Download 7 - Dr. Par Mohammadian

PowerPoint® Lecture Slides
prepared by
Barbara Heard,
Atlantic Cape Community
Ninth Edition
College
Human Anatomy & Physiology
CHAPTER
7
The Skeleton:
Part A: The
Axial
Revised by Dr. Par
Mohammadian
© Annie Leibovitz/Contact Press Images
© 2013 Pearson Education, Inc.
Overview of the Skeleton
• Axial (Ch 7a)
– The Skull
– The Vertebral Column
– The Thoracic Cage
• Appendicular (Ch 7b)
– The Pectoral (Shoulder) Girdle
– The Upper limb
– The Pelvic (Hip) Girdle
– The Lower limb
• Developmental Aspects (Ch 7b)
Cranium
Skull
Bones of
pectoral
girdle
Clavicle
Upper
limb
Rib
Humerus
Vertebra
Radius
Ulna
Bones
of
pelvic
girdle
Carpals
Facial bones
Clavicle
Scapula
Sternum
Cranium
Thoracic
cage
(ribs and
sternum)
Scapula
Sternum
Rib
Humerus
Vertebra
Radius
Ulna
Vertebral
column
Sacrum
Carpals
Phalanges
Metacarpals
Femur
Phalanges
Metacarpals
Femur
Patella
Lower
limb
Tibia
Tibia
Fibula
Fibula
Posterior view
Anterior view
Tarsals
Metatarsals
Phalanges
Overview of the Axial Skeleton
• Axial (80 bones)
– The Skull
• Cranium (8 bones)
–
–
–
–
–
–
Frontal 1x
Parietal 2x
Occipital 1x
Temporal 2x
Sphenoid 1x
Ethmoid 1x
• Facial (14 bones)
–
–
–
–
–
–
–
–
Mandible
Maxillary 2x
Zygomatic 2x
Nasal 2x
Lacrimal 2x
Palatine 2x
Vomer
Inferior nasal conchae 2x
– The Vertebral Column
– The Thoracic Cage
Figure 7.4 Anatomy of the anterior and posterior aspects of the skull.
Frontal bone
Parietal bone
Temporal bone
Glabella
Frontonasal suture
Supraorbital foramen
(notch)
Supraorbital margin
Superior orbital
fissure
Optic canal
Inferior orbital
fissure
Squamous part
of frontal bone
Nasal bone
Sphenoid bone
(greater wing)
Ethmoid bone
Lacrimal bone
Zygomatic bone
Ethmoid
bone
Inferior nasal concha
Middle nasal concha
Perpendicular plate
Infraorbital foramen
Maxilla
Vomer
Mandible
Mental
foramen
Anterior view
Sagittal suture
Parietal bone
Sutural
Mandibular bone
symphysis
Lambdoid
suture
Occipital bone
Superior nuchal line
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External
occipital protuberance
Occipitomastoid
External
suture
occipital
Posterior view crest
Mastoid
process of
temporal bone
Occipital
condyle
Inferior
nuchal line
Frontal Bone
• Anterior part: squamous part or forehead
• Forms the coronal suture with parietal
bones
Parietal Bones and Major Associated Sutures
• Four sutures mark articulations of parietal bones
with frontal, occipital, and temporal bones:
1. Coronal suture—between parietal bones and frontal
bone
2. Sagittal suture—between right and left parietal
bones
3. Lambdoid suture—between parietal bones and
occipital bone
4. Squamous (squamosal) sutures—between parietal
and temporal bones on each side of skull
Figure 7.5a Bones of the lateral aspect of the skull, external and internal views.
Frontal bone
Sphenoid bone
(greater wing)
Coronal suture
Parietal bone
Ethmoid bone
Temporal bone
Lacrimal bone
Lambdoid
suture
Squamous
suture
Occipital
bone
Zygomatic
process
Occipitomastoid
suture
External acoustic
meatus
Mastoid process
Styloid process
Lacrimal fossa
Nasal bone
Zygomatic bone
Maxilla
Alveolar
processes
Condylar process
Mandibular notch
Mandible
Mental foramen
Mandibular ramus
External anatomy of the
right side of the skull
© 2013 Pearson Education, Inc.
