chapter 09 lecture outline
TRANSCRIPT
1Copyright © McGraw-Hill Education. Permission required for reproduction or display.
Chapter 09
Lecture Outline
See separate PowerPoint slides for all figures and tables pre-
inserted into PowerPoint without notes.
9.1 Classification of Joints
• Joints (articulations)
– Places of contact between bones, bones and
cartilage, or bones and teeth
– Arthrology—study of joints
2
9.1 Classification of Joints
• Range of motion at joints
– Motion ranges from no movement to extensive
movement
– Structure of each joint determines its mobility and
stability
– Inverse relationship (tradeoff) between mobility
and stability
o For example, skull sutures are immobile but very stable
3
9.1 Classification of Joints
• What are the functional classes of joints?
– Synarthroses
o Immobile joints
o Can be fibrous or cartilaginous joints
– Amphiarthroses
o Slightly mobile joints
o Can be fibrous or cartilaginous joints
– Diarthroseso Freely mobile joints
o All synovial joints
4
• What are the structural classes of joints?
– Fibrous joint
o Bones held together by dense connective tissue
– Cartilaginous joint
o Bones joined by cartilage
– Synovial joint
o Bones joined by ligaments with fluid-filled joint cavity
separating bone surfaces
9.1 Classification of Joints
5
9.2 Fibrous Joints
• Characteristics of fibrous joints
– Connected by dense regular connective
tissue
– Have no joint cavity
– Immobile or only slightly mobile
– Three most common types
o Gomphoses
o Sutures
o Syndesmoses
7
9.2a Gomphoses
• Gomphoses (peg in a
socket)
– Articulations of teeth with
sockets of mandible and
maxillae
– Tooth held in place by
fibrous periodontal
membranes
– Function as synarthroses
Figure 9.2a
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.8
9.2b Sutures
• Sutures (seams)– Found between some skull bones
o Very short fibers
– Interlocking, irregular edges
o Increase strength and decrease risk
of fracture
– Function as synarthroses
– Allow growth in childhood
– Become ossified synostoses in
older adults
Figure 9.2b
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.9
9.2c Syndesmoses
• Syndesmoses
– Bound by interosseous
membrane, broad
ligamentous sheet
– Found between radius and
ulna and between tibia and
fibula
– Function as amphiarthroses
o Provide pivot for two long
bonesFigure 9.2c
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
10
Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill EducationCopyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education
What did you learn?
• Where are gomphoses
located?
• Where can I find
syndesmoses joints?
• Functionally, how are
syndesmoses classified? (In
other words, how much
movement do they allow?)
11
9.3 Cartilaginous Joints
• Properties of cartilaginous joints
– Either hyaline cartilage or fibrocartilage
between bones
– Lack a joint cavity
– Immobile or slightly mobile
– Synchondroses or symphyses
12
9.3a Synchondroses
• Synchondroses
– Bones joined by hyaline cartilage
– Immobile (synarthroses)
Figure 9.3a
13
9.3b Symphyses
• Symphyses
– Pads of fibrocartilage between articulating bones
o Resist compression and act as shock absorbers
– Allow slight mobility (amphiarthroses)
Figure 9.3b
14
Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill EducationCopyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education
What did you learn? • What type of cartilage is
found in a synchondrosis?
• What type of cartilage is
found in a symphyses?
