U1: C6: Musculoskeletal Flashcards
name 3 types of muscles 1. fiber organization 2. innervation 3. nuclei 4. strength 5. endurance
skeletal, cardiac, smooth(visceral) 1. striated, striated, no striation 2. somatic, autonomic (myogenic), autonomic (myogenic) 3. multiple, 1-2, one 4. strong, strong, weak 5. low, high, high 6. rectangular, rectangular branching, converging at ends
Basic contractile unit of muscle__, they attach longitudinally to build __. Entire unit is covered by __. Many ___ make up the muscle cell (__)
- sarcomere 2. myofibril 3. sarcoplasmic reticulum (analogous to ER= contain Ca2+) 4. myofirbril, myocytes
Striation
organization of the thick and thin filaments (skeletal and cardiac) *smooth is not striated bc the thick and thin filaments are not arranged in orderly fashion
Red vs White fibers 1. respiration 2. mitochondria 3. twitch speed/ endurance
- aerobic/ anaerobic 2. many & many capillaries and myoglobin/ few & stores glycogen 3. slow and high/ fast and low
Thick filaments
Inside: myosin filament 1. gulf club, head is the active site that binds to actin. 2. requires ATP to go back to relaxation
Thin filament
Edges: actin (microfilament) 1. tropomyosin: wraps actin to cover active site (myosin binding site) 2. troponin: protein on tropomyosin, that moves tropomyosin when calcium binds to it. Leading to active site uncovering. (recall: microfilament, intermediate filaments, microtubules) intermediate filaments: maintenance & integrity microtubules: make up centrioles (involved in chromosomal division) & precursor to cilia.)
Sarcomere structure
M HAIZ M: midline H: H zone = only thin filament (actin, tropomyosin, troponin) A: A band = thin and thick filament I: I band: only thick filament (myosin) Z: end and beginning
Contraction Mechanism (describe what is occuring at each location: thick and thin) a. at rest b. activation c. power stroke d. deattachment e. recover stroke
a. Actin active site covered by tropomyosin, troponin active site empty (no Ca2+). Myosin head contains ADP + P b. Active active site uncovered by tropomyosin bc troponin binded to Ca2+. Myosin head binds to actin, Myosin head still contains ADP. c. Thin filament same as b (shortening of sarcomere) Myosin head, release ADP d, Thin filament either a of b Myosin head binds to ATP, to release from actin (w/o actin rigor mortis) e. Thin filament same as a Myosin head, hydrolysis ATP to ADP + P, therefore Myosin head contains ADP + P.
Muscle contraction Initiation (in macro level)
- efferent nerve: action potential release acetylcholine into neuromuscular junction. 2. acetylcholine attach to muscle receptors (graded potential), enough concentration will lead to action potential (depolarization of sarcolemma). 3. depolarization reaches the cell via T-Tubules, and causes increase permeability of sacroplasmic reticulum. 4. sacroplasmic reticulum release Ca+ that is used to bind troponin.
What is required for myosin head to.. 1. attach to actin 2. power stroke (bend) 3. detach from actin 4. unbend
- calcium ions 2. ADP and P release (dissociation) 32. ATP bind 4. ATP hydrolysis -> ADP + P (ATP req for contracting and relaxing)
- Latent Period 2. Refractory Period a. absolute b. relative
- reaching threshold (onset of contractions) 2a., no stimuli can affect force 2b. higher than threshold stimuli can affect force
Stimulus intensity
All or none fashion, stimuli must reach threshold value
Force of muscles
Strength is a result of the number of fibers recruited
- Summation 2. Tetanus 3. Fatigue
- freq or prolonged stimulation 2. constant stimulation 3. 1 and 2 may lead to fatigue if there is insufficient time to relax.
Refractory periods
absolute and relative
Latent Period
Skeletal system
axial vs appendicular
axial: skull, ribs, vetebral column
appendicular: limbs, pelvis, pelvic girdle
Microscopic bone components (Draw)
http://test.classconnection.s3.amazonaws.com/853/flashcards/36853/png/picture_5.png
Osteon (one unit)
- lamaella: concentric rings (matrix)
- lacunae: houses osteocytes along the lamaella
- canalcilli: connections between the lacunae, similar to capillaires, perpandicular of the lamaella.
- havarsins canal: center the first lamaella, where nutrients and waste ports.
Long bone formation
Endochondrial: cartiledge model replaced with bone
http://jdr.sagepub.com/content/89/12/1333/F2.large.jpg
flat bone formation
Intramembrous: (spongy) mesenchymal tissue (undifferentiated embryonic tissue) transformed into bone.
http://higheredbcs.wiley.com/legacy/college/tortora/0470565101/hearthis_ill/pap13e_ch06_illustr_audio_mp3_am/simulations/figures/ossification_intra.jpg
Connective Tissue
- Function
- name the 3 components
- name the 6 different types
- is a kind of animal tissue that supports, connects, or separates different types of tissues and organs of the body
- ground substances, fibers, and cells. All are immersed in the body fluids.
- The different types
- Loose connective tissue
- Dense connective tissue ( aka collagen, firbous)
- adipose tissue
- blood
- cartilage
- bone
- osteclasts
- osteoblasts
- osteocytes
- breaks down and remodel (from stemcells in bone marrow)
- deposites matrix and build bone (osteogenic)
- mature bone cell, maintains bone (osteoblasts that are trapped within the lacunae)
- Tendon vs ligament
- Tendon: connects muscle to bone
- LIgament:: connects bone to bone
What is Hydroxyapatite
Ca2+ and PO43-two main constituents of hydroxyapatite, the bone mineral that strengthens the mechanical resistance of the organic matrix
