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Exercise Science
Section 2: The Skeletal System
An Introduction to Health and Physical Education
Ted Temertzoglou
Paul Challen
ISBN 1-55077-132-9
Learning Objectives for Chapter 2
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The differences between the human male and female skeletons
The role and functions of the skeleton in the human body
The human skeleton’s basic structure and composition
The five types of human bones
The names and locations of the body’s key bones and bone structures
The concepts of bone landmarks and insertions, and key landmark/insertion sites throughout
the body
The process of ossification and bone formation
The process of bone remodelling
Epiphyseal or growth plates of bones
Bone fractures and their three main categories
How bones heal
Bone disease, stress fractures, and the effects of aging on bone
Musculoskeletal System
• Composed of 3 distinct yet
interdependent components; bones,
joints, muscles
• Each have own contribution- the
interaction of these systems allow
human movement
• Bones form a rigid skeletal framework
with numerous joints that can be
moved as a result of the forces
produced by the attaching muscles
• As the muscles pull against the bones,
the bones act as levers.
The Skeleton
- ‘skeletal’- greek for skeletos= ‘dried up,’ truth it only appears this way
as they are actually composed of living tissue- fat, bone cells and blood
vessels and nerves- non-living material- water and minerals
-made up of bones
- 300 at birth  206 by adulthood. WHY?
-some fuse over time as growth takes place (ex. Plates
in the skull and lower parts of the vertebral column)
The main functions of the skeletal system are:
Structural support
-support for muscles and skin
Protection
-protects the sensitive/delicate
parts of organs(brain, heart,
lungs,etc)
Growth centre for cells
-red blood cells and platelets
Reservoir for minerals
-stores calcium and phosphorus
Movement
- Muscles attach to bones by
tendons. Muscles contract and
move bones to facilitate
movement
Shape
Example
Skeleton-purpose
Long
Femur, tibia, fibula, humerus, radius, ulna,
metatarsals, metacarpals, phalanges
- Proximal and distal
enlargements
- appendicular
Short
Carpals, tarsals (bones of the wrist and
ankle)
- Serve as good shock
absorbers
- Appendicular
Flat
Scapula
Clavical
Ribs, sternum
Frontal, parietal, occipital, mandible
- Bones of skull and scapula
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Appendicular
Appendicular
Axial
Axial
Protect underlying
organs and provide
areas for muscle
attachment
Bone Shape Cont…
Sesamoid
Patella
-Shaped like a pea and
found wrapped in
tendons- glide over
surfaces
-appendicular
Irregular
Facial bones of skull, vertebrae
Pelvis
- Axial
- Appendicular
• Workbook Exercise 2.4-pg.22
Using page 11 in your text,
label each one of these bones,
and provide a short
description
Long bone
-found in arms and
legs
Flat bones
-flat and thin
-protect vital organs
Sesamoid bones
-small, flat and wrapped in
tendons
-glide over body surfaces
Short bones
-commonly
found in wrists
& ankles
-serve as shock
absorbers
Irregular bones
- “odd-looking”
bones not
otherwise
classified
Axial Skeleton: comprised mainly of the vertebral
column (spine), much of the skull, and the rib
cage.
-most of the body’s muscles originate from the
axial skeleton, since it is medially located with
respect to the appendicular skeleton.
-Most muscles anchor or originate here and
insert on the appendicular skeleton.
-muscles which attach here are referred to as
“core muscles” as they are centrally located and
provide the body with stability and support.
Appendicular Skeleton: Includes movable limbs
and supporting structures (girdles)
-Plays a key role in allowing us to move
-upper limbs attached to pectoral girdle (shoulder
girdle) lower limbs attached to the pelvic girdle
(hip girdle)
About Bone …
 Bone is very strong for its light weight
 Major components- calcium carbonate, calcium
phosphate, collagen, zinc, magnesium, fluorine, iron,
chlorine and water
 Calcium Compounds- make up approx. 60-70% of bone
weight- provide much of bones stiffness and resistance to
pressing or squeezing forces.
