Journal# 1: Which bones are
part of the axial skeleton?
Fun Fact
Trepanation, or
removing a piece of the
skull, was practiced in
ancient and even
prehistoric times. The
reason is not known, but
it may have been a
tribal ritual or
rudimentary treatment
for brain disorders.
• Objective:
– Identify the bones of the
cranium and face
– Describe the function of
the sinuses
– Give the key differences
in the skull structure of
infants, children, &
adults
Chapter 7:
The Axial Skeleton
Part I: The Skull
pgs. 204-223
The Axial Skeleton
• The axial skeleton - forms the
longitudinal axis of the body (has 80
bones):
• The skull
• The vertebral column
• The thoracic cage
The Axial Skeleton
Figure 7–1a
Functions of the Axial Skeleton
• Supports and protects organs in body
cavities
• Attaches to muscles of:
– head, neck, and trunk
– respiration
– appendicular skeleton
The Skull
• Has 22 bones:
– 8 cranial bones:
• form the braincase or cranium
– 14 facial bones:
• protect and support entrances to digestive and
respiratory tracts
The Skull
http://www.youtube.com/watch?v=Nc5IRj3OJhE
Figure 7–2
Sinuses
• Cavities which decrease the weight of
the skull:
– lined with mucus membranes
– protect the entrances of the respiratory
system
Sutures
• The immovable joints of the skull
Figure 7–3a, b
The Cranial Bones
•
•
•
•
•
•
Occipital bone
Frontal bone
Sphenoid
Ethmoid
Parietal bones (2)
Temporal bones (2)
Cranial Bones
Figure 7–4a, b
Foramina of the Occipital Bone
• Foramen magnum:
– connects cranial and spinal cavities
• Jugular foramen:
– for jugular vein
• Hypoglossal canals:
– for hypoglossal nerves
The Occipital Bone
Figure 7–5a
Functions of the Temporal Bones
• Part of lateral walls of cranium and
zygomatic arches
• Articulate with mandible
• Surround and protect inner ear
• Attach muscles of jaws and head
The Temporal Bones
Figure 7–7
Foramina of the Sphenoid
• Optic canals:
– for optic nerves
• Foramen ovale:
– for blood vessels and nerves of the face
The Sphenoid
Figure 7–8
Functions of the Ethmoid
• Roof of the nasal cavity
• Part of the nasal septum and medial
orbital wall
• Contains ethmoidal air cells (sinuses)
The Ethmoid
Figure 7–9
Foramina of the Ethmoid
• Olfactory foramina:
– in the “cribriform plate”
– for olfactory nerves
Functions of the Maxillary Bones
• Support upper teeth
• Form upper jaw and hard palate
• Contain maxillary sinuses (largest
sinuses)
Foramina of the Maxillary Bones
• Infraorbital foramen:
– for sensory nerve to brain (via foramen
rotundum of sphenoid)
• Inferior orbital fissure:
– for cranial nerves and blood vessels
The Maxillary Bones
• The largest facial bones
Figure 7–10a
Foramina of the Mandible
• Mental foramina:
– for sensory nerves of lips and chin
• Mandibular foramen:
– entrance to the mandibular canal
– for blood vessels and nerves of lower
teeth
The Mandible
Figure 7–12a,b
The Hyoid Bone
•Supports the larynx
•Attaches muscles of the
larynx, pharynx, and tongue
Figure 7–12c
Functions of the Inferior
Nasal Conchae
• To create air turbulence in the nasal
cavity
• To increase the epithelial surface area
• To warm and humidify inhaled air
The Small Bones of the Face
Figure 7–11
The Infant Skull
• Grows rapidly
• Is large compared to the body
• Has many ossification centers
The Infant Skull
Figure 7–15
Fontanels
• Are areas of fibrous connective tissue
(soft spots)
• Cover unfused sutures in the infant
skull
• Allow the skull to flex during birth
Axial Lab Part A
• Figure 1: use pg. 210
• Figure 2: pg. 209
• Figure 3: pg. 210
• Figure 4: pg. 211
*Make sure you can name and identify all
of the bones/structures on the lilst
Journal #4: Which parts of the
axial skeleton have we not yet
studied?
• Vocabulary
4. Primary curve
5. Secondary curve
6. Whiplash
7. Thoracic cage
8. True Ribs
9. False Ribs
10. Costae
• Objective:
– Identify and describe the
curvatures of the spinal
column and their
functions
– Identify the vertebral
regions, and describe the
distinctive structural and
function characteristics
of each vertebral group
Diagram 24 & 25 Quiz
1. What are the 2 types of bones that the
skull is made of?
