Bill Nye song:
http://www.youtube.com/watch?v=Y1abT5
0xXyk&feature=related
Pre-assessment
• 3-2-1- Cards
– List 3 things you already know about
the skeletal system.
– List 2 questions you have about the
skeletal system.
– List 1 thing you want to learn about
the skeletal system.
Function of the skeletal system
• 1. Support
• 2. Protection
• 3. Movement
• 4. Blood Cell Formation
• 5. Storage of Nutrients
Classification of Bones
I . Composition of bones: two types of bone
A. Compact
B. Spongy
II. Shape of bones:
A. Long bones
B. Short bones
C. Flat bones
D. Irregular bones
E. Sesamoid
Every bone is made up
of either spongy bone,
compact bone, or both.
I. Composition of Bones:
A. Compact bone: dense,
smooth and
homogeneous
throughout.
B. Spongy bone:
composed of small
needle-like or flat pieces
of bone called
trabeculae and has
many open spaces filled
with bone marrow.
• Aka cancellous bone
A. Compact
Bone
The structural unit of compact
bone is an osteon.
Each osteon consists of
concentric bone layers called
lamellae, making the bone
extremely hard and dense.
The lamellae surround a long
hollow passageway, the
Haversian canal.
This canal contains small blood
vessels responsible for the blood
supply to osteocytes (individual
bone cells) a nerves.
Canaliculi are little canals which
connect bone cell and are used
to exchange nutrients and waste.
MATRIX
B. Spongy Bone
• Light, porous bone
enclosing numerous large
spaces that give a
honeycombed or spongy
appearance.
• The bone matrix, or
framework, is organized
into a three-dimensional
latticework of bony
processes, called
trabeculae, arranged along
lines of stress.
• The matrix is organized to
provide maximum strength
similar to braces that are
used to support a building.
• The spaces between are
often filled with marrow.
Bone Marrow
• Is made in the spongy bone
• When someone is born, all marrow is red.
• Eventually, some of it gets converted into
yellow marrow.
• WHAT’S THE DIFFERENCE?
THERE ARE TWO TYPES OF BONE MARROW
FOUND IN MOST BONES:
• YELLOW BONE MARROW CONSISTS MOSTLY OF FAT • RED BONE MARROW CELLS (ADIPOSE TISSUE).
FOUND IN SPONGY
BONE, THE ENDS OF
• IT SERVES AS AN ENERGY
LONG BONES, RIBS,
RESERVE.
VERTEBRAE, THE
• CAN ALSO BE CONVERTED
STERNUM, AND THE
TO RED BONE MARROW
PELVIS –
AND PRODUCE BLOOD
• PRODUCES RED BLOOD
CELLS WHEN SEVERE
CELLS AND SPECIAL
BLOOD LOSS OCCURS.
WHITE BLOOD CELLS
CALLED LYMPHOCYTES,
AND OTHER ELEMENTS
OF BLOOD (platelets)
II. Shape of Bones:
A. Long Bones
• Bones that are longer than they are wide
are called long bones.
• They consist of a long shaft with two bulky
ends or extremities.
• They are primarily compact bone but may
have a large amount of spongy bone at
the ends or extremities. Ex. Humerus
You need to know this one for lab
• Even though these are small, finger bones
are still classified as long bones.
• Growth plates are located on
the long bones of children and
young people. These plates
are areas of growing tissue
near the end of the bones.
• Each long bone has at least
two growth plates-one at each
end. This is where the long
bones grow. When young
people finish growing, the
growth plates close and are
replaced by solid bone.
• Most growth plate fractures
get better and do not cause
any lasting problems.
Growth
Plate
II. Shape of Bones:
B. Flat Bones
• Flat bones are thin, flattened, and usually
curved.
• Most of the bones of the cranium are flat
bones.
II. Shape of Bones:
C. Short Bones
• Short bones are roughly cube shaped with
vertical and horizontal dimensions
approximately equal.
• They consist primarily of spongy bone,
which is covered by a thin layer of
compact bone.
• Short bones include the bones of the wrist
and ankle.
II. Shape of Bones:
D. Irregular Bones
• Bones that are not in any of the above
three categories are classified as irregular
bones.
• They are primarily spongy bone that is
covered with a thin layer of compact bone.
• The vertebrae and some of the bones in
the skull are irregular bones.
II. Shape of Bones:
E. Sesamoid
• Sesamoid bones can
be found on joints
throughout the body,
they are the hardest
form of cartilage.
• Ex. the patella (within
the quadriceps
tendon)
FYI: The only floating bone
• Is the hyoid
bone.
