Skeletal
System
&
Articulations
What Is
Osteoporosis?
• Loss of bone density.
– Due to low hormone
levels.
– Occurs prematurely due
to extreme weight loss.
– Results in low estrogen
levels.
Tortora
Pages: 113
What Is
Osteology?
• Study of bone
structure &
treatment of
bone disorders.
Tortora
Pages: 114
Functions of the
Skeletal System
•
•
•
•
•
•
Support
Protection
Assisting in movement
Mineral homeostasis
Production of blood
Triglyceride storage
Dancing Skeleton
Tortora
Pages: 114
Types of Bones
• Long bones
– Longer than wide
– Slightly curved
– Compact and
spongy bone
– Ex - Radius, ulna,
femur.
Tortora
Pages: 114
Types of Bones
• Flat bones
– Thin
– Composed of two
plates compact
bone.
– Spongy bone in
between.
• Ex: cranium,
ribs, scapula.
Tortora
Pages: 114
Types of Bones
• Short bones
– Cubed shaped
– Mostly spongy
bone.
– Surface of
compact bone
• Ex: wrist
(carpals) &
ankles (tarsals)
Tortora
Pages: 114
Types of Bones
• Irregular bones
– No consistant
shape.
– Varies in
compact and
spongy bone.
• Ex: Vertebrae
Tortora
Pages: 114
Types of Bones
• Others
• Sutural bones
– Small bones found
in joints between
bones of skull.
• Sesamoid bones
– Bones located in
tendons.
– Vary in number.
• Ex: Patellas
Tortora
Pages: 114
Macroscopic
Structure of Bone
•
•
•
•
•
•
•
•
Diaphysis
Epiphysis
Metaphysis
Epiphyseal plate
Articular cartilage
Periosteum
Medullary cavity
Endosteum
Tortora
Pages: 115
Histology
• Consists of 4 types
of connective
tissue.
–
–
–
–
Cartilage
Bone
Bone marrow
periosteum
Histology
• Bone consists of:
– loosely spaced
cells.
– Matrix
• 25% water
• 50% mineral salts
• 25% collagenous
fibers.
Histology
• Bone contains 4
types of cells:
– Osteoprogenitor
• Give rise to other
cells.
– Osteoblasts
• Bone forming cells.
– Osteocytes
• Mature bone
maintaining cells
– Osteoclasts
• Bone breakdown
Pages: 98 - 100
Macroscopic
Structure of Bone
Articular cartilage
Monday 10/28
Pages: 98 - 100
Microscopic
Structure of Bone
• Compact bone
– Gives strength
– Covers spongy bone.
– Composed of osteons
(Haversian systems)
Monday 10/28
Pages: 98 - 100
Exhibit 6.1 Quiz
1.
What two of the following minerals make the bone
matrix hard?
A) Calcium
B) Iron
C) Zinc
D) ATP
E) Phosphorus
2. Which vitamin controls the activity, distribution,
and coordination of osteoblasts and osteoclasts?
A) Vitamin E
B) Vitamin A
C) Vitamin C
D) Vitamin D
3. General purpose growth hormone that causes
growth in all tissues including bone.
A) HGH
B) Estrogens C) Parathyroid hormone
D) Calcitonin
E) Thyroxine
Exhibit 6.1 Quiz
4. Which vitamin helps maintain the bone
matrix and whose deficiency leads to
decrease in collagen?
A) Vitamin E
D
B) Vitamin A
C) Vitamin C
D) Vitamin
5. Which hormone promotes bone formation by
inhibiting osteoclasts?
A) HGH
B) Estrogens C) Parathyroid hormone
D) Calcitonin
E) Thyroxine
Exhibit 6.1 Quiz
1)
2)
3)
4)
5)
A,E
B
A
C
D
Macroscopic
Structure of Bone
• Spongy bone
– Contains
trabeculae
– Formed from
collagenous
fibers
– Reduces weight
– Maintains
strength
Tortora
Pages: 98 - 100
Ossification
• Process by which
bone forms.
• Starts during the
6th or 7th week of
life.
Tortora
Pages: 102-104
Ossification
• Intramembraneous
ossification:
• Starts as a
membrane shaped
like a bone.
– Ex: skull, mandible,
clavicle
Tortora
Pages: 102-104
Ossification
•
•
•
•
Endochondral
ossification:
Starts with
hyaline cartilage.
Forms most
bones.
Ex: femur, tibia,
humerus, etc.
Tortora
Pages: 102-104
Ossification
•
Step #1
–
Cartilage model of
bone develops.
–
Surrounded by a
perichondrium.
Tortora
Pages: 102-104
Ossification
•
Step #2
–
–
–
–
–
Cartilage model grows.
Cartilage begins to
calcify.
Cartilage cells start to
die.
Nutrient artery grows
into cartilage model.
Osteoblasts in
perichondrium start
ossification
Tortora
Pages: 102-104
Ossification
•
Step #3
–
–
–
–
Primary ossification
occurs.
Forms collar around
shaft of bone.
Osteoblasts create
new bone.
Medullary canal
created by action
of osteoclasts.
Tortora
Pages: 102-104
Ossification
•
Step #4
–
–
–
Secondary ossification
starts in the ends of
the bone.
Occurs about the time
of birth
Growth is outward
from the center of the
epiphysis towards the
outside of the bone
Tortora
Pages: 102-104
Ossification
•
•
•
•
Cartilage remains
at ends of the
bone (articular
cartilage)
Epiphyseal plate
is last to ossify.
Ends growth.
Remodeling is
only change
possible
afterwards.
Tortora
Pages: 102-104
Homeostasis
•
•
Bone replaces itself
throughout life.
