Question | Answer |
Consists of: Bones, cartilage, joints, and ligaments | The Skeleton |
How many bones are in the Axial Skeleton? | 80 |
How many bones are in the Appendicular Skeleton? | 126 |
The Axial Skeleton consists of: | the skull, vertebral column, and bony thorax |
Look at slide 3-4 in PP CHAP-7 to see a diagram of the Axial Skeleton | Look at slide 3-4 in PP CHAP-7 to see a diagram of the Axial Skeleton |
Formed by cranial and facial bones | The Skull |
Look at slide 5 in PP CHAP-7 to see a diagram of the Skull | Look at slide 5 in PP CHAP-7 to see a diagram of the Skull |
Encloses and protects brain
Provides attachment for head and neck muscles
Is the body’s the most complex bony structure | The Cranium |
Look at slide 6 in PP CHAP-7 to see a diagram of the Cranium | Look at slide 6 in PP CHAP-7 to see a diagram of the Cranium |
Form framework of the face
Form cavities for the sense organs of sight, taste, and smell
Provide openings for the passage of air and food
Hold the teeth in place
Anchor muscles of the face | Facial Bones |
2 divisions of the Cranium | cranial vault and the base |
Internally, prominent bony ridges divide skull into: | distinct fossae |
How many named openings does the skull contain? (eg Foramina, canals, and fissures) | 85 |
What is the purpose of Skull openings? | Provide openings for important structures
Spinal cord
Blood vessels serving the brain
12 pairs of cranial nerves |
The Cranium is formed from how many large bones? | 8 |
Paired bones of the Cranium | Temporal bones
Parietal bones |
Unpaired bones of the Cranium | Frontal bone
Occipital bone
Sphenoid bone
Ethmoid bone |
form superior and lateral parts of skull | Parietal bones |
Four sutures of the cranium | Coronal-where parietal bones meet the frontal bone
Squamous—where each parietal bone meets a temporal bone inferiorly
Sagittal—where right and left parietal bones meet superiorly
Lambdoid-where parietal bones meet the occipital bone posteriorly |
Small bones that occur within sutures
Irregular in shape, size, and location | Sutural Bones
(note: Not all people have sutural bones) |
Look at slide 16 in PP CHAP-7 to see a Posterior View of the Skull | Look at slide 16 in PP CHAP-7 to see a Posterior View of the Skull |
Forms the forehead and roofs of orbits | Frontal Bone |
superior margin of orbits | Supraorbital margin |
smooth part of frontal bone between superciliary arches (Frontal sinuses within frontal bone) | Glabella
(Contributes to anterior cranial fossa) |
Forms the posterior portion of the cranium and cranial base
Articulates with the temporal bones and parietal bones
Forms the posterior cranial fossa
Foramen magnum located at its base | Occipital Bone |
Features and Structures of the Occipital Bone | Occipital condyles
Hypoglossal foramen
External occipital protuberance
Superior nuchal lines
Inferior nuchal lines |
Look at slide 20 in PP CHAP-7 to see an Inferior View of the Skull | Look at slide 20 in PP CHAP-7 to see an Inferior View of the Skull |
Lie inferior to parietal bones
Form the inferolateral portion of the skull
Term comes from Latin word for time | Temporal Bones |
Regions of Temporal Bones | Squamous, temporal, petrous, and mastoid regions |
Look at slide 20 in PP CHAP-7 to see a Lateral View of the Skull | Look at slide 20 in PP CHAP-7 to see a Lateral View of the Skull |
Look at slide 21 in PP CHAP-7 to see an illustration of The Temporal Bone | Look at slide 21 in PP CHAP-7 to see an illustration of The Temporal Bone |
Site for neck muscle attachment
Contains air sinuses | The mastoid process |
Projects medially, contributes to cranial base
Houses cavities of middle and internal ear
Contributes to the middle and posterior cranial fossae | Petrous region |
smallest and lightest vertebrae | Seven cervical vertebrae (C1–C7) |
typical cervical vertebrae | C3–C7 |
Body is wider laterally
Spinous processes are short and bifid (except C7)
Vertebral foramen are large and triangular
Transverse processes contain transverse foramina
Superior articular facets face superoposteriorly | Typical Vertebrae (C3–C7) |
