Exam 2 Info - Slides Flashcards
skeletal muscle tissue: attached to ... and ... .... ... (i.e. conscious control) powerful
bones; skin;
striated;
voluntary
cardiac muscle tissue:
only in the ..
…
…
heart
striated
involuntary
smooth muscle tissue: in the walls of ... (e..g stomach, urinary bladder, and airways) not ... ... ... to act compared to striated muscle
hollow organs;
striated;
involuntary;
slower
special characteristics of muscle tissue:
… (… or …): ability to receive and respond to stimuli
…: ability to shorten when stimulated
…: ability to be stretched
…: ability to recoil to resting length
excitability; responsiveness; irritability;
contractility;
extensibility;
elasticity
muscle functions: ... of bones/fluids (e.g. blood) maintaining ... and ... ... ... (especially skeletal muscle)
movement;
posture; body position;
stabilizing joints;
heat generation
(skeletal muscle) each muscle is served by one …, one …, and one or more …
artery; nerve; veins
(skeletal muscle)
connective tissue sheaths of skeletal muscle:
…: dense regular connective tissue surrounding entire muscle
…: fibrous connective tissue surrounding fascicles (groups of muscle fibers)
…: fine areolar connective tissue surrounding each muscle fiber
epimysium;
perimysium;
endomysium
(skeletal muscle)
muscles attach:
directly – … of muscle is fused to the … of bone or … of cartilage
epimysium; periosteum; perichondrium
(skeletal muscle)
muscles attach:
indirectly - connective tissue wrappings extend beyond the muscle as a … or …
ropelike tendon; sheetlike aponeurosis
(skeletal muscle)
periosteum: double layered connective tissue that … and … bone
perichondrium: fibrous, connective membrane covering the …. of … structures
covers; nourishes;
external surface; cartilaginous
(skeletal muscle) skeletal muscle fiber: ... cell 10-100 micrometers in diameter, up to 30 cm long multiple ... many ...
cylindrical;
peripheral nuclei;
mitochondria
(skeletal muscle)
skeletal muscle fiber:
… for glycogen storage, … for oxygen storage
glycosomes; myoglobin
(skeletal muscle) skeletal muscle fiber: also contain: ... ... ...
myofibrils;
sarcoplasmic reticulum;
T tubules
(skeletal muscle)
myofibrils:
densely packed, … elements
about …% of cell volume
rodlike; 80
(skeletal muscle) myofibrils: exhibit ...: perfectly aligned repeating series of dark A bands and light I bands A bands = ... filaments I bands = ... filaments
striations;
myosin thick;
actin thin
(skeletal muscle)
sarcomere:
smallest …. (… unit) of a muscle fiber
the region of a myofibril between two successive … (…)
composed of … and … filaments
contractile unit; functional unit;
Z discs; alpha-actinin;
thick; thin
(skeletal muscle) …: run the entire length of an an A band (dark)
…: run the length of the I band (light) and partway into the A band
thick filaments; thin filaments;
(skeletal muscle) …: coin shaped sheet of proteins that anchors the thin filaments and connects myofibrils to one another (protein is …)
…: line of protein … that holds adjacent thick filaments together
Z disc; alpha-actinin
M line; myomesin
(thick filament)
composed of the protein myosin
myosin tails contain: 2 interwoven, …
heavy polypeptide chains
(thick filament) myosin heads contain: 2 smaller, ... that act as cross bridges during contraction binding sites for ... of thin filaments binding sites for ... ... enzymes
light polypeptide chains;
actin;
ATP;
ATPase
(thin filament)
twisted double strand of fibrous protein … (…)
F actin; filamentous
(thin filament)
F actin consists of … subunits
G (globular) actin
(thin filament)
G actin bears active sites for … attachment during contraction
… and …: regulatory proteins bound to actin
myosin head;
tropomyosin; troponin
(tropomyosin and troponin) several regulatory proteins are also present in the thin filament
two strands of …, a rod-shaped protein, spiral about the actin core and help … it. Successive … molecules are arranged end to end along the actin filaments, and in a relaxed muscle fiber, they block … on actin so that the myosin heads cannot …
tropomyosin; stiffen; tropomyosin; myosin binding sites; bind to the thin filaments
(tropomyosin and troponin)
the other major protein in the thin filament, …, is a three polypeptide complex. one of these polypeptides (…) is an … subunit that binds to actin; another (…) binds to tropomyosin and helps … on actin
the third (…) binds …
Both troponin and tropomyosin help control the myosin-actin interactions involved in contraction
troponin;
Tnl; inhibitory;
TnT; position it;
TnC; calcium ions;
in the center of the sarcomere, the thick filaments lack …
These are present only in areas of …
myosin heads;
myosin-actin overlap
(sarcoplasmic reticulum) network of … surrounding each myofibril
pairs of terminal cisternae form …
functions in the regulation of … levels
smooth endoplasmic reticulum;
perpendicular cross channels;
intracellular Ca2+
(T tubules) continuous with the ….