Mandibular angle
Coronoid process
© 2013 Pearson Education, Inc.
Figure 7.5b Bones of the lateral aspect of the skull, external and internal views.
Coronal suture
Parietal bone
Squamous
suture
Temporal bone
Zygomatic
process
Lambdoid
suture
Occipital
bone
Occipitomastoid
suture
External acoustic
meatus
Mastoid process
Styloid process
Condylar
process
Mandibular angle
Photograph of right side of skull
© 2013 Pearson Education, Inc.
Frontal bone
Sphenoid bone
(greater wing)
Ethmoid bone
Lacrimal bone
Nasal bone
Lacrimal fossa
Zygomatic bone
Coronoid process
Maxilla
Alveolar
processes
Mandible
Mental foramen
Mandibular notch
Mandibular ramus
Occipital Bone
• Articulates with 1st vertebra
• Sites of attachment for many neck and
back muscles
Temporal Bones
• Temp = time (came about because gray
hairs, sign of time’s passing; usually
appears first at the temples.
• Major regions
– Squamous
– Tympanic
– Petrous
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Figure 7.8 The temporal bone.
External acoustic
meatus
Squamous
part
Zygomatic
process
Petrous
part
Mastoid process
Styloid process
Mandibular
fossa
Tympanic
part
Sphenoid Bone
• Complex, bat/butterfly-shaped bone
• Keystone bone
– Articulates with all other cranial bones
• Central body with three pairs of processes
– Greater wings
– Lesser wings
– Pterygoid processes
© 2013 Pearson Education, Inc.
Optic
canal
Greater
wing
Hypophyseal
fossa of
sella turcica
Body of sphenoid
Superior view
Body of sphenoid
Greater
wing
Lesser wing
Superior
orbital
fissure
Foramen
rotundum
Foramen
ovale
Foramen
spinosum
Lesser
wing
Superior
orbital
fissure
Pterygoid
process
Posterior view
Ethmoid Bone
• Deepest skull bone
• Superior part of nasal septum, roof of
nasal cavities
Crista galli
Cribriform plate
with cribriform
foramina
Left
lateral
mass
Orbital
plate
Ethmoidal
air cells
Perpendicular
plate
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Middle
nasal concha
Figure 7.4a Anatomy of the anterior and posterior aspects of the skull.
Frontal bone
Parietal bone
Glabella
Frontonasal suture
Supraorbital foramen
(notch)
Supraorbital margin
Superior orbital
fissure
Optic canal
Inferior orbital
fissure
Squamous part
of frontal bone
Nasal bone
Sphenoid bone
(greater wing)
Temporal bone
Ethmoid bone
Lacrimal bone
Zygomatic bone
Infraorbital foramen
Ethmoid
bone
Inferior nasal concha
Middle nasal concha
Perpendicular plate
Maxilla
Vomer
Mandible
Mental
foramen
Anterior view
© 2013 Pearson Education, Inc.
Mandibular
symphysis
Figure 7.7a The base of the cranial cavity.
View
Cribriform
Ethmoid plate
bone
Crista galli
Anterior cranial fossa
Lesser wing
Sphenoid
Greater wing
Hypophyseal fossa
of sella turcica
Middle cranial
fossa
Temporal bone
(petrous part)
Posterior
cranial fossa
Parietal bone
Occipital bone
Foramen magnum
Superior view of the skull, calvaria removed
© 2013 Pearson Education, Inc.
