Lecture 15 The Skeletal System1 Objectives Chapter 8

Lecture # 15: The Skeletal System-1 Objectives: (Chapter 8) 1 - Identify the bones of the axial and appendicular skeletons. 2 - Describe the general structure and components of the vertebral column. 3 - Describe the criteria used to classify joints structurally and functionally. 4 - Describe the anatomical features common to all synovial joints, the six types of synovial joints, and the movements allowed at each type.

Anatomical Features (markings) of Bones Projections that help to form joints: Process: Any bony prominence Costal facets Head of the femur Olecranon process Condyles Head of the humerus

Projections that are sites of muscle and ligament attachment: Tibial tuberosity Trochanters Linea aspera Anterior crest Epicondyle Condyle Lesser tubercle Spine of scapula

Depressions: Alveolus: A pit or socket (tooth socket) Frontal sinus Hypophyseal Fossa Fovea capitis Fovea: A small pit Passages and cavities: Internal acoustic meatus Canal: A tubular passage or tunnel in a bone Superior orbital fissure Meatus: An opening into a canal Infraorbital foramen Alveolus Auditory canal

Skeleton Axial Skeleton Appendicular Skeleton

Axial Skeleton Skull Hyoid bone Vertebral column Thoracic or rib cage

Cranial and Facial Bones Sagittal suture Coronal suture Frontal bone Parietal bone Ethmoid bone Sphenoid bone Nasal bone Occipital bone Squamous suture Lambdoid suture Lacrimal bone Squamous Region Maxilla Zygomatic bone Temporal process Zygomatic process External acoustic meatus Mastoid process Mandible Mental foramen Styloid process Mandibular condyle

Cranial and Facial Bones FRONTAL BONE Coronal suture Squamous suture PARIETAL BONE SPHENOID BONE TEMPORAL BONE ETHMOID BONE Zygomatic process NASAL BONE LACRIMAL BONE Mandibular fossa External acoustic meatus ZYGOMATIC BONE MAXILLA OCCIPITAL BONE Mastoid process Styloid process MANDIBLE Mandibular condyle CRANIAL BONES FACIAL BONES Lateral view

Parietal bone Frontal bone Supraorbital foramen Supraorbital margin Temporal bone Nasal bone Sphenoid bone Ethmoid bone Lacrimal bone Perpendicular plate of Ethmoid Middle nasal concha Infraorbital foramen Zygomatic bone Vomer Inferior nasal concha Maxilla Mandible Mental foramen

Nasal septum Vomer Perpendicular plate of Septal ethmoid cartilage Supra-orbital foramen Infra-orbital foramen Mental foramen Alveolar process of maxilla Alveolar process of mandible Middle nasal concha Inferior nasal concha

Anterior view FRONTAL BONE NASAL BONE PARIETAL BONE TEMPORAL BONE SPHENOID BONE LACRIMAL BONE ETHMOID BONE Middle nasal concha (part of ethmoid) Perpendicular plate of ethmoid bone ZYGOMATIC BONE INFERIOR NASAL CONCHA VOMER MAXILLA MANDIBLE CRANIAL BONES FACIAL BONES

Frontal bone Crista galli of ethmoid bone Cribriform plate of ethmoid bone Sphenoid bone Sella turcica Hypophyseal fossa Temporal bone Petrous region Parietal bone Foramen magnum Occipital bone

Crista galli of ethmoid bone Cribriform plate of ethmoid bone Optic foramina SPHENOID BONE Hypophyseal fossa Petrous region of temporal bone Foramen magnum OCCIPITAL BONE Interior view Sella turcica

Zygomatic bone Zygomatic arch Temporal process Palatine process of maxilla Palatine bone Hard (bonny) palate Zygomatic process Vomer Sphenoid bone Mandibular fossa Styloid process External acoustic meatus Occipital condyles Mastoid process Foramen magnum Temporal bone Parietal bone Occipital bone Lambdoid suture

