Chapter 9-- Joints
9-1
Famous Quotes
• I figured my body always would be able
to repair itself. I think all of us believe
that – until you begin to age and get hit
with deteriorating joints. Lee Majors
• It had not occurred to me that marriage
requires the same effort as a career. And
unlike a career, marriage requires a joint
effort. Jessica Savitch (1947-1983)
9-2
Ch. 9 (Joints) Study Guide
1. Critically read Chapter 9 pp. 278-297 before 9.3
(Anatomy of selected diarthroses). Study all
figures in the PowerPoint slides as well.
2. Comprehend Terminology (those in bold in the
textbook) within the reading scope above
3. Study-- Figure questions, Think About It questions,
and Before You Go On (section-ending) questions
(within the reading scope above)
4. Do end-of-chapter questions—
– Testing Your Recall— 1-4, 6-7, 9, 11-16, 18
– True or False– 2, 4, 5, 9, 10
5. Review/study review sheet document (4 pages)
posted on Blackboard
9-3
I. Overview of the joints
9-4
Figure
9.1– a
gymnast
and joint
flexibility
9-5
§ Why Knuckles Crack and
Joints Creak
• Some peoples' bodies play a
percussive symphony of cracking and
creaking, thanks to the large orchestra
of noise-making human joints.
• What's behind it all?
9-6
§ Joints and their names
1. What are joints?
• Arthrology = study of the joints
• Kinesiology = study of musculoskeletal
movement (motion of human body)
2. How joints are named?
• From the names of the bones involved
• Ex. The atlantoccipital joint
• Ex. The humeroscapular joint
9-7
II. Functional classification
of joints
9-8
1. Are all joints able to move?
– Immovable joints– where? Why?
– Less movable– ex. vertebral column; why?
– Moveable—shoulder, elbow, knee
2. Functional classification (freedom of
movement)
– synarthrosis (little/no movement) (“Syn”-together)
– amphiarthrosis (slightly movable)
– diarthrosis (freely movable) (‘Dia”– through)
9-9
III. Structural classification
of joints
9-10
§ Structural classification
How adjacent bones are joined?
1. Bony joints (synostosis; synarthrosis)– two
bones fused
2. Fibrous joints (synarthrosis)—held together
by collagen fibers; lack a synovial cavity
3. Cartilaginous joints (amphiarthrosis)– held
together by cartilage; lack a synovial cavity
4. Synovial joints (diarthrosis)– having
synovial (joint/articular) cavity (Fig. 9.5 next
slide)
9-11
Fig. 9.5 Synovial Joint
• Joint in
which two
bones are
separated by
a space
called a
synovial
(joint) cavity
• Most are
freely
movable
9-12
§ 1. Bony Joints (Synostosis)
A. Gap between “two bones ossify”–
become a single bone
•
TWO frontal/mandibular bones in infants
B. Can occur in either fibrous joints or
cartilaginous as well; Examples:
•
•
Aging: cranial sutures (fibrous joints)
destroyed (ex. Parietal bones fuse) in elderly
Aging: attachment of first rib to the sternum
(cartilaginous joint) becomes a synostosis
with age
9-13
§ 2. Fibrous Joints (SynarthrosisAmphiarthrosis)
• Collagen fibers span the space
between bones
• Three kinds of fibrous joints
– A. Sutures— the fibers are short and allow
for little movement
– B. Gomphoses— the fibers are also _____
and allow for little movement; between
teeth and the jaw
– C. Syndesmoses—longer fibers and more
movable
• Figure 9.2
9-14
Fibrous Connective Tissue
Fig. 9.2
R. Tibia
B
A
Suture
Syndesmosis
Gomphosis
9-15
Fibrous Joint – A. Sutures
• Immovable fibrous joints
– Bind bones together; only in skull
• 3 types— (Fig. 9.3 next slide)
• Serrate sutures - interlocking
lines
– coronal, sagittal and lambdoid
sutures
• Lap sutures - overlapping
beveled edges
– Between temporal and parietal
bones; Name the suture?
• Plane sutures - straight,
nonoverlapping edges
– palatine processes of the maxillae
Suture
9-16
Three types of suture--
Serrate suture
Lap suture
Plane suture
Miter joint
Butt joint
Bone
Wood
Dovetail joint
9-17
Fibrous Joint – B. Gomphoses
• Attachment of a tooth to
its socket
• Held in place by fibrous
periodontal ligament
– Consisting of collagen
fibers attach
teeth to jawbones (which
bones?)
• Little movement
(Synarthrosis) while
chewing
Gomphoses
9-18
Fibrous Joint – C. Syndesmosis
• Two bones bound by broad
fibrous sheet called
– Interosseous membrane
• More/less movable than that
of sutures/gomphoses
• Examples: radius to ulna (a
more movable one,
Amphiarthrosis) allow
supination and pronation
(next slide); tibia to fibula
(less movable one)
Tibia &
fibula
Syndesmosis
9-19
Supination and Pronation
