Lecture # 15: The Skeletal System-1(Chapter 8)

Objectives: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.

Costal facets

Projections that help to form joints: Head of the femurHead of the

humerus

Condyles

Anatomical Features (markings) of Bones

Process: Any bony prominence Olecranon process

Linea aspera

Condyle

Epicondyle

Trochanters

Projections that are sites of muscle and ligament attachment:

Spine of scapula

Tibial tuberosity

Anterior crest

Lesser tubercle

Frontal sinus

Hypophyseal Fossa

Depressions:

Superior orbital fissure

Infraorbital foramen

Auditory canal

Fovea: A small pit

Alveolus: A pit or socket (tooth socket)

Alveolus

Passages and cavities:Canal: A tubular passage or tunnel in a bone

Meatus: An opening into a canal

Fovea capitis

Internal acoustic meatus

Skeleton Axial Skeleton Appendicular Skeleton

Axial Skeleton Skull

Vertebral column

Thoracic or rib cage

Hyoid bone

Cranial and Facial Bones

Parietal boneFrontal bone

Ethmoid bone

Zygomatic bone

Maxilla

Nasal bone

Lacrimal bone

Mandible

Sphenoid bone

Occipital bone

Temporal bone

Squamous suture

Lambdoid suture

Zygomatic process

External acoustic meatus

Mastoid process

Styloid processMandibular

condyle

Coronal suture

Temporal process

Mental foramen

SquamousRegion

Sagittal suture

CRANIAL BONES

FACIAL BONES

FRONTAL BONECoronal suture

SPHENOID BONE

Squamous suture

PARIETAL BONE

TEMPORAL BONE

Styloid process

External acoustic meatus

Mastoid process

Mandibular condyle

ETHMOID BONE

MANDIBLE

NASAL BONE

LACRIMAL BONE

ZYGOMATIC BONE

MAXILLA OCCIPITAL BONE

Mandibular fossa

Lateral view

Zygomatic process

Cranial and Facial Bones

Frontal boneParietal bone

Temporal bone

Ethmoid bone

Sphenoid bone

Lacrimal bone

Nasal bone

Middle nasal conchaPerpendicular plate of Ethmoid

Vomer

Mandible

Zygomatic bone

Inferior nasal concha

Supraorbital margin

Supraorbital foramen

Infraorbital foramen

Maxilla

Mental foramen

Perpendicular plate of ethmoid

Nasal septum

Middle nasal concha

Inferior nasal concha

Vomer

Alveolar process of

maxilla

Alveolar process of mandible

Septal cartilage

Mental foramen

Supra-orbital foramen

Infra-orbital foramen

FRONTAL BONE

Anterior view

CRANIAL BONES

FACIAL BONES

MAXILLA

VOMER

MANDIBLE

Perpendicular plate of ethmoid bone

LACRIMAL BONE ETHMOID BONE

SPHENOID BONE

INFERIOR NASAL CONCHA

ZYGOMATIC BONE

NASAL BONE

TEMPORAL BONE

PARIETAL BONE

Middle nasal concha (part of ethmoid)

Cribriform plateof ethmoid bone

Hypophyseal fossa Sella turcica

Frontal bone

Sphenoid bone

Crista galli of ethmoid bone

Temporal bone

Parietal bone

Foramen magnum

Occipital bone

Petrous region

Interior view

Foramen magnum

Crista galli of ethmoid bone

Hypophyseal fossa

Cribriform plate of ethmoid bone

Optic foraminaSPHENOID

BONE

OCCIPITAL BONE

Petrous region of temporal

bone

Sella turcica

Palatine processof maxilla

Palatine bone

Foramen magnum

Lambdoid suture

Zygomatic bone

Temporal process

Zygomatic process

Zygomatic arch

Vomer

Hard (bonny) palate

Mandibular fossa

Sphenoid bone

Styloid process

External acoustic meatus

Mastoid process

Temporal bone

Parietal bone

Occipital bone

Occipital condyles

Hard (bonny) palate

OCCIPITAL BONE

TEMPORAL BONE

Inferior view

Palatine process of

maxillaPALATINE

BONE

VOMER BONE

Mandibular fossaStyloid process

Mastoid process

Occipital condyles

Foramen magnum

External acoustic meatus

Temporal process

Zygomatic processZygomatic

arch

4- Provides attachments for limbs thoracic cage, and postural muscles

Vertebra ColumnFunctions:1- Supports the skull and trunk, and allows for their movement2- Protects the spinal cord3- Absorbs stress of walking, running, and lifting

Cervical vertebrae

Thoracic vertebrae

Lumbar vertebrae

Sacrum

Coccyx

Cervical curvature

Thoracic curvature

Lumbar curvature

Pelvic curvature

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

Abnormal Spinal Curvatures

Cervical region (7 vertebrae)

Thoracic region (12 vertebrae)

Lumbar region (5 vertebrae)

Sacral region (5 vertebrae)

E. The Vertebral Column

Lateral view

C7T1

T12L1

L5

Atlas (C1)

Axis (C2) Intervertebral discs

(fibrocartilage)

Intervertebral foramina

Coccyx

Sacrum

Coccygeal region (3 or 4 vertebrae)

Spinous process

Body

Anterior

Posterior

Superior articularfacet

Transverseprocess

Vertebral foramen

Axis of rotationDens

Axis

Atlas

Transverseligament

Atlantoaxial joint (pivot joint)

Superior articularfacet ( articulates with the occipital condyle)

Occipital condyles

Occipital

Parietal Parietal

Occipital

Parietal Parietal

Vertebral foramen

Body

Cervical Vertebra

Superior view Lateral view

Spinous process

Transverse foramen

Spinous process

Body

Bifid tip of spinous process

Transverse foramen

Transverse process

Vertebral foramen

Transverse costal facet for tubercle of rib

Body

Body

Superior view Lateral view

Spinous process

Superior costal facet for head

of rib

Superior costal facet for head of rib

Inferior costal facet for head of rib

Spinous process

Thoracic Vertebra

Vertebral foramen

Body

Body

Superior view Lateral view

Spinous process

Transverse process

Spinous process

Lumbar Vertebra

Superior view

Lateral view

Thoracic (12) Cervical (7) Lumbar (5)

A comparison of vertebrae from cervical, thoracic and lumbar regions

Intervertebral foramina are passageways for spinal nerves running to or from the enclosed spinal cord

Intervertebral foramina

Vertebral foramen

Transverse foramina

Together, the vertebral foramina of successive vertebrae form the vertebral canal , which encloses the spinal cord

Transverse foramina of cervical vertebrae are passageways for vertebral artery (and vein, no shown)

Anterior view

Posterior view

Sacrum and Coccyx

Coccyx

Sacrum(Fused components of 5 vertebrae)

S1

S2

S3

S4

S5

Coccyx (3 to 5 coccygeal

vertebrae)

Superior articular processes

It articulates with the last lumbar vertebra (L5)

11

2 2

3 3

4 4

5 5

6 6

7 7

8 8 9 9

T1

They are connected to the sternum by separated costal

cartilages

True or vertebrosternal

ribs (ribs 1-7)

False ribs (ribs 8-12)

T12

L1

1 1

2 2

3 3

44

55

6

7 7

6

Floating ribs Floating ribs

Floating or vertebral (11,12)

Costal cartilages

12 1211 11 1010

The Thoracic Cage

The Sternum

Anterior view

Manubrium

Body

Xiphoid process

Jugular notch

Sternal angle

It articulates with the sternal end of the scapula