Hard (bonny) palate Zygomatic arch Palatine process of maxilla PALATINE BONE Temporal process Zygomatic process VOMER BONE Mandibular fossa External acoustic meatus Styloid process TEMPORAL BONE Occipital condyles Mastoid process OCCIPITAL BONE Inferior view Foramen magnum

Functions: Vertebra Column 1 - Supports the skull and trunk, and allows for their movement 2 - Protects the spinal cord 3 - Absorbs stress of walking, running, and lifting 4 - Provides attachments for limbs thoracic cage, and postural muscles Cervical vertebrae Thoracic vertebrae Cervical curvature Thoracic curvature Lumbar vertebrae Lumbar curvature Sacrum Pelvic curvature Coccyx

Abnormal Spinal Curvatures Scoliosis: It is an abnormal lateral curvature, due to a developmental abnormality in which the body and arch fail to develop on one side of the vertebrae. It is the most common, usually in thoracic region. It is particularly frequent in adolescent girls Kyphosis (hunchback): It is an exaggerated thoracic curvature, usually from osteoporosis, also osteomalacia or spinal tuberculosis, or wrestling or weightlifting in young boys Lordosis (swayback): It is an exaggerated lumbar curvature. It is from pregnancy or obesity

E. The Vertebral Column Cervical region (7 vertebrae) C 7 T 1 Atlas (C 1) Axis (C 2) Thoracic region (12 vertebrae) Intervertebral discs (fibrocartilage) T 12 L 1 Lumbar region (5 vertebrae) L 5 Sacral region (5 vertebrae) Coccygeal region (3 or 4 vertebrae) Sacrum Intervertebral foramina Coccyx Lateral view

Posterior Spinous process Superior articular facet Transverse process Vertebral foramen Body Anterior

Atlantoaxial joint (pivot joint) Dens Superior articular facet ( articulates with the occipital condyle) Transverse ligament Axis of rotation Atlas Axis

Parietal Occipital condyles Parietal Occipital

Cervical Vertebra Bifid tip of spinous process Spinous process Transverse process Vertebral foramen Body Transverse foramen Superior view Transverse foramen Spinous process Lateral view

Thoracic Vertebra Transverse costal facet for tubercle of rib Spinous process Superior costal facet for head of rib Vertebral foramen Body Superior costal facet for head of rib Inferior costal facet for head of rib Spinous process Superior view Lateral view

Lumbar Vertebra Spinous process Transverse process Vertebral foramen Body Superior view Body Spinous process Lateral view

A comparison of vertebrae from cervical, thoracic and lumbar regions Superior view Lateral view Cervical (7) Thoracic (12) Lumbar (5)

Transverse foramina Intervertebral foramina Vertebral foramen Transverse foramina of cervical vertebrae are passageways for vertebral artery (and vein, no shown) Intervertebral foramina are passageways for spinal nerves running to or from the enclosed spinal cord Together, the vertebral foramina of successive vertebrae form the vertebral canal , which encloses the spinal cord

Sacrum and Coccyx Sacrum (Fused components of 5 vertebrae) Superior articular It articulates with the last lumbar vertebra processes (L 5) S 1 S 2 S 3 S 4 Anterior view Coccyx (3 to 5 coccygeal vertebrae) Posterior view S 5 Coccyx

The Thoracic Cage T 1 1 2 Costal cartilages 3 4 5 6 2 2 3 3 4 4 5 5 6 6 7 7 3 True or vertebrosternal ribs (ribs 1 -7) 4 They are connected to the sternum by separated costal cartilages 5 6 7 7 T 12 8 9 10 2 1 8 9 L 1 11 12 Floating ribs 12 11 Floating ribs False ribs (ribs 8 -12) 10 Floating or vertebral (11, 12)

The Sternum Jugular notch Manubrium It articulates with the sternal end of the scapula Sternal angle Body Xiphoid process Anterior view