THE
SKELETAL
SYSTEM
FACT OR MYTH
Babies have more bones than
adults.
FACT – Babies are born with about
300 bones. Adults have 206 bones.
FACT OR MYTH
Your funny bone is a bone in your
elbow.
Myth – It’s a nerve that runs down the
humerus to the inside part of your elbow.
FACT OR MYTH
Bones usually stop growing at
puberty.
Myth – Bones usually stop growing
when you’re in your late 20’s.
FACT OR MYTH
Blood cells are produced in bone.
Fact – red and white blood cells are produced in the
bone marrow in the center of some bones
FACT OR MYTH
The collar bone gets broken the most often.
Fact – The clavicle leads the list of breaks.
FACT OR MYTH
There are 5 bones in the body not connected to
other bones.
Myth – There is only one bone (hyoid) that is not
connected to other bones.
FACT OR MYTH
Your big toe has fewer bones than your other toes.
Fact – Most toe bones have three tiny bones, but
your big toe has two. You also have three bones in
each of your fingers, but only two in each of your
thumbs.
FACT OR MYTH
The smallest bone in your body is located in your
cheek.
Myth – The smallest bone is located in your ear (bone
behind your eardrum called the stirrup).
FACT OR MYTH
A giraffe has the same number of bones in the neck
as humans do.
Fact – Giraffes and humans have 7 cervical
vertebrae (neck bones).
FACT OR MYTH
Bone is 5x harder than steel.
FACT! Bone is often compared to the
strength of steel and concrete.
HOW MANY BONES DOES AN
ADULT BODY HAVE?
206
How many bones are babies
born with?
350
LARGEST BONE?
Femur: thigh bone
Shortest Bone?
Stirrup: located in the ear
OSTEOGENESIS (BONE FORMATION)
Ossification - the process of replacing other
tissues with bone
• The growth of the skeleton determines the size and
proportions of your body
• The bony skeleton begins to form about 6 weeks
after fertilization
• Bone growth continues through adolescence, and
portions of the skeleton do not stop growing until
approx. the age of 25
WHAT’S IN A BONE?
• Bones, Muscles, and Joints
FUNCTIONS OF THE SKELETAL
SYSTEM
1.
2.
3.
4.
5.
Support
Protection
Movement
Mineral storage
Hematopoiesis (blood cell
formation)
CLASSIFICATION OF BONES
Bones are identified by:
1. Shape
A. Long bones
B. Short bones
C. Flat bones
D. Irregular bones
2. Internal tissues
A. Compact – dense bone tissue
found on the outside of bone
B. Spongy – found on the interior
of the bone which is filled with marrow
(in some bones; not all bones)
3. Bone markings
SHAPE: LONG BONES
• Are typically longer than they are wide
• As a rule they have a shaft with heads at both
ends
• Mostly compact bone
• All of the limbs (femur, tibia, humerus), (except
the wrist and ankle bones).
SHAPE: LONG BONES
Diaphysis (long part):
• Covered by periosteum
• Sharpey’s Fibers secure the
periosteum to the
underlying bone
Epiphysis (ends):
• Articulate with other bones
• Covered by Articular
cartilage
Metaphysis:
• Location where diaphysis
and epiphysis meet
SHAPE: FLAT BONES
• Are thin, flattened and usually
curved
• Have two thin layers of compact
bone sandwiching a layer of
spongy bone between them
• Found in the skull, sternum, ribs,
and scapula
SHAPE: SHORT BONES
• Are small and thick
• Cube-shaped and contain mostly spongy bone
• Examples: Carpals, Tarsals,
Calcaneus
SHAPE: SESAMOID (SES’AH-MOYD)
BONES
Special type of short bone
- Form within tendons
- Best known example is the patella
- Develop inside tendons near joints of
knees, hands, and feet
SHAPE: IRREGULAR BONES
• Have complex shapes
• Examples: Vertebrae, Mandible, Sacrum, Pelvis
CHECK POINT
1. Approximately how many bones are there in the
human body?