15
9.4a Distinguishing Features and
Anatomy of Synovial Joints
• Synovial joints
– Bones separated by a joint cavity
– Include most joints in the body
– Diarthroses (freely mobile)
16
9.4a Distinguishing Features and
Anatomy of Synovial Joints
All with the basic features
o Articular capsule and joint cavity
o Outer fibrous layer and Inner synovial membrane
o Joint cavity
o synovial fluid lubricates articular cartilage
o Articular cartilage
o Hyaline cartilage (avascular)
o Reduces friction during movement
o Ligaments, nerves, and blood vessels
o Stabilize, strengthen, and reinforce synovial joints
o Numerous nerves detect painful stimuli
18
9.4a Distinguishing Features and
Anatomy of Synovial Joints
• Bursae
– Fibrous, saclike structures containing synovial fluid
– Lined internally by synovial membrane
– Found in synovial joints where bones, ligaments, muscles,
skin, or tendons rub together
– Connected to or separate from joint cavity
– Alleviate friction
19
9.4a Distinguishing Features and
Anatomy of Synovial Joints
• Other accessory structures
– Tendon sheaths, elongated bursae
o Wrap around tendons where friction is excessive
o Common in wrist and ankle
– Fat pads
o Act as protective packing material in joint periphery
o Can fill spaces when joint shape changes
20
9.4b Classification of Synovial Joints
• Classified by movements allowed and shapes
of joint surfaces
• Classes by movement– Uniaxial joint
o Bone moves in just one plane or axis
– Biaxial joint
o Bone moves in two planes or axes
– Multiaxial joint
o Bone moves in multiple planes or axes
23
9.4b Classification of Synovial Joints
• Classes by shape of joint surfaces (from least to
most mobile)– Plane joints
– Hinge joints
– Pivot joints
– Condylar joints
– Saddle joints
– Ball-and-socket joints
24
9.4b Classification of Synovial Joints
• Plane joint– Articular surfaces flat
– Simplest, least mobile synovial articulation
– Uniaxial: limited side-to-side gliding movement in a single plane
• Hinge joint– Convex surface within concave depression
– Uniaxial: like the hinge of a door
• Pivot joint– Bone with rounded surface fits into ligament ring
– Uniaxial joint: rotation on longitudinal axis
26
9.4b Classification of Synovial Joints
• Condylar joint– Oval, convex surface articulating with concave surface
– Biaxial
• Saddle joint– Convex and concave surfaces resembling saddle shape
– Biaxial
• Ball-and-socket joint– Spherical head of one bone fitting into cuplike socket
– Multiaxial, permitting movement in three planes
– The most freely mobile type of joint
27
9.6b Angular Motion
• Angular motion
– Increases or decreases angle between two bones
– Includes specific types
o Flexion and extension
o Hyperextension
o Lateral flexion
o Abduction and adduction
o Circumduction
28
9.6b Angular Motion
• Flexion
– Movement in an anterior-posterior plane
– Decreases the angle between bones: brings bones closer together
– E.g., bending finger
• Extension
– Also in anterior-posterior plane, but opposite of flexion
– Increases angle between articulating bones
– E.g., straightening your fingers after making a fist
29
9.6b Angular Motion
• Hyperextension
– Joint extended more than 180 degrees
– E.g., glancing up at the ceiling while standing
• Lateral flexion
– Trunk of body moving in coronal plane laterally
– Occurs between vertebrae in the cervical and
lumbar region
30
9.6b Angular Motion
• Abduction
– Lateral movement of body part away from midline
– E.g., arm or thigh moved laterally from body
midline
• Adduction
– Medial movement of body part toward midline
– E.g., thigh brought back to midline
32
9.6b Angular Motion
• Circumduction
– Proximal end of
appendage
relatively stationary
– Distal end makes a
circular motion
– Movement makes
an imaginary cone
shape
– E.g., drawing a
circle on the
blackboard(both) © The McGraw-Hill Companies, Inc./JW Ramsey, photographer
34Figure 9.10
9.6c Rotational Motion
• Rotation
– Bone pivots on its own longitudinal axis
– Lateral rotation
o Turns anterior surface of bone laterally
– Medial rotation
o Turns anterior surface of bone medially
– Pronation
o Medial rotation of forearm so palm of hand posterior
– Supination
o Lateral rotation of forearm so palm of hand anterior
35
9.6d Special Movements
• Depression
– Inferior movement of a body part
– E.g., movement of mandible while opening mouth
• Elevation
– Superior movement of a body part
– E.g., movement of mandible when closing mouth
37
9.6d Special Movements
• Dorsiflexion– Limited to ankle joint
– Talocrural (ankle) joint bent so the
dorsum (superior surface) of foot
moves toward the leg
– E.g., when digging in your heels
• Plantar flexion– Talocrural joint bent so dorsum
pointed inferiorly
– E.g., ballerina on tiptoes in full
plantar flexion
Figure 9.12b39
9.6d Special Movements
• Inversion
– Occurs only at intertarsal
joints of the foot
– Sole turns medially
• Eversion
– Occurs only at intertarsal
joints of foot
– Sole turns laterally
Figure 9.12c
9.6d Special Movements
• Protraction
– Anterior movement from
