Joints and Muscles PDF

# Joints ## Fibrous Joints - No moving - Bones connected by fibrous tissue - No joint cavity - 3 types: 3 fibrous joints - Sutures - Syndesmoses - Gomphoses ### 3 Types of Fibrous Joints | Type | Sutures | Syndesmoses | Gomphoses | |---|---|---|---| | Location | Skull bones | Between...

# Joints ## Fibrous Joints - No moving - Bones connected by fibrous tissue - No joint cavity - 3 types: 3 fibrous joints - Sutures - Syndesmoses - Gomphoses ### 3 Types of Fibrous Joints | Type | Sutures | Syndesmoses | Gomphoses | |---|---|---|---| | Location | Skull bones | Between long bones (e.g., tibia-fibula) | Tooth socket | | Characteristics | Continuous fibrous tissue<br>Ossify and fuse with age | Movement depends on fiber length<br>Connected by ligaments | Peg-in-socket structure <br>Periodontal ligament | | Examples | Coronal suture | Interosseous membrane (radius-ulna) | Teeth in alveolar sockets | ## Cartilaginous Joints - Articulating bones connected by cartilage - Lack a joint cavity - Not highly moveable - Has 2 types: - Primary cartilaginous - Secondary cartilaginous ### 2 Types of Cartilaginous Joints | Type | Description | Characteristics | Examples | |---|---|---|---| | Primary Cartilaginous Joints | Unites the bones with hyaline cartilage | Immovable<br>Ossify with age | Epiphyseal plates <br>Manubrium of the sternum | | Secondary Cartilaginous Joints | Resilient shock absorber using a layer of fibrocartilage on hyaline cartilage | Provides strength and flexibility<br>Slightly movable | Intervertebral discs <br>Pubic symphysis | ## Synovial Joints - Most common in the body - All are diarthroses (freely moveable) - All contain a fluid-filled joint cavity ### General Structure of Synovial | Component | Description | |---|---| | Articular Cartilage | - Covers the ends of bones with a layer of hyaline cartilage<br>- Spongy cushions that absorb pressure from movement or weight-bearing<br>- Prevents bones from being crushed | | Joint Cavity | - Potential space between bones forming the joint <br>- Contains synovial fluid <br>- Lubricates to reduce friction and nourishes cartilage | | Articular or Joint Capsule | - Essential part of the synovial joint structure <br>- Composed of dense fibrous capsule and synovial membrane <br> - Produces synovial fluid <br> - Protects internal joint from wear and tear | | Synovial Fluid | - Filtrate of blood <br>- Contains special glycoproteins <br>- Nourishes the cartilage<br>- Slippery lubricant <br>- Reduces friction between bones <br>- Keeps the joint lubricated <br>- Compressed during movement | | Reinforcing Ligaments | - Some joints have them <br>- Stabilizing method <br>- Types: capsular, extracapsular, and intracapsular <br>- Most common: part of the capsule <br>- Outside the capsule: extracapsular<br>- Inside the capsule: intracapsular <br>- Contained within the synovial fluid | | Nerves | - Detect pain<br>- Monitor stretch <br>- Play a crucial role in movement control | | Blood Vessels | - Rich blood supply <br>- Extensive capillary beds in the synovial membrane <br>- Blood filtrate <br>- Enters the synovial fluid | ## Synovial Joints Classified by Shape: | Type | Description | |---|---| | Plane Joints | Allow simple gliding movements | | Hinge Joints | Movement in one direction, flexion & extension | | Pivot Joints | Rotational movement | | Condyloid Joints | Biaxial movement | | Saddle Joints | Biaxial movement | | Ball-and-Socket | Multiaxial movement | ### Examples: | Type | Examples | |---|---| | Plane Joint | Carpal bones, tarsal bones | | Hinge Joint | Elbow joint, knee joint | | Pivot Joints | Proximal radioulnar joint, atlantoaxial joint | | Condyloid Joints | Metacarpophalangeal joints, wrist joint | | Saddle Joints | Carpometacarpal joint of the thumb | | Ball and socket | Hip joint, shoulder joint | ## Shoulder (Glenohumeral) Joint and Rotator Cuff Muscles | Component | Description | |---|---| | Joint Type | Ball-and-socket joint | | Characteristics | - Provides great flexibility in movement<br>- Relies on rotator cuff muscles for stability | | Muscles | Rotator cuff muscles | | Importance | Stability and injury prevention | ## Hip Joint (Ball-and-Socket Joint) | Component | Description | |---|---| | Joint Type | Ball-and-socket joint | | Characteristics | - Allows for a wide range of movement <br>- Provides high stability <br>- Due to anatomical structure and surrounding ligaments | | Stability | | ## Elbow Joint (Hinge Joint) | Component | Description | |---|---| | Joint Type | Hinge Joint | | Characteristics | - Allows only flexion and extension | | Ligaments | - Annular ligament <br>- Radial collateral ligament<br>- Ulnar collateral ligament | | Muscles | - Triceps<br>- Biceps | | Trauma | Dislocations, fractures, ligament injuries | ## Wrist Joint (Condyloid Joint) | Component | Description | |---|---| | Joint Type | Condyloid joint | | Characteristics | - Two major joint surfaces <br>- Several ligaments stabilize | | Radiocarpal Joint | - Location: Between radius and proximal carpals<br>- Movement: Flexion, extension, adduction, abduction, circumduction | | Intercarpal Joint | - Location: Between proximal and distal rows of carpals | ## Injuries | Type | Description | |---|---| | Sprains | Injury to ligaments | | Dislocation | Bones forced out of alignment | | Torn Cartilage | Damage to the cartilage | ## Inflammatory and Degenerative Conditions | Type | Description | |---|---| | Bursitis | Inflammation of bursa sacs | | Tendinitis | Inflammation of tendons | | Arthritis | Inflammation of joints | ## Skeletal Muscle | Component | Description | |---|---| | Function | - Attached to bones<br> - Helps in voluntary movements like walking, running, lifting | ## Cardiac Muscle | Component | Description | |---|---| | Location | Found only in the heart | | Function | Contracts involuntarily to pump blood | | Characteristics | Striated muscle | ## Smooth Muscle | Component | Description | |---|---| | Location | Found in organs like stomach, intestines, and blood vessels | | Function | Helps in digestion and regulating blood flow. | | Characteristics | Non-striated | ## Skeletal Muscles | Component | Description | |---|---| | Attachments | Attach to bones by tendons | | Examples | Biceps muscle and tendon <br> Triceps muscle and tendon | | Largest Tendon | Achilles tendon | ## Smooth Muscles | Component | Description | |---|---| | Location | Lines organs | | Function | Involuntary movements: move food, empty liquids, control blood vessel width | | Example | Smooth muscles around arteries regulate blood flow. | ## Cardiac Muscle | Component | Description | |---|---| | Location | Only found in the heart | | Function | Pumps blood throughout the body | | Characteristics | Contains more mitochondria than skeletal muscle cells |