Upload
julissa-blake
View
234
Download
0
Tags:
Embed Size (px)
Citation preview
Articulations!!
(the Joints)
Section 1: Joint Design and Movement
• Articulations (_____________________)– Where two bones interconnect– Bones are relatively inflexible so necessary to
allow movement– Reflect compromise between need for strength
versus need for ______________________– Anatomical structure of each joint determines
type and amount of movement possible• Categories from range of motion and subgroups from
anatomical structure
Joint types
• No Movement– Have we seen this before?
• Limited Movement– Can you think of any?
• Free Movement– Examples?
Joint Design and Movement
• Three functional categories1. _______________________ (no movement)2. Amphiarthrosis (little movement)3. ____________________________ (free movement)– Synarthrotic and amphiarthrotic joints
• Relatively simple structure• Direct connections between bones
– Diarthrotic joints• Complex in structure• Permit greatest range of motion
Synovial joints
• Components of synovial joints– ___________________
cartilages• Resemble hyaline
cartilages– Matrix contains more
water comparatively• Have no perichondrium• Slick and smooth, so
reduce friction• Are separated by thin film
of synovial fluid
Articular Cartilage
Components of synovial joints (continued)
– ______________ fluid• Similar in texture to egg
whites • Produced at the synovial
membrane• Circulates from areolar
tissue to joint cavity• Percolates through
articular cartilages• Total quantity is less than
3 mL
Synovial fluid
Components of synovial joints (continued)
– _________________ capsule• Dense and fibrous• May be reinforced with
accessory structures (tendons and ligaments)
• Continuous with periosteum of each bone
Joint capsule
Functions of synovial fluid
– Lubrication• With articular cartilage compression, synovial fluid is squeezed out
and reduces friction between moving surfaces– _______________________________ distribution
• Provide nutrients and oxygen, as well as waste disposal for the chondrocytes of articular cartilages
• Compression and reexpansion of articular cartilages pump synovial fluid in and out of cartilage matrix
– ________________________ absorption• Distributes compression forces across articular surfaces and
outward to joint capsule
Joint Accessory
– ____________________ (a pouch)• Small pocket filled with
synovial fluid• Often form in areas
where tendon or ligament rubs against other tissues
• Reduce friction and act as shock absorbers
Bursa
Accessory structures in knee (continued)
– Fat pads• Adipose tissue covered by
synovial membrane• Protect articular cartilages• Act as packing material for
joint
– _____________________ (a crescent)• Pad of fibrous cartilage
between bones of synovial joint
• May subdivide joint cavity and affect fluid flow or allow variations in shapes of articular surfaces
Meniscus
Fat pad
• Accessory structures in knee– Tendons of
quadriceps• Pass across joint
– Limit movement
– Provide mechanical support
• Accessory ligaments• __________________,
strengthen, and reinforce joint• Intrinsic ligaments
– Localized thickening of joint capsule– Example: cruciate liagments of knee
• ___________________ ligaments– Separate from joint capsule– May pass inside (intracapsular) or
outside (extracapsular) the joint capsule
– Intracapsular example: cruciate ligaments
– Extracapsular example: patellar ligament
Synovial joints
• _________________ vs. strength in joints– Greater range of motion = ______________
joint• Examples:
– Synarthrosis (strongest type of joint, no movement)– Diarthrosis (far weaker but broad range of motion)
– _____________________________ (luxation)• Movement beyond normal range of motion• Articulating surfaces forced out of position• Can damage joint structures• No pain from inside joint but from nerves or
surrounding structures
Types of motion and structural types of synovial joints
– _____________________• Movement along two axes in
one plane– Angular motion
• Movement along two axes in one plane with additional change in angle
– ______________________– Special complex angular