anatomic position
– E.g., jutting jaw anteriorly at
temporomandibular joint
• Retraction
– Posterior movement from
anatomic position
– E.g., pulling in jaw
posteriorly at
temporomandibular joint
Figure 9.12d
9.6d Special Movements
• Opposition
– Movement of thumb toward
tips of fingers at
carpometacarpal joint
– Enables the thumb to grasp
objects
• Reposition
– Opposite movement
Figure 9.12e
9.7a Temporomandibular Joint
• Features of the temporomandibular joint
(TMJ)
– Head of mandible articulates with temporal bone
– Only mobile joint between bones in the skull
– Has loose articular capsule
• Surrounds joint
• Promotes extensive range of motion
– Hinge, gliding, and some pivot
– Joint moves anterior and inferior during jaw opening
– Has articular disc
• Thick pad of fibrocartilage
• Divides synovial cavity into two chambers
43
Clinical View: TMJ Disorders
• Most common due to alteration in the ligaments
securing the joint
• Possible spasm in the lateral pterygoid muscle
• Articular disc forced out of normal position
• Clicking or popping heard as person opens or
closes mouth
• Possible pain in joint, paranasal sinuses,
tympanic membrane, oral cavity, eyes, and teeth
45
9.7b Shoulder Joint
• Sternoclavicular Joint
– Saddle joint
– Formed by manubrium and sternal end of clavicle
– Articular disc
o Partitions joint into two parts forming two synovial
cavities
– Elevation, depression, circumduction possible
– Stability provided by fibers and ligaments
o Makes this specific joint very stable and difficult to
dislocate
47
9.7b Shoulder Joint
• Acromioclavicular Joint
– Plane joint
– Formed from acromion and lateral end of clavicle
– Fibrocartilaginous articular disc within joint cavity
– Joint capsule strengthened superiorly by acromioclavicular
ligament
– Clavicle bound to coracoid process by coracoclavicular
ligament
o If torn, acromion and clavicle no longer align (shoulder
separation)
49
9.7b Shoulder Joint
• Glenohumeral (Shoulder) Joint
– Ball-and socket joint
o Formed by head of humerus and glenoid cavity of scapula
– Permits greatest range of motion of any joint in the
body
o Most unstable and most frequently dislocated
– Fibrocartilaginous glenoid labrum
• Encircles the socket in all directions except inferior
– Abundant bursae
o Decrease friction where tendons and muscles extend across
capsule
50
9.7b Shoulder Joint
• Glenohumeral (Shoulder) Joint (continued)
– Supporting ligaments and tendons
o Coracoacromial ligament, coracohumeral ligament,
glenohumeral ligaments
o Tendon of long head of biceps brachii
– Most joint stability due to rotator cuff muscles
o Subscapularis, supraspinatus, infraspinatus, teres minor
o Work as a group to hold head of humerus in glenoid cavity
o Tendons encircle joint and fuse with articular capsule
51
9-54
Shoulder Joint Dislocations
• Shoulder separation refers to
acromioclavicular dislocation
– Pain when arm abducted more than
90 degrees
– Acromion appearing prominent
• Shoulder dislocation
– Downward displacement of the humerus is the most common shoulder dislocation
– Dislocations most often occur when the arm is abducted and then receives a blow from above
• Children especially prone to dislocation
9.7c Elbow Joint
• Elbow is a hinge joint composed of two articulations
- Humeroulnar joint
o Trochlear notch of ulna articulating with trochlea of
humerus
- Humeroradial joint
o Capitulum of humerus articulating with head of radius
- Both enclosed within a single articular capsule
55
9.7c Elbow Joint
• Elbow is very stable because
– Articular capsule is thick
– Bony surfaces of humerus and ulna interlock closely
– Multiple, strong ligaments reinforce articular capsule
o Radial collateral ligament
– Stabilizes joint at lateral surface
– Extends around head of radius
o Ulnar collateral ligament
– Stabilizes medial side of the joint
– Extends from medial epicondyle of humerus to coronoid and olecranon of
ulna
o Anular ligament
– Surrounds the neck of the radius
– Binds head of the radius to the ulna
57
Clinical View: Subluxation of the Head
of the Radius
• Subluxation refers to incomplete dislocation
• Subluxation of the head of the radius
– Head pulled out of anular ligament
– Occurs almost exclusively in children (usually < 5 yrs)
• Nursemaid’s elbow: subluxation when in pronation
– Child’s anular ligament thin and radial head not fully
formed
– Doctor may maneuver radial head back into anular
ligament
58
9.7d Hip Joint
• What are the main components and functional
characteristics of the hip joint?– Articulation between head of the femur and acetabulum of
os coxa
– Acetabular labrum—fibrocartilaginous ring that deepens
socket
– More stable, less mobile than glenohumeral joint
59
9.7d Hip Joint
• Intracapsular ligaments
– Iliofemoral ligament
o Ligament providing support for anterior articular capsule
– Ischiofemoral ligament
o Intracapsular ligament posteriorly located
– Pubofemoral ligament
o Triangular thickening of capsule’s inferior region
– Become taut when hip extended
• Ligament of the head of femur (ligamentum teres)