• It is not joined to any
other bone but is
suspended in position
by muscles that
connect it to the
mandible, each
temporal bone, at the
base of the skull, to the
thyroid cartilage, to the
sternum and to the
scapula.
•
Cartilage
• Cartilage is a solid connective tissue
that is to a certain extent pliable,
making it resilient. These
characteristics of cartilage are due to
the nature of its matrix.
• There are three kinds of cartilage:
1. hyaline cartilage
2. elastic cartilage
3. fibrocartilage.
1. Hyaline cartilage
• is the most abundant type of cartilage.
• Most of the skeleton of the fetus is laid
down in cartilage before being replaced by
bone.
• Hyaline cartilage in the adult is found in
the nose, parts of the respiratory tract, at
the ends of ribs and at the articular
surfaces of bones.
2. Elastic cartilage
• similar to that of hyaline cartilage, but in addition
to the other components, its matrix has elastic
fibers and interconnecting sheets of elastic
material.
• This gives elastic cartilage an elasticity not
present in hyaline cartilage.
• Elastic cartilage is found in the external ear, the
walls of the external auditory canal, the
Eustachian tube, the epiglottis and the larynx.
3. Fibrocartilage
• is the strongest and most rigid type of
cartilage.
• Fibrocartilage makes up the intervertebral
discs, connects tendons and ligaments to
bones, and appears in other high-stress
areas.
• Damaged hyaline cartilage is often replaced with
fibrocartilage, which unfortunately does not bear
weight as well due to its rigidity.
Ligaments and Tendons
• Bones are connected together by fibrous tissue
called Ligaments.
• Tendons are also fibrous tissue and attach
muscle to bone. Both have some elasticity and
do not heal on their own if torn.
• Bone to bone = ligaments
• Muscle to bone = tendon
• An inflamed tendon is called tendonitis and is
caused by overstretching the tendon. Cartilage
is also fibrous tissue but is not elastic. Cartilage
is used to cushion the junction of two bones.
OUCH!
Most PCL ruptures occur in car
accidents when the dashboard
rams into the knee. OUCH!
There's 2 problems with the ACL and healing: 1)
It's not highly vascularized (it has a poor blood
supply) and 2) It tends to fray like a wire, which
makes the ends difficult to put back together. A
lot of times, for a rupture, surgeons will just
clean out the old ACL and replace it with either a
cadaver's (a dead guy's), part of the patellar
tendon, or part of the hamstring.
Common injuries involving
ligaments/tendons
Cartilage Disorders
• There are a few disorders associated with cartilage.
• Chondrodystrophies are a group of disorders in which
the cartilage is ossified, or transformed into bone.
• Arthritis is characterized by the degradation of
cartilage in the joints, leading to limited movement and
pain.
• Achondroplasia is a cartilage disorder resulting in
dwarfism.
• Benign tumors called chondroma can also arise in the
cartilage.
General Skeleton Info.
• The adult human
skeleton usually
consists of 206
named bones.
• These bones can be
grouped in two
divisions:
– Axial skeleton (80
bones) and
– Appendicular
skeleton (126
bones).
1. Skull (adult, child, infant)
– Cranium
– Facial bones
– Hyoid bone
2. Vertebral column
3.Thoracic cage
Axial Skeleton
Appendicular Skeleton
•
•
•
•
Shoulder Girdle
Upper limbs
Pelvic Girdle
Lower Limbs
Pelvic Girdle
• Males have greater height and narrower pelvic
width. The absence of testosterone in girls
prevents these skeletal developments; the
presence of high levels of estrogen in a
pubertal girl helps stimulate the growth and
shape of the pelvic bones, but otherwise
actually act to limit bone growth and final adult
height.
Axial Skeleton:
Cranium
Ribs & Sternum
Vertebrae
Appendicular
Skeleton:
Arm & hand bones
Leg & feet bones
Clavicles
Scapulas
Hips
Classwork
• Play the skeleton game at:
• http://www.aaronmartini.com/network/gam
es/skeleton/index.html
• Print out your results
Bone Injuries
Bone fractures
1.
2.
3.
4.
5.
6.
7.
