Chapter 10 (Part 2) Flashcards by Kaitlin C

Single stimulus contraction relaxation sequence in a muscle fiber

twitch

How well did you know this?

Not at all

Perfectly

What are the 3 parts to a muscle twitch?

latent, contraction, relaxation

How well did you know this?

Not at all

Perfectly

Lag period between the arrival of the stimulus before contraction starts where no tension is produced

Latent

How well did you know this?

Not at all

Perfectly

how long does the latent period last?

2msec

How well did you know this?

Not at all

Perfectly

Repetetive power strokes pull thin filaments past thick filaments shortening the sarcomere increasing tension to a peak

contraction period

How well did you know this?

Not at all

Perfectly

Tension returns to resting levels

relaxation

How well did you know this?

Not at all

Perfectly

how long does the relaxation phase last?

25msec

How well did you know this?

Not at all

Perfectly

force generated when a skeletal muscle is stimulated to contract

muscle tension

How well did you know this?

Not at all

Perfectly

what is muscle tension based on?

frequency of stimulation

How well did you know this?

Not at all

Perfectly

stimulus directly follows relaxation phase of previous contraction resulting in stepwise increase in strength of contraction

treppe

How well did you know this?

Not at all

Perfectly

More calcium = ____ crossbridges forming

How well did you know this?

Not at all

Perfectly

prior contractions produced heat which increases efficiency of molecular interactions

warming up effect

How well did you know this?

Not at all

Perfectly

second stimulus arrives before relaxation period causing twitches to combine and produce greater tension; muscle contraction os sustained as each new wave is added to the previous

wave (temporal) summation

How well did you know this?

Not at all

Perfectly

stimulus frequency increased resulting in rapid cycles of contraction relaxation near maximum tension

incomplete tetany

How well did you know this?

Not at all

Perfectly

stimulus frequency so high that relaxation period is eliminated

tetany

How well did you know this?

Not at all

Perfectly

increasing number of active motor units

recruitment

How well did you know this?

Not at all

Perfectly

all muscle fibers innervated by single motor neuron

motor unit

How well did you know this?

Not at all

Perfectly

more motor units activated = ____ force generated by muscle

greater

How well did you know this?

Not at all

Perfectly

variable number of motor units are always active even when not contacting

muscle tone

How well did you know this?

Not at all

Perfectly

more muscle tone = ___ resting rate of metabolism

greater

How well did you know this?

Not at all

Perfectly

sarcomere length is at optimal range, max number of cross bridges can form; generates greatest amount of tension

normal resting length

How well did you know this?

Not at all

Perfectly

zone of overlap decreases, less potential cross bridges that can form, decreases the amount of tension it can produce

stretched sarcomeres

How well did you know this?

Not at all

Perfectly

thin filaments overlap portion of myosin tails, sarcomeres have less distance to shorten before thick filaments run into the z-line, decreases the amount of tension

compressed sarcomeres

How well did you know this?

Not at all

Perfectly

contraction where muscle maintains same length even as the amount of tension changes, different tension

isometric contraction

How well did you know this?

Not at all

Perfectly

contraction where muscle maintains tension as it changes to cause movement; sam tension, different length

isotonic contraction

muscle shortens during contraction

concentric contraction

what is an example of concentric contraction?

tension in biceps brachii while lifting barbell

muscle elongates, tension is less than the load than the peak tension so the muscle lengthens

eccentric contraction

what is an example of eccentric contraction?

tension in biceps brachii while lowering your coffee

contractions require ATP to ___

re-cock myosin heads, pump calcium into SR

ultimate energy stored in cells

ATP

high energy compound produced within skeletal muscles composed of amino acids

creatine phosphate

stored glucose

glycogen

if glycogen is broken down through anaerobic respiration, ______ of work is done

130 seconds

if glycogen is broken down through aerobic respiration, _____ of work is done

40 minutes

requires no oxygen

anaerobic

where does glycolysis happen

cytosol

what are the products of glycolysis

4 ATP (net gain 2), 2 pyruvate

where does aerobic respiration happen

mitochondria

what are the products of aerobic respiration

CO2, H2O, ATP

Removes hydrogen ions and electrons to be used in the electron transport chain

citric acid cycle

what are the products of the citric acid cycle?

1 ATP, 2 CO2

series of inner mitochondrial membrane proteins pass along electrons and pump across hydrogen to create a gradient which is used to create ATP with he help of ATP synthase

Electron transport chain

what are the products of the electron transport chain

6 H2O, 34 ATP

demand for ATP is low and fatty acids are broken down in mitochondria to produce ATP

muscle at rest

Extra ATP produced in muscles at rest are used to build reserves of ____ and ___

creatine phosphate, glycogen

demand for ATP increases, glucose is released down from glycogen storage and broken down using aerobic and anaerobic respiration

muscle at moderate activity levels

Not enough oxygen present for aerobic respiration to keep with demands

Muscles at peak activity levels

What is the remaining pyruvate converted to when muscles are at peak activity levels?

Lactic acid

What does lactic acid dissociate into?

Hydrogen ion, lactate

Can be converted back into pyruvate and broken down

lactate

muscle can no longer continue to perform at the required level of activity

muscle fatigue

What are the factors attributing to muscle fatigue?

Depletion of metabolic resources, less calcium, change in concentration of potassium and sodium, elevated concentration of phosphate

Amount of oxygen required to restore the fiber back to pre-exercise conditions

Oxygen debt, EPOC

What happens to the depth and rate of breathing when debt is being replaced?

increase

What does endurance exercise increase?

capillary network, mitochondria, myoglobin

Protein which stores oxygen in muscle fiber

myoglobin

What does resistance exercise increase?

Number of myofilaments

What are the 3 types of skeletal muscle fiber?

Fast, slow, intermediate

Contains sparse capillary network, few mitochondria, small amount of myoglobin, and fatigue rapidly

fast fibers

what color do fast fibers appear?

white

where are fast fibers found?

upper limb

What type of respiration are fast fibers powered by?

anaerobic

Contains lots of capillary networks, many mitochondria, many myoglobin, fatigue slowly

Slow fibers

what color do slow fibers appear?

red

what types of respiration are slow fibers powered by?

aerobic

where are slow fibers found?

trunk and lower limb

contains moderate capillary network, many mitochondria, medium amount of myoglobin

intermediate fiber

what color do intermediate fibers appear?

pink

what types of respiration are intermediate fibers powered by?

aerobic respiration

where are intermediate fibers found?

lower limb

how can the ratio of intermediate to fast fibers be altered?

athletic training

What determines the amount of fast and slow fibers

genetics

enlargement of stimulated muscle

hypertrophy

what increases due to repeated stimulation in the muscle?

mitochondria, glycogen, enzymes, myofilaments, myofibrils

reduction in muscle tone, size and power

atrophy

generalized skeletal muscle contraction following death

rigor mortis

what is rigor mortis caused by?

deterioration of SR, lack of ATP

when does rigor mortis begin?

2-7 hours

when does rigor mortis disappear?

1-6 days

What happens if there is no ATP during rigor mortis?

myosin heads cannot be reset, calcium cannot be pumped out of sarcoplasm