Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Mechanic of Movement - Fulton County Schools
Document related concepts
no text concepts found
Transcript
Mechanic of Movement Tissues and Structures Involved Muscle Nerve Bone Cartilage What are Tendons & Ligaments? Types of Joints Mechanics of Joints Nerve and Muscle--the Motor Unit Motor Unit is one motor neuron plus the muscle cells it synapses “Action potential”-controlled conduction of electrical messages in neurons and muscle by depolarization of cell membrane Neuro-Muscular Junction Action potential in nerves triggers chemical release at synapse which triggers action potential in muscle Bone and Cartilage Bone as tissue Bones as structures formed from bone, cartilage and other tissues Location of cartilage in skeleton and relation to joints HOW DOES MOVEMENT HAPPENS? Muscles Pull on Tendons to Move Bones at Connections called Joints or Articulations Tendons Tendons are structures that connect bone to muscle, muscle to muscle, or bone to bone Made up of tendon tissue (connective tissue) Can have various shapes Typical is cord-like tendon of biceps Frolich, Human Anatomy, Mechanics of Movement Ligaments Ligaments connect bone-tobone or reinforce joints--they are made up of tendinous tissue as well Typical are knee ligaments Frolich, Human Anatomy, Mechanics of Movement Joints or Articulations Connections between bones Usually, but not always allow for movement Formed from various connective tissues Functions of joints Fibrous Cartilaginous Synovial (most complex--typical limb joints) Hold bones together Allow for mobility Ways joints are classified Functionally Structurally Frolich, Human Anatomy, Mechanics of Movement Functional Classification The amount of movement the joint allows Synarthroses immovable joints Amphiarthroses slightly moveable joints Diarthroses freely moveable joints Frolich, Human Anatomy, Mechanics of Movement Structural Classification Fibrous joints Generally immovable Fibrous tissue separate the boney region at the joint Cartilaginous joints Immovable or slightly moveable Cartilage separates the boney regions at the joint Synovial joints Freely moveable The boney regions of the joint are separated by a space Frolich, Human Anatomy, Mechanics of Movement Fibrous Joints Bones united by fibrous tissue – synarthrosis or largely immovable. Skull Bones tightly bound by minimal fiber Syndesmoses Longer connecting fibers Joint has more give Frolich, Human Anatomy, Mechanics of Movement Cartilaginous Joints Mostly amphiarthrosis Bones connected by cartilage Pubic symphysis Intervertebral joints Hyaline cartilage unites bones Epiphyseal growth plates Costal cartilagesternum Frolich, Human Anatomy, Mechanics of Movement Synovial Joints Diarthroses – movable joint Most common joint in the body Articulating ends of bones are covered with hyaline cartilage Enclosed by a capsule of fibrous connective tissue lined with synovial membranes Joint cavity is filled with synovial fluid for lubrication Ligaments reinforce the joint Frolich, Human Anatomy, Mechanics of Movement Typical Synovial Joint Frolich, Human Anatomy, Mechanics of Movement Structures Associated with the Synovial Joints Bursae – flattened fibrous sacs Lined with synovial membranes Filled with synovial fluid Not actually part of the joint Tendon sheath Elongated bursa that wraps around a tendon Types of Synovial Joints The type of joint, in part, determines the range and direction of movement Types of Synovial Joints The type of joint, in part, determines the range and direction of movement HOW DOES MOVEMENT HAPPEN? The elbow joint - a hinge joint allowing movement in 1 plane Upper arm bone humerus The Capsule. Holds the bones of the joint in place. Capsule (ligaments) Synovial membrane Cartilage Cartilage Synovial fluid tendon Triceps muscle The synovial membrane. Secretes synovial fluid The synovial fluid. Lubricates the movement of the cartilage surfaces against each other – reducing friction and preventing arthritis (inflammation and joint damage). Cartilage. Lubricates the movement of the cartilage surfaces against each other – reducing friction and preventing arthritis (inflammation and joint damage). HOW DOES MOVEMENT HAPPEN? The elbow joint - how the bicep and triceps control When the biceps contracts movement humerus the elbow joint flexes (its joint angle decreases). biceps (flexor When the triceps contracts muscle), contracts the elbow joint extends (its joint angle increases). Triceps (extensor) The biceps and triceps are relaxes called antagonistic muscles because they have the radius opposite effect on the same ulna joint. THE BICEPS AND TRICEPS ARE AN ANTAGONISTIC PAIR Remember that for this to work properly the biceps must relax when the triceps contracts, and vice versa. Inflammatory Conditions Associated with Joints Bursitis – inflammation of a bursa usually caused by a blow or friction Tendonitis – inflammation of tendon sheaths Arthritis – inflammatory or degenerative diseases of joints Over 100 different types The most widespread crippling disease in the United States Clinical Forms of Arthritis Osteoarthritis Most common chronic arthritis Probably related to normal aging processes Rheumatoid arthritis An autoimmune disease – the immune system attacks the joints Symptoms begin with bilateral inflammation of certain joints Often leads to deformities Frolich, Human Anatomy, Mechanics of Movement X-ray of hand affected by arthritis Frolich, Human Anatomy, Mechanics of Movement Frolich, Human Anatomy, Mechanics of Movement Artificial Hip Joint Frolich, Human Anatomy, Mechanics of Movement Lots of problems with joints result from sports injuries Click on the picture for the web sports injury clinic What can go wrong with joints Dislocation The bones move Tendons strain or tear Making movement of the joint painful and difficult out of position, causing pain and preventing joint movement Cartilage damage Antagonistic muscle damage due to too overloading Making movement of the joint painful and difficult Movement becomes painful or impossible and the joint becomes inflamed.