Referred to as
remodeling.
Tortora
Pages: 104-106
Bone Surface
Markings
•
Depressions and
openings
–
–
Foramen
Fossa
Tortora
Pages: 107-108
Bone Surface
Markings
•
Processes that form
joints
–
Condyle
–
Head
–
•
Knuckle-like process
•
Rounded projection,
supported by
constricted portion
of bone.
Facet
•
Smooth, flat
surface
Tortora
Pages: 104-106
Bone Surface
Markings
•
Processes that
connect to
ligaments and other
connective tissue.
–
Tuberosity
–
Spinous process
–
Trochanter
–
Crest
•
•
•
•
Large rouned
area.
Slender
projection
Large blunt
projection
ridge
Tortora
Pages: 104-106
Male/female
Differences
1.
General
Structure
–
–
Male: Heavy/thick
Female: Light/thin
–
–
Male: Less than 90
Female: Greater
than 90
2. Pubic Arch
3. Obturator
Foramen
–
–
Male: Round
Female: Oval
Tortora
Pages: 132-133
Articulations
•
Gravity mandates a
stiff and rigid
skeleton.
•
Movement requires
flexibility.
•
Flexibility created by
articulations (joints)
Tortora
Page: 156
Articulations
•
•
Structure determines
function.
Movement is determined by
–
–
–
–
Structure of bones
forming the joint.
The flexibility of
connective tissue
connecting the bones.
Position of ligaments,
tendons, and muscles.
Hormones
Tortora
Page: 157
Structural
Classification
•
•
•
Fibrous: bones
connected with
fibrous connective
tissue.
•
EX: tibia - fibula
•
EX: Ribs - sternum
•
EX: knee, elbow, hip.
Cartilaginous: Bones
connected by
cartilage.
Synovial: Joint
surrounded by synovial
membrane.
Tortora
Pages: 157-160
Classification of
Synovial Joints
•
•
Gliding Joints
– Surfaces are flat
– Side to side motion
– Ex; Between
carpals, tarsals.
Hinge Joint
–
–
–
Convex surface concave surface.
Single plane movement
EX: knee
Tortora
Pages: 160-163
Classification of
Synovial Joints
•
Pivot Joint
–
–
–
•
Rounded or pointed with
ring-like structure.
Rotation movement
EX: atlas - axis, radius
ulna.
Condyle Joint
–
–
–
Oval shaped depression
Side to side movement,
back and forth
movement.
Radius - carpals
Tortora
Pages: 160-163
Classification of
Synovial Joints
•
Saddle Joint
–
•
Ball and Socket Joint
–
–
–
•
Metacarpaland carpal
of thumb.
Rounded end - cup like
depression.
Movement in three planes.
EX: Hip and shoulder.
Condyloid
–
Ex: radius and wrist bones.
Tortora
Pages: 160-163
Structures of a
Synovial Joint
•
•
•
Tortora
Pages: 164-165
Synovial cavity
Articular cartilage
Articular capsule
–
–
–
–
Fibrous capsule (outer)
Ligaments
Synovial membrane
(inner)
Synovial fluid
ATC
Surgery
ATC
Animation
Saddle
Structures of a
Synovial Joint
•
•
•
Tortora
Pages: 164-165
Accessory ligaments
–
Lie outside the
articular capsule.
Articular discs
(menisci)
Bursae
Knee Structure
Meniscus Repair
Surgery
Saddle
MOVEMENT AT
SYNOVIAL JOINTS
Classification of
Joints
•
•
Tortora
Pages: 157-160
Structural classification
–
–
–
Fibrous
Cartilaginous
Synovial
–
–
–
Synarthrosis
Amphiarthrosis
Diarthrosis
Functional Classification
Osteoarthritis
Basic Anatomical
Position
• Standing erect
– Toes forward
– Head facing
forward.
– Hands at side.
– Palms facing
forward.
Tortora
Pages 160-163
Basic Anatomical
Position
•
•
Structural classification
–
–
–
Fibrous
Cartilaginous
Synovial
–
–
–
Synarthrosis
Amphiarthrosis
Diarthrosis
Functional Classification
Tortora
Pages 160-163
Categories of
Movement
• Gliding
– Flat bones form joint
• Back and forth
• Side to side
• Angular
– Increase or decrease in
angle of bones.
• Rotation
– A bone rotates on long
axis
• Special Movewment
Tortora
Pages 160-163
Angular
Movements
• Flexion
– Reducing angle of
joint
– Extension
• Increasing angle of
joint
– Hyperextension
• Beyond basic
anatomical position
Tortora
Pages 160-163
Angular
Movements
• Abduction
– Movement away
from midline of
body.
• Adduction
– Movement towards
midline of body.
Tortora
Pages 160-163
Angular
Movements
• Circumduction
– Moving distal
end of arm or
leg in a circle.
• Ex: shoulder
– hip
Tortora
Pages 160-163
Special Movements
• Inversion
– Lifting of medial
side of foot so
that soles face
each other.
• Eversion
– Lifting of lateral
side of foot so that
sole faces outward.
Tortora
Pages 160-163
Special Movements
• Pronation
– Movement of hand
such that palm
faces backward.
• Supination
– Movement of
palm such that it
faces forward.
Tortora
Pages 160-163
Special Movements
• Dorsiflexion
– Bending foot in
the superior
direction
Plantar Flexion
Bending of foot
in the inferior
direction
Tortora
Pages 160-163
Synovial Joint
Movements
•
•
•
•
•
Flexion Vs Extension
Abduction Vs Adduction
Circumduction
Elevation Vs Depression
Supination Vs Pronation
Tortora
Pages: 160-163