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Learn about joint classification, functions, types, and ranges of motion. Explore how different joints work and discover key terms in joint anatomy.
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Bones articulate via joints. Each joint has a very special function. 10/16 and 10/18 • How are joints classified? • Where do we find fibrous joints? • What is the special need for cartilaginous joints? • What are bony joints called? • What are the six types of synovial joint? • What are the terms used to describe our ranges of motion away/towards the centerline? • What is rheumatoid arthritis? • How are ranges of motion described?
Joints can be classed by how they attach two bones (structure) and the way they allow two bones to move (function). • How does the joint hold two bones together? Synovial: joint cavity with synovial fluid Fibrous: no cavity and collagenous adhesive Cartilaginous: no cavity and cartilagenous adhesive • How do the two bones move across a joint? Diathroses: freely moving Amphiarthroses: Slightly moveable Synarthroses: Little or no movement • Note: there is a lot of crossover between these “classes” of joint.
What is the special function of the three kinds of synarthrosis or low-flexibility fibrous joint? What limits to skull does the type of overlap create? >>Sutures between bones of skull are classic examples of fibrous joints (ligaments): Five types • Serrate: Wavy Overlap-Sagittal Suture • Lap: Single Overlap-Temporal/Parietal Suture • Plane: Flat-Two halves of palate • Gomphoses: Tooth and socket-Peridontal Ligament: What happens during scurvy? • Syndesmoses: a simple ligament holds bones together. Side by side bones are found where? • Why are ligaments rich in collagen not elastin!
The three type of synarthrosis Suture Gomphoses Syndesmosis Low Flexibility + High Collagen Content
Cartilaginous joints are designed to have “little” mobility. • Synchondrosis: link is via hyalin cartilage Epiphyseal Plate linking epiphysis to diaphysis Attachment between rib and sternum Sensitivity to breakage/dislocation? • Symphysis: link is via fibrocartilage Tougher than hyaline cartilage- Pubic Symphysis- Male vs. Female Vertebral discs- What happens when discs rupture? Synostosis: (Bony Link) occurs when two bones become ossified together (fuse) Consider the saccrum
Basically all synovial joints share these features: articular cavity, synovial fluid/membrane, ligaments, and a Fibrous capsule. Some joints also have a meniscus and/or bursa.
There are six kinds of diarthrotic synovial joint, these differ in their ranges of motion. Can you match the picture to the type of synovial joint?
What causes joint soreness/swelling? • Osteoarthritis- • Important contrast with osteoporosis • Rheumatoid arthritis- • Problems with a bursa- • Overuse • Infection • Treatments: Anti- inflammatory drugs- Immunosuppressive drugs- Glucosamine/Chondroitin-
Joints can be classed by how they attach two bones together (structure) OR by how they allow two bones to move (function). • The way a joint holds two bones together: Synovial: joint cavity with synovial fluid Fibrous: no cavity and collagenous adhesive Cartilaginous: no cavity and cartilagenous adhesive • The way two bones move across a joint: Diathrosis: Freely moving Amphiarthrosis: Slightly moveable Synarthrosis: Little or no movement
What terms are used to describe movement of shoulders, ankles and jaws!
What terms are used to describe the movements of Thighs, Legs, and Hands!
What are the terms used to describe range of motion in a diarthrosis? Movements are used by physical therapists to diagnose the severity of injuries! Measurement of Range of Motion- Proprioceptors: let you perceive your limb orientation relative to the anatomical (or any) position. What are types of motions? • Flexion vs. Extension vs. Hyperextension- • Abduction vs. Adduction- • Front/Back: Protraction vs. Retraction- • Inward/Outward: Inversion vs. Eversion-
Forearm: Supination vs. PronationThumbs: Opposition vs. Reposition • Bone Raising: Elevation vs. Depression- • Foot (toes): Dorsiflexion vs. Plantar flexion • Circumduction vs. Rotation: • Sole of foot: Inversion vs. Eversion
How and why do our limbs move? How do muscles work through levers to generate force and cause limbs to pass through a range of motion? What does mechanical advantage tell us? What terms are used to describe muscles? What muscles return limbs to their original position? What types of muscle do we have?
