Download Bony Thorax - Northwest ISD Moodle

The Axial Skeleton
 the
skull
 the vertebral column
 the thoracic cage
 the
cranium
• Surround and protect the brain
• Curvature is structurally strong in resisting impact
forces
 the
facial bones
• protect the front of the head
• Give our faces their individual shape
• Protect and orient the eyes
• Allow chewing of food
 Sutures
are irregularly shaped,
interlocking, and immovable joints
 Bound by strong, tiny fibers
 Permit a very small amount of movement
which contributes to the compliance
(ability to change size and shape in
response to force) and elasticity
 Only exception to sutures in the skull is
the mandible which is a hinge joint
 Infants
have large heads in comparison
to their bodies/represents1/4th of body
height
 Adult skull accounts for 1/8th of total
body height
 French
for “little fountain” because the baby’s
pulse can be felt through the soft spots
 Openings
connected only by pockets of fibrous
membranes where bones join together
 Allows
compression of the skull during birth
 Enables
brain growth during late pregnancy
and early infancy
 Ossify
to bone by 22 to 24 months
 frontal
bone – forms the forehead, forms
part of the orbits
 parietal bones (2) – form the majority of
the top and sides of the skull
 temporal bones (2) – surround the ears
 occipital bones (2) – forms the base and
lower back portion of the skull
 ethmoid
bone – forms part of the nasal
septum, forms part of the orbits
 sphenoid bone – butterfly shaped,
centrally located with the skull, supports
the base of the brain, forms part of the
orbits, connected to all the other bones of
the skull
 maxillary
bones (2) – form the upper jaw,
house the upper teeth, connects to all
bones of the face except the mandible,
forms part of the orbits
 palatine bones (2) – forms the posterior
part of the hard palate
 zygomatic bones (2) – cheekbones, forms
much of the sides of the orbits
 lacrimal bones (2) – surround the tear
ducts, forms part of the orbits
 nasal
bones (2) –forms the bridge of the
nose
 vomer – comprises most of the bony
nasal septum
 inferior concha bones (2) – forms the
sides of the nasal cavity
 mandible – lower jawbone, largest facial
bone; only moveable facial bone
External Auditory
meatus
Styloid Process
 regions
of the spine
• Cervical
• Thoracic
• Lumbar
• Sacrum
• Coccyx
C1- C7
T1 – T12
L1 – L5
5 fused bones
4 fused bones
 curves
of the spine
Primary spinal curves (present at
birth)
* thoracic curve (anteriorly
concave), present at birth
* sacral curve (anteriorly
concave), present at birth
Secondary spinal curves (develop
after birth as baby raises head, sits
and stands)
* cervical curve (posteriorly
concave) raises head
* lumbar curve (posteriorly
concave) begins to stand and
walk
 Develop
due to genetic or congenital
abnormalities or when the spine is
habitually subjected to asymmetrical
forces.
 Lordosis – exaggeration of the lumbar
curve
 Kyphosis – accentuation of the thoracic
curve
 Scoliosis – any lateral deviation of the
spine






vertebral body – thick, disc-shaped portion that bears
weight and forms the anterior portion of the vertebra
vertebral arch – round projection of bone on the
posterior aspect of the vertebra
vertebral foramen – opening in vertebra where the
spinal cord passes through
transverse processes – bony projections on the lateral
sides of the vertebral arch
spinous process – bony projection that extends
posteriorly
superior and inferior articular processes – indentations
or facets where a vertebra articulates, or joins, with the
vertebra immediately above or below (facet joints)
 Composed
 located
 shock
 allow
of fibrocartilage
between vertebrae
absorbers
flexibility
 Account
for ¼ of he height of the spine
1.
2.
3.
Support the shoulder girdle and upper
limbs
Protect the viscera in the thoracic and
upper abdominal cavities
Play a role in breathing
3 fused bones
1. Manubrium
2. Body
3. Xiphoid process
12 pair of ribs that attach posteriorly to the
Thoracic Vertebrae and then curve
downward and forward toward the
anterior body surface.
