Transcript Martini_FAP7_ch9

Unit
2
Support and Movement
Fundamentals of
Anatomy & Physiology
Frederic H. Martini
PowerPoint® Lecture Slides prepared by
Professor Albia Dugger, Miami–Dade College, Miami, FL
Professor Robert R. Speed, Ph.D., Wallace Community College, Dothan, AL
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Chapter 9:
Articulations
Articulations
• Body movement occurs at joints
(articulations) where 2 bones connect
Joint Structure
• Determines direction and distance of
movement (range of motion)
• Joint strength decreases as mobility
increases
What are the major categories
of joints, and the structure
and function of each category?
Functional Classification
Table 9–1
Functional Classifications
• Synarthrosis:
– no movement
• Amphiarthrosis:
– little movement
• Diarthrosis:
– more movement
Synarthroses
• Also called immovable joints
• Fibrous or cartilaginous connections
• May fuse over time
Amphiarthroses
• Also called slightly moveable joints
• Fibrous or cartilaginous connections
Diarthroses
• Synovial joints
• Also called freely moveable joints
• Subdivided by type of motion
Structural Classification
Table 9–2
Structural Classifications
•
•
•
•
Bony
Fibrous
Cartilaginous
Synovial
Synarthroses (Immovable Joints)
• Are very strong
• Edges of bones may touch or interlock
4 Types of Synarthrotic Joints
•
•
•
•
Suture
Gomphosis
Synchondrosis
Synostosis
Suture
• Bones interlocked
• Are bound by dense fibrous connective
tissue
• Are found only in skull
Gomphosis
• Fibrous connection (periodontal
ligament)
• Binds teeth to sockets
Synchondrosis
• Is a rigid cartilaginous bridge between
2 bones:
– epiphyseal cartilage of long bones
– between vertebrosternal ribs and sternum
Synostosis
• Fused bones, immovable:
– metopic suture of skull
– epiphyseal lines of long bones
Amphiarthroses
• More moveable than synarthrosis
• Stronger than freely movable joint
2 Types of Amphiarthroses
• Syndesmosis:
– bones connected by ligaments
• Symphysis:
– bones separated by fibrocartilage
What is the basic structure
of a synovial joint, and what
are the common accessory
structures and their functions?
Synovial Joints (Diarthroses)
•
•
•
•
Also called moveable joints
At ends of long bones
Within articular capsules
Lined with synovial membrane
Articular Cartilages
• Pad articulating surfaces within
articular capsules:
– prevent bones from touching
• Smooth surfaces lubricated by synovial
fluid:
– reduce friction
Synovial Fluid
• Contains slippery proteoglycans
secreted by fibroblasts
Functions of Synovial Fluid
1. Lubrication
2. Nutrient distribution
3. Shock absorption
Synovial Joints:
Accessory Structures
•
•
•
•
•
Cartilages
Fat pads
Ligaments
Tendons
Bursae
Cartilages
• Cushion the joint:
– fibrocartilage meniscus (articular disc)
Fat Pads
• Superficial to the joint capsule
• Protect articular cartilages
Accessory Ligaments
• Support, strengthen joints
• Sprain:
– ligaments with torn collagen fibers
Tendons
• Attach to muscles around joint
• Help support joint
Bursae
• Pockets of synovial fluid
• Cushion areas where tendons or
ligaments rub
Synovial Joints:
Stabilizing Factors
• Prevent injury by limiting range of
motion:
–
–
–
–
collagen fibers (joint capsule, ligaments)
articulating surfaces and menisci
other bones, muscles, or fat pads
tendons of articulating bones
Injuries
• Dislocation (luxation):
– articulating surfaces forced out of position
– damages articular cartilage, ligaments,
joint capsule
• Subluxation:
– a partial dislocation
What are the dynamic
movements of the skeleton?