penetrate the cell’s interior at the …
associate with the paired terminal cisternae to form … that encircle each sarcomere
sarcolemma;
A band- I band junction;
triads
(triad relationships)
T tubules … deep into muscle fiber
… protrude into the intermembrane space from T tubule and SR cisternae membranes
T tubule proteins: …
…: gated channels that regulate calcium release from the SR cisternae
conduct impulses;
integral proteins;
voltage sensors;
SR foot proteins
(contraction)
the …
does not necessarily cause … of the fiber
generation of force; shortening
(contraction) shortening occurs when tension generated by cross bridges on the thin filaments …
exceeds forces opposing shortening
(sliding filament model of contraction) in the relaxed state, thin and thick filaments … only slightly
during contraction, myosin heads bind to …, …, and … again, to propel the thin filaments toward the …
overlap;
actin; detach; bind; M line
(sliding filament model of contraction)
as H zones shorten and disappear, … shorten, … shorten, and the …shortens
sarcomeres; muscle cells; whole muscle
(requirements for skeletal muscle contraction) activation: neural stimulation at a …
excitation-contraction coupling:
generation and propagation of an … along the …; final trigger: a brief rise in … levels
neuromuscular junction;
action potential; sarcolemma;
intracellular calcium
(events at the neuromuscular junction) skeletal muscles are stimulated by …
axons of motor neurons travel from the … via nerves to …
somatic motor neurons;
central nervous system;
skeletal muscles
(events at the neuromuscular junction) each axon forms … as it enters a muscle
each axon ending forms a … with a single muscle fiber
several branches;
neuromuscular junction
(neuromuscular junction) situated midway along the length of a …
axon terminal and muscle fiber are separated by a gel-filled space called the …
muscle fiber;
synaptic cleft
(neuromuscular junction) synaptic vesicles of axon terminal contain the neurotransmitter …
junctional folds of the sarcolemma contain …
acetylcholine (ACh);
ACh receptors
(neuromuscular junction)
nerve impulse arrives at …
ACh is released and binds with receptors on the …
electrical events lead to the generation of an …
sarcolemma;
action potential
(destruction of acetylcholine) ACh effects are quickly terminated by the enzyme …
Break ACh into … and …
acetylcholinesterase;
choline; acetic acid
(destruction of acetylcholine)
choline will get recycled back to … in the NMJ …
prevents continued … in the absence of additional stimulation
ACh; axon terminal;
muscle fiber contraction
(events in generation of an action potential)
1. local depolarization (…):
ACh binding opens …
simultaneous diffusion of … and …
end plate potential;
chemically (ligand) gated ion channels;
Na+ (inward); K+ (outward)
(events in generation of an action potential)
more … diffuses, so the interior of the sarcolemma becomes …
… - …
Na+; less negative;
local depolarization. - end plate potential
(events in generation of an action potential)
generation and propagation of an action potential:
… spreads to adjacent membrane areas
… open
Na+ influx decreases the membrane voltage toward a …
if threshold is reached, an … is generated
end plate potential
voltage-gated Na+ channels;
critical threshold;
action potential
(events in generation of an action potential)
local depolarization wave continues to spread, changing the …. of the sarcolemma
… open in the adjacent patch, causing it to depolarize to threshold
permeability;
voltage-regulated sodium channels
(events in generation of an action potential)
repolarization:
sodium channels close and … open
… rapidly restores the resting polarity
fiber cannot be stimulated and is in a … until repolarization is complete
ionic conditions of the resting state are restored by the …
voltage-gated K+ channels;
K+ efflux;
refractory period;
Na+-K+ pump
(excitation contraction (E-C) coupling) sequence of events by which transmission of an AP along the sarcolemma leads to …
… period: time when E-C coupling events occur; time between … and the beginning of …
sliding of the myofilaments;
latent; AP initiation; contraction
(excitation contraction (E-C) coupling) AP is propagated along the sarcomere to …
voltage-sensitive proteins stimulate … from SR –> … is necessary for contraction
T tubules; Ca2+ release; Ca2+
(role of calcium in contraction) at low intracellular Ca2+ concentration:
… blocks the active sites on actin
…. cannot attach to actin
muscle fiber …
tropomyosin;
myosin heads;
relaxes
(role of calcium in contraction) at higher intracellular Ca2+ concentrations:
calcium binds to …, which changes shape and moves … away from active sites
events of the … occur
troponin; tropomyosin; cross bridge cycle
(role of calcium in contraction)
at higher intracellular Ca2+ concs:
when nervous stimulation ceases, … is pumped back into the … and contraction ends
Ca2+; SR
(cross bridge cycle) continuous as long as the … and … are present
… - high energy myosin head attaches to thin filament
… - myosin head pivots and pulls thin filament toward M line
Ca2+ signal; adequate ATP;
cross bridge formation;
working (power) stroke
(cross bridge cycle)
…: ATP attaches to myosin head and the cross bridge detaches
… - energy from … cocks the myosin head into the high-energy state
cross bridge detachment;
“cocking” of the myosin head;
hydrolysis of ATP
(muscle metabolism) … only source used directly for contractile activities –> move and detach …, … pumps in SR, return of … and … after excitation-contraction coupling
available stores of ATP depleted in … seconds
ATP; cross bridges; calcium; Na+; K+;
4-6
(muscle metabolism) ATP regenerated by: 1. direct ... of ADP by ... 2. ... (... --> ...) 3. ...