Frontal bone
Cribriform foramina
Optic canal
Foramen rotundum
Foramen ovale
Foramen spinosum
Foramen lacerum
Internal acoustic meatus
Jugular foramen
Hypoglossal canal
Overview of the Axial Skeleton
• Axial (80 bones)
– The Skull
• Cranium (8 bones)
–
–
–
–
–
–
Frontal 1x
Parietal 2x
Occipital 1x
Temporal 2x
Sphenoid 1x
Ethmoid 1x
• Facial (14 bones)
–
–
–
–
–
–
–
–
Mandible
Maxillary 2x
Zygomatic 2x
Nasal 2x
Lacrimal 2x
Palatine 2x
Vomer
Inferior nasal conchae 2x
– The Vertebral Column
– The Thoracic Cage
Fourteen Facial Bones
• Mandible
• Maxillary bones
(maxillae) (2)
• Zygomatic bones (2)
• Nasal bones (2)
© 2013 Pearson Education, Inc.
•
•
•
•
Lacrimal bones (2)
Palatine bones (2)
Vomer
Inferior nasal
conchae (2)
Mandible
• Lower jaw
• Largest, strongest bone of face
• Temporomandibular joint
– Only freely movable joint in skull
Temporomandibular
joint
Mandibular notch
Mandibular fossa
of temporal bone
Coronoid
process
Mandibular foramen
Condylar
process
Alveolar
process
Mental
foramen
Ramus
of mandible
Mandibular
angle
Body of mandible
Mandible, right lateral view
Maxillary Bones
• Medially fused to form upper jaw and central portion of facial skeleton
• Keystone bones
– Articulate with all other facial bones except mandible
Orbital surface
Zygomatic
process
(cut)
Maxilla, right lateral view
Articulates
withfrontal
bone
Frontal
process
Infraorbital
foramen
Anterior
nasal spine
Alveolar
process
Figure 7.4a Anatomy of the anterior and posterior aspects of the skull.
Frontal bone
Parietal bone
Glabella
Frontonasal suture
Supraorbital foramen
(notch)
Supraorbital margin
Superior orbital
fissure
Optic canal
Inferior orbital
fissure
Squamous part
of frontal bone
Nasal bone
Sphenoid bone
(greater wing)
Temporal bone
Ethmoid bone
Lacrimal bone
Zygomatic bone
Infraorbital foramen
Ethmoid
bone
Inferior nasal concha
Middle nasal concha
Perpendicular plate
Maxilla
Vomer
Mandible
Mental
foramen
Anterior view
© 2013 Pearson Education, Inc.
Mandibular
symphysis
Zygomatic Bones
• Irregularly shaped bone (Cheekbones)
Nasal bone
Sphenoid bone
(greater wing)
Temporal bone
Ethmoid bone
Lacrimal bone
Zygomatic bone
Infraorbital foramen
Maxilla
Mandible
Mental
foramen
Anterior view
© 2013 Pearson Education, Inc.
Mandibular
symphysis
Nasal Bones and Lacrimal Bones
Frontal bone
Sphenoid bone
(greater wing)
Coronal suture
• Nasal bones
– Form
Temporal
bone bridge of nose
• Lacrimal bones
Lambdoid
suture
– In medial walls of orbits
Squamous
suture
Occipital
– Lacrimal fossa houses
bone
Zygomatic lacrimal sac
process
Parietal bone
Occipitomastoid
suture
External acoustic
meatus
Mastoid process
Styloid process
Ethmoid bone
Lacrimal bone
Lacrimal fossa
Nasal bone
Zygomatic bone
Maxilla
Alveolar
processes
Condylar process
Mandibular notch
Mandible
Mental foramen
Mandibular ramus
Mandibular angle
Coronoid process
External anatomy of the
right side of the skull
Palatine Bones and Vomer
Ethmoid
bone
Frontal sinus
Sella turcica
Nasal bone
Sphenoidal
sinus
Perpendicular plate
of ethmoid bone
Septal cartilage
Vomer
Palatine bone
Alveolar process
Hard
Palatine process
of maxilla
palate of maxilla
Nasal cavity with septum in place showing the contributions of the
ethmoid bone, the vomer, and septal cartilage
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Inferior Portion of the Skull
Figure 7.4a
© 2013 Pearson Education, Inc.