2. What is hematopoiesis?
3. What are the five functions of the bones?
4. What is the difference between compact bone
and spongy bone?
5. Name the parts of a long bone.
BONE MARKINGS
(Surface Features)
• Each bone in the body has characteristic
external and internal features.
• Every bump, groove, and hole has a
name on your bones.
• Detailed examination can yield an
abundance of anatomical information.
Bone Markings
• Two types of bone markings:
– Projections (aka processes) that grow out
from the bone
– Depressions (cavities) that indent the bone
The Axial Skeleton
• Includes 80 bones
• 40% of the bones in the
human body
Axial Skeleton
• Three Regions:
1. Skull (8 cranial & 14 facial)
** bones associated with skull (6 auditory
ossicles and hyoid)
2. Vertebral column (24 vertebrae, the sacrum
& coccyx)
3. Thoracic cage (sternum & 24 ribs)
The Skull
• The bones of the skull protect the brain and
guard the entrances to the digestive & respiratory
systems
• The skull (22 bones), the body’s most complex
bony structure, is formed by the cranium (8
bones) and facial bones (14 bones)
• 6 auditory ossicles (tiny bones) are situated
within the temporal bones of the cranium
(smallest bones in the body that are contained in
the middle ear space; hammer, anvil, stirrup)
• Hyoid bone (connected to the inferior surfaces of
the temporal bones)
The Skull
• Cranium – protects the brain and is the site of
attachment for head and neck muscles
• Facial bones
– Supply the framework of the face, the sense organs,
and the teeth
– Provide openings for the passage of air and food
– Anchor the facial muscles of expression
Anatomy of the Cranium
Eight cranial bones:
1.
2.
3.
4.
5.
6.
•
•
2 parietal
2 temporal
Frontal
Occipital
Sphenoid
Ethmoid
The cranial bones enclose the cranial cavity, a
fluid-filled chamber that cushions and supports
the brain
Cranial bones are thin and remarkably strong
for their weight
Skull – Anterior View
Figure 7.2a
Frontal Bone
• Forms the anterior portion
of the cranium & the roof
of the orbits (eye sockets)
Parietal Bones
• Forms most of the superior and lateral aspects of
the skull
Figure 7.3a
Occipital Bone
• Located at the back and lower part of the
cranium
Temporal Bones
Form part of both
the lateral walls of
the cranium
Figure 7.5
Parietal Bones & Major Associated Sutures
• Four sutures mark the articulations of the
parietal bones
1. Coronal suture – articulation between parietal bones
and frontal bone anteriorly
2. Sagittal suture – where right and left
parietal bones meet superiorly
Parietal Bones & Major Associated Sutures
3. Lambdoid suture – where parietal bones
meet the occipital bone (posterior)
4. Squamosal or
squamous suture –
where parietal and
temporal bones meet
Sphenoid Bone
• Butterfly-shaped bone that forms part of the
floor of the cranium, unites the cranial and
facial bones, and acts as a cross brace that
strengthens the sides of the skull
• Forms the central wedge that articulates
with all other cranial bones
Ethmoid Bone
• Most deep of the skull bones; lies between
the sphenoid and nasal bones
Figure 7.7
Facial Bones
• Fourteen bones of which only the
mandible and vomer are unpaired
• The paired bones are the maxillae,
zygomatics, nasals, lacrimals, palatines,
and inferior conchae
Mandible
• The mandible
(lower jawbone) is
the strongest bone
of the face
Figure 7.8a
Maxillary Bones
• Medially fused bones that make up the
upper jaw and the central portion of the
facial skeleton (largest facial bones)
Figure 7.8b
Zygomatic Bones
• Irregularly shaped bones (cheekbones)
that form the prominences of the cheeks
and the inferolateral margins of the orbits
Other Facial Bones
• Nasal bones – thin medially fused bones that
form the bridge of the nose
• Lacrimal bones – contribute to the medial walls of
the orbit and contain a deep groove that house
the tear ducts
Facial Bones
• Palatine bones – two bone plates that form
portions of the hard palate and contribute
to the floor of each orbit
Other Facial Bones
• Vomer – forms part of the nasal septum
• Inferior nasal conchae – paired, curved
bones in the nasal cavity that form part of
the lateral walls of the nasal cavity
Hyoid Bone
• Lies just inferior to the mandible in the anterior
neck
• Only bone of the
body that does not
articulate directly
with another bone
• Attachment point
for neck muscles
that raise and
lower the larynx
during swallowing
and speech
Figure 7.12
Vertebral Column
• 26 irregular bones (vertebrae)
• Provide a column of support, bearing the
weight of the head, neck, and trunk.
