Articulations and Body Movements PDF

**[Exercise \#13]** **[Articulations and Body Movements]**\ \ An Articulation is a joint.\ Functions of articulations are to allow for flexibilty for gross body movements and to hold bones together.\ \ Articulations can be classified either structurally or functionally.\ [Structurally there are:\ ]...

**[Exercise \#13]** **[Articulations and Body Movements]**\ \ An Articulation is a joint.\ Functions of articulations are to allow for flexibilty for gross body movements and to hold bones together.\ \ Articulations can be classified either structurally or functionally.\ [Structurally there are:\ ]1. **Fibrous.\ **2**. Cartilaginous.\ **3**. Synovial joints.\ **\ [Functionally there are:\ ]1. **Synarthroses.\ **2. **Amphiarthroses.\ **3. **Diarthroses.**\ \ **[Fibrous joints ]** **[\ ]**These are bones held together by fibrous tissues, most are synarthrotic or non-movable. They have no joint cavity.\ [2 types:\ ]1. **Sutures** are joints with bones with irregular edges interlocked by short connective tissue fibers (ex. skull). Sutures are immovable joints.\ 2. **Syndesmoses** are joints with bones connected by short ligaments (ex. tibia and fibula at the distal joint). Syndesmoses are slightly movable joints. 3\. A **Gomphosis** is a joint that holds the teeth in the mandible via the periodontal ligament. Gomphoses are immovable joints.\ \ **[Cartilaginous joints]** These are joints that have articulating bones connected by plates or pads of cartilage, have no joint cavity, and are mostly amphiarthrotic or slightly movable.\ [2 types:\ ]1. **Symphses** are joints which have bones that are connected by a broad flat disc of fibrocartilage (ex. the pubic symphisis).\ 2. **Synchondroses** are bones connected by hyaline cartilage (ex. the epiphiseal plates of children).\ \ **[Synovial joints]** These are joints that have bones separated by joint cavities filled with synovial fluid. They are diarthrotic or freely movable.\ [Characteristics of synovial joints]:\ 1. **Articular Capsule**, 2 layers a fibrous capsule of dense irregular connective tissue and a layer of synovial membrane which secretes synovial fluid.\ 2. **Articular cartilage** (hyaline) on the surfaces of the articulating bones.\ 3. **Ligaments** (hold bones of joint together).\ 4. **Bursae** (fluid filled sacs).\ 5. **Articular discs** may be found (**meniscus**), (padding between articulating bones).\ \ [6 types]:\ 1**. Plane** or **gliding**, ex. intercarpal joints.\ 2. **Hinge**, ex. elbow.\ 3. **Pivot,** ex. atlas/ axis.\ 4. **Condyloid**, ex. metacarpalphalangael joints.\ 5. **Saddle**, ex. metacarpal/ carpal.\ 6. **Ball and socket**, ex. shoulder or hip.\ \ The **Origin** is the point of attachment of muscle thatis immobile.\ The **Insertion** is the point of attchment of muscle that moves.\ A **Contraction** is the insertion moving towards the origin.\ \ **[Synovial Joint Body Movements]** **Flexion** decreases the angle between the origin and the insertion.\ **Extension** increases the angle between the origin and the insertion.\ **Abduction** is a movement away from the midline.\ **Adduction** is a movement towards the midline.\ **Rotation** is a movement around the long axis of a bone.\ **Circumduction** is a movement that makes an imaginary cone along the long axis of a bone.\ **Pronation** is a turning of the hand or palm from the anatomical position, crossing the ulna and the radius.\ **Supination** is the turning of the hand to return to the anatomical position, the radius and the ulna parallel.\ \ [Foot movements] **Inversion** is the turning of the feet medially, inward.\ **Eversion** is the lateral movement of the feet, outward.\ **Dorsiflexion** is the movement of the feet upward.\ **Plantar flexion** is the movement of the toes downward, on the tip toes.\ \ [Joint disorders]\ A **Sprain** is the excessive stretching or tearing away of the ligaments reinforcing the joint.\ \ A **Dislocation** is the forcing out of normal position of bones.\ \ An **Adhesion** is the connecting of bones at there surfaces via fibrous bands in joints.\ \ A **Spur** is any extraneous growth of bone tissue, bone where it doesn\'t usually grow.