ANATOMY BIOS252 midterm
Muscle Tissue: Functions - ANSWER > producing movements (skeletal muscle =
pulls on tendon moving bone at joint, smooth muscle = moving things in/out of body,
cardiac muscle = pump blood throughout the body)
> stabilizing positions (skeletal muscle = maintain tension on tendons and
bones/hold joints in place)
> stores/mobilizes substances within body (smooth muscle = sphincter by absorbing,
storing, and using glycogen)
> generates heat (20-30% at rest, up to 85% of body heat in exercise; constantly
being used/produced)
Muscle Tissue - Properties: Electrical Excitability - ANSWER ability to take on ions
to trigger electrical current for contractions (like when getting tased)
Muscle Tissue - Properties: Contractility vs Extensibility - ANSWER ability go
muscles to shorten/contract (myosin) vs to stretch (actin)
Muscle Tissue - Properties: Elasticity - ANSWER ability of muscle to return to its
original length following stretching/contractions
Muscle Formation - ANSWER "myogenesis" = fusion of myoblasts into muscle
fibers as mainly composed of proteins
> joining together of myoblasts
> fused together creates immature fiber (cell)
> overtime will become mature fiber (accounting for being multi-nucleated)
Muscle Type: Skeletal - ANSWER > move bones voluntarily
> appear multi-nucleated (unable to perform mitosis) and striated
> thin, attached via tendon to bones
> ATP demands: controlled and short durations (low demand)
Muscle Growth - ANSWER building in size rather than in number
> grow w/ slight tears causing inserting myoblast to fiber
Skeletal Muscle: Fibers - ANSWER > slow oxidative (myoglobin = red color;
resistant to fatigue as ATP is generated through aerobic respiration to maintain
posture and aerobic exercise)
,> fast oxidative glycolytic (many capillaries = pink color; intermediate resistance to
fatigue as ATP is created through aerobic/anaerobic respiration to walk or sprint)
> fast glycolytic fiber (few capillaries = white color; low resistance to fatigue for
rapid/intense movements of short durations)
Muscle Type: Cardiac - ANSWER > pumps blood/moves involuntarily
> has one nucleus w/ striations and intercalated discs
> fat and branched, attached to intercalated discs of exoskeleton
> ATP demands: contracting infinitely (higher demands)
Muscle Type: Visceral (Smooth) - ANSWER > various organs w/ various functions
involuntarily
> w/ one nucleus and no striations
> contain intermediate filaments connected via gap junctions
> ATP demands: latch-bridge mechanisms make it resistant to fatigue (low
demands)
Exciting Smooth Muscle - ANSWER > autonomic nerve fibers and
neurotransmitters
> chemicals (hormones, pH, oxygen)
> temperature (cold = contracts, heat = relaxes)
> stretch (digestive/urinary contract when stretched)
> autorhythmicity (spontaneously depolarize)
Gates - ANSWER > mechanically (open due to stretch)
> voltage (open due to depolarization of sarcolemma)
> ligand (open due to neurotransmitters/chemicals)
Muscle Tissue: Layers - ANSWER "tubes within tubes"
> myofilaments
> myofibrils
> fascicles
> skeletal muscle
Muscle Fiber: Layers - ANSWER > filaments
> myofibril
> fiber
> fascicle
> skeletal muscle
Muscle Tissue - Layers: Separating Connective Tissue - ANSWER > endomysium
(separates individual fibers)
> perimysium (separates 10-100 fibers into fascicles)
> epimysium (outer layer encircling entire muscle)
Muscle Fiber: Components - ANSWER > sarcolema (muscle cell's plasma
membrane)
> sarcoplasmic reticulum (calcium storage) = smooth ER
> transverse (T) tubule (penetrated enfolding) = increase surface area to action
, > sacromere (contractile unit between z-discs) = striations
Sarcomere: Proteins - ANSWER > myosin (thick "gold club head" filament
contractile protein)
> actin (thin "necklace bead" filament contractile protein)
>tropo-nin/myosin (regulatory proteins that determine if actin/myosin can bind