phosphorylation; creatine phosphate (CP);
anaerobic pathway; glycolysis; lactic acid;
aerobic respiration
(anaerobic pathway)
glycolysis: does not require oxygen
glucose degraded to … molecules
normally enter mitochondria –> …
2 pyruvic acid;
aerobic respiration
(anaerobic pathway) at 70% maximum contractile activity:
bulging muscles …; … is impaired
pyruvic acid converted to …
compress blood vessels; oxygen delivery;
lactic acid
(anaerobic pathway) lactic acid:
diffuses into bloodstream
used as fuel by …, …, and …
converted back into … or … by liver
liver; kidneys; heart;
pyruvic acid; glucose
(anaerobic pathway) lactic acid:
anaerobic respiration yields only … as much ATP as aerobic respiration, but produces ATP … times faster
5%; 2.5
(aerobic pathway) produces 95% of ATP during … and …; …
rest and light to moderate exercise; slow
(aerobic pathway) series of chemical reactions that require …; occur in …
breaks glucose into …, …, and large amount of …
oxygen; mitochondria;
CO2; H2O; ATP
(aerobic pathway) fuels- stored …, then bloodborne …, … from glycolysis, and …
glycogen; glucose; pyruvic acid; free fatty acids
…: length of time muscle contracts using aerobic pathways
…: point at which muscle metabolism converts to anaerobic
aerobic endurance;
anaerobic threshold
(muscle fatigue) physiological inability to … despite …
contract; continued stimulation
(muscle fatigue)
occurs when:
… (K+, Ca2+, Pi) interfere with E-C coupling
prolonged exercise damages … and interferes with … and …
ionic imbalances;
SR; Ca2+ regulation and release
(muscle fatigue) total lack of ATP occurs rarely, during states of …, and causes … (continuous contractions)
continuous contraction; contractures
(excess postexercise oxygen consumption) to return muscle to resting state
.. reserves replenished
… converted to …
… stores replaced
… and … reserves replenished
all require extra oxygen; occur post exercise
oxygen;
lactic acid; pyruvic acid;
glycogen;
ATP; creatine phosphate
(heat production during muscle activity) about …% of energy released in muscle activity useful as work
remaining energy given off as …
dangerous heat levels prevented by … from skin and sweating
… - result of muscle contractions to generate heat when cold
40;
heat;
radiation of heat;
shivering
(blood composition) blood: a fluid connective tissue composted of ... formed elements: 3 types ... (..) ... (...) ...
plasma;
erythrocytes; RBCs
leukocytes; WBCs
platelets
(blood composition)
….: percent of blood volume that is RBCs
…% +- …% for males
…% +- …% for females
hematocrit;
47; 5;
42; 5
(blood composition)
hematocrit:
…: least dense component, 55% of whole blood
…: leukocytes and platelets, <1% of whole blood
…: 45% of whole blood, most dense component
plasma;
buffy coat;
erythrocytes
(physical characteristics and volume of blood)
sticky, opaque fluid
color scarlet to dark red
pH …-…
38 degrees C
about 8% of body weight
average volume: … L for males, and … L for females
7.35- 7.45;
5-6; 4-5
(functions of blood) 1. distribution of:
… and … to body cells
… to the lungs and kidneys for elimination
… from endocrine organs to target organs
oxygen; nutrients;
metabolic wastes;
hormones
(functions of blood)
2. regulation of:
… by … and …
body temperature; absorbing and distributing heat
(functions of blood)
regulation of:
normal … using …
adequate … in the circulatory system
pH; buffers;
fluid volume