• Transfers weight to the appendicular
skeleton of the lower limbs
• Protects spinal cord
• Helps maintain an upright body position
• Approx. length of an adult column is 71cm
Vertebral Column
Cervical vertebrae
7 bones of the neck
Thoracic vertebrae
12 bones of the torso
Lumbar vertebrae
5 bones of the lower back
Sacrum - 5 fused vertebrae
Coccyx – 4 fused vertebrae
Figure 7.13
Disks are small shock absorbers between
the vertebrae (gel-like interior)
General Structure of Vertebrae:
1. Vertebral body (centrum) – disc-shaped,
weight-bearing region
2. Vertebral arch – composed of pedicles
(walls) and flat layers called laminae (roof)
** forms the posterior margin of each
vertebral foramen (together they form the
vertebral canal which encloses the spinal
cord)
3. Articular processes– projections on each
vertebra
Cervical Vertebrae
• Most mammals have 7 cervical vertebrae
(giraffes, whales, mice & humans)
• Seven vertebrae (C1-C7) are the smallest,
lightest vertebrae
Cervical Vertebrae: The Atlas
(C1)
– Holds up the head
– The superior surface articulates with the
occipital condyles of the skull (permits you to
nod)
»Has no body and no spinous process
Cervical Vertebrae: The Axis
(C2)
• The axis has a body, spine, and vertebral
arches as do other cervical vertebrae
• Articulates with the atlas to permit rotation
Figure 7.16c
Thoracic Vertebrae
• There are twelve vertebrae (T1-T12)
• Distinctive heart-shaped body (more massive than that of
a cervical vertebra)
• Each thoracic vertebra articulate with ribs
Lumbar Vertebrae
• The five lumbar vertebrae (L1-L5) are located in
the small of the back and have an enhanced
weight-bearing function
• Largest vertebrae
Tip: Mealtimes
Breakfast: 7 a.m. (7 cervical)
Lunch: 12 p.m. (12 thoracic)
Dinner: 5 p.m. (5 lumbar)
Table 7.2
Sacrum
• The sacrum
– Consists of five fused vertebrae (S1-S5), which
shape the posterior wall of the pelvis
– Begin fusing after puberty and are completely
fused at age 25-30
– Protects reproductive, digestive, and urinary
organs
– It articulates with L5 superiorly, and with the
auricular surfaces of the hip bones
Coccyx
• Coccyx (Tailbone)
– The coccyx is made up
of four (in some cases
three to five) fused
vertebrae that articulate
superiorly with the
sacrum
– Generally begun fusing
by age 26
Bony Thorax (Thoracic Cage)
Functions:
– Forms a protective
cage around the
heart, lungs, and
great blood vessels
– Supports the
shoulder girdles
and upper limbs
– Provides
attachment for
many neck, back,
chest, and shoulder
muscles
Sternum (Breastbone)
• A dagger-shaped, flat bone that lies in the
anterior midline of the thorax
• Fusion is not complete until at least age 25 (until
this age the sternal body consist of four separate
bones)
Ribs
• There are twelve pair of ribs
• All ribs attach posteriorly to the thoracic vertebrae
• The superior 7 pair (true, or vertebrosternal ribs)
attach directly to the sternum via costal cartilages
• Ribs 8-10 (false, or vertebrocondral ribs) attach
indirectly to the sternum via costal cartilage
• Ribs 11-12 (floating, or vertebral ribs) have no
anterior attachment
Ribs
Figure 7.19a
Appendicular Skeleton
• The appendicular
skeleton is made up of
the bones of the limbs
and their supporting
elements (girdles) that
connect them to the
trunk
• Pectoral (shoulder)
girdles attach the
upper limbs to the
body trunk
• Pelvic girdle secures
the lower limbs
Clavicles (Collarbones)
• S-shaped bones