 Collagen(protein)- gives bone its flexibility, and
contributes to its ability to resist pulling and stretching
forces
 Bones of children are significantly more pliable than those of
adults
 With aging, collagen is lost progressively and bone becomes
more brittle
 Human body consists of 60% of water, bone only contains
approx. 20% (20-25%) total bone weight
 Resists compression and tension
 Bound by joints (through ligaments)
 Muscles attach to bone (through tendons) to produce
movement
Anatomy of a Long Bone
Complete Workbook Exercise 2.3 on Pg.21
Cartilage
Periosteum
Medullary cavity
Compact bone
Cancellous bone
Epiphysis
Diaphysis
Epiphysis
Anatomy of a Long Bone
Cartilage
Periosteum
Medullary cavity
Compact bone
Cancellous bone
Epiphysis
Diaphysis
Epiphysis
Workbook Exercise 2.2
• Write the definitions of the seven terms from
the above diagram in the chart on Pg.19
Anatomy of a Long Bone
• Articulating Cartilage – allows smooth movement (articulation) within joints while protecting
the ends of the bones-no blood supply or nerve endings
• Periosteum – outer connective tissue of bone(covers entire length of bone), does not connect to
articulating cartilage, periosteum fibres and those of ligaments and tendons unite to connect bone to
bone or muscle to muscle.
• Medullary(marrow)Cavity – inside the diaphysis(shaft) of the bone and filled with
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red(blood-cell formation) and yellow(adipose-fat) bone marrow
Compact Bone/Cortical Bone – 5-10% porous(low), VERY strong and stiff,- less flexible and
can resist greater stress- responsible for structural integrity of the bone.
• Epiphysis – ends of the bone- outer surface made up of compact bone, and the part that
articulates with another bones is covered with cartilage.
• Diaphysis – thickest part of the bone, the shaft
• Cancellous/Spongy Bone/trabecular – very porous (50-90%)there fore how it gets
its spongy name- NOT dense- very weak and not stiff- found at ends of long bones and areas
where shock absorption and a better ability to change shape are important i.e. vertebrae
• Mineral storage, red blood cell regeneration
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Interior core- contains network of bony plates and rods (trabeculae) that results in
a lattice look- mesh with blood vessels and the bone marrow
Cortex- exterior layer of bones- dense and smooth- varying thickness depending on
type of bone.
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What bones strengthen with exercise?
Skeleton
Complete and study the
following handouts!
Human
Skeleton
Anterior
view
Human
Skeleton
Posterior
view
Bone Landmarks
• Workbook Exercise 2.5 (Pg.25-35)
– Using your textbook (Pg.16-28) start familiarizing
yourself with the major bone landmarks and
muscle origins and insertions associated with
these landmarks
Cont’d…
Bone Landmarks (Cont’d)
• Workbook Exercise 2.7
– Colour code the important landmarks
– Pay attention to the names of the landmarks ex
Supraspinous fossa, Infraspinous fossa, Medial
border, Lateral border
©Thompson Educational Publishing,
Inc. 2003. All material is copyright
protected. It is illegal to copy any of this
material.
This material may be used only in a
course of study in which Exercise
The Skull – Anterior View
Frontal bone
Parietal bone
Temporal bone
Nasal bone
Zygomatic bone
Maxilla
Mandible
The Skull – Lateral View
Frontal bone
Parietal bone
Temporal bone
Zygomatic bone
Occipital bone
Maxilla
Nuchal line
Mastoid process
External auditory meatus
Mandible
©Thompson Educational Publishing, Inc. 2003. All material is copyright protected. It is illegal to copy any of this
material.
This material may be used only in a course of study in which Exercise Science: An Introduction to Health and
Physical Education (Temertzoglou/Challen) is the required textbook.
The Vertebral Column – Lateral View
Composed of 36
bones.
Cervical region
- 7 cervical (neck)
vertebrae- first
two named atlas
(C1) and the axis
(C2)
- 12 Thoracic
Thoracic region
(chest) vertebrae
- 5 Lumbar (lower
back) vertebrae
- 1 Sacrum(midline region of
buttocks) made
up of 5 fused
Lumbar region
vertebrae
- 1 coccyx (tail
bone) made up of
4-5 fused Sacral and coccygeal region
vertebrae
Atlas
Axis
Seventh cervical vertebra
Intervertebral disk
Twelfth thoracic vertebra
First lumbar vertebra
Fifth lumbar vertebra
Sacrum
Coccyx
Vertebral Column
• Arranged in cylindrical column
interspersed with fibrocartilaginous
(intervertebral) discs
• Forms a strong and flexible support for
the neck and trunk
• Point of attachment for back muscles
• Protects the spinal cord and nerves, but
also provides support for the body and
the ability to keep the body erect.