• For example: In the
forearm
• Supination
– rotation of forearm so
that the palm faces
forward
• Pronation
– rotation of forearm so
the palm faces to the rear
A
B
Supine means up. In order to carry a bowl of
soup, your hand must be in the supine position
9-20
Check point question #1-• Functionally, why are sutures
classified as synarthroses,
and syndesmoses as
amphiarthroses?
9-21
9-21
§ 3. Cartilaginous Joints
(amphiarthrosis)
Two bones are linked by cartilage
Two types–
A. synchondroses and
B. symphyses
9-22
Cartilaginous Joint – A. Synchondrosis
• Bones are joined by
hyaline cartilage
• Examples:
– First rib attachment
to sternum (A on the
right)
– Temporary joint
between epiphysis
and diaphysis in
growing bones:
called Epiphyseal
?__________
A
B,
next
9-23
Cartilaginous Joint – B. Symphyses
• 2 bones joined by
fibrocartilage
• Examples:
– See figure at right
2
• Only slight amount
of movement is
possible
• Examples– 1 & 2
on the right
1
9-24
Check point question #2-• What is the structural difference in
histology between a
synchondrosis and a symphysis?
9-25
9-25
IV. Focusing on synovial
joints
9-26
§ 4. Synovial Joint
• Most are freely movable;
two bones in fact Do / Do
not touch each other
• Two bones are separated by
a space called A. _________
cavity (with fluid in it) and
a soft tissue called
B._____________
• B. Articular cartilage -hyaline cartilage covering
the joint surfaces
• Synovial fluid —a lubricant;
feeds cartilages
A
B
Next slide
9-27
§ Synovial joints
1. Joint (Articular) capsule encloses joint cavity
– (Outer) Fibrous capsule: continuous with periosteum
– (Inner) synovial membrane; secretes ____________
2. Articular discs or menisci: cartilage grows
inward and forms pads (Fig. 9.29 c-d; 8.39)
– jaw, wrist, sternoclavicular and knee joints
– absorbs shock, guides bone movements and
distributes forces
•
•
Tendon: attaches muscle to bone
Ligament: attaches bone to bone
9-28
Knee
Joint
9-29
Right Knee Joint – Superior View
• Medial meniscus
& lateral meniscus
absorb shock and
shape joint
PCL
ACL
Lateral condyle of tibia
?
Medial condyle of tibia
9-30
Anterior view
Posterior view
9-31
§ Tendon Sheaths and Bursae
• Bursa = a sac
filled with
synovial fluid
• Tendon sheaths
= elongated
bursae lined
with synovial
membrane and
wrapped around
a tendon
Ulnar bursa
Tendons (flexor
digitorum)
Tendon
sheaths
9-32
Tendon Sheaths and Bursae
• Bursa = a sac filled with synovial fluid
– (Locations) between muscles or between a tendon & a
bone etc.; Good examples– Shoulder joint etc. Fig.
9.24
• Tendon sheaths = elongated bursae
– (Locations) where there is considerable friction; such
as the hand, wrist, fingers, the ankle, foot, toes etc.
• Functions of bursa and tendon sheaths:
– Reduce friction in joints (such as the shoulder),
– Cushion the movement of one body part over
another
9-33
Fig. 9.24 Humeroscapular joint
9-34
Check point question #3-• A) What is the functional
classification of synovial joints?
• B) Why is a meniscus in an
interphalangeal joint unnecessary?
9-35
V. Types of synovial joints
9-36
§ 6 Types of Synovial Joints—in
descending order of mobility
1.
9-37
9-38
1. Ball-and-Socket Joints
• Features: Smooth hemispherical head
fits within a cuplike depression
• Examples:
– (shoulder) head of humerus into glenoid
cavity of scapula
– (hip) head of femur into acetabulum of hip
bone
• Type: only multiaxial joints in the body
• Demonstration: (next slide)
9-39
Planes of movement (A-C) & axes of rotation
• Shoulder joint has 3
degrees of freedom
= multiaxial joint;
• Other joints –
monoaxial or biaxial
• Axis of rotation–
Def.--perpendicular
to the plane of
movement;
examples— A, B, C
The arm moves through
the sagittal plane
A
The arm rises in the
frontal plane
C
B
9-40
The arm rotates in the
transverse plane
Planes of movement & axes of rotation
• A—Abduction
(away from midline)
vs. adduction
• B—Flexion
(decreases a joint
angle) vs.
extension
• C—Medial (internal)
rotation vs. lateral
rotation
9-41
It moves through
the _________ plane
A
The arm rises in the
frontal plane
C
B
The arm rotates in
the ______ plane
2.
9-42
9-43
2. Condyloid (ellipsoid) Joints
• Features: Oval convex surface on one
bone fits into a similarly shaped
depression on the next
• Examples:
– radiocarpal joint of the wrist
– metacarpophalangeal joints at the bases
of the fingers
• Type: Biaxial joints– why?
• Demonstration: index finger (or 2nd - 5th
digits) and Fig. 9.21
9-44

