Download 7 - Riverside City College

PowerPoint® Lecture Slides
prepared by
Janice Meeking,
Mount Royal College
CHAPTER
7
The Skeleton:
Part A
Copyright © 2010 Pearson Education, Inc.
Introduction
• The skeleton accounts of 20% of body mass
• There are 206 bones in the human skeleton
• Ligaments –band of fibrous tissue that
connects bones
• Divisions of the Skeleton
• Axial Skeleton and Appendicular
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The Axial Skeleton
• Contains of 80 bones that collectively form the
axis of the body trunk
• Protect the brain and spinal cord and organs
within the thoracic cavity
• Three major regions of the axial skeleton
• Skull
• Vertebral column
• Thoracic cage
• Hyoid
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Skull
Thoracic cage
(ribs and
sternum)
Vertebral
column
Sacrum
Cranium
Facial bones
Clavicle
Scapula
Sternum
Rib
Humerus
Vertebra
Radius
Ulna
Carpals
Phalanges
Metacarpals
Femur
Patella
Tibia
Fibula
(a) Anterior view
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Tarsals
Metatarsals
Phalanges
Figure 7.1a
The Skull
•
General Characteristics
•
•
Composed of: cranial and facial bones
•
Cranial bones enclose and protect the brain
•
Facial bones form the framework of the face,
contain cavities for special sense organs,
provide openings for food & air, secure teeth,
anchor facial muscles
Most bones of the skull are: paired
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Bones of cranium (cranial vault)
Coronal
suture
Squamous
suture
Lambdoid
suture
Facial
bones
(a) Cranial and facial divisions of the skull
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Figure 7.2a
Major Sutures of the Skull
•Four sutures mark the articulations of parietal bones
with frontal, occipital, and temporal bones:
• Coronal (frontal) suture—between parietal bones and
frontal bone
• Sagittal suture—between right and left parietal bones
• Lambdoid suture—between parietal bones and occipital
bone
• Squamous suture—between parietal and temporal
bones on each side of skull
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Coronal suture
Parietal bone
Frontal bone
Sphenoid bone
(greater wing)
Temporal bone
Lambdoid
suture
Squamous
suture
Occipital
bone
(a) External anatomy of the right side of the skull
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Figure 7.5a
Sagittal suture
Parietal
bone
Lambdoid
suture
Occipital bone
Superior nuchal line
External
occipital
protuberance
(b) Posterior view
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Occipital
condyle
Figure 7.4b
The Skull
• Calvaria – Cranial vault “skull cap”
• Cranial Base (floor) of the skull is divided into
three regions:
• Anterior cranial fossa-accommodates the
frontal lobes of brain
• Middle cranial fossa- accomodates the
temporal lobes
• Posterior cranial fossa-deepest region houses
cerebellum
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Anterior cranial
fossa
Middle cranial
fossa
Posterior cranial
fossa
(b) Superior view of the cranial fossae
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Figure 7.2b
Cavities
Four pair of cavities within the skull bones
called: paranasal sinuses
• The four pair are:
•
•
•
•
Sphenoid
Ethmoid
Maxillary
Frontal
• Each cavity is lined with mucous membranes
that form mucus, which drains into the nasal
cavity
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Frontal
sinus
Ethmoidal
air cells
(sinus)
Sphenoid
sinus
Maxillary
sinus
(a) Anterior aspect
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Frontal
sinus
Ethmoidal
air cells
Sphenoid
sinus
Maxillary
sinus
(b) Medial aspect
Figure 7.15
The Orbits
• Composed of: Cranial and facial bones; 7
bones in each orbit –frontal, sphenoid,
zygomatic, maxilla, palatine, lacrimal, and
ethmoid
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Roof of orbit
Supraorbital notch
Superior
orbital fissure
Optic canal
• Lesser wing of
sphenoid bone
• Orbital plate of
frontal bone
Medial wall
• Sphenoid body
Lateral wall of orbit
• Orbital plate
of ethmoid bone
• Zygomatic process
of frontal bone
• Frontal process
of maxilla
• Greater wing of
sphenoid bone
• Lacrimal bone
• Orbital surface of
zygomatic bone
Nasal bone
Floor of orbit
Inferior orbital fissure
• Orbital process of
palatine bone
Infraorbital groove
Zygomatic bone
• Orbital surface of
maxillary bone
Infraorbital foramen
• Zygomatic bone
(b) Contribution of each of the seven bones forming the right orbit
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Figure 7.13a
The Nasal Cavity
• The roof, superior/lateral walls and superior
portion of the nasal septum are formed by: the
ethmoid bone
• The floor is formed anteriorly by the palatine