• Intervertebral discs- absorb shock when
the load increases- allowing the vertebrae
to move without causing damage to other
vertebrae or the spinal cord.
Thoracic Cage – Anterior View
-12 pairs of ribs- made up
of bone and cartilage thus
giving strength to the chest
cage and permit it to
expand
- Upper 7- true ribs
(attaching to both the
Seven true ribs
vertebrae and the
sternum)
- 8-20- 3 pairs are false
ribs- (attaching to the
sternum indirectly)
- 11-12= floating ribs- only
attach to the vertebrae
column
- All 12 ribs articulate with Three false ribs
the 12 thoracic
vertebrae, posteriorly
Two floating ribs
First thoracic vertebra
Manubrium
Sternal Body
Xiphoid
process
Sternum
Thoracic Cage – Posterior View
Clavicle
Scapula
Left Scapula – Anterior View
Acromion process
Coracoid process
Glenoid cavity
Subscapular fossa
Lateral border
Medial border
Inferior angle
Left Scapula – Lateral View
Coracoid process
Acromion
Supraglenoid tubercle
Glenoid fossa
Infraglenoid tubercle
Subscapular fossa
Lateral border
Inferior angle
Left Scapula – Posterior View
Coracoid process
Acromion process
Scapular notch
Superior angle
Supraspinous fossa
Glenoid cavity
Infraglenoid tubercle
Scapular spine
Infraspinous fossa
Medial border
Lateral border
Left Humerus – Anterior View
Head
Greater tubercle
Lesser tubercle
Intertubercular
(bicipital)
groove
Deltoid tuberosity
Shaft
Capitulum
Radial fossa
Coronoid fossa
Medial epicondyle
Lateral epicondyle
Trochlea
Left Humerus – Posterior View
Head
Shaft
Deltoid tuberosity
Olecranon fossa
Lateral epicondyle
Trochlea
Medial epicondyle
Left Ulna – Anterior View
Olecranon
Olecranon process
Coronoid process
Styloid process of ulna
Trochlear (semilunar) notch
Radial notch of ulna
Ulna tuberosity
Left Radius – Anterior View
Head
Radial tuberosity
Styloid process of radius
Left Hand – Anterior View
Carpals
(proximal)
Ulna
Scaphoid bone
Lunate bone
Triquetrum bone
Pisiform bone
Radius
Hamate bone
Capitate bone
Trapezoid bone
Trapezium bone
Carpals
(distal)
Metacarpals
Sesamoid bone
Proximal phalax
(of thumb)
Distal phalanx (of thumb)
Phalanges
(Digits)
Proximal phalanx (of finger)
Middle phalanx (of finger)
Distal phalanx (of finger)
Pelvis (Male) – Anterior View
Sacrum
Crest of ilium
Sacroiliac joint
Ilium
Anterior
superior
iliac spine
Anterior
inferior iliac
spine
Acetabulum
Obturator foramen
Os coxae
Pubis
Ischium
Superior ramis of pubis
Symphysis pubis
Inferior ramis of pubis
Pelvis (Male) – Posterior View
Fifth lumbar
vertebra
Sacrum
Posterior
superior iliac
spine
Posterior
inferior iliac
spine
Ischial spine
Ischial tuberosity
Coccyx
Right Femur – Anterior View
Head
Greater trochanter
Neck
Intertrochanteric
line
Lesser trochanter
Shaft
Adductor tubercle
Lateral epicondyle
Medial epicondyle
Patellar groove
Medial condyle
Right Femur – Posterior View
Head
Greater trochanter
Neck
Intertrochanteric crest
Gluteal tuberosity
Lesser trochanter
Pectineal line
Linea aspera
Shaft
Intercondylar fossa
Adductor tubercle
Medial epicondyle
Lateral epicondyle
Lateral condyle
Medial condyle
Right Fibula and Tibia – Anterior View
Intercondylar eminence
Lateral condyle of tibia
Head
Medial condyle of tibia
Tibial tuberosity
Intercondylar eminence
Lateral condyle
Medial condyle
Anterior crest
Fibula
Tibia
Lateral malleolus
Medial malleolus
Tibial tuberosity
Right Foot – Superior View
Calcaneus
Talus
Tarsals
Cuboid
Metatarsals
Navicular
Medial cuneiform
Intermediate cuneiform
Lateral cuneiform
Proximal phalanx
Phalanges
(Digits)
Middle phalanx
Distal phalanx
Proximal phalanx (of great toe)
Distal phalanx (of great toe)
Bone Formation
Ossification
(Osteogenesis):
the process by which new bone is produced
Osteoblasts –bone forming cells
2 Forms:
1) Compact bone (long bones)
-begins as cartilage
3 steps:
1)hormones excite osteoblasts
2) gelatin-like(osteoid) substance
discharged from osteoblasts in
cartilage
3) minerals deposited in gel and
harden into bone
2) Cancellous bone (flat bones of skull)
-begin as fibrous membranes
-osteoblast release osteoid into
membrane which forms a sponge-like
bundle of fibres
-new bone forms “outward” from
centre of bundle
- converts “soft spots” at birth into bone
because bone formation is still incomplete
Bone Remodelling
• Bones do not just grow by osteoblasts laying down new bone.