8.
simple - bone breaks cleanly, does not penetrate the
skin
compound - broken ends of bone protrude through
skin
comminuted - bone fragments into many pieces
compression - bone is crushed
depressed - broken bone portion is pressed inward
impacted - broken bone ends are forced into each
other
spiral - ragged break occurring when excessive
twisting forces are applied to bone
greenstick - bone breaks incompletely similar to a
green twig
Jack Pires
• Simple full
break of the
right radius
• May 2010
• In a cast:
14 weeks
X*rays
Gross and a bit violent
http://www.youtube.co
m/watch?v=muURh4vs
XHc&feature=PlayList&
p=CFE046E46D75EF3
1&index=0&playnext=1
Name the type of break
Try again
A
B
C
D
E
F
Bone break
and repair:
http://www.you
tube.com/watc
h?v=qVougiC
EgH8
Broken Bones
• There are three main types of joints based
on structure:
Fibrous
Cartilaginous
Synovial
• Fibrous joints (immovable
joints) connect bones without
allowing any movement. The
bones of your skull and pelvis
are held together by fibrous
joints.
Cartilaginous joints are
joints in which the
bones are attached by
cartilage. These joints
allow for only a little
movement, such as in
the spine or ribs.
In common usage, the word "joints"
generally refers to the freely moving
joints with joint cavities. These are called
synovial joints. They allow for much
more movement than cartilaginous
joints.
Cavities between bones in synovial joints
are filled with synovial fluid. This fluid Bursa sacks contains the synovial fluid.
helps lubricate and protect the bones.
Bursa sacks contains the synovial fluid.
3 of the 6 types of synovial joints
1.
2.
Ex.
Ex.
3.
Ex.
The other 3 types of synovial joints
5.
4.
Ex.
Ex.
6.
Ex.
Infant/child Skeleton
• Many of the bones in the
body start off, in the early
embryo, as tiny hyaline
cartilaginous structures,
with essentially the same
shape as the eventual
adult bone.
• As early as 8 weeks after
conception, in the case
of some of the long
bones of the limbs, bone
starts to be laid down, in
the centre of the
cartilage of the shaft, and
gradually extends
towards the ends.
• The ends remain as
cartilage until just before
birth or, in many cases,
until some time later.
• Then, secondary bone
centers appear at the ends
(epiphyses) but do not join
with the bone in the shafts:
an intervening area of
cartilage remains. This is
known as the growth
(epiphyseal) cartilage and is
the region where the bone
grows most in length.
• Growth continues, and the
epiphyseal cartilage
persists, in many of the long
bones, until well after
puberty; in girls until 16-17
and in boys a year or two
later.
Six Common Bone Disorders
1.
-is a long-term disease that
leads to inflammation of the
joints and surrounding
tissues. It can also affect
other organs.
Eventually, joint pain
appears.
When the lining of the joint
becomes inflamed, it gives off
more fluid and the joint
becomes swollen.
Joint pain is often felt on
both sides of the body, and
may affect the fingers, wrists,
elbows, shoulders, hips,
knees, ankles, toes, and
neck.
http://www.youtube.com/watch
?v=ae4ZdRfZR3I
- is caused
by the
breakdown
and
eventual
loss of the
cartilage of
one or
more
joints.
2. Osteoarthritis
3. Osteoporosis
-the thinning of bone
tissue and loss of bone
density over time
4. Bone Spur
Pump Bump
• A bone spur forms as the body tries to repair
itself by building extra bone. It generally forms in
response to pressure, rubbing, or stress that
continues over a long period of time.
• Bone spurs do not require treatment unless they
are causing pain or damaging other tissues.
• Examples of spurs that may need surgery might
include repair of a bunion or heel spur in the
foot or removal of small spurs underneath the
point of the shoulder.
5. Spinal
Curvatures
• A. Scoliosis: “S” shaped curve of the spine
• B. Kyphosis: Hunchback
• C. Lordosis: Sway back
Not so Common Anymore:
6.
• Primary cause of scurvy is insufficient
intake of vitamin C (ascorbic acid).
• This may be due to ignorance, famine,
anorexia, restrictive diets (due to allergies,
food fads, etc.), or difficulty orally ingesting
foods.
• Historically, scurvy was the result of
long sea voyages where sailors did not
bring along enough foods with vitamin
C.
• Rickets is a disorder
caused by a lack of
vitamin D, calcium,
or phosphate. It
leads to softening
and weakening of the
bones.
• Positioning or
bracing may be used
to reduce or prevent
deformities. Some
skeletal deformities
may require
corrective surgery.
7. Ricketts
Virtual Knee & Hip Replacement &
Hip Resurfacing
• Go to www.edheads.com
• Click on:
– Virtual Knee Replacement or
– Virtual Hip Replacement or
– Virtual Hip Resurfacing
• Don’t forget your ear plugs!
• Complete all three surgeries.