1.4 - Joints Flashcards
Discuss the Trade-Off of Strength and Mobility in Joints
- Bones Fitting Close Together = A stronger, more stable joint but with less movement allowed
- Bones Fitting Loosely together = More movement, but a weaker, less stable joint
What does degree of joint movement depend on?
- How loosely the bones fit together (looser fit = more movement, but a weaker, less stable joint)
- Manner in which bones fit together
- Flexibility/tension/tautness of tissues binding bones together
- Position of surrounding ligaments, muscles and tendons
Describe the relative levels of mobility and strength of fibrous, synovial, and cartilaginous joints.
- Fibrous: Most stable, but also least moveable
- Cartilaginous: Intermediate stability and movement
- Synovial: Least stable, but most movable
Define solid/hinge joints, and list the types of solid/hinge joints
Solid Joints / Hinge Joints- Connections between skeletal elements where the adjacent surfaces are linked together either by fibrous connective tissue or cartilage (either hyaline cartilage or fibrocartilage). Movements at these joints are more restricted than at synovial joints. Can be divided based on whether adjacent surfaces are linked by fibrous connective tissue (sutures, syndesmosis, and gomphosis joints), or cartilaginous connective tissue (synchondroses and symphyses joints).
Define synovial joints, and list the types of solid/hinge joints
•Connections between skeletal components where the elements are separated by a narrow articular cavity containing a joint capsule surrounded by hyaline cartilage. Can be divided based on movement and shape. Uniaxial joints include hinge and pivot joints. Biaxial joints include condylar/ellipsoid joints and saddle joints. Multiaxial joints include ball and socket joints and plane/gliding joints.
Define fibrous joints
Solid joints with fibrous connective tissue that allow little to no movement. Include sutures, syndesmosis joints, and gomphosis joints.
Define cartilaginous joints
Solid joints with hyaline cartilage and/or fibrocartilage which allow slight movement. Include synchondrosis joints and symphysis joints.
Outline sutures including their function, movement, and an example
Solid joints only occurring in the skull where adjacent bones are linked by a thin layer of strong fibrous connective tissue.
- E.g. Coronal suture between parietal and frontal bones
- Function: Stability to protect the brain
- Movement: Little movement, useful for birth and brain growth
Outline syndesmosis joints including their structure, function, movement, and an example
Syndesmosis joints involve two adjacent bones are linked by fibrous tissue, also called an interosseous membrane
- E.g. Interosseous membrane between the radius and ulna
- Function: Ensure adjacent bones move together and is a site for muscle attachment
- Movement: Little to no movement
Outline gomphosis joints including their structure, function, movement, and an example
Only at tooth anchorage points in the mandible or maxilla. Joints in which fibrous tissue runs between the root of the tooth and its bony socket.
- E.g. Roots of teeth in sockets of the mandible
- Function: Hold teeth in their sockets
- Movement: Little to no movement
Outline synchondrosis joints including their structure, function, movement, and an example
Synchondroses joints / primary cartilaginous joints are joints separated by a layer of hyaline cartilage
- E.g. 1st Sternocostal joint between the sternum and 1st rib
- Function: Creates a stable union between bone
- Movement: Slight movement (e.g. to enable breathing)
Outline symphysis joints joints including their structure, function, movement, and an example
Symphysis joints, also known as secondary cartilaginous joints, are cartilaginous joints in which the bones are covered by a layer of hyaline cartilage and are then separated by fibrocartilage.
- E.g. Pubic symphysis between the two os coxae
- E.g. Interbody joint between vertebrae (fibrocartilage is called the intervertebral disc in this case)
- Function: Shock absorption, weight bearing
- Movement: Slight movement
Label the joint. What type of joint is this and what are the functions of each section?
Synovial Joint
Outline hinge joints including their structure, axes, movement, and an example
Hinge joints are synovial joints.
- Structure: Convexity with a concavity
- Axes: Uniaxial / Movement around the sagittal plane
- Allow: Flexion/extension / plantarflexion/dorsiflexion
- E.g. Talocural joint (tubia, fibula, and talus)
Outline hinge joints including their structure, axes, movement, and an example
Pivot joints are synovial joints
- Structure: One bone rotating around another
- Axes: Uniaxial / Movement around the transverse plane
- Allow: Rotation (pivoting)
- E.g. Atlanto-axial joint (between atlas and axis, allowing rotation of the neck)
Outline condylar/ellipsoid joints including their structure, axes, movement, and an example
Condylar/Ellipsoid joints are synovial joints
- The same movement as saddle joints, but articular surfaces are not saddle-shaped
- Structure: An oval concavity with an oval convexity
- Axes: Biaxial / Movement around the sagittal and coronal planes
- Allow: Flexion/extension, abduction/adduction, and circumduction
- E.g. Atlantooccipital joint (atlas and occipital)
Outline saddle joints including their structure, axes, movement, and an example
Saddle joints are synovial joints only found at the thumb and big toe between carpal/tarsal and 1st metacarpal
- The same movement as condylar/ellipsoid joints, but are saddle-shaped
- Structure: Saddle-shaped
- Axes: Biaxial / Movement around the sagittal and coronal planes
- Allow: Flexion/extension, abduction/adduction, and circumduction
- E.g. 1st Carpometacarpal joint (between trapezium and metacarpal of the thumb)
Outline plane/gliding joints including their structure, axes, movement, and an example
Plane/gliding joints are synovial joints
- Structure: Two bones gliding against each other
- Axes: Multiaxial / Movement around all axes
- Allow: Abduction/adduction, flexion/extension, circumduction, and rotation
- E.g. Intercarpal joints
Outline ball and socket joints including their structure, axes, movement, and an example
- Structure: Spherical convexity with a spherical concavity
- Axes: Multiaxial / Movement around all planes
- Allow: Flexion/extension, abduction/adduction, circumduction, and rotation
- E.g. Hip Joint / Acetabulofemoral joint (between acetabulum of os coxa and femur)
