11. Musculoskeletal System Flashcards
Know epimysium vs perimysium vs endomysium
Connects to tendon vs lining surrounding fascicle vs lining of muscle cell/myofiber
Know sarcolemma vs sarcoplasm vs myofibril
cell membrane of myofiber vs cytoplasm of myofiber for smaller cell component of myofiber
Know z line vs M line vs H zone vs A band vs I band vs sarcomere
squiggly thing vs midline vs just entire myosin aka thick filaments vs actin + myosin aka both thick and thin filaments vs just actin aka thin filaments vs region that covers z line to z line. Sarcomeres attached end to end make up myofibrils
Know myosin, actin, tropomyosin and troponin mechanism for muscle contraction
Begins at neuromuscular junction: motor neurons release acetylcholine to bind to receptors on sarcolemma —> depolarization spreads to T tubules releasing Ca2+ —> high [Ca2+] in sarcoplasm –> troponin changes conformation –> tropomyosin changes conformation –> myosin can hop on actin’s next rung
Axial vs appendicular skeleton
Basic body framework: skull, vertebral column, ribs, hyoid (bone that helps with swallowing), rib cage, ossicles vs bones for limbs, pectoral girdle (clavicle and scapula) and pelvis
Perks of endoskeleton
support movement/provides framework, protects vital organs, stores calcium, hematopoiesis
Flat bones vs long bones
ex: skull, ribs, pelvis; protects organs and hematopoiesis vs ex: femur, humerus; framework, movement, hematopoiesis in epiphysis. Both have inner spongy cancellous bones and and outer compact hard bones
Diaphysis vs epiphysis vs metaphysis vs epiphyseal/growth plate
long part vs short part vs in between part vs plate within epiphysis for linear bone growth
Where does hematopoiesis occur?
in bone marrow
Red bone marrow vs yellow bone marrow
hematopoiesis (that’s why it’s red b/c it makes RBCs), found in flat bones and epiphysis of long bones vs fat storage and adipocytes, found at diaphysis of long bones
Name and consistency of inner most bone vs outer most bone
spongy bone aka cancellous bone aka trabecular bone vs periosteum
What surrounds spongy bone?
compact bone made up osteons aka Haversian systems
What makes up Haversian system?
Haversian/central canal in center of layers, it contains blood vessels and nerves; lamellae = concentric layers surrounding central canal; canaliculi = tiny channels in b/w lamellae; lacunae = empty spaces occupied by osteocytes
How do osteocytes/bone cells in lacunae communicate and transport nutrients?
via gap junctions
What are Volkmann’s canals?
Perpendicular to Haversian canals, they carry their own set of blood vessels
What makes up the bone matrix?
organic osteoid made up of proteins osteocalcin and osteopontin to give tensile strength and Type I collagen, and inorganic hydroxyapatite made up of calcium phosphate crystals to give rigid strength
Osteoprogenitor cells vs osteoblasts vs osteocytes vs osteoclasts
precursor to osteoblasts, contain growth factors to let them mature to osteoblasts vs synthesize collagen, osteocalcin and osteopontin to build bone, alkaline phosphatase synthesize hydroxyapatite vs bone cells that occupy lacunae and maintain bone vs in charge of bone resorption/breakdown, tartrate resistant acid phosphatase, occupy Howship’s lacunae, derived from monocytes
Tendons vs ligaments
Connects muscle to bone vs connects bone to bone
What is cartilage and describe 3 types of cartilage? What about articular cartilage?
Avascular connective tissue secreted by chondrocytes. Hyaline - in larynx and trachea, reduce friction and absorb shock; elastic - in outer ear and epiglottis, shape and support; fibrous - intervertebral discs, pubic symphysis (where 2 pelvic bones meet in middle), rigidity and absorb shock. Articular cartilage - made up of hyaline cartilage that line the surfaces of bone in joints to prevent bones from making contact w/ e/o
What are chondrocytes?
Secrete fibrous materials like collagen and elastin that give cartilage its strength and flexibility (collagen = fibrous protein found in cartilage); derived from fibroblasts
What’s a joint and name 3 types?
where bone meets bone. Synarthroses - stiff/immoveable, skull; amphiarthroses - slightly stiff and a little moveable, intervertebral discs; diarthroses/synovial joints - contain synovium/synovial membrane that secrete synovial fluid (to lubricate joint movement) in joint/articulate cavity, the synovial capsule that surrounds the entire joint, ball and socket (moveable all around like shoulders and hips), hinge (moves in one plane like elbows and knees)
What happens in high osteoblast activity vs high osteoclast activity?
Ca2+ and PO43- move from blood to bone vs Ca2+ and PO43- move from bone to blood
What does parathyroid hormone (PTH), calcitonin, and calcitriol (vit D) do? What about intestinal/renal absorption of Ca?
high PTH and calcitriol –> high osteoclast activity –> high intestinal/renal absorption of Ca; high calcitonin –> high osteoblast activity –> low intestinal/renal absorption of Ca
Tetany vs tonus vs twitch vs tremor vs frequency summation
continuous full contraction vs continuous partial contraction vs spasm vs involuntary quivering vs addition of multiple simple twitches before fully relaxing
What does sarcomere look like in muscle contraction?
A band stays same (ie. Actin and myosin don’t change in length during muscle contraction); H, I, Z and M distances are smaller
Sarcoplasmic reticulum aka SR
a modified ER with lots of Ca2+ ions. Covers myofibrils. Contains transverse tubule aka T tubule that triggers release of Ca ions from SR
Know different names of muscle cell
Myocyte aka myofiber. Muscles cells contain myofibrils which consist of sarcomeres
Differences between skeletal, smooth and cardiac muscles
Know which ones are voluntary, nucleated, spindle-shaped, striated, branched. Smooth and cardiac have myogenic activity (can contract without neural input) and are controlled by autonomic nervous system. Skeletal muscle has red slow twitch (Type I) fibers doing oxidative phosphorylation and white fast twitch (Type IIb) fibers doing anaerobic metabolism (like glycolysis). Cardiac muscle has intercalated discs containing gap junctions
Where can muscle get energy to stall O2 debt and fatigue?
Creatine phosphate and myoglobin
Endochondral ossification vs intramembranous ossification
Hardening of cartilage transformed into bone like most long bones vs undifferentiated embryonic connective tissue (mesenchymal tissue) transformed into bone like the skull
Antagonistic vs synergistic muscles
Muscles working in opposite directions for same function: one muscle contracts while other muscle relaxes (like biceps, triceps, elbow) vs working together to do same function
Flexor vs extensor vs abductor vs adductor muscles. Medial vs lateral rotation
Dec angle across a joint like biceps vs inc angle across a joint like triceps vs moving a body part away from midline like deltoid vs moving a body part towards midline like pecs. Rotates axis of limb toward midline vs rotates axis of limb away from midline