Look at slide 27 in PP CHAP-7 to see an illustration of Cervical Vertebrae | Look at slide 27 in PP CHAP-7 to see an illustration of Cervical Vertebrae |
C1:
Lacks a body and spinous process
Supports the skull
Superior articular facets receive the occipital condyles
Allows flexion and extension of neck
Nodding the head “yes” | The Atlas |
Look at slide 29-30 in PP CHAP-7 to see an illustration of The Atlas | Look at slide 29-30 in PP CHAP-7 to see an illustration of The Atlas |
Has a body and spinous process | The Axis |
projects superiorly
Formed from fusion of the body of the atlas with the axis
Acts as a pivot for rotation of the atlas and skull
Participates in rotating the head from side to side | Dens (odontoid process) |
Look at slide 32 in PP CHAP-7 to see where the Dens is located | Look at slide 32 in PP CHAP-7 to see where the Dens is located |
All articulate with ribs
Have heart-shaped bodies from the superior view | Thoracic Vertebrae (T1—T12) |
bears demifacts for articulation with ribs on each side of body | T1–T10 |
has a full facet for the first rib | T1 |
only have a single facet | T10–T12 |
articular facets pointing posteriorly | Superior articular facets |
articular processes pointing anteriorly | Inferior articular processes
(Allows rotation and prevents flexion and extension) |
Bodies are thick
Transverse processes are thin and tapered
Spinous processes are thick, and point posteriorly
Triangular Vertebral foramina
Superior and inferior articular facets directly medially
Allows flexion and extension—rotation prevented | Lumbar Vertebrae (L1—L5) |
Look at slide 40 in PP CHAP-7 to see an illustration of Lumbar Vertebrae | Look at slide 40 in PP CHAP-7 to see an illustration of Lumbar Vertebrae |
Shapes the posterior wall of pelvis
Formed from 5 fused vertebrae
Superior surface articulates with L5
Inferiorly articulates with coccyx | Sacrum (S1—S5) |
Where the first sacral vertebrae bulges into pelvic cavity | Sacral promontory |
How far is the center of gravity posterior to sacral promontory | 1cm |
develops from fused rib elements | Ala |
2 parts of Sacral foramina | Ventral foramina
Passage for ventral rami of sacral spinal nerves
Dorsal foramina
Passage for dorsal rami of sacral spinal nerves |
Is the “tailbone”
Formed from 3—5 fused vertebrae
Offers only slight support to pelvic organs | Coccyx |
Forms the framework of the chest
Protects thoracic organs
Supports shoulder girdle and upper limbs
Provides attachment sites for muscles | The Thoracic Cage |
Components of The Thoracic Cage | Thoracic vertebrae—posteriorly
Ribs—laterally
Sternum and costal cartilage—anteriorly |
Look at slide 47 in PP CHAP-7 to see an illustration of The Thoracic Cage | Look at slide 47 in PP CHAP-7 to see an illustration of The Thoracic Cage |
3 sections of The Sternum | Manubrium—superior section
Articulates with medial end of clavicles
Body—bulk of sternum
Sides are notched at articulations for costal cartilage of ribs 2–7
Xiphoid process—inferior end of sternum
Ossifies around age 40 |
Central indentation at superior border of the manubrium | Jugular notch |
A horizontal ridge where the manubrium joins the body | Sternal angle |
Where sternal body and xiphoid process fuse
Lies at the level of the 9th thoracic vertebra | Xiphisternal joint |
All ribs attach to vertebral column: posterior or anterior? | posterior |
superior seven pairs of ribs
Attach to sternum by costal cartilage | True ribs |
inferior five pairs of ribs | False ribs |
Ribs 11–12 are known as: | floating ribs |
A common congenital disorder
Right and left halves of palate fail to fuse medially | Cleft palate |
Narrowing of the vertebral canal
Can compress roots of spinal nerves | Stenosis of the lumbar spine |
an abnormal lateral curvature | Scoliosis |
an exaggerated thoracic curvature | Kyphosis |
an accentuated lumbar curvature; “swayback” | Lordosis |
Unossified remnants of membranes | Fontanels |
Many bones of the face and skull form by: | intramembranous ossification |
Endochondral bones of the skull | Occipital bone
Sphenoid
Ethmoid bones
Parts of the temporal bone |
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