Inferior NasalSuperior,
Conchae
middle, and
inferior meatus
• Form part of
lateral walls of
nasal cavity
• Largest of three
pairs of conchae
Frontal sinus
Superior
nasal concha Ethmoid
Middle
bone
nasal concha
Inferior nasal concha
Nasal bone
Anterior nasal spine
Maxillary bone
Sphenoidal
(palatine process)
sinus
Sphenoid
Pterygoid
bone
process
Palatine bone
Palatine bone
(horizontal plate)
(perpendicular
plate)
Bones forming the left lateral wall of the nasal cavity
(nasal septum removed)
© 2013 Pearson Education, Inc.
Figure 7.4a Anatomy of the anterior and posterior aspects of the skull.
Frontal bone
Parietal bone
Glabella
Frontonasal suture
Supraorbital foramen
(notch)
Supraorbital margin
Superior orbital
fissure
Optic canal
Inferior orbital
fissure
Squamous part
of frontal bone
Nasal bone
Sphenoid bone
(greater wing)
Temporal bone
Ethmoid bone
Lacrimal bone
Zygomatic bone
Infraorbital foramen
Ethmoid
bone
Inferior nasal concha
Middle nasal concha
Perpendicular plate
Maxilla
Vomer
Mandible
Mental
foramen
Anterior view
Mandibular
symphysis
Orbits
• Cavities that encase eyes and lacrimal
glands
• Sites of attachment for eye muscles
• Formed by parts of seven bones
– Frontal, sphenoid, zygomatic, maxilla,
palatine, lacrimal, and ethmoid
© 2013 Pearson Education, Inc.
Figure 7.12b Bones that form the orbits.
Roof of orbit
• Lesser wing of
sphenoid bone
• Orbital plate of
frontal bone
Supraorbital notch
Lateral wall of orbit
• Zygomatic process
of frontal bone
• Greater wing of
sphenoid bone
• Orbital surface of
zygomatic bone
Inferior orbital fissure
Zygomatic bone
Superior
orbital fissure
Optic canal
Medial wall
• Sphenoid body
• Orbital plate
of ethmoid bone
• Frontal process
of maxilla
• Lacrimal bone
Nasal bone
Floor of orbit
• Orbital process of
palatine bone
• Orbital surface of
maxillary bone
• Zygomatic bone
Infraorbital
foramen
Contribution of each of the seven bones forming the right orbit
© 2013 Pearson Education, Inc.
Nasal Cavity
• Constructed of bone and hyaline cartilage
• Roof – formed by the cribriform plate of the ethmoid
• Lateral walls – formed by the superior and middle
conchae of the ethmoid, the perpendicular plate of
the palatine, and the inferior nasal conchae
• Floor – formed by palatine process of the maxillae
and palatine bone
© 2013 Pearson Education, Inc.
Figure 7.13b Bones of the nasal cavity.
Ethmoid
bone
Crista galli
Cribriform
plate
Frontal sinus
Sella turcica
Nasal bone
Sphenoidal
sinus
Perpendicular plate
of ethmoid bone
Septal cartilage
Vomer
Palatine bone
Alveolar process
Hard
Palatine process
of maxilla
palate of maxilla
Nasal cavity with septum in place showing the contributions of the
ethmoid bone, the vomer, and septal cartilage
© 2013 Pearson Education, Inc.
Paranasal Sinuses
•
•
•
•
•
Mucosa-lined, air-filled spaces
Lighten skull
Enhance resonance of voice
Warm and humidify air
Found in frontal, sphenoid, ethmoid, and
maxillary bones
© 2013 Pearson Education, Inc.
Figure 7.14a Paranasal sinuses.
Frontal sinus
Ethmoidal air cells
(sinus)
Sphenoidal sinus
Maxillary sinus
Anterior aspect
© 2013 Pearson Education, Inc.
Hyoid Bone
•
•
•
•
Not bone of skull
Does not articulate directly with another bone
Movable base for tongue
Site of attachment for muscles of swallowing and speech
Greater horn
Lesser horn
Body
© 2013 Pearson Education, Inc.