• Small, fragile
• Smooth superior
surface lies just
beneath the skin
Figure 7.22b, c
Scapulae (Shoulder Blades)
• The scapulae are triangular, flat bones lying on
the dorsal surface of the rib cage, between the
second and seventh ribs
• Have three sides or borders (superior, medial,
and lateral) and three angles (superior, inferior,
and lateral)
Scapulae (Shoulder Blades)
Figure 7.22d, e
The Upper Limb
• Consists of the bones
of the arms, forearms,
wrists, and hands
Arm (Brachium)
• The humerus is the sole bone of the arm
• It articulates with the scapula at the
shoulder, and the radius and ulna at the
elbow
Arm
Figure 7.23 a, b
Ulna
• In anatomical position, the ulna lies medial
to the radius
• Slightly longer than the radius
• Forms the major portion of the elbow joint
with the humerus
Radius
• Lateral bone (to the ulna) of the forearm
• Thin at its proximal end, widened distally
• The superior surface of the head articulates
with the humerus
Ulna & Radius
Figure 7.24 a, b
Carpus (Wrist)
• Consists of eight carpal bones:
– Scaphoid
– Lunate
– Triquetrum
– Pisiform
– Trapezium
– Trapezoid
– Capitate
– Hamate
“Sam Likes To Push The Toy Car Hard”
Metacarpus (Palm)
• Five numbered (1-5) metacarpal bones
radiate from the wrist to form the palm
– Their bases articulate with the carpals
proximally, and with each other medially and
laterally
– Heads articulate with the phalanges
Phalanges (Fingers)
• Each hand contains 14 miniature long bones
called phalanges
• Fingers (digits) are numbered 1-5, beginning with
the thumb (pollex)
• Each finger (except the thumb) has three
phalanges – distal, middle, and proximal
• The thumb has no middle phalanx
Wrist & Hand
Pelvic Girdle (Hip)
• The hip is formed by a pair of hip bones (coxal)
• Together with the sacrum and the coccyx, these
bones form the bony pelvis
• The pelvis
– Attaches the lower limbs to the axial skeleton
with the strongest ligaments of the body
– Transmits weight of the upper body to the
lower limbs
– Supports the visceral organs of the pelvis
– Forms by the fusion of 3 bones: ilium, ischium,
and pubis
Pelvic Girdle (Hip)
Figure 7.27a
Illium
Figure 7.27b
Comparison of Male and Female Pelvic
Structure
• Female pelvis
– Tilted forward, adapted for childbearing
– True pelvis defines birth canal
– Cavity of the true pelvis is broad, shallow, and
has greater capacity
• Male pelvis
– Tilted less forward
– Adapted for support of heavier male build and
stronger muscles
– Cavity of true pelvis is narrow and deep
Comparison of Male and Female
Pelvic Structure
Table 7.4
Lower Limbs
• Each lower limb consists of a femur
(thigh), patella (knee cap), tibia & fibula
(lower leg), tarsal bones (ankle),
metatarsal (foot), and phalanges (toes)
• They carry the weight of the erect body,
and are subjected to exceptional forces
when one jumps or runs
• The sole bone of
the thigh
Femur (Thigh)
• Longest and
heaviest bone in
the body
• Articulates
proximally with
the hip and
distally with the
tibia and fibula
Figure 7.28b
Patella (Knee cap)
• Large sesamoid bone
Tibia (Shinbone)
• Large medial bone of the leg
• Receives the weight of the body from the
femur and transmits it to the foot
Fibula
• Slender bone of the leg
• Site for attachment of muscles that move
the foot and toes
Fibula
• Sticklike bone with slightly expanded
ends located laterally to the tibia
• Major markings include the head and
lateral malleolus
Tibia & Fibula
Figure 7.29a, b