together)
>titin (returns sarcomere to original shape after contraction)
Sarcomere: Arrangement - ANSWER (striations due to arrangement)
> A band; entire myosin filament (dark band; beginning to end of same thick
filament)
> I band; actin and titin (light band; end of one to the beginning of the next thick
filament)
> M line (provides an anchor at the center of/for thick filaments)
> H zone; myosin (end of one to the beginning of the next thin filament)
> Z disc (provides anchorage for actin and titin filaments)
Sliding Filament Theory: Steps - ANSWER > calcium binding to toponin
> tropomyosin blocking, but move over
> myosin is able to bind to actin
> actin = door, calcium = unlocking of the door (triggering contraction)
> tropomyosin = door lock, troponin, key moving (allowing movement)
Sliding Filament Theory: Logistics - ANSWER ("power stroke")
> myosin pulls on actin = thin filaments slide inward
> z discs move towards each other = sarcomere shortens
> structural proteins = transmission force throughout entire muscle = whole muscle
contraction initiated
Contraction Cycle of Myosin - ANSWER > myosin head hydrolyzes ATP becoming
energized/oriented = cock back 3rd phosphate
> myosin binds to actin creating cross bridge = fire the 3rd phosphate (securing
contraction)
> myosin head pivots and pulls thin past thick filaments towards center of sarcomere
(powerstroke) = replace 3rd phosphate (keeps going unless runs out of ATP)
> as myosin binds with ATP, cross bridge detaches from actin
Muscle Metabolism - ANSWER (obtain/produce ATP)
> creatine phosphate (sprinting energy = phosphagen system)
> anaerobic glycolysis (glucose breakdown w/out oxygen)
> cellular respiration (glucose breakdown w/ oxygen)
Muscle Metabolism: Systems - ANSWER > aerobic respiration (using oxygen from
myoglobin and supported by cardiopulmonary function)
> phosphogen system (immediate energy) **
> glycogen lactate system (anaerobic fermentation) **
Muscle Tissue: Functions - ANSWER > producing movements (skeletal muscle =
pulls on tendon moving bone at joint, smooth muscle = moving things in/out of body,
cardiac muscle = pump blood throughout the body)
> stabilizing positions (skeletal muscle = maintain tension on tendons and
bones/hold joints in place)
> stores/mobilizes substances within body (smooth muscle = sphincter by absorbing,
storing, and using glycogen)
> generates heat (20-30% at rest, up to 85% of body heat in exercise; constantly
being used/produced)
Muscle Tissue - Properties: Electrical Excitability - ANSWER ability to take on ions
to trigger electrical current for contractions (like when getting tased)
Muscle Tissue - Properties: Contractility vs Extensibility - ANSWER ability go
muscles to shorten/contract (myosin) vs to stretch (actin)
Muscle Tissue - Properties: Elasticity - ANSWER ability of muscle to return to its
original length following stretching/contractions
Muscle Formation - ANSWER "myogenesis" = fusion of myoblasts into muscle
fibers as mainly composed of proteins
> joining together of myoblasts
> fused together creates immature fiber (cell)
> overtime will become mature fiber (accounting for being multi-nucleated)
Muscle Type: Skeletal - ANSWER > move bones voluntarily
> appear multi-nucleated (unable to perform mitosis) and striated
> thin, attached via tendon to bones
> ATP demands: controlled and short durations (low demand)
Muscle Growth - ANSWER building in size rather than in number
> grow w/ slight tears causing inserting myoblast to fiber
Skeletal Muscle: Fibers - ANSWER > slow oxidative (myoglobin = red color;
resistant to fatigue as ATP is generated through aerobic respiration to maintain
posture and aerobic exercise)
,> fast oxidative glycolytic (many capillaries = pink color; intermediate resistance to
fatigue as ATP is created through aerobic/anaerobic respiration to walk or sprint)
