Transcript lab 3 - axial Lecture Notes Page

LABORATORY THREE
SKELETAL SYSTEM
Axial
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Classification of Bones (Shape)
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Long (femur)
Short (wrist)
Flat bones (skull)
Irregular (scapula)
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Anatomy of a Long Bone
• Diaphysis (Shaft – compact bone)
• Contains yellow marrow inside
medullary canal (marrow cavity)
• Epiphyses (spongy bone)
• Expanded ends of long bones
• Contains red marrow (RBC
production)
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Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Microscopic Anatomy of Compact Bone
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Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
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The Skeletal System
Axial
• Two subdivisions
• Axial skeleton
• lie along the body’s central
axis (bones found along
midline)
• Appendicular skeleton
• appendages and the bones that
attach them to axial skeleton
Appendicular
• the pectoral & pelvic girdles serve as points
of articulation for the arms and legs
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The Axial System
• Three subdivisions:
• Skull – formed from many
articulated bones
• Hyoid bone - (U-shape)
• Thorax
• Sternum
• Rib cage
• Costal cartilages
• Vertebral column
• Vertebrae
• Sacrum and coccyx
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Bones of The Skull
Articulate at immovable joints called sutures
Supraorbital
foramen/notch
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The Skull
Figure 6.14
Take the top of the
skull off of the model
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The Skull
Take the mandible
off of 4/11/2017
the model
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Fetal Skull
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Anterior fontanel
Posterior fontanel
Frontal bone
Parietal bone
Temporal bone
Occipital bone
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The Vertebral Column
• Provide axial support between the
skull and pelvis
• Protects the delicate structure of
spinal cord
• Primary curve: thoracic & sacral
– Has already developed at birth
• Secondary curve: cervical & lumbar
– develops as an infant learns to hold his
head up, stand, and walk
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Abnormal Spinal Curvature
• Scoliosis (lateral curvature)
• Kyphosis (hunchback)
• Lordosis (swayback)
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The Vertebral Column
•24 individual bones-named for the associated body region
•7 Cervical (C1-C7) - neck
•12 Thoracic (T1-T12) – ribs attached to
•5 Lumbar (L1-L5) - lower back
•On practicum: number and type of vertebra
•2 fused bones
•sacrum (part of pelvis)
•coccyx (tailbone)
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A Typical Vertebra
TP to SP
TP to body
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ID Different Vertebrae
The first two cervical vertebrae are significantly modified from a
typical vertebra
• C-1 or atlas (shoulder pads) - articulates with the occipital bone
– no body & no spinous process, but has transverse foramina
• C-2 or axis (football player)
– dens or odontoid process (body of C-1, important for “no” rotation)
– bifid
– has transverse foramina
• Typical cervical vertebrae (C3-C7)
– transverse foramina
– spinous process is split in some (bifid)
• Thoracic vertebrae (giraffe )
– long narrow spinous process & small body
– demi-facet where ribs are attached
– the superior articular facets are flat and protrude upward
• Lumbar vertebrae (moose)
– massive bodies because of more weight upon them
– short blunt spinous process
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Sacrum
•Sacrum consists of five fused sacral vertebrae
•Coccyx consists of 3-5 fused coccygeal vertebrae
•Median sacral crest: spinous process
•Ventral and Dorsal sacral foramina: intervertebral foramina
•Sacral canal: vertebral foramina
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The Thorax
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Form a bony cage around the heart & lungs
The sternum:
• Manubrium - Jugular notch is a superficial landmark where manubrium articulates
with clavicles
• Gladiolus (body) – inferior to sternal angle
• Xiphoid process – apex of the heart – A landmark for cardiopulmonary resuscitation
Humans have 12 pairs of ribs - each is attached to a thoracic vertebra and form the wall of the thoracic cage
• 7 pairs of true ribs
• 3 pairs of false ribs
• 2 pairs of floating ribs
Costal cartilage
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Hyoid Bone
• Body
• Greater Horn
• Lesser Horn
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