Tarsus (Ankle)
• Composed of seven tarsal bones:
1.Talus
2.Calcaneus (heel bone)
3.Cuboid
4.Navicular
5.Medial Cuneiform
6.Intermediate Cuneiform
7.Lateral Cuneiform
“Tom Can Control Not Much In Life”
Tarsus
Figure 7.31b, c
Metatarsal Bones & Phalanges
• Metatarsals
– Five (I - V) long
bones
• Phalanges
– The 14 bones of
the toes
– Each digit has
three phalanges
except the hallux,
which has no
middle phalanx
Figure 7.31a
Clinical Disorders and Diseases
of the Skeletal System
Cleft Lip/Palate
• Facial and oral malformations that occur
very early in pregnancy
• Results when there is not enough tissue in
the mouth or lip area, and the tissue that is
available does not join together properly
• Cleft lip – split or separation of the two
sides of the upper lip
• Cleft palate – split or opening in the roof of
the mouth (hard or soft palate)
• 1 in 700 babies; 4th most common birth
defect in the US
Cleft lip/palate cont.
• The cause is unknown
• May be linked to genetic and
environmental factors (drugs, exposure to
viruses or chemicals)
• Eating, speech, and dental problems could
result
• Often requires multiple surgeries to treat
Cleft Palate
Vertebral Column: Curvatures
Scoliosis: abnormal lateral curvature of the
spine (occurs most often in the thoracic
region)
• Caused by a bone abnormality present at birth,
abnormal muscles or nerves, trauma, or genetic
• 2-3% of Americans at age 16 (girls are more prone
to developing the condition)
• Diagnosed by screening exams, bone exam, and
X-ray
• Treatments include braces or surgery (spinal
fusion)
Scoliosis
Osteomalacia
 Softening of the bones due to a lack
of Vitamin D or a problem with the
body’s ability to break down and
use Vitamin D
 Rickets - Children's form of
osteomalacia
 Causes – not enough Vitamin D;
not enough exposure to sunlight or
malabsortption of Vitamin D by the
intestines
 Symptoms - bone weakness,
fractures that occur without real
injury, and numbness
 Treatments – Vitamin D, calcium,
and phosphorus supplements
Osteoporosis
• Bone loss outpaces
bone regeneration
• Bones weaken and
lose mass
• Bones become brittle
and fractures occur
more often
• Found most often in
women
• Treatment may
include; medication,
diet changes,
exercise
Osteoarthritis
•
•
•
•
Degenerative joint disease
Most common type of arthritis (21 million)
Breakdown of cartilage in joints
Mostly occurs in the weight bearing joints,
but it can occur anywhere
• Causes cartilage to become stiff and lose
its elasticity
• As cartilage deteriorates, tendons and
ligaments stretch, causing pain
Osteoarthritis
Symptoms:
•Joint aching and
soreness
•Pain after overuse or
long periods of inactivity
•Joint swelling
•Fluid accumulation
Treatment: medication,
physical therapy, surgery
Knee Replacement surgery
• Generally reserved for people over the
age of 50 with severe osteoarthritis
• Helps relieve pain & restore function in
severely diseased knee joints
• During surgery; a surgeon cuts away
damaged bone and cartilage from your
femur, patella, and tibia and replaces it
with an artificial joint made of metal alloys,
high-grade plastics, and polymers
Fractures
• A crack or break in a bone
• Despite its mineral strength,
bone can crack or even
break if subjected to
extreme loads, sudden
impacts, or stresses from
unusual directions
Types of Fractures
• Named according to their external
appearance, their location, and the nature
of the crack or break in the bone.