movement– Proximal end of bone
remains fixed while distal end can move in a circle (“trace circumference”)
– Rotation• Bone ends remain fixed and
shaft rotates
Figure 8.2 6
Gliding joint
Hinge joint
Pivot joint
Ellipsoid joint
Saddle joint
Ball-and-socket joint
The anatomical types of synovial joints, with joint models and examples
Types of Synovial Joints Models of Joint Motion Examples
Manubrium
Clavicle
Ulna
Humerus
Atlas
Axis
Scaphoid bone
UlnaRadius
Metacarpal boneof thumb
Trapezium
Scapula
Humerus
• Acromioclavicular and claviculosternal joints• Intercarpal and intertarsal joints• Vertebrocostal joints• Sacro-iliac joints
• Elbow joints• Knee joints• Ankle joints• Interphalangeal joints
• Atlas/axis• Proximal radio-ulnar joints
• Radiocarpal joints• Metacarpophalangeal joints 2–5• Metatarsophalangeal joints
• First carpometacarpal joints
• Shoulder joints• Hip joints
• Flexion and extension– Usually applied to
movements of long bones of limbs but also axial skeleton
– ______________________• Anterior/posterior
movement that reduces angle between articulating elements– Lateral flexion
» Vertebral column bending to the side
– Dorsiflexion» Flexion at ankle joint
and elevation of sole– ___________________
flexion (planta, sole)» Extension at ankle
joint and elevation of heel
– Extension• Anterior/posterior
movement that increases angle between articulating elements– __________________
» Extension past anatomical position
• Abduction and Adduction– Always refers to movements
of appendicular skeleton, not axial
– Movements are usually toward or away from body midline• For fingers or toes,
movements are spreading digits apart or bringing them together
– ____________________ (ab, from)• Movement away from body
longitudinal axis in frontal plane
– ____________________ (ad, to)• Movement toward body
longitudinal axis in frontal plane
• Circumduction– Moving arm or thigh as
if to draw a big _________________ at distal end of limb
• Wrist• Arm
• Rotation– When applied to the
trunk, described as left and right _____________________
– When applied to limbs• Medial rotation (internal
or inward rotation)– Anterior surface of limb
toward trunk long axis• Lateral rotation (external
or outward rotation)– Anterior surface of limb
away from trunk long axis
• Rotation (continued)– Other special terms for
rotation of forearm• ____________________
– Proximal end of radius rotates near ulna
– Distal end rolls across anterior ulnar surface
– Turns the wrist and hand from palm facing front to palm facing back
• ____________________– Opposing movement– Palm is turned
anteriorly
• Special movements– _______________________
• Movement of thumb toward palm surface or other fingers– Protraction
• Movement forward in anterior plane– ___________________
• Reverse of protraction– Inversion (in, into + vertere, to turn)
• Twisting foot motion to turn sole inward– ________________________ (e, out)
• Opposing movement to inversion
Figure 8.4 2
Special movements
Opposition
Eversion Inversion
Retraction Protraction
Depression Elevation
Articulations
• ____________________skeleton articulations– Typically are strong but very little movement
• ___________________________ skeleton articulations– Typically have extensive range of motion– Often weaker than axial articulations
Figure 8 Section 2 1
Joints of theAxial Skeleton
Sutures of the skull
Temporomandibular joint(temporal bone andmandible)
Atlanto-occipital joint(occipital bone and atlas)and the atlanto-axial joint(C1–C2)
Joints of the thoracic cage
Intervertebral joints
The lumbosacral joint,which attaches the lastlumbar vertebra to thesacrum
The sacrococcygeal andintercoccygeal joints,which structurallyresemble simplifiedintervertebral joints
Figure 8 Section 2 2
Joints of the foot and toes
Ankle joint
Knee joint
Hip joint
Joints of the handand fingers
Wrist joint
Pubic symphysis
Superior and inferiorradio-ulnar joints
Elbow joint
The sacro-iliac joint, whichfirmly attaches the sacrumof the axial skeleton to thepelvic girdle of theappendicular skeleton
Shoulder joint
The sternoclavicular joint,the only articulation betweenthe axial skeleton and thepectoral girdle and upperlimb