Overview of the Axial Skeleton
• Axial
– The Skull
– The Vertebral Column (26 irregular bones;
Surrounds and protects spinal cord)
• Cervical vertebrae (7 bones of the neck)
• Thoracic vertebrae (12 bones of the torso)
• Lumbar vertebrae (5 bones of the lower back)
• Sacrum (bone inferior to the lumbar vertebrae that articulates
with the hip bones)
• Coccyx (terminus of vertebral column)
– The Thoracic Cage
• Sternum
• Ribs
Figure 7.16 The vertebral column.
C1
2
3
4
5
6
7
Cervical curvature (concave)
7 vertebrae, C1 – C7
T1
Spinous
process
2
3
Transverse
processes
4
5
6
7
8
Thoracic curvature
(convex)
12 vertebrae,
T1 – T12
9
10
11
Intervertebral
discs
Intervertebral
foramen
12
L1
2
3
Lumbar curvature
(concave)
5 vertebrae, L1 – L5
4
5
Sacral curvature
(convex)
5 fused vertebrae
sacrum
Coccyx
4 fused vertebrae
Anterior view
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Right lateral view
Vertebral Column: Curvatures
• Abnormal spine curvatures
– Scoliosis - abnormal lateral curve
– Kyphosis (hunchback) – exaggerated thoracic
curvature
– Lordosis (swayback) – accentuated lumbar curvature
© 2013 Pearson Education, Inc.
Figure 7.17 Abnormal spinal curvatures.
Scoliosis
© 2013 Pearson Education, Inc.
Kyphosis
Lordosis
Ligaments: Help keep the vertebral column upright by itself
Supraspinous
ligament
Transverse
process
Sectioned
spinous process
Ligamentum
flavum
Interspinous
ligament
Inferior articular
process
Intervertebral
disc
Anterior
longitudinal
ligament
Intervertebral foramen
Posterior longitudinal
ligament
Anulus fibrosus
Nucleus pulposus
Sectioned body
of vertebra
Median section of three vertebrae, illustrating
the composition of the discs and the ligaments
© 2013 Pearson Education, Inc.
Intervertebral Discs
•
Cushionlike pad composed
of two parts
– Nucleus pulposus
• Inner gelatinous
nucleus
• Gives disc its
elasticity and
compressibility
– Anulus fibrosus
• Outer collar
composed of
collagen and
fibrocartilage
© 2013 Pearson Education, Inc.
Posterior
longitudinal
ligament
Anterior
longitudinal
ligament
Body of a
vertebra
Intervertebral
disc
Anterior view of part of the spinal
column, showing the anterior
longitudinal ligament
Herniated
portion of disc
Herniated
nucleus
pulposus
MRI of lumbar region of
vertebral column in sagittal
section showing herniated disc
© 2013 Pearson Education, Inc.
General Structure of Vertebrae
• Body or centrum
– Anterior weight-bearing region
• Vertebral arch
– Composed of pedicles and laminae that, along with
centrum, enclose vertebral foramen
• Vertebral foramina
– Together make up vertebral canal for spinal cord
© 2013 Pearson Education, Inc.
Figure 7.19 Typical vertebral structures.
Posterior
Spinous
process
Transverse
process
Superior
articular
facet
and
process
Vertebral
Arch:
• Lamina
• Pedicle
Vertebral
foramen
Body
(centrum)
© 2013 Pearson Education, Inc.
Anterior
Cervical Vertebrae
• C1 to C7: smallest, lightest vertebrae
• C3 to C7 share following features
– Oval body
– Spinous processes are bifid or split at its tip
(except C7)
– Large, triangular vertebral foramen
– Transverse foramen in each transverse
process
– C7 is vertebra prominens
© 2013 Pearson Education, Inc.
Table 7.2 Regional Characteristics of Cervical
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Figure 7.21a Posterolateral views of articulated vertebrae.
