Biology 211Anatomy & Physiology I

Joints

Last week: Defined bones as organs of skeletal system

Also organs: joints (one or more types of tissues, all serving a common function)

Joints: Classified two ways:

1. What type of tissue connects the bones at the joint

2. How much motion the joint allows

FCS

No motion = SLimited motion = AFreely movable = D

Fibrous Joints:

Bones connected by dense regular or dense irregular connective tissue with many collagen fibers.No joint cavity.

Depending on length of collagen fibers, may be synarthrotic (no motion) or amphiarthrotic (limited motion)

Fibrous Joints:

Three subtypes:1. S Collagen fibers very short Always synarthrotic Only in skull

Fibrous Joints:

Three subtypes:(1. Suture: Collagen fibers very short, synarthrotic, only in skull)

2. S Collagen fibers longer Amphiarthrotic (some motion)

Fibrous Joints:

Three subtypes:(1. Suture: Collagen fibers very short, synarthrotic, only in skull)(2. Syndesmosis: Collagen fibers longer, amphiarthrotic)

3. G Collagen fibers very short Synarthrotic (no motion) Teeth in mandible or maxilla

Cartilagenous Joints:

Bones connected by some form of cartilageNo joint cavity.

Depending on length of collagen fibers, may be synarthrotic (no motion) or amphiarthrotic (limited motion)

Cartilagenous Joints:

Two subtypes:1. S Bones connected by hyaline cartilage Synarthrotic or amphiarthrotic Costosternal; Epiphyseal plates

Cartilagenous Joints:

Two subtypes:(1. Synchondrosis: Bones connected by hyaline cartilage Synarthrotic or amphiarthrotic; Costosternal; Epiphyseal plates)

2. S Bones connected by fibrous cartilage Amphiarthrotic or synarthrotic Intervertebral disks; Pubic symphysis

Synovial Joints:

Bones separated by synovial joint cavity; connected by ligaments of dense regular C.T.

Most are diarthroticSome are amphiarthrotic

Synovial Joints:

Components: Proximal bone with articular cartilage Distal bone with

articular cartilage

Articular capsule with: Fibrous capsule Synovial membrane surrounding Synovial cavity

Ligaments of dense irregular C.T. Intrinsic = thickenings of fibrous capsule Extracapsular = outside of fibrous capsule Intracapsular = inside synovial cavity

Synovial Joints: Proximal bone with articular cartilage

Distal bone with articular cartilage Articular capsule with Fibrous capsule, Synovial membrane surrounding Synovial cavity Intrinsic ligament = thickenings of fibrous capsule Extracapsular ligament = outside of fibrous capsule Intracapsular ligament = inside synovial cavity

In knee, sternoclavicular, and temporomandibular joints:Also meniscus of fibrous cartilage

Synovial Joints:

Six types based on structure and type of motion:

Synovial Joints: Six types

1. P or G Gliding motion along flat articular surfaces.

Amphiarthrotic

Synovial Joints: Six types

2. H Motion around single axis perpendicular to long axis of bones.

Often convex articular surface on one bone and concave articular surface on other bone.

Diarthrotic

Synovial Joints: Six types

3. P Motion around single axis parallel to long axis of bones.

Often convex articular surface on one bone and concave articular surface on other bone.

Diarthrotic

Synovial Joints: Six types

4. C Motion around two axes.

Articular surfaces of both bones round or oval. One shallowly convex. One shallowly concave

Diarthrotic

Synovial Joints: Six types

5. S Motion around two axes.

Articular surfaces of both bones are: Convex one direction Concave other direction

Diarthrotic

Synovial Joints: Six types

6. B Motion around all three axes.

Articular surfaces of one bone forms "ball" which fits into "socket" on other bone

Diarthrotic

Synovial joints stabilized by

a)

b)

Synovial joints stabilized by

a) Shapes of the articular surfaces of bones

b) Ligaments

c)

Synovial joints stabilized by

a) Shapes of the articular surfaces of bones

b) Ligaments

c) Menisci

d)

Synovial joints stabilized by

d) Muscles and tendons which cross the joint

Synovial joints often cushioned by a fluid-filled sac called a b located between the joint and overlying muscles, tendons, or ligaments.

Specific joints are described in your Saladin text.

In lecture, specific joints will be identified for which you should be able to briefly but accurately describe the structure, including all major ligaments; and for which you should be able to describe the actions.

Movements of synovial diarthrotic joints:

Flexion and Extension

Movements of synovial diarthrotic joints:

Abduction and Adduction

Movements of synovial diarthrotic joints:

Rotation and Circumduction

Movements of synovial diarthrotic joints:

Protraction and Retraction

Movements of synovial diarthrotic joints:

Elevation and Depression

Movements of synovial diarthrotic joints:

Inversion and Eversion

Movements of synovial diarthrotic joints:

Opposition (and Reposition)