> fast glycolytic fiber (few capillaries = white color; low resistance to fatigue for
rapid/intense movements of short durations)
Muscle Type: Cardiac - ANSWER > pumps blood/moves involuntarily
> has one nucleus w/ striations and intercalated discs
> fat and branched, attached to intercalated discs of exoskeleton
> ATP demands: contracting infinitely (higher demands)
Muscle Type: Visceral (Smooth) - ANSWER > various organs w/ various functions
involuntarily
> w/ one nucleus and no striations
> contain intermediate filaments connected via gap junctions
> ATP demands: latch-bridge mechanisms make it resistant to fatigue (low
demands)
Exciting Smooth Muscle - ANSWER > autonomic nerve fibers and
neurotransmitters
> chemicals (hormones, pH, oxygen)
> temperature (cold = contracts, heat = relaxes)
> stretch (digestive/urinary contract when stretched)
> autorhythmicity (spontaneously depolarize)
Gates - ANSWER > mechanically (open due to stretch)
> voltage (open due to depolarization of sarcolemma)
> ligand (open due to neurotransmitters/chemicals)
Muscle Tissue: Layers - ANSWER "tubes within tubes"
> myofilaments
> myofibrils
> fascicles
> skeletal muscle
Muscle Fiber: Layers - ANSWER > filaments
> myofibril
> fiber
> fascicle
> skeletal muscle
Muscle Tissue - Layers: Separating Connective Tissue - ANSWER > endomysium
(separates individual fibers)
> perimysium (separates 10-100 fibers into fascicles)
> epimysium (outer layer encircling entire muscle)
Muscle Fiber: Components - ANSWER > sarcolema (muscle cell's plasma
membrane)
> sarcoplasmic reticulum (calcium storage) = smooth ER
> transverse (T) tubule (penetrated enfolding) = increase surface area to action
, > sacromere (contractile unit between z-discs) = striations
Sarcomere: Proteins - ANSWER > myosin (thick "gold club head" filament
contractile protein)
> actin (thin "necklace bead" filament contractile protein)
>tropo-nin/myosin (regulatory proteins that determine if actin/myosin can bind
together)
>titin (returns sarcomere to original shape after contraction)
Sarcomere: Arrangement - ANSWER (striations due to arrangement)
> A band; entire myosin filament (dark band; beginning to end of same thick
filament)
> I band; actin and titin (light band; end of one to the beginning of the next thick
filament)
> M line (provides an anchor at the center of/for thick filaments)
> H zone; myosin (end of one to the beginning of the next thin filament)
> Z disc (provides anchorage for actin and titin filaments)
Sliding Filament Theory: Steps - ANSWER > calcium binding to toponin
> tropomyosin blocking, but move over
> myosin is able to bind to actin
> actin = door, calcium = unlocking of the door (triggering contraction)
> tropomyosin = door lock, troponin, key moving (allowing movement)
Sliding Filament Theory: Logistics - ANSWER ("power stroke")
> myosin pulls on actin = thin filaments slide inward
> z discs move towards each other = sarcomere shortens
> structural proteins = transmission force throughout entire muscle = whole muscle
contraction initiated
Contraction Cycle of Myosin - ANSWER > myosin head hydrolyzes ATP becoming
energized/oriented = cock back 3rd phosphate
> myosin binds to actin creating cross bridge = fire the 3rd phosphate (securing
contraction)
> myosin head pivots and pulls thin past thick filaments towards center of sarcomere
(powerstroke) = replace 3rd phosphate (keeps going unless runs out of ATP)
> as myosin binds with ATP, cross bridge detaches from actin
Muscle Metabolism - ANSWER (obtain/produce ATP)
> creatine phosphate (sprinting energy = phosphagen system)
> anaerobic glycolysis (glucose breakdown w/out oxygen)
> cellular respiration (glucose breakdown w/ oxygen)
Muscle Metabolism: Systems - ANSWER > aerobic respiration (using oxygen from
myoglobin and supported by cardiopulmonary function)
> phosphogen system (immediate energy) **
> glycogen lactate system (anaerobic fermentation) **
