A&P Module 10

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Isotonic

(True Story) After the stalemate, the stronger person wins (Mr. Harris). When Mr. Harris stops taking it easy and begins to produce more force than Mr. Mirabito, the contraction is now:

mechanical advantage

A lever is a simple machine which creates __________ ___________ for the body, so work may be done.

A rigid structure that moves on a fixed point called the fulcrum

A lever is defined as which of the following?

excitability

Ability of a muscle fiber to respond rapidly to electrical or chemical signals

isometric contractions

Active muscle contraction without changing the muscle length. ex: "Stalemate" during an arm wrestling match

Mechanical Advantage

Allows you to use a simple machine to multiple your raw output of force *Use the ratio of output to input

isometric

An elderly patient at a physical rehabilitation clinic is trying to perform an exercise where they push against a wall as hard as they can without bending their elbows. What type of contraction are they performing?

Does not change length because the contractile force is equal to the resistive force

An isometric muscle action is a muscle action in which the muscle:

concentric contraction

Assuming a light load, which of the following will happen the fastest?

Elasticity

Capacity of muscle to return to its normal resting length after a stretch

Extensibility

Capacity of muscle to stretch to normal resting length and beyond after contraction

the relationship between force and velocity is inverse

During a concentric muscle action,

increases

During an eccentric contraction as the force of an object (weight) increases the speed of the contraction _________.

the relationship between force and velocity is direct

During an eccentric muscle action,

concentric and eccentric

During which type of muscle contraction(s) does the muscle length change?

lever system

FA = effort force (muscle) (applied force) FR = resistance force (gravity or load) (force resisting the lever's rotation) Fulcrum - joint

how levers work

FR= force resisting the lever's rotation MRF= moment arm of the resistive force MAF= moment arm of the applied force FA= force applied to the lever

Type IIB muscle fibers

Fastest twitch time Most easily fatigued

The ability to move a joint through a full range of motion

Flexibility is defined as:

More motor units are involved in a contraction.

Generally, muscle force is greater when which of the following occur?

isotonic contractions

Generation of muscle force with constant muscle tension and change in muscle length. -types: concentric & eccentric

it is hydrolyzed and releases a phosphate group and breaking a high-energy bond

How does ATP produce energy?

128lb

How much torque (in-lbs.) would be generated by a wrench that is 8 inches long, with an effort of 16 lbs of force?

growth (muscle adaptation)

Hypertrophy: enlargement of muscle fiber cross-sectional area following training• -Involves: --Actin and myosin synthesis --Titin and nebulin synthesis --Increase in number of myofibrils in muscle fiber

isotonic contraction

If a muscle is attempting to shorten, but due to a large resistance force, is stretched, which of the following contraction type is occurring?

isotonic.

If a person attempts to pick up a 5 lbs stone and they produce 6 lbs of applied force with their muscle which of the following would occur?

Isotonic.

If the force of a muscle is greater than the resistance force of an object, which type of contraction would occur?

isotonic

If the force of a muscle is greater than the resistance force of an object, which type of contraction would occur?

Sitting too much because it causes atrophy of muscle fibers

In an apparently healthy person, which kinds of activities should be avoided to prevent a decline in muscular health?

Type I, Type IIa, Type IIb

In what order are muscle fiber types recruited?

Fiber size is small.-Type I Mitochondria and capillary density is high.-Type I Color is red/white.-Type IIa Fatigue resistance is intermediate/low-Type IIa Color is white and fiber size is large-Type IIb Power output is high-Type IIb

Match the following muscle fiber characteristic with its associated muscle fiber type:

Red in color-Type I Endurance-Type I Intermediate force production-Type IIA Fast contraction speed-Type IIA White in color-Type IIB Large in size-Type IIB

Match the muscle fiber characteristics with the correct type of muscle fiber:

concentric

Mr. Harris is moving a box of textbooks out of his office. What type of contraction is being performed as Mr. Harris successfully lifts the box?

less, isotonic, eccentric

Mr. Harris is setting down a box of new anatomy models for lab. As he lowers the box, his muscles are producing _______ force than the weight of the box. This allows him to lower the box to the ground thus performing a type of _______contraction called an _____contraction.

isometric

Mr. Mirabito challenges Mr. Harris to an arm wrestling match. At first the match is close. The force output from Mr. Harris and Mr. Mirabito is the same and no movement occurs. What type of contraction is occurring during this stalemate?

torque

Multiplying force using a lever -Torque = Force x Moment arm distance -Can be Tresistance or Teffort τ= FA x MAF τ= FR x MRF

agonist

Muscle/muscle group most directly involved in movement

synergist

Muscles that stabilize the body during movement but are not responsible for the movement

antagonist

Opposing muscle group; slows down limbs during fast movement

anaerobic training muscle adaptations

Regular anaerobic training improves muscle strength, power, hypertrophy, endurance, motor skills and coordination -Exercise less than 10 seconds: uses energy from creatine phosphate system -Longer, repeated exercise: uses energy from glycolytic system -Progressive overload: gradual adaptation to increased stress on muscles from exercise

biochemistry (muscle adaptation)

Resistance/sprint training: -Increased cytoplasmic density -Increased sarcoplasmic reticulum and T-tubule density -Increased calcium release Anaerobic training: -Decreased blood and muscle pH

a)Increasing its size b)Facilitating fiber type transitions c)Enhancing its biochemical and ultra-structural components

Skeletal muscle adapts to anaerobic training primarily by:

Type I.

Someone that is able to run a relatively fast marathon likely has a high percentage of which type of muscle fiber?

a)Reduced risk of disease b)Improved emotional and social