Bones

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Bone Tissue
Dynamic Tissue,
full of cells,
blessed are you
among tissues
and blessed is
the fruit of thy
marrow, red
blood cells
Objectives
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Name tissues and organs of skeletal
system
State its functions
Classify four types of bone by shape
Describe general features of long bone
List cells, fibers, and ground
substances
The skeletal system,
what’s up with that?
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Bones, cartilage, and ligaments make it up
Functions include…
–
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Support: hold us up
Protection for soft, weak organs
Movement; leverage for muscles
Blood formation: also cells of immune system
Electrolyte balance: Calcium & Phosphate stores
Acid/Base balance: absorbing/releasing alkaline
salts
– Detoxification: takes up heavy metals
What do you need
electrolytes for?
Definition: Any of various
ions, such as sodium,
potassium, or chloride,
required by cells to
regulate the electric
charge and flow of
water molecules across
the cell membrane.
Calcium: Activates your
muscles
Phosphates: are needed
for ATP
Bones classified by shape
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Long bones, include
humerus of arm,
phalanges, femur.
Rigid levers for
muscles to act on
Short Bones
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Equal in length and
width
Limited in motion
Carpals in wrist
Tarsals in ankle
dude he said bones
Flat bones
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Protect soft organs
Examples include the
ribs, sternum, scapula,
os coxae (hip bone),
and cranial
Irregular bones
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Irregular
Fit no
preconcieved
categories
Rebels, maverics
Include vertebrae,
and bones in the
skulll
Parts of the long bone
This will aid you on Friday’s
lab
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Cylinder of dense white tissue: enclosing medullary cavity (contains
marrow)
At the ends: spongy (cancellous bone)
Shaft: daphysis
Heads: epiphysis
Joints covered with articular cartilage
Nutrient foramina: small holes to let in blood vessels
Peristoneum: external sheath, helps attach bones and muscle
Endosperm: internal lining of bone
Cells
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Osteogenic cells: in endosteum, AKA:
stem cells
Osteoblasts: make the bone matrix,
mineralize the bone. Non-mitotic.
Osteocytes: former Osteoblasts that
have gotten trapped in the matrix.
They reside in lacunae. Communicate
where more bone is needed.
The matrix
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1/3 organic; collagens
2/3 inorganic;
hyrdoxyapatite, calcium
carbonate, and trace
elements
The mineral component
gives support, the organic
protein gives flexibility
Compact Bone
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Transverse
slices show
concentric
lamellae –
layers of
matrix
arranged
around
Haversian
canals
This is the
basic
structural unit
of bone
Bone Marrow
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Soft Tissue in the medullary cavity &
spaces in spongy bone
– Red: hemopoietic: makes red blood cells,
looks like blood, but thicker
– Yellow: this is what middle aged people
have instead of red bone marrow, doesn’t
produce blood, but it can revert to red
bone marrow. Adults only have red
marrow in certain spots
– Gelatinous: found in old age: yellow has
turned to reddish jelly.
Bone Growth and
Remodeling
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The wily bone, it
changes throughout
life to accommodate
our selfish, selfish,
needs.
Tension leads to
individual spines and
ridges
Those who do heavy
manual labor have
denser bones
Growth Mechanisms
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Interstitial growth: adding more matrix internally
Appositional growth: add more matrix to the surface. It starts
with osteogenic cells which develop into osteocytes. This is
the only way adult bone can grow.
– Why is bone growth so complicated?
– interstitial bone growth impossible (too rigid) so all bone growth
must occur on surfaces
– appositional growth OK for width, but not for length (because of
articular cartilage)
– interstitial growth essential for length, so this must be
cartilaginous to start with
– then, need to create free surfaces within growing cartilage for
bone deposition
– so, chondrocytes hypertrophy to create cavities, then secrete
calcified (stiffened) cartilage to prevent cavities collapsing when
cells die
– bone can then be deposited on free internal surfaces, as the
temporary calcified cartilage is removed
Healing Fractures
Types of Fractures
Bad Breaks
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Broken femur
Broken Collar Bone
Fractured Skull
Chapter 8 the chapter of skeletons that you will
be tested on, determining the future of those of you
not yet accepted to prestigious colleges. Have fun at
McDonald’s. Thank you for serving my freedom fries.
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Cranial bones
correspond to
lobes of brain
Parietal bone
Occipital bone
Frontal bone
Temporal bone
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Note sutures
where bones
have fused
together
Temporomandibular Joint
Syndrome
Temporomandibular Joint
Syndrome
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one of the most complicated joints in
the body.
Moves in many directions
During chewing, it sustains an
enormous amount of pressure.
contains a piece of special cartilage
called a disk that keeps the skull and
the lower jawbone from rubbing
against each other.
Problems from strain, abnormal
chewing, or arthritis can lead to acute
pain
Treatment depends on severity. For
mild cases; analgesics, heat therapy,
massage
Cleft pallet
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split in the roof of the mouth
resulting in a passageway
into the nose.
can be corrected with
surgery.
likelihood of cleft lip and
cleft palate can be reduced if
a woman takes folic acid
before pregnancy and
through the 1st trimester of
pregnancy.
Warning disturbing
image of cleft pallet
babies to follow
Cleft Pallet
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In the past, it was
also known as a
hare lip and was
more conspicuous
even with surgery
In some cases
speech
impediments remain
Vertebral Column
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Cervical area:
around neck
Thoracic
vertebrae noted
for spinous
process
Lumbar: lower
back
Sacrum: at the
back of the
pelvis
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Thoracic vertebrae
attach to the ribs
Sacrum once
thought to be the
seat of the soul
Originally 5 bones in
infants it fuses
around age 16 and
is one bone by age
26
Upper
Limbs
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Humerus
– hemispherical
head that
attaches to the
shoulder in a ball
and socket joint
– Radius and ulna
articulated by the
other end
Radius vs. Ulna
Death match
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Ulna is longer
Radius has the
large styloid
process and a
rounder head
Warning
gruesome
vile bloody
images to
follow
So many people
break these
bones.
Metacarpals
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Bones of the palm
Look like
extensions of the
fingers, so they
seem much longer
than they really
are.
Phalanges are the
actual finger bone
Femur
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Attaches to the ox
coxae (hip) at the
spherical head
Attaches to the
patella, fibia and
tibia at the other
Bones of the lower leg
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Tibia: thicker, stronger,
weight bearing
Fibula: slender,
stabilizes the ankle,
bears no weight.
– Can be removed at times
to replace other lost
bone.
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Warning horrible,
disgusting, Sweet
mother of mercy
why? images to
follow
The photograph below shows long jumper, Llewellyn Starks,
who suffered a compound fracture to his right tibia and fibula
when attempting a jump at the 1992 New York games. The
bone can be clearly seen protruding through Stark's leg.
Dr. Leonard
“Bones” McCoy
U.S.S.
Enterprise
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