Dens of axis
Transverse ligament
of atlas
C1 (atlas)
C2 (axis)
C3
Inferior articular process
Bifid spinous process
Transverse processes
C7 (vertebra
prominens)
Cervical vertebrae
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Cervical Vertebrae
• C1 (atlas) and C2 (axis) have unique
features
• Atlas (C1)
– No body or spinous process
– Consists of anterior and posterior arches, and
two lateral masses
– Superior surfaces of lateral masses articulate
with occipital condyles
– Movement for "Yes"
© 2013 Pearson Education, Inc.
Figure 7.20a–b The first and second cervical vertebrae.
C1
Posterior
Posterior
Lateral
masses
Posterior
tubercle
Posterior
arch
Transverse
foramen
Superior
articular
facet
Anterior arch
Anterior tubercle
Superior view of atlas (C1)
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Posterior tubercle
Posterior
arch
Inferior
articular
facet
Transverse
process
Lateral
masses
Transverse
foramen
Facet for dens
Inferior view of atlas (C1)
Anterior arch
Anterior tubercle
Cervical Vertebrae
• Axis (C2)
– Dens projects superiorly into anterior arch of
atlas
• Is "missing" body of atlas
– Dens is a pivot for rotation of atlas
– Movement for "No"
© 2013 Pearson Education, Inc.
Figure 7.20c The first and second cervical vertebrae.
C2
Posterior
Inferior
articular
process
Transverse
process
Dens
Superior view of axis (C2)
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Spinous process
Lamina
Pedicle
Superior
articular
facet
Body
Thoracic Vertebrae
• T1 to T12
• All articulate with ribs at facets and
demifacets
• Long, spinous process that points inferiorly
• Circular vertebral foramen
• Location of articular facets allows rotation
of this area of spine
© 2013 Pearson Education, Inc.
Table 7.2 Regional Characteristics of Thoracic
© 2013 Pearson Education, Inc.
© 2013 Pearson Education, Inc.
Figure 7.21b Posterolateral views of articulated vertebrae.
Transverse
process
Superior articular
process
Transverse costal
facet (for tubercle of rib)
Intervertebral disc
Body
Spinous
process
Inferior costal facet
(for head of rib)
Inferior articular
process
Thoracic vertebrae
© 2013 Pearson Education, Inc.
Lumbar Vertebrae
• L1 to L5
• Receives most stress; weight bearing
function
• Short, thick pedicles and laminae
• Flat hatchet-shaped spinous processes
point posteriorly
• Vertebral foramen triangular
• Orientation of articular facets locks lumbar
vertebrae together to prevent rotation
© 2013 Pearson Education, Inc.
Table 7.2 Regional Characteristics of Vertebrae
© 2013 Pearson Education, Inc.
Figure 7.21c Posterolateral views of articulated vertebrae.
Superior
articular
process
Transverse
process
Body
Intervertebral
disc
Inferior articular
process
Spinous
process
Lumbar vertebrae
© 2013 Pearson Education, Inc.
Sacrum and Coccyx
• Sacrum
– 5 fused vertebrae
(S1–S5)
– Forms posterior wall
of pelvis
– Articulates with L5
superiorly, and with
auricular surfaces of
hip bones, forming
sacroiliac joints
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• Coccyx
– Tailbone
– 3–5 fused
vertebrae
– Articulates
superiorly with
sacrum
Figure 7.22a The sacrum and coccyx.
Sacral promontory
Ala
Body of
first sacral
vertebra
Transverse
ridges (sites of
vertebral fusion)
Apex
Anterior
sacral
foramina
Coccyx
Anterior view
© 2013 Pearson Education, Inc.
Figure 7.22b The sacrum and coccyx.
Ala
Sacral
canal
Body
Facet of
superior
articular
process
Auricular
surface
Median
sacral
crest
Lateral
sacral
crest
Posterior
sacral
foramina
Coccyx
Posterior view
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Sacral
hiatus
Thoracic Cage
• Composed of
– Thoracic vertebrae posteriorly
– Sternum and costal cartilages anteriorly
– Ribs laterally
• Functions
– Protects vital organs of thoracic cavity
– Supports shoulder girdles and upper limbs
– Provides attachment sites for muscles of
neck, back, chest, and shoulders
© 2013 Pearson Education, Inc.