Joints of theAppendicular Skeleton
• Vertebral articulations– Between superior and inferior articular processes
of adjacent vertebrae• Gliding ______________________________ joints
– Permit flexion and rotation
– Adjacent vertebral bodies form symphyseal joints with _______________________________ discs
– Numerous ligaments attach bodies and processes of vertebrae to stabilize column
• Intervertebral discs– Composition
• __________________________ fibrosis– Tough outer layer of fibrous cartilage– Collagen fibers attach to adjacent vertebrae
• ___________________ pulposus– Soft, elastic, gelatinous core– Provides resiliency and shock absorption
– Account for ¼ length of vertebral column• Water loss from discs causes shortening of vertebral
column with age and increases risk of disc injury
Figure 8.5 2
The ligaments attached to the bodies and processes of all vertebrae
Primary Vertebral Ligaments
Ligamentum flavum
Posterior longitudinal ligament
Interspinous ligament
Supraspinous ligament
Anterior longitudinal ligament
Lateral view Sectional view
Posteriorlongitudinalligament
Spinal nerve
Spinal cord
Anulus fibrosus
Nucleus pulposus
Intervertebral disc
• Primary vertebral ligaments– Ligamentum ______________________
• Connects adjacent vertebral laminae– Posterior longitudinal ligament
• Connects posterior surfaces of adjacent vertebral bodies– Interspinous ligament
• Connects spinous processes of adjacent vertebrae– Supraspinous ligament
• Connects spinous processes from sacrum to C7 – Ligamentum nuchae from C7 to base of skull
– _______________________________ longitudinal ligament• Connects anterior surfaces of adjacent vertebral bodies
• Disorders of vertebral column– _______________________ disc• Posterior longitudinal ligaments weaken causing more
pressure on discs• Nucleus pulposus compresses, distorts anulus fibrosus• Disc bulges into vertebral canal (doesn’t actually slip)
– ________________________ disc• Nucleus pulposus breaks through anulus fibrosus• Spinal nerves are often affected
• Disorders of vertebral column (continued)– ______________________
(penia, lacking)• Inadequate ossification
leading to loss of bone mass• Often occurs with age
beginning between ages 30 and 40
• More severe in women than men
• Osteoporosis (porosus, porous)– Bone loss sufficient to affect
normal function
Figure 8.5 5
The effects of osteoporosis on spongy bone
Clinical scan of a compressionfracture in a lumbar vertebra
Figure 8.5 5
The effects of osteoporosis on spongy bone
Normal spongy bone SEM x 25 SEM x 21Spongy bone withosteoporosis
Ball and Socket• Shoulder joint (glenohumeral
joint)– __________________ range
of motion of any joint– Most frequently dislocated
joint• Demonstrates stability
sacrificed for mobility• Most stability provided by
surrounding skeletal muscles, associated tendons, and various ligaments
– Ball-and-socket diarthrosis• Formed by head of humerus
and glenoid cavity of scapula
• Hip joint– Sturdy ball-and-socket joint
• Although not directly aligned with weight distribution along femur shaft, which can produce fractures of femoral neck or intertrochanteric region
– Permits _______________, extension, adduction, abduction, circumduction, and rotation
– Formed by head of femur and acetabulum of hip bone
Figure 8.6 5
Greatertrochanter
Inter-trochantericline
Lesser trochanter Anterior view
The ligaments of the hip joint in anterior view
The ligaments of the hip joint in posterior view
Posterior view
Ischialtuberosity
Pubofemoral ligament
Iliofemoral ligament
Ischiofemoral ligament
Reinforcing Ligaments
The ligaments of the hip joint
Hinge• Elbow joint
– Complex __________________ joint involving humerus, radius, and ulna
– Extremely strong and stable due to:
1. Bony surfaces of humerus and ulna interlock
2. Single, thick articular capsule surrounds both humero-ulnar and proximal radio-ulnar joints
3. Articular capsule reinforced by strong ligaments
– Severe stresses can still produce dislocations or other injuries• Example:
___________________ elbow– Muscles flexing elbow attach on
anterior while those extending attach on the posterior