2. Name the only joint of the skull that is not
made of immovable fibrous sutures.
3. What is a process?
4. What is a foramen?
5. Which suture would you find between the
sphenoid and temporal bones?
Axial Skeleton Notes Part II
Interactive pgs 224-234
The Vertebral Column
• The spine or vertebral column:
– protects the spinal cord
– supports the head and body
Regions and Curves of the
Vertebral Column
• 26 bones:
– 24 vertebrae, the
sacrum, and coccyx
Figure 7–16
Vertebrae of the
Vertebral Column
• The neck:
– 7 cervical vertebrae
• The upper back:
– 12 thoracic vertebrae
– each articulate with one or more pairs of
ribs
• The lower back:
– 5 lumbar vertebrae
Structure of a Vertebra
Figure 7–17a,b
The 3 Parts of a Vertebra
• The vertebral body (centrum):
– transfers weight along the spine
• The vertebral arch:
– posterior margin of vertebral foramen
• The articular processes:
– lateral projections between laminae and
pedicles
The Vertebral Arch
• Pedicles:
– walls of the vertebral arch
• Laminae:
– roof of the vertebral arch
• Spinous process:
– projection where vertebral laminae fuse
• Transverse process:
– projection where laminae join pedicles
The Vertebral Arch
Figure 7–17c
The Articular Processes
• Superior articular process
• Inferior articular process:
– have articular facets on articular faces
Vertebral Foraminae
• Intervertebral foraminae:
– gaps between pedicles of adjacent
vertebrae
– for nerve connections to spinal cord
• Vertebral canal:
– formed by vertebral foraminae
– encloses the spinal cord
The Vertebral Canal
Figure 7–17d,e
Intervertebral Discs
• Are pads of fibrocartilage
• Separate the vertebral bodies
• Absorb shocks
Journal # 4: Name the types of
vertebra and the number of each.
• Fun fact: You can
determine the sex
of a skeleton based
on the angle of the
pubic bones.
• Objective: Identify
the vertebral
regions and describe
their structure and
function.
Vertebral Regions
• Vertebrae are numbered:
– by region, from top to bottom
– C1 articulates with skull, L5 with sacrum
• Vertebrae of each region:
– have characteristics determined by
functions
The Cervical Vertebrae
•small body (support only head)
•C1 (atlas) has no body or spinous process
Whiplash
• Whiplash:
– a traumatic dislocation of cervical
vertebrae
http://www.youtube.com/watch?v=FQ-42D-2hw&feature=related
Hangman’s Fracture
• Pedicle fracture of C2
• Common in car
accidents (head
striking windshield)
The Thoracic Vertebrae
Figure 7–19a
The Lumbar Vertebrae
Figure 7–20a
The Lumbar Vertebrae
1. largest vertebrae
2. oval-shaped bodies
Figure 7–20b, c
Comparing Vertebrae
Table 7–2
The Sacrum and Coccyx
Figure 7–21
Sacrum and Coccyx
• The sacrum:
– is curved, more in males than in females
– protects reproductive, urinary, and
digestive organs
• The coccyx:
– attaches ligaments and a constricting
muscle of the anus
– consists of fused coccygeal vertebrae
The Thoracic Cage
• The skeleton of the chest:
– supports and protects the thoracic cavity
• Consists of:
– thoracic vertebrae
– ribs
– sternum (breastbone)
The Rib Cage
• Formed of ribs and sternum
Figure 7–22a
Functions of Ribs
• Ribs:
– are flexible & mobile
– can absorb shock
• Ribs 1–7 (true ribs)
– connected to the sternum by costal
cartilages
• Ribs 8–12 (false ribs):
– do not attach directly to the sternum
3 Parts of the Sternum
1. The manubrium
– the superior portion of sternum
– articulates with clavicles & 1st ribs
2. The sternal body
–
is tongue-shaped
3. The xiphoid process
–
attaches to diaphragm and rectus
abdominis muscles
Journal # 5: What is the main
difference between vertebrosternal
and vertebrochondral ribs?
• Fun Fact: Women and
• Objective: Identify the
men have the exact same
vertebral regions and
number of ribs. The
describe their structure
belief that women have
and function.
more comes from a verse
in the bible.