Osteoclasts-bone destroying (reabsorption-reabsorbs minerals into the blood) maintain bone matrix made by osteoblasts In bone outpaces bone osteoporosis, degradation (reabsorption) deposition. Bone is degraded and Ca +2 in response to a need for calcium in the body; this released is controlled by parathyroid hormone (PTH) Fig 6.12 PTH stimulates osteoclasts PTH also stimulates kidney to convert Vit D to active form (calcitrol) which increases Ca+2 absorption from the intestine. Calcium salt deposit in bone is stimulated by in the thyroid when calcitonin-produced calcium levels are high Muscular System A. Functions of the Muscular system a. Movement b. Heat generation c. Maintenance of posture d. Stabilization of joints B. Muscle Tissue/Muscles Common properties of the 3 different muscle types: a. i. Comprised of cells called fibers’ ‘muscle ii. Contain myofilaments (thick, thin, elastic) iii. Function in movement C. Skeletal Muscles: Fig 9.2 a. Voluntary muscle, striated, made of muscle cells, CT wrapping, blood vessels, and nerves. are wrapped in a CT covering called the a. Muscles epimysim. b. Bundles of skeletal muscle cells (called ) are wrapped in a CT covering fasicles called the perimysium. a. Individual skeletal muscle cells (muscle are wrapped in the CT covering fibers) called the endomysium (surrounds plasma membrane of the cell). Microscopic anatomy of skeletal muscle Fig 9.3, 9.5 1. Skeletal muscle cells (muscle fibers)-long cylindrical cells with formed multiple nuclei by fusion of embryonic cells; contain myofibrils. 2. Sarcolemma-specialized plasma membrane of skeletal muscle invaginates into t-tubules at the A-band I-band junction 3. Sarcoplasm-cytosol of a muscle cell. 4. myofibrils- (an organelle) rod-like structures comprised of proteins (actin, myosin, nebulin, titin, tropomysin, troponin) contained within skeletal muscles cells that re the contractile elements. Composed of myofilaments (3 types) a. of with and regions. filament-comprised myosin, ‘head’ ‘tail’
Osteoclasts-bone destroying (reabsorption-reabsorbs minerals into the blood) maintain bone matrix made by osteoblasts In osteoporosis, bone degradation (reabsorption) outpaces bone deposition. Bone is degraded and Ca +2 released in response to a need for calcium in the body; this is controlled by parathyroid hormone (PTH) Fig 6.12 PTH stimulates osteoclasts PTH also stimulates kidney to convert Vit D to active form (calcitrol) which increases Ca+2 absorption from the intestine. Calcium salt deposit in bone is stimulated by calcitonin-produced in the thyroid when calcium levels are high Muscular System A. Functions of the Muscular system a. Movement b. Heat generation c. Maintenance of posture d. Stabilization of joints B. Muscle Tissue/Muscles a. Common properties of the 3 different muscle types: i. Comprised of cells called ‘muscle fibers’ ii. Contain myofilaments (thick, thin, elastic) iii. Function in movement C. Skeletal Muscles: Fig 9.2 a. Voluntary muscle, striated, made of muscle cells, CT wrapping, blood vessels, and nerves. a. Muscles are wrapped in a CT covering called the epimysim. b. Bundles of skeletal muscle cells (called fasicles ) are wrapped in a CT covering called the perimysium. a. Individual skeletal muscle cells (muscle fibers) are wrapped in the CT covering called the endomysium (surrounds plasma membrane of the cell). Microscopic anatomy of skeletal muscle Fig 9.3, 9.5 1. Skeletal muscle cells (muscle fibers)-long cylindrical cells with multiple nuclei formed by fusion of embryonic cells; contain myofibrils. 2. Sarcolemma-specialized plasma membrane of skeletal muscle invaginates into t-tubules at the A-band I-band junction 3. Sarcoplasm-cytosol of a muscle cell. 4. myofibrils- (an organelle) rod-like structures comprised of proteins (actin, myosin, nebulin, titin, tropomysin, troponin) contained within skeletal muscles cells that re the contractile elements. Composed of myofilaments (3 types) a. filament-comprised of myosin, with ‘head’ and ‘tail’ regions.
2014_final_exam_review.docx