Figure 8.7 1
The elbow joint
Humeroulnar joint
Posteriorview
Olecranonfossa
Olecranon
Ulna
Humerus
Elbow and knee joints
• Elbow joint (continued)– Specific joints of the elbow• _____________________joint
– Capitulum of humerus articulating with head of radius
• Humero-ulnar joint– Largest and strongest articulation– Trochlea of humerus articulates with trochlear notch of ulna– Shape of ulnar notch determines plane of movement– Shapes of olecranon fossa and olecranon limit degree of extension
• Proximal radio-ulnar joint is ___________part of elbow joint
Elbow and knee joints
• Elbow joint (continued)– Reinforcing ligaments• Radial _________________ ligament
– Stabilizes lateral surface of joint
• Ulnar collateral ligament– Stabilizes medial surface of joint
• ____________________ ligament– Binds head of radius to ulna
Elbow and knee joints
• Knee joint– Contains
_____________separate articulations
1. Medial condyle of tibia to medial condyle of femur
2. Lateral condyle of tibia to lateral condyle of femur
3. Patella and patellar surface of femur
– Permits flexion, extension, and very limited _______________
Elbow and knee joints
• Knee joint (continued)– External support
• Quadriceps tendon to patella– Continues as patellar ligament to anterior tibia
• Fibular collateral ligament– Lateral support
• Tibial collateral ligament– Medial support
• _________________________ligaments– Posterior support extending between femur and heads of tibia and
fibula• Tendons of several muscles that attach to femur and tibia
Elbow and knee joints
• Knee joint (continued)– Internal support• ___________________ ligaments limit
anterior/posterior movement of femur and maintain alignment of condyles– Anterior cruciate ligament (ACL)
» At full extension, knee becomes “locked” (slight lateral rotation tightens ACL, and lateral meniscus forced between tibia and femur)
» Opposite motion to “unlock”– Posterior cruciate ligament (PCL)
Elbow and knee joints
• Knee joint (continued)– Internal support (continued)• Medial and lateral _______________
– Fibrous cartilage pads between tibial and femoral condyles
– Act as cushions and provide lateral stability to joint
Disruption to normal joint function
• Arthritis– Damage to articular cartilages but specific cause varies
• Exposed surfaces change from slick, smooth-gliding to rough feltwork of collagen fibers increasing friction
• Rheumatism (pain and stiffness affecting the skeletal and/or muscular systems) is often a symptom
– Osteoarthritis• Also known as degenerative arthritis or degenerative joint disease• Generally affects individuals age 60 and older
– 25% of women, 15% of men• Can result from cumulative wear and tear of joints or genetic factors
affecting collagen formation
Figure 8.8 1 – 2
Comparisons of normal articular cartilage with articular cartilage damaged by osteoarthritis
Normal Joint Arthritic Joint
Articularcartilage
LM x 180
Fibrousremainsof thearticularcartilage
Degeneratingarticularcartilage
LM x 180
Arthroscopic view of normal cartilage Arthroscopic view of damaged cartilage
Disruption to normal joint function
• Visualizing problematic joints– Arthroscopic surgery• Optical fibers (arthroscope) inserted into joint through
small incision without major surgery to visualize joint interior
• If necessary, other instruments can be inserted through other incisions to permit surgery within view of arthroscope
– _____________________ resonance imaging• Cost-effective and noninvasive viewing technique that
allows examination of soft tissues around joint as well
Figure 8.8 3
An arthroscopic view of the interior of the left knee,showing injuries to the anterior and
posterior cruciate ligaments.PCL
ACL
Femoralcondyle
Meniscus
Figure 8.8 4
Disruption to normal joint function
• _____________________ joints– May be last resort if other solutions (exercise,
physical therapy, drugs) for joint problems fail– Not as strong as natural joints, so most suitable for
elderly– Typically have service life of about 10 years
Figure 8.8 5
Next Monday
• Exam: Framework• Start new section: Organization!