Anatomy and Physiology: Chapter 9- Articulations
Circumduction
( combination of flexion, extension, abduction and adduction ex. Draw circle on board)
Flexion
(decrease angle between articulating bones ex. Bending arm)
Hyperextension
(extension past anatomical position )
Extension
(increase angle between articulating bones ex. Straightening arm)
Abduction
(movement away from body along frontal plane ex. Move arm away from side)
Adduction
(movement toward body along frontal plane ex. Bring arm close to body)
Slightly moveable joint
AMPHIARTHROSIS
General Structure of a Synovial Joint
Articular cartilage
Joints are classified in two ways
Functional (physiology) Structural (anatomy)
Immovable joint
SYNARTHROSIS
Freely moveable joint
SYNOVIAL
shapes
There are many different types of joints which are classified on the basis of the ______________ of the articulating bones. Each joint type permits a different type and range of motion.
Circumduction
a more complex angular motion. Example is drawing a circle on the board . The result is that that your hand moves in a circle but your arm doesn't rotate
Structural (anatomy)
a)Fibrous b)Cartilagenous c)Boney d)Synovial
Functional (physiology)
a)Immovable joint b)Slightly moveable joint c)Freely moveable joint
Primary functions-3 of Synovial fluid
a)Lubrication b)Nutrient distribution c)Shock Absorption
Hinge joint
allows for angular motion in a single plane ex-elbow, knee
Joints
also called articulations, are where two bones come together. At all of these there is a compromise between the need for strength and the need for mobility. Thus, the more mobile a joint, the weaker it is.
Lubrication
articular cartilages act like sponges filled with synovial fluid that when compressed squeeze out fluid and coats surfaces. When compression stops, fluid is picked back up by cartilage
Symphysis
articulating bones are separated by pad of fibrocartilage -cartilagineous ex. Intervertabral discs, pubic symphysis-between coxal bones.
Ligaments
attach bone to bone at joint-stabilize joint
Tendons
attach muscle to bone-may limit range of motion of joint & provide support
Sutures
between bones of the skull, bones interlocked and bound together by dense fibrous connective tissue
Gomphosis
binds teeth to boney sockets in mandible and maxilla, fibrous tissue
Syndesmosis
bones connected by a ligament-fibrous, ex. Distal articulation of tibia & fibula
Saddle joint
both bones have a concave face like a saddle, allowing bones to nestle together- ex. Base of thumb
Articular cartilage
cartilage-covers articulating surfaces a)Resembles hyaline cartilage but has no perichondrium and matrix contains more water b)Slick and smooth c) two cartilages always separated by thin layer of synovial fluid (lubricant)
Shock Absorption
cushions shocks in joint.
Rotation
described in reference to anatomical position. Left or right rotation of head Lateral or medial rotation of arm supination pronation
Meniscus
fibrocartilage pad between opposing bones within synovial joint-protect and stabilize joint
Plane Joint
flattened or slightly curved faces which allows for minimal sliding motion ex, clavicle & sternum
Dorsiflexion
flexion of ankle joint-point toes upward
DIARTHROSIS
freely moveable - 1 type
Collagen fibers
from joint capsule, ligaments
Accessory Structures
help joint work better a)Meniscus b)Fat pads c)Ligaments d)Tendons e)Bursa f)Synovial Tendon Sheath
SYNARTHROSIS
immovable joint-4 types: 1)Sutures 2)Gomphosis 3)Synchondrosis 4)Synostosis-totally rigid immovable joint created when two separate bones fuse and boundary between them disappears examples-metotopic suture of frontal bone, epiphyseal line of mature bones.
Synovial cavity
joint cavity surrounding articulating bones-contains synovial fluid
Synovial joint
joint-allow for wide range of movement ex. Shoulder, knee, hip, elbow
Ball and socket joint
joint-round head of one bone rests in a cup-like depression of other bone. Allows for all types of angular motion ex. Hip, shoulder
three types of movement
linear, angular and rotation
Fat pads
localized mass of adipose tissue covered by synovial membrane-protect articular cartilage, space filler
Synovial fluid
made of hyaluronic acid-similar to interstitial fluid but has a high concentration of proteoglycans-secreted by the fibroblasts of the synovial membrane
Opposition
movement of thumb toward fingers-grasping motion
Protraction
moving part of your body anteriorly along a horizontal plane-bite upper lip with lower teeth
Retraction
moving part of your body posteriorly along a horizontal plane-reverse of protraction
Angular motion
occurs when there is a change in angle between two bones such as bending arm at elbow.
Linear movement
occurs when two opposing surfaces slide past one another. This kind of motion is called Gliding and can occur in any direction and is a slight movement. Occurs between articulating carpel bones, tarsal bones, clavicle and sternum
Condylar joint
oval articular face nestles in depression on opposing surface, allows for angular motion in two planes Ex. Between metacarpels and phlanges
Pronation
palm facing down
Supination
palm turned upward
Pivot joint
permits rotation only ex. Atlas and axis of vertebral column
Synchondrosis
rigid cartilaginous bridge between two articulating bones- ex. first rib & sternum
Rotation
similar to spinning around a point.
AMPHIARTHROSIS
slightly moveable joints-2 types
Bursa
small fluid-filled pockets in connective tissue, contain synovial fluid & lined by synovial membrane. Formed where tendon or ligament rub against another tissue thus reducing friction.
Plantar flexion
stand on toes
Articular capsule
surrounds synovial cavity but doesn't cover articulating surfaces. Composed of an outer fibrous layer and an inner synovial membrane
Nutrient distribution
synovial fluid circulates continuously to provide nutrients and pick up waste from chondrocytes of articular cartilage.
Synostosis
totally rigid immovable joint created when two separate bones fuse and boundary between them disappears examples-metotopic suture of frontal bone, epiphyseal line of mature bones.
Synovial Tendon Sheath
tubular bursa (shaped like a donut) with tendon running thru center hole. Found where tendon is touching bone surfaces from many sides.
Inversion
turn sole of foot inward
Eversion
turn sole of foot outward
Lateral flexion
vertebral column bends side to side
Elevation
when structure move in an superior direction-close mouth
Depression
when structure moves in an inferior direction-open mouth
Factors that stabilize joints
•Collagen fibers •Shape of articulatng surfaces and mensci ( plueral for meniscus)-may prevent movement in specific direction •Presence of other bones, skeletal muscle & fat around the joint •Tension in tendons attached to articulating bones
Types of Angular Motion-paired
•Flexion •Extension •Hyperextension -Abduction •Adduction •circumduction
Special Movements-in pairs
•Inversion •Eversion •Dorsiflexion •Plantar flexion •Opposition •Protraction •Retraction •Depression •Elevation Lateral flexion