Types of Dynamic Motion
• Linear motion (gliding)
• Angular motion
• Rotation
Linear Motion
• Pencil maintains
vertical orientation,
but changes position
Figure 9–2a, b
Angular Motion
• Pencil maintains
position, but changes
orientation
Figure 9–2c
Circumduction
• Circular angular motion
Figure 9–2d
Rotation
• Pencil maintains position and
orientation, but spins
Figure 9–2e
Planes (Axes) of Dynamic Motion
• Monaxial (1 axis)
• Biaxial (2 axes)
• Triaxial (3 axes)
Types of Movements
at Synovial Joints
• Terms describe:
– plane or direction of motion
– relationship between structures
Linear Motion
• Also called gliding
• 2 surfaces slide past each other:
– between carpal or tarsal bones
Flexion
Figure 9–3a
Flexion
• Angular motion
• Anterior–posterior plane
• Reduces angle between elements
Extension
• Angular motion
• Anterior–posterior plane
• Increases angle between elements
Hyperextension
• Angular motion
• Extension past anatomical position
PLAY
Angular Movements (Flexion,
Extension, Hyperextension)
Abduction
Figure 9–3b, c
Abduction
• Angular motion
• Frontal plane
• Moves away from longitudinal axis
Adduction
• Angular motion
• Frontal plane
• Moves toward longitudinal axis
Circumduction
• Circular motion
without rotation
• Angular motion
Figure 9–3d
Rotation
Figure 9–4
Rotation
• Direction of rotation from anatomical
position
• Relative to longitudinal axis of body
Rotation
• Left or right rotation
• Medial rotation (inward rotation):
– rotates toward axis
• Lateral rotation (outward rotation):
– rotates away from axis
Pronation and Supination
• Pronation:
– rotates forearm, radius over ulna
• Supination:
– forearm in anatomical position
Inversion and Eversion
Figure 9–5a
Inversion and Eversion
• Inversion:
– twists sole of foot medially
• Eversion:
– twists sole of foot laterally
Dorsiflexion and Plantar Flexion
Figure 9–5b
Dorsiflexion and Plantar Flexion
• Dorsiflexion:
– flexion at ankle (lifting toes)
• Plantar flexion:
– extension at ankle (pointing toes)
Opposition
• Thumb movement toward
fingers or palm (grasping)
Figure 9–5c
Protraction and Retraction
Figure 9–5d
Protraction and Retraction
• Protraction:
– moves anteriorly
– in the horizontal plane (pushing forward)
• Retraction:
– opposite of protraction
– moving anteriorly (pulling back)
Elevation and Depression
Figure 9–5e
Elevation and Depression
• Elevation:
– moves in superior direction (up)
• Depression:
– moves in inferior direction (down)
Lateral Flexion
• Bends vertebral
column from side
to side
Figure 9–5f
What are the types of synovial
joints, and the relationship
of motion to structure?
Classification of
Synovial Joints by Shape
•
•
•
•
•
•
Gliding
Hinge
Pivot
Ellipsoidal
Saddle
Ball-and-socket
PLAY
A Functional Classification of Synovial Joints
Gliding Joints
• Flattened or slightly curved faces
• Limited motion (nonaxial)
Figure 9–6 (1 of 6)
Hinge Joints
• Angular motion in a single plane
(monaxial)
Figure 9–6 (2 of 6)
Pivot Joints
• Rotation only (monaxial)
Figure 9–6 (3 of 6)
Ellipsoidal Joints
• Oval articular face within a depression
• Motion in 2 planes (biaxial)
Figure 9–6 (4 of 6)
Saddle Joints
• 2 concave faces, straddled (biaxial)
Figure 9–6 (5 of 6)
Ball-and-Socket Joints
• Round articular face in a depression
(triaxial)
Figure 9–6 (6 of 6)
KEY CONCEPT
• A joint can’t be both mobile and strong
• The greater the mobility, the weaker
the joint
• Mobile joints are supported by muscles
and ligaments, not bone-to-bone
connections
How do vertebrae in the
vertebral column articulate?
Intervertebral Articulations
Figure 9–7
Intervertebral Articulations
• C2 to L5 spinal vertebrae articulate:
– at inferior and superior articular processes
(gliding joints)
– between adjacent vertebral bodies
(symphyseal joints)
Intervertebral Discs
• Intervertebral discs:
– pads of fibrocartilage
– separate vertebral bodies
Disc Structure
• Anulus fibrosus:
– tough outer layer
– attaches disc to vertebrae
• Nucleus pulposus:
– elastic, gelatinous core
– absorbs shocks
Verterbral Joints
• Also called symphyseal joints
• As vertebral column moves:
– nucleus pulposus shifts
– disc shape conforms to motion
Intervertebral Ligaments
• Bind vertebrae together
• Stabilize the vertebral column
Damage to Intervertebral Discs
Figure 9–8
Damage to Intervertebral Discs
• Slipped disc:
– bulge in anulus fibrosus
– invades vertebral canal
• Herniated disc:
– nucleus pulposus breaks through anulus
fibrosus
– presses on spinal cord or nerves
Movements of the
Vertebral Column
• Flexion:
– bends anteriorly
• Extension:
– bends posteriorly
• Lateral flexion:
– bends laterally
• Rotation
What are the structures
and functions of the shoulder,
elbow, hip, and knee
joints, and what is the
relationship between joint
strength and mobility?