Biomechanics describes what a limb can move and why it can (cannot) move it. • Muscle Contractions: shorten their length to exert force on a tendon (EFFORT) • Resistance: What the muscle attempts to move against (Gravity or elasticity or other LOAD) • Fulcrum: fixed point that motion occurs across • Effort Arm: distance from fulcrum to muscle insertion • Resistance Arm: distance from fulcrum to resistance site
By shortening the length of a muscle, contractions create force. Tendons then transmit force to bones at the insertion. Ligaments limit the range of motion. • What three types of lever do muscles use: • 1) Tilt head back? First ClassTeeter-Tooter • 2) Close Jaw? Second ClassWheelbarrow • 3) Lift Leg? Third ClassTweezers MATH: What is mechanical advantage? MA=Le/Lr MA is a ratio of output force to input force • HighMA= High Power: can move against a large resistance • At cost of low mobility and slow speed (range of motion) • MA greater than 1.0 • LowMA= Low Power: can move limb quickly • At cost of inability to move against a big resistance • MA less than 1.0
How does a first class level prevent your head from drooping during a lecture (nap)? Dr Wilson’s jaw and neck: Effort Arm: 5 cm Resistance Arm: 15 cm MA= 5cm/15cm = 0.33 First Class levels work like teeter tooters!Trapezius(muscle)-Fulcrum-Gravity(Resistance
Second class levers generate force in a manner similar to that of a wheel barrow.Fulcrum---↑Resistance---↑Effort (muscle)
Third-class levels generate force in a manner similar to that of a tweezers.↑Resistance---↑Effort (muscle)---Fulcrum
Ultimately MA describes how easy it will be to accomplish a desired range of motion. • Why do we develop large biceps brachii to move things? • Why do you need large temporalis muscles to crack a nut on your molars (back)? • Why can’t you crack the nut on your incisors (front)? • Why isn’t the digastric muscle larger than the temporalis? • Why do muscles atrophy when in space? • Remember: that with respect to muscle exercise only increase the size of individual myocytes, not the number of myocytes.
Skeletal muscle structure and Function: Chapter 10 • Functions • Requirements • Structural organization • Connective/Supportive tissue types • Origins and Insertions • Types of muscles • Sports injuries
What is the function of skeletal muscle? • Movement of body or limbs • Stabilization of limbs in space • Control of mouth/anus • Protection • Heat production
Requirements for Skeletal Muscle • Blood supply- oxygenated and arteries • Nutrient Delivery- capillary density • Waste Removal- veins Metabolic waste Heat Injury • Production of proteins of contraction, et al • Neural Control mechanism • Protection from self-damage
Structural Organization: From Smallest to Largest:Actin/myosin>Filaments>Myofibrils>Myofiber>Endomysium>Perimysium> Epimysium(Fascia)> Muscle attached to bone by tendons
Orientation of Muscle between bones • Origin • Insertion • Function • Tendons vs Ligaments • Dense regular vs Dense Irregular CT
Structural Types of skeletal muscle • Fusiform • Parallel • Triangular • Pennate (Uni, Bi, Multi) • Circular • Can you match these to above? • Anus, Gastrocnemious, Pactoralis major, Rectus abdominus, Deltoid, Palma interosseous
Functional types of skeletal muscle • Agonist- extensor digitorum • Synergist- • Antagonist- flexor carpi radialis • Fixator- i.e. rhomboids and scapula • Agonist/Antagonist Pairs:
Common athletic injuries (Insight 10.5)Great multiple choice option for test: • Baseball finger- • Blockers arm- • Charley horse- • Pitchers arm- • Pulled groin- • Pulled hamstring- • Riders bones- • Rotator cuff injury- • Shin splints- • Tennis elbow-Tennis leg- • Carpal tunnel syndrome- • Inguinal hernia- • Compartment Syndrome- Sign-Up Sheets for Lab Exam #3 Go up Friday morning!