– Small ligament from acetabulum to fovea of head of femur
– Provides no strength
– Contains artery supplying head of femur
61
Clinical View: Fracture of the Femoral Neck
• Fracture of femur is often incorrectly referred to as
“fractured hip”
• Intertrochanteric fractures
– Extracapsular fractures
– Usually in younger and middle-aged individuals
• Subcapital fractures
– Occur within hip articular capsule
– Usually in elderly people with osteoporosis
– May result in tearing of retinacular arteries
o May have avascular necrosis in the region
63
9.7e Knee Joint
• Structures of the knee joint
– Articular capsule
o Encloses only medial, lateral, and posterior knee regions
– Quadriceps femoris muscle tendon
o Passes over knee’s anterior surface, surrounds patella
– Patellar ligament
o Extends from patella to tibial tuberosity
– Fibular collateral ligament
o Reinforces lateral surface of joint
o Extends from femur to fibula
o Prevents hyperadduction
65
9.7e Knee Joint
• Structures of the knee joint (continued )
– Tibial collateral ligament
o Reinforces medial surface of joint
o Extends from femur to tibia
o Prevents hyperabduction
– Medial meniscus and lateral meniscus
o Deep to articular capsule within knee joint
o C-shaped fibrocartilage pads on top of tibial condyles
o Cushioning between articular surfaces
o Change shape to conform to articulating surfaces
o Partially stabilize joint medially and laterally
66
9.7e Knee Joint
• Structures of the knee joint (continued )– Cruciate ligaments—cross each other
o Deep to articular capsule
– Anterior cruciate ligament (ACL)
o Extends from posterior femur to anterior tibia
o Prevents hyperextension and anterior displacement of tibia
– Posterior cruciate ligament (PCL)
o Extends from anteroinferior femur to posterior tibia
o Prevents hyperflexion and posterior displacement of tibia
67
Clinical View: Knee Ligament and
Cartilage Injuries
• Tibial collateral ligament injury when leg forcibly abducted
• Fibular collateral ligament injury when medial side of knee is
struck
• ACL injury when leg hyperextended
• PCL injury when leg hyperflexed
• Meniscus injury due to trauma and/or overuse
• Unhappy triad: injury of tibial collateral ligament, medial
meniscus, and ACL
– Occurs due to a lateral blow to the knee that abducts and
laterally rotates leg
69
9.7f Talocrural (Ankle) Joint
• Talocrural joint
– Highly modified hinge joint
– Permits dorsiflexion and plantar flexion
– Includes two articulations within one joint capsule
o Between distal end of tibia and talus
o Between distal end of fibula and lateral aspect of talus
70
Figure 9.19b
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 72
Talocrural Joint
9.7f Talocrural (Ankle) Joint
• Anatomical features of talocrural joint
– Medial and lateral malleoli of tibia and fibula
o Prevent talus from sliding medially or laterally
– Articular capsule covers distal tibia, medial malleolus, lateral
malleolus, and talus
– Deltoid ligament binds tibia to foot on medial side
o Prevents overeversion
– Lateral ligament binds fibula to foot on lateral side
o Prevents overinversion
o Prone to sprains and tears
– Anterior and posterior tibiofibular ligaments
73
Clinical View: Ankle Sprains and Pott Fractures
• Sprain
– Stretching or tearing of ligaments without fracture or dislocation
– Results from twisting foot, usually overinversion
– Fibers of lateral ligament stretched or torn
– Localized swelling and tenderness anteroinferior to lateral
malleolus
• Pott fracture
– Occurs with overeversion
– Medial malleolus avulsed off of tibia (fracture)
– Talus moves laterally and fractures fibula
74
Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill EducationCopyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education
What did you learn?
• What direction does the jaw move
when opening?
• What are the three joints that make
up the shoulder?
• What is the common direction for
shoulder dislocation?
• What makes the elbow so stable?
• What are the 3 main ligaments of
the hip?
• What makes up the unhappy triad
of the knee?
75
9.8 Development and Aging of the Joints
• Arthritis
– Rheumatic disease involving damage to articular cartilage
– Osteoarthritis
o Primary problem of aging joint due to wear and tear
• Exercise and joint health
– Increases flow of synovial fluid to chondrocytes
– Strengthens muscles that support and stabilize joints
– In extreme, may aggravate potential joint problems and
may worsen osteoarthritis
76
Clinical View: Arthritis
• Arthritis
– Group of inflammatory or degenerative diseases of the joints
– Symptoms of joint swelling, pain, and stiffness
• Gouty arthritis
– Typically seen in middle-aged or older males
– Due to increased levels of uric acid
• Osteoarthritis
– Degenerative joint condition in older individuals
– Due to wearing down of articular cartilage
– Fingers, knuckles, hips, knees, and shoulders most affected
• Rheumatoid arthritis
– Seen in younger to middle-aged adults, often women
– Autoimmune disorder
– Starts with synovial membrane inflammation77