• Two general categories:
1. Closed (simple) – fracture is internal
2. Open (compound) – fracture projects
through the skin
Common fracture types (cont’d)
Common fracture types
• Comminuted fractures
• Spiral fractures
Figure 6–16 (4 of 9)
• Greenstick fracture
Figure 6–16 (7 of 9)
• Compression
fractures
Figure 6–16 (9 of 9)
Depression fracture of the skull
Treatment of a Fracture
• Initial treatment for fractures of arms, legs,
hands, and feet include splinting the
extremity in the position it is found,
elevation, and ice.
• Edema (or swelling)
What does this have to do with splinting and
casting?
• Closed Reduction – manual realignment
• Open Reduction – surgically realignment
Steps in the Repair of a Fracture
Step 1 –
• Immediately after the fracture, extensive
bleeding occurs (blood vessels are broken).
• A large blood clot, or fracture hematoma, soon
closes off the injured vessels and leaves a
fibrous meshwork in the damaged area.
• The disruption of the circulation kills osteocytes
(mature bone cells) around the fracture.
• Dead bone soon extends along the shaft.
Steps in the Repair of a Fracture
Step 2 –
• The cells of the endosteum (cellular layer) and
periosteum undergo cell division and the
daughter cells migrate into the fracture zone.
• An external callus (hard skin) forms and
encircles fracture
• An internal callus organizes within the cavity
and between the broken ends of the shaft
• The broken ends have been temporarily
stabilized
Steps in the Repair of a Fracture
Step 3 –
• Osteoblasts (bone building cells) replace the
central cartilage of the external callus with
spongy bone
• Calluses form a brace at the fracture site
• Spongy bone now unites the broken ends
• Fragments of dead bone are removed and
replaced
• If the fracture required a cast, it can be removed
at this stage
Steps in the Repair of a Fracture
Step 4 –
• Osteoclasts (remove and recycle bone matrix)
and osteoblasts continue to remodel the region
of the fracture (4 months to 1 year)
• When remodeling is complete, the bone of the
calluses is gone and only living compact bone
remains.
• The bone could be slightly thicker and stronger
than normal at the fracture site
Fracture repair
Fracture repair (cont’d)
Casts
• Holds a broken bone in place as it heals
• Help to prevent or decrease muscle
contractions
• Provide immobilization (the joints above
and below the area)
• Casts are made of plaster and fiberglass
• Typically worn for 6-8 weeks
Dislocation
• Separation of two bones where they meet
at a joint (no longer in normal position)
• Caused by a sudden impact to the joint
• May be hard to tell a dislocated bone from
a broken bone
• Generally take 3-6 weeks to heal
• Possible ligament damage can occur
Joints (Articulations)
Joint (articulation) - Where
two bones interconnect
• Functions
– Bind parts of the skeletal
system
– Enable the body to move in
response to skeletal
muscle contractions
Classification of Joints:
The three structural (by the type of tissue that binds the
bones at each junction) classifications are:
1. Fibrous joints
2. Cartilaginous joints
3. Synovial joints
Joints can also be grouped functionally according to the
degree of movement possible at the bony junction:
1. Immovable joints
2. Slightly movable joints
3. Freely movable joints
Fibrous Joints
• The bones are close together and may
interlock; between bones in close contact
• Extremely strong joints
• There is no/limited joint movement
Examples:
1. Between tibia and
fibula (bound by a
sheet)
2. Suture – between flat
bones of the skull
3. Binds the teeth to bony
sockets in jaw
Figure 8.1a
Cartilaginous Joints
• Hyaline and fibrocartilage connects the bones of this type
of joint
• Limited movement
Examples:
1. Joints that are temporary structures that disappear during
growth (immature long bone)
2. Sternum and first rib
