc. A Typical Vertebrae Transverse process Two lateral projections from the vertebral arch Provides levers for the muscles to pull against May also articulate with ribs (only in thoracic vertebrae)

© 2012 Pearson Education, Inc. Figure 5.19 Posterior Lamina Transverse process Vertebral arch Pedicle Vertebral foramen Body Anterior

© 2012 Pearson Education, Inc. A Typical Vertebrae Spinous process Single projection Arising from the posterior aspect of the vertebral arch (Usually the fused laminae) At the back of the arch Also used for muscle attachment

© 2012 Pearson Education, Inc. Figure 5.19 Posterior Lamina Transverse process Superior articular process and facet Spinous process Vertebral arch Pedicle Vertebral foramen Body Anterior

© 2012 Pearson Education, Inc. A Typical Vertebrae Superior articular process Paired projection Lateral to the vertebral foramen Allowing the vertebra to form joints with adjacent vertebra on the side, pointing up

© 2012 Pearson Education, Inc. Figure 5.19 Posterior Lamina Transverse process Superior articular process Spinous process Vertebral arch Pedicle Vertebral foramen Body Anterior

© 2012 Pearson Education, Inc. A Typical Vertebrae Inferior articular process Paired projection Lateral to the vertebral foramen Allowing the vertebra to form joints with adjacent vertebra on the side, pointing down

© 2012 Pearson Education, Inc. Articular processes & facets

© 2012 Pearson Education, Inc. Key terms Process = projection Foramen/foramina = holes

© 2012 Pearson Education, Inc. Figure 5.16 Anterior Posterior 1st cervical vertebra (atlas) 2nd cervical vertebra (axis) Cervical curvature (concave) 7 vertebrae, C 1 – C 7 1st thoracic vertebra Transverse process Spinous process Intervertebral disc Intervertebral foramen Thoracic curvature (convex) 12 vertebrae, T 1 – T 12 1st lumbar vertebra Lumbar curvature (concave) 5 vertebrae, L 1 – L 5 Sacral curvature (convex) 5 fused vertebrae Coccyx 4 fused vertebrae

© 2012 Pearson Education, Inc. Figure 5.20a (a) ATLAS AND AXIS Transverse process Posterior arch Anterior Arch  NO BODY Superior view of atlas Spinous process Transverse process Facet on superior articular process Pivot point = Dens Body Superior view of axis C1C1 C2C2

© 2012 Pearson Education, Inc. Figure 5.20b TYPICAL CERVICAL VERTEBRAE Facet on superior articular process Spinous process Vertebral foramen Transverse process Superior view Body Superior articular process Spinous process Transverse process Facet on inferior articular process Right lateral view Smallest & lightest Foramina (small openings) in transverse process (vertebral arteries pass through on their way to the brain. C 3 -C 7

© 2012 Pearson Education, Inc. Figure 5.20c Right lateral view Spinous process Costal Facet for rib Facet on superior articular process Facet on transverse process Body Superior view Body Facet on superior articular process Facet for rib THORACIC VERTEBRAE Transverse process Vertebral foramen Spinous process Part of thoracic cage Larger than cervical vertebrae T 1 – T 12

© 2012 Pearson Education, Inc. Figure 5.20d LUMBAR VERTEBRAE Spinous process Transverse process Vertebral foramen Body Facet on superior articular process Superior view Body: Massive & Block-like Superior articular process Spinous process Facet on inferior articular process Right lateral view Sturdiest Most of the stress on the spine occurs in the lumbar region. L 1 – L 5

© 2012 Pearson Education, Inc. Sacrum and Coccyx Sacrum Formed by the fusion of five vertebrae Located between L 5 & coccyx Forms the posterior wall of the pelvis Coccyx Formed from the fusion of 3-5 vertebrae “Tailbone,” or remnant of a tail that other vertebrates have

© 2012 Pearson Education, Inc. Figure 5.21 Superior articular process Auricular surface Sacral canal Ala Sacrum Body Median sacral crest Posterior sacral foramina Sacral hiatus Coccyx

© 2012 Pearson Education, Inc. Sternum Typical flat bone Part of thoracic cage Composed of 3 bones: Manubrium Body Xiphoid process Attached to the first 7 pair of ribs Test red marrow for blood diseases.

© 2012 Pearson Education, Inc. Ribs 12 pair Form the walls of the bony thorax (thoracic cage) Posterior articulation= vertebral column Curve downward toward anterior body surface

© 2012 Pearson Education, Inc. Two Classifications of Ribs 1.True ribs First seven pair (pairs 1–7) Attach directly to the sternum via cartilage 2.False ribs Next five pair(pairs 8–12) May indirectly attach to sternum OR not at all **Last 2 pair are Floating ribs (pairs 11–12) Do NOT attach to sternum at all

© 2012 Pearson Education, Inc. Bony thorax Summary: Forms a cage to protect major organs Consists of three parts: Sternum Ribs True ribs (pairs 1–7) False ribs (pairs 8–12) Floating ribs (pairs 11–12) Thoracic vertebrae

© 2012 Pearson Education, Inc. Figure 5.22a T 1 vertebra Jugular notch Manubrium Sternal angle Body Xiphisternal joint Xiphoid process Sternum Intercostal spaces Costal cartilage Floating ribs (11, 12) False ribs (8 –12) True ribs (1 – 7) L 1 Vertebra (a) Clavicular notch

© 2012 Pearson Education, Inc. Figure 5.22b T2T2 T3T3 T4T4 T9T9 Jugular notch Sternal angle Heart Xiphisternal joint (b)