Exam 3: pt. 2- Musculoskeletal System

sarcomeres shorten & muscle tension increases but there is NO change in muscle length

isometric contraction

muscle length shortens or lengthens so there is movement but the loas is FIXED

isotonic contraction

2 types of isotonic contractions

concentric & eccentric

muscle length shortens under a fixed load

concentric contraction

muscle lengthens under fixed load

eccentric contraction

deltoid abducting the shoulder/arm is an example of what type of contrsction?

concentric

when lifting the weight up in a bicep curl, the biceps undergoes what type of contraction?

concentric

when lifting the weight up in a bicep curl, the triceps undergo what type of contraction?

eccentric

when lowering the weight in a bicep curl, the biceps undergo what kind of contraction?

eccentric

when lowering the weight in a bicep curl, the triceps undergo what type of contraction?

concentric

deltoid adducting the shoulder/arm is an example of what type of contraction?

eccentric

what type of contraction is most likely to cause injury & why?

eccentric isotonic contraction

stretches/lengthens the muscle while sarcomeres are shortening so more likely to tear

what type of muscles contract parallel to the bone & pulls bones together rather than moving them apart?

stabilizer/shunt muscles

what type of muscles contract diagonally to the bone in order to produce the most effect movement?

also known as “spurt muscles”

oblique muscles

what type of joint is also known as Diarthroses & is freely moving?

synovial joint

what two structures comprise the articular capsule of synovial joints?

fibrous layer

synovial membrane

what 3 structures comprise the synovial joint from superficial to deep?

fibrous capsule

synovial membrane

articular cartilage

what part of the synovial joint is the outer layer with nerves, blood vessels, & ligaments?

fibrous capsule

what are the 2 types of specialized cells in the synovial membrane?

Type A synoviocytes

Type B synoviocytes

which cells of the synovial membrane are similar to macrophages & function to remove debris to protect from infection (immune function) ?

Type A Synoviocytes

which cells of the synovial membrane are similar to fibroblasts & function to secrete synovial fluid (protection) ?

Type B Synoviocytes

what substance is synovial fluid rich in that provides shock absorption & lubrication of the joint?

hyaluronic acid

what are the 3 main functions of synovial fluid?

1. Lubrication (to decrease bone friction)

2. Nourishment (since the articular cartilage within the joint is avascular)

3. Shock Absorption (distributes mechanical stress)