2Joint synovial cavity Fluid filled 3Articular capsule Outer fibrous capsule of

2joint synovial cavity fluid filled 3articular

This preview shows page 43 - 48 out of 58 pages.

2.Joint (synovial) cavity: Fluid-filled. 3.Articular capsule: Outer fibrous capsule of dense irregular CT, inner synovial membrane of loose CT. 4.Synovial fluid: Fills joint cavity and reduces friction; lubricates and nourishes articular cartilage. 5.Reinforcing ligaments: Restrict movement of joint. *Capsular: Thickened part of fibrous layer. *Extracapsular: outside the capsule. *Intracapsular: Deep to capsule, covered by synovial membrane. 6.Rich nerve and blood vessel supply: Nerve fibers detect pain, monitor joint position and stretch. Capillary beds produce filtrate for synovial fluid. •Some synovial joints have fatty pads for cushioning (hip, knee joints) or articular discs to improve fit (knee, jaw joints). Structures associated with synovial joints •Bursae; -Sac lined with synovial membrane and containing a thin film of synovial fluid. -Found where ligaments, muscles, skin or muscle tendons overlie and rub against bone. •Tendon sheaths; -Elongated bursa that wraps around a tendon. -Found where several tendons are crowded together (wrist). 43
Image of page 43
Synovial joints •Factors that influence stability: Synovial joints allow of movement, not as stable as fibrous/cartilaginous joint. 1.Articular surfaces: Shape of articular surfaces of many joints are such that they don’t contribute stability. *Deep ball and socket joints have good shape for stability. 2.Ligaments: gives more strength. *Ligaments can only stretch 6% of length before they break, stretched ligaments stay stretched, but scar. 3.Muscle tone: Tendons of muscles crossing joints usually most important stabilizing factor, kept taut by muscle tone. *Shoulder, knee, arches of foot. Movements allowed by synovial joints •Angular movements; 44
Image of page 44
•Abduction: Move away from the midline (abduct a child from its home). •Adduction: Move closer to the midline. •Extension and flexion are the contrary for the arms and legs. •Rotational movements; •Special movements; 45
Image of page 45
Classification of synovial joints 1.Plane joint; -2 flat opposing surfaces. -Gliding. -EX: Intercarpal joints. 2.Hinge joint; -Cylinder into trough. -Flexion and extension. -EX: Elbow. 3.Pivot joint: Rounded end into a ring or sleeve. -EX: Proximal radioulnar. 4.Condyle joint; -Knuckle-like. -Articulating surfaces oval. -All planes of motion. 5.Saddle joint; -Similar to condyloid. -Saddle shape permits even more freedom of movement. 6.Ball and socket joint; -Multiaxial joints. -Most freely moving. -EX: Shoulder and hip joints. Selected synovial joints •Synovial joints are diverse. •All have general features, but some also have unique structural features, abilities, and weaknesses. •Five synovial joints; -Shoulder, elbow, hip, knee, TMJ. Shoulder (glenohumeral) joint •Articulation: Head of humerus and glenoid fossa of the scapula. •Ball and socket joint: The glenoid cavity is broadened slightly by the glenoid labrum (fibrocartilaginous rim) but is still only 1/3 rd the size of the head of the humerus. 46
Image of page 46
-The only ligaments of note is the coracohumeral.
Image of page 47
Image of page 48

You've reached the end of your free preview.

Want to read all 58 pages?

  • Winter '18

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask You can ask (will expire )
Answers in as fast as 15 minutes
A+ icon
Ask Expert Tutors