Instead, it is more a process of give and take
• Actually, it’s more TAKE and GIVE
OSTEOBLASTS
OSTEOCLASTS
• protein secreting cells
(osteoblast) deposit new
tissue (bone)
• bone-resorbing cells
• remove old bone by releasing
acids and enzymes
Birth to ~ 35  deposition > removal =
growth
After 35  deposition < removal = shrink
Epiphyseal Plates and Lines
 Epiphyseal plates (growth plates)
 Occur at various locations at the
Epiphyseal
line
epiphyses of long bones
 Growth possible
 X-rays pass through cartilage and they
appear as black spaces between the
diaphysis and epiphyses
 Epiphyseal lines
 Occur when epiphyseal plates have fused
or come together
 Growth not possible
Epiphyseal
 X-ray shows a solid epiphysis
plate
Epiphyseal Plates and Lines
Bone Fractures
Bones, like all other structural supports need to contend with 4 different
types of forces:
TENSION: pulling
TORSION: twisting force
apart or stretching
force
SHEAR:
COMPRESSION:
pushing together
What happens if one of those forces becomes too great?
Bone Fractures:
:
• Problems with the skeletal system can be associated with many factors;
nutrition, infection, physical accidents.
• Young children have weaker bones since calcification is still incomplete,
older people have weaker bones because of the loss of calcium associated
with aging.
• Fractures are bone “breaks,” and are normally divided into two types:
1. Simple Fractures there is no separation of the bone into parts, but a break
or crack is detectable “hairline/greenstick fracture”- bone is not exposed to the
air through the skin.
2. Compound Fractures Occurs when the bone breaks into separate pieces.
Bones is exposed to the air through the skin. Result of a major blow.
• If bone breaks through the skin there is usually more serious
complications i.e. muscle and ligament damage
3. Comminuted Fracture Occurs when the broken ends of the bone
have been shattered into many pieces.
©Thompson Educational Publishing,
Inc. 2003. All material is copyright
protected. It is illegal to copy any of this
Bone Fractures:
SYMPTOMS
• sharp pain and tenderness when palpated
• swelling and discolouration
• grinding sound on movement
• inability to use
HEALING OF BONES
•bones heal using the same process as remodeling
•if dealt with correctly, the process will go smoothly
•result may be an even stronger bone
-video- Bob and Claude
Types of Fractures
Compound fracture
•Bone breaks into separate pieces
http://www.youtube.com/watch?v=_wxebhExcTk
Comminuted fracture
•Bone shatters into many pieces
Types of Fractures
Simple fracture
Stress Fracture
•Most difficult to detect
•Muscles become too fatigued to absorb shock
•Transfers impact to bone which results in tiny crack
•No separation (hairline/greenstick fracture)
Effects of Aging – Skeletal System
 Remodelling declines from fourth decade onward
 Process of bone remodelling reverses – resorption occurs
 Results in a 5–10% loss in bone mass per subsequent decade
 Affects overall calcium levels in the body
 Osteoporosis (low bone mass and deterioration of the bone tissue)
may result from resorption
 Leads to bone fragility
 Increased susceptibility to bone fractures
 Preventative measures include:
 Balanced diet rich in calcium and vitamin D, and a healthy lifestyle
 Weight-bearing exercises
 Bone density testing and medication when appropriate