3. Pubic symphysis in the pelvis
4. The joint formed by the bodies of two adjacent vertebrae
Figure 8.2a
Synovial (Freely Movable) Joints
• Most joints of the
skeletal system are
synovial
• Allow free movement
• More complex structure
• Consist of articular
cartilage; joint capsule;
synovial membrane
(synovial fluid)
Synovial Joints: General Structure
1. Articular cartilage
(hyaline cartilage) –
resists wear and
tear/minimizes friction
2. Joint capsule – holds
together the bones
3. Ligaments – reinforce
the joint capsule/bind
the ends of the
bones/prevents
excess movement
Figure 8.3a
Synovial Joints: General Structure
4. Synovial membrane –
inner layer of the
joint/cover all surfaces
within the joint capsule
a. Synovial cavity – sac
within the membrane
b. Synovial fluid –
moistens and
lubricates the smooth
cartilaginous
surfaces of the joint
Synovial Joints: General Structure
5. Menisci – some synovial joints are divided into
two compartments by discs of fibrocartilage
6. Bursae – fluid-filled sacs found in some synovial
joints/cushion and aid the movement of tendons
that glide over bony parts or other tendons (knee
and elbow for example)
7. Tendons – connect bones to muscles/limit ROM
8. Fat pads – protection/packing material
Types of Synovial Joints
• Based on the shapes of the articular
surfaces
• Each type of joint permits a different type
and range of motion
Types:
• Gliding/Plane
• Hinge
• Pivot
• Condylar/Ellipsoidal
• Saddle/Sellar
• Ball and socket
Types of Synovial Joints
Ball and Socket Joints
- Consists of a bone with a slightly
egg-shaped head that articulates
with the cup-shaped cavity of
another bone
- Allows a wider range of motion;
movements in all planes as well as
rotational movement
- Examples – hips and shoulder
joints
Types of Synovial Joints
Hinge joints
- Convex surface of one bone fits in the
concave surface of another bone
- Examples – elbow, joints of the phalanges,
knee, jaw
Types of Synovial Joints
Condylar (Ellipsoidal) Joints
- The ovoid condyle of one bone fits into the
elliptical cavity of another bone
- Permits a variety of movements in different
planes (rotational movement is not possible)
- Examples – joints between the metacarpals
and phalanges
Types of Synovial Joints
Gliding (Plane) joints
– Articular surfaces (the part of the bone that
connects with the other bone) are essentially
flat or slightly curved
– Allows sliding or back and forth motion and
twisting movements
– Examples: wrist and ankles; between the
articular processes of the vertebrae; sacroiliac
joints; joints formed by ribs 2 – 7 connecting
with the sternum
Gliding (Plane) Joint
Types of Synovial Joints
Saddle Joints
- Forms between bones whose
articulating surfaces have both
concave and convex regions
- The surface of one bone fits the
complementary surface of the
other
- Permits a variety of movements,
mainly in two planes
- Example – joint between the carpal
and metacarpal of the thumb
Types of Synovial Joints
Pivot Joints
- The cylindrical surface of one bone rotates in a
ring formed of bone and a ligament
- Movement is limited to rotation around a central
axis
- Examples – joint between the proximal ends of
the radius and ulna; the arch of the atlas rotates
around the dens of the axis (neck)
Injuries/Conditions Review
Match the condition with the pictures
1.
2.
A. Osteoarthritis
B. Osteoporosis
C. Osteomalacia
D. Scoliosis
3.
4.
Fractures
Match the fracture with the pictures
A. Depressed
B. Greenstick
C. Compression
D. Spiral
3.
1.
2.
4.
Fractures
Match the fracture with the pictures
1.
A. Compound
B. Simple
C. Comminuted
D. Transverse
2.
3.
4.
Bone Bingo
Frontal
Lacrimal
Clavicle
Sternum
Humerus
Phalanges
Patella
Metatarsals
Coccyx
Zygomatic
Mandible
Scapula
Vertebrae
Radius
Femur
Fibula
Metacarpals
Occipital
Nasal
Maxilla
Ribs
Ulna
Carpals
Tibia
Tarsals
Sacrum
Parietal