 
When someone is
abducted, they are
taken away, just as
abduction takes
the limb away from
the body.
During adduction,
the limb is added to
the body.
Metacarpophalangeal joints
9-45
3.
9-46
Condyloid joint


9-47
3. Saddle Joints
• Features: Each articular surface is
shaped like a saddle, concave in one
direction and convex in the other bone
(like a sitting rider)
• Examples: trapeziometacarpal joint at
the base of the thumb
• Type: Biaxial joint (see demo below)
• Demonstration:
– A) frontal plane (palmar abduction)
– B) sagittal plane (opposition)
primates’ anatomical hallmark: __________
Fig. 1.5 & 9.21 c-d
9-48
Monkey
Primate adaptations:
The thumbs
became
opposable; they
made the hands
prehensile
Human
9-49
Figure 9.21d

ID this movement of thumb
9-50
Figure 9.21e

ID this movement of thumb
9-51
4.
9-52
4. Gliding (plane) Joints
• Features: Flat articular surfaces in
which bones slide over each other
• Examples: Fig. Z tarsal bones
– between the carpal bones of the wrist,
– the tarsal bones of the ankle,
– articular processes of the vertebrae
• Type: Biaxial joints
• Demonstration: head is tilted side-toside and back-and-forth, the vertebrae
slide accordingly
9-53
Can Talented Naval Medics Interest Lazy Cubs?
Calcaneus
Talus
Cuboid
(Intermediate)
(Lateral)
Gliding
Medial cuneiform
9-54
5.
9-55
Anterior view
Capitulum
Funny
bone
9-56
5. Hinge Joints
• Features: One bone with convex surface
that fits into a concave depression on other
bone
• Examples:
– ulna and humerus at elbow joint (trochlea of the
humerus fits into the trochlear notch of the ulna)
– femur and tibia at knee joint (tibiofemoral)
– finger and toe joints (interphalangeal)
• Type: Monaxial (uniaxial) joints
• Fig. 9.25b
9-57
A hinge joint --the elbow
(Trochlear notch)
9-58
6.
9-59
9-60
6. Pivot Joints
• Features: One bone rotates on its
longitudinal axis relative to the other
• Examples:
– proximal radioulnar joint; the radius pivots
during pronation and supination
– atlantoaxial joint (dens of axis to atlas); Fig.
8.24 (rotation of the atlas)
• Type: Monaxial joints
• Demonstration: see next 3 slides
9-61
Supination and Pronation


• For example: In the
forearm
• Supination
– rotation of forearm so
that the palm faces
forward
• Pronation
A
B
– rotation of forearm so
the palm faces to the rear
9-62
of the atlas (the next slide)
9-63
Anterior arch
?
(C1)
(C2)
9-64
Check point question #4-• Which of the 6 type of synovial
joints are biaxial?
• Give one specific example for each
biaxial synovial joint.
9-65
Questions (muddiest
points)?
9-66