The ribs increase in length from 1 to 7 and
then decrease in length from 8 to 12.
True Ribs: upper 7 that are attached to the
sternum by costal cartilage
False Ribs: remaining 5; either attach indirectly
to the sternum or lack sternal attachment
entirely
Floating Ribs: pairs 11 & 12; have no anterior
attachment; their costal cartilages lie
embedded in the muscles of the lateral body
wall
Appendicular Skeleton
Supports the upper limbs
Attachment for several muscles that move
the upper limbs
Braces the freely movable scapulae,
helping to hold the shoulder in place.
Provides attachment for muscles of the
upper limbs, chest, and back.
Triangular bones located on either side of
the upper back.
A spine divides the posterior surface of
each scapula into unequal portions.
The spine leads to 2 processes:
1. Acromium process that forms the tip of
the shoulder; articulates with the clavicle
2. Coracoid process that curves
anteriorly and inferiorly to the clavicle
Between the process is a depression called
the glenoid cavity that articulates with
the head of the humerus (arm bone)
Humerus:
Ulna:
Radius:
Carpus: 8 bones in 2 rows
Metacarpals: Palm, 1 to 5 from thumb to
little finger
Phalanges:
Fingers, 14 bones
1.
2.
3.
4.
Attaches the lower limbs to the axial skeleton
Supports the visceral organs of the pelvic
cavity
Formed by the 2 coxal bones that articulate
anteriorly at the symphysis pubis and
posteriorly with the sacrum
The 3 bones fuse in the region of a cupshaped cavity called the acetabulum, which
receives the rounded head of the femur
3 fused bones:
1. Ilium – Largest and uppermost portion that forms the
prominance of the hip (iliac crest); joins the sacrum to
form the sacroiliac joint
2. Ischium – lowest portion; L-shaped; ischial tuberosity
points posteriorly and downward and supports the
weight of the body when sitting; ischial spine near the
junction of the ilium and ischium
3. Pubis – anterior portion forms the joint called the
symphysis pubis; joins with the ischium to form the
largest foramen in the skeleton, the obturator foramen
Iliac Crest
Ilium
acetabulum
Ischium
Pubis
Obturator
foramen
Ischial
Spine
Ischial
tuberosity
1.
2.
3.
4.
False Pelvis: portion superior to the pelvic brim
True Pelvis: region inferior to the pelvic brim that is
almost entirely surrounded by bone and forms a
deep “bowl” containing the pelvic organs
Pelvic Inlet: pelvic brim; widest dimension is along
the frontal plane
Pelvic Outlet: inferior margin of the true pelvis;
bounded anteriorly by the pubic arch, laterally by
the ischia, and posteriorly by the sacrum; since both
the coccyx and the ischial spines protrude into the
outlet, a sharply angled coccyx or large spines can
cause problems during childbirth
Male
Characteristic
Female
Female
Male
General Structure &
Functional Modifications
Tilted forward, modified for
childbearing; cavity of the true
pelvis is broad, shallow, and has
a greater capacity
Tilted backward; adapted for
support of a strong body; cavity
of the true pelvis is narrow and
deep
Bone Thickness
Less; bones lighter, thinner and
smoother
Greater; bones heavier and
thicker, and markings are more
prominent
Acetabulum
Smaller; farther apart
Larger; closer together
Pubic angle/arch
Broader (over 90 ), more
rounded
o
Angle is more acute (less
o
than 90 )
1.
2.
3.
Carry the entire weight of the erect
body
Subjected to exceptional forces when
jumping and running
Thicker and stronger than comparable
bones of the upper limbs
Longest bone in the body
Located on the medial side
Non weight bearing bone
Located laterally
Knee Cap
Foot
“A segmented structure can only hold up weight
if it is arched.”
The foot has 3 arches that “give when weight is
applied to the foot and spring back when the
weight is removed:
2 longitudinal
1. Medial
2. Lateral
1 transverse