Sternum (Breastbone)
• Three fused bones
– Manubrium – Superior portion
• Articulates with clavicles and ribs 1 and 2
– Body (midportion)
• Articulates with costal cartilages of ribs 2 through 7
– Xiphoid process – Inferior end
• Site of muscle attachment
• Not ossified until ~age 40
© 2013 Pearson Education, Inc.
Overview of the Axial Skeleton
• Axial
– The Skull
– The Vertebral Column
• Cervical vertebrae
• Thoracic vertebrae
• Lumbar vertebrae
• Sacrum
• Coccyx
– The Thoracic Cage
• Sternum
• Ribs
© 2013 Pearson Education, Inc.
Figure 7.23a The thoracic cage.
Jugular notch
Clavicular notch
True ribs
(1–7)
Manubrium
Sternal angle
Body
Xiphisternal Sternum
(like a “tie”)
joint
Xiphoid
process
False ribs
(8–12)
Intercostal
spaces
L1
Costal cartilage
Floating ribs
Vertebra
Costal margin
(11, 12)
Skeleton of the thoracic cage, anterior view
© 2013 Pearson Education, Inc.
Anatomical Landmarks Of Sternum
• Jugular notch
– Central indentation in superior border of
manubrium
• Sternal angle
– Horizontal ridge across front of sternum
• Xiphisternal joint
– Point where sternal body and xiphoid process
fuse
© 2013 Pearson Education, Inc.
Ribs and Their Attachments
• 12 pairs
• All attach posteriorly to bodies and
transverse processes of thoracic vertebrae
• Pairs 1 through 7
– True (vertebrosternal) ribs
– Attach directly to sternum by individual costal
cartilages
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Ribs and Their Attachments
• Pairs 8 through12
– False ribs
– Pairs 8–10 also called vertebrochondral ribs
• Attach indirectly to sternum by joining costal
cartilage of rib above
– Pairs 11–12 also called vertebral (floating)
ribs
• No attachment to sternum
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Figure 7.23a The thoracic cage.
Jugular notch
Clavicular notch
True ribs
(1–7)
Manubrium
Sternal angle
Body
Xiphisternal Sternum
joint
Xiphoid
process
False ribs
(8–12)
Intercostal
spaces
L1
Costal cartilage
Floating ribs
Vertebra
Costal margin
(11, 12)
Skeleton of the thoracic cage, anterior view
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Rib Structure
• Main parts:
– Head (posterior end)
• Articulates with facets (demifacets) on bodies of
two adjacent vertebrae
– Neck (constricted portion beyond head)
– Tubercle (lateral to neck)
• Articulates posteriorly with transverse costal facet
of same-numbered thoracic vertebra
– Shaft
• Most of rib
© 2013 Pearson Education, Inc.
Figure 7.24a Ribs.
Transverse costal facet
(for tubercle of rib)
Angle
of rib
Superior costal facet
(for head of rib)
Body of vertebra
Head of rib
Intervertebral disc
Neck of rib
Tubercle of rib
Shaft Sternum
Crosssection
of rib
Costal groove Costal cartilage
Vertebral and sternal articulations of a typical true rib
© 2013 Pearson Education, Inc.
Figure 7.24b Ribs.
Articular facet
on tubercle of rib
Spinous process
Shaft
Ligaments
Neck of rib
Head of rib
Superior costal facet
(for head of rib)
Transverse
costal facet
(for tubercle
of rib)
Body of
thoracic
vertebra
Superior view of the articulation between a rib and a
thoracic vertebra
© 2013 Pearson Education, Inc.
Figure 7.24c Ribs.
Shaft
Facets for articulation
with vertebrae
Articular facet
Head Neck on tubercle
Junction with
Costal groove Angle of rib
costal cartilage
A typical rib (rib 6, right), posterior view
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