The Shoulder Joint
Figure 9–9a
The Shoulder Joint
Figure 9–9b
The Shoulder Joint
• Also called the glenohumeral joint:
– allows more motion than any other joint
– is the least stable
– supported by skeletal muscles, tendons,
ligaments
Structure of the Shoulder Joint
• Ball-and-socket diarthrosis
• Between head of humerus and glenoid
cavity of scapula
Processes of the Shoulder Joint
• Acromion (clavicle) and coracoid
process (scapula):
– project laterally, superior to the humerus
– help stabilize the joint
Shoulder Ligaments
•
•
•
•
•
Glenohumeral
Coracohumeral
Coracoacromial
Coracoclavicular
Acromioclavicular
Shoulder Separation
• Dislocation of the shoulder joint
Shoulder Muscles
• Also called rotator cuff:
–
–
–
–
supraspinatus
infraspinatus
subscapularis
teres minor
Shoulder Bursae
•
•
•
•
Subacromial
Subcoracoid
Subdeltoid
Subscapular
The Elbow Joint
Figure 9–10
The Elbow Joint
• A stable hinge joint
• With articulations between humerus,
radius, and ulna
Articulations of the Elbow
• Humeroulnar joint:
– largest articulation
– trochlea of humerus and trochlear notch
of ulna
– limited movement
• Humeroradial joint:
– smaller articulation
– capitulum of humerus and head of radius
Elbow Muscle
• Biceps brachii muscle:
– attached to radial tuberosity
– controls elbow motion
The Hip Joint
Figure 9–11a
The Hip Joint
Figure 9–11b, c
The Hip Joint
• Also called coxal joint
• Strong ball-and-socket diarthrosis
• Wide range of motion
Structures of the Hip Joint
• Head of femur fits into it
• Socket of acetabulum
• Which is extended by fibrocartilage
acetabular labrum
The Knee Joint
Figure 9–12a, b
The Knee Joint
Figure 9–12c, d
The Knee Joint
• A complicated hinge joint
• Transfers weight from femur to tibia
Articulations of the Knee Joint
• 2 femur–tibia articulations:
– at medial and lateral condyles
– 1 between patella and patellar surface of
femur
Menisci of the Knee
• Medial and lateral menisci:
–
–
–
–
fibrocartilage pads
at femur–tibia articulations
cushion and stabilize joint
give lateral support
Locking Knees
• Standing with legs straight:
– “locks” knees by jamming lateral
meniscus between tibia and femur
7 Ligaments of the Knee Joint
• Patellar ligament (anterior)
• 2 popliteal ligaments (posterior)
• Anterior and posterior cruciate
ligaments (inside joint capsule)
• Tibial collateral ligament (medial)
• Fibular collateral ligament (lateral)
What are the effects of aging
on articulations, and the most
common clinical problems?
Rheumatism
• A pain and stiffness of skeletal and
muscular systems
Arthritis
• All forms of rheumatism that damage
articular cartilages of synovial joints
Osteoarthritis
• Caused by wear and tear of joint
surfaces, or genetic factors affecting
collagen formation
• Generally in people over age 60
Rheumatoid Arthritis
• An inflammatory condition
• Caused by infection, allergy, or
autoimmune disease
• Involves the immune system
Gouty Arthritis
• Occurs when crystals (uric acid or
calcium salts):
– form within synovial fluid
– due to metabolic disorders
Joint Immobilization
• Reduces flow of synovial fluid
• Can cause arthritis symptoms
• Treated by continuous passive motion
(therapy)
Bones and Aging
• Bone mass decreases
• Bones weaken
• Increases risk of hip fracture, hip
dislocation, or pelvic fracture
Integration with Other Systems
Figure 9–13
Bone Recycling
• Living bones maintain equilibrium
between:
– bone building (osteoblasts)
– and break down (osteoclasts)
Factors Affecting Bone Strength
1.
2.
3.
4.
Age
Physical stress
Hormone levels
Calcium and phosphorus uptake and
excretion
5. Genetic and environmental factors
Bones Support Body Systems
• The skeletal system:
– supports and protects other systems
– stores fat, calcium, and phosphorus
– manufactures cells for immune system
Body Systems Support Bones
• Disorders in other body systems can
cause:
–
–
–
–
bone tumors
osteoporosis
arthritis
rickets (demineralization)
SUMMARY (1 of 6)
• Joint classification by motion and
structure
• 4 types of synarthroses:
– suture, gomphosis, synchondrosis,
synostosis
• 2 types of amphiarthroses:
– syndesmosis, symphysis
SUMMARY (2 of 6)
• Structures of diarthroses
• 3 forms of dynamic motion:
– linear or gliding, angular, rotation
• 3 planes of motion:
– monaxial, biaxial, triaxial
SUMMARY (3 of 6)
• Movements of synovial joints:
– gliding, flexion, extension, abduction,
rotation, pronation, inversion,
dorsiflexion, opposition, protraction,
depression, etc.
SUMMARY (4 of 6)
• 6 structural types of synovial joints:
–
–
–
–
–
–
gliding
hinge
pivot
ellipsoidal
saddle
ball-and-socket
SUMMARY (5 of 6)
• Structures and movements of:
–
–
–
–
–
intervertebral articulations
shoulder joint
elbow joint
hip joint
knee joint
SUMMARY (6 of 6)
• Effects of aging on joints
• Relationship of the skeleton to other
body systems