processes of the maxillae and the palatine
bones
• The cavity is divided into right and left halves
by the nasal septum
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Frontal sinus
Superior
nasal concha Ethmoid
Middle
bone
nasal concha
Inferior nasal
concha
Nasal bone
Sphenoid
bone
Palatine bone
(perpendicular plate)
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Maxillary bone
(palatine process)
Palatine bone
(horizontal plate)
Figure 7.14a
The Nasal Cavity
• Nasal conchae- on the lateral walls: formed by
the superior and middle nasal conchae of
ethmoid bone
• The conchae and septum are lined with a
mucus secreting mucosa that moistens &
warms air, helps cleanse it of debris
• Cribriform plate –porous superior surface of
ethmoid for passage of olfactory fibers (smell)
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Olfactory
foramina
Perpendicular
plate
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Crista galli
Cribriform
plate
Middle nasal concha
Figure 7.10
The Vertebral Column
• General Characteristics
• Contains 33 vertebrae, some of which are
fused in adults
• Intervertebral discs-
• Inner part
• Nucleus pulposus- gelatinous nucleus that
gives the disc its elasticity and
compressibility
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The Vertebral Column
• Outer part
• Anulus fibrosus- Outer collar composed of
collagen and fibrocartilage
• Herniated disc – usually involves rupture of
the anulus fibrosus followed by protrusion of
the spongy nucleus pulposus through the
anulus
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Intervertebral
disc
Anulus fibrosus
Nucleus pulposus
Median section of three vertebrae, illustrating the composition
of the discs and the ligaments
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Figure 7.17a
Spinal cord
Herniated portion
of disc
Anulus fibrosus
of disc
Nucleus
pulposus
of disc
(c) Superior view of a herniated intervertebral disc
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Figure 7.17c
Vertebral Column: Curvatures
• Increase the resilience and flexibility of the spine
• Four normal curvatures
• Two primary curvatures- Thoracic and sacral
• Born with primary curvatures
• Two secondary curvatures- Cervical and lumbar
• Develop after birth
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Figure 7.37
The Appendicular Skeleton
• Characteristics
• Includes: The upper and lower limbs and their
girdles (pectoral and pelvic girdle)
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Comparison of Male and Female Pelves
• The true pelvis is: the region inferior to the
pelvic brim containing pelvic organs
• The pubic angle is 80-90 degrees in females
and 50-60 degrees in males
• The acetabula are: smaller and farther apart
in females and larger and closer together in
males
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Base of sacrum
Iliac fossa
Coxal
bone
llium
(os coxae
or hip
Pubic
bone)
bone
Iliac crest
Sacroiliac
joint
Anterior
superior
iliac spine
Sacral
promontory
Sacrum
Coccyx
Anterior inferior
iliac spine
Pelvic brim
Acetabulum
Pubic tubercle
Pubic crest
Pubic symphysis
Ischium
Pubic arch
PLAY
Animation: Rotatable pelvis
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Figure 7.29
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Table 7.4
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Table 7.4
Frontal bone
Glabella
Frontonasal suture
Supraorbital foramen
(notch)
Supraorbital margin
Superior orbital
fissure
Optic canal
Inferior orbital
fissure
Middle nasal
concha
Ethmoid
Perpendicular bone
plate
Inferior nasal concha
Vomer
Parietal bone
Squamous part
of frontal bone
Nasal bone
Sphenoid bone
(greater wing)
Temporal bone
Ethmoid bone
Lacrimal bone
Zygomatic bone
Infraorbital foramen
Maxilla
Mandible
Mental
foramen
(a) Anterior view
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Mandibular symphysis
Figure 7.4a
Maxilla
(palatine process)
Hard
Palatine bone
palate
(horizontal plate)
Zygomatic bone
Temporal bone
(zygomatic process)
Vomer
Mandibular
fossa
Styloid process
Mastoid process
Temporal bone
(petrous part)
Pharyngeal tubercle
of basilar region of
the occipital bone
Parietal bone
External occipital crest
External occipital
protuberance
(a) Inferior view of the skull (mandible removed)
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Incisive fossa
Intermaxillary suture
Median palatine suture
Infraorbital foramen
Maxilla
Sphenoid bone
(greater wing)
Foramen ovale
Foramen spinosum
Foramen lacerum
Carotid canal
External acoustic meatus
Stylomastoid
foramen
Jugular foramen
Occipital condyle
Inferior nuchal line
Superior nuchal line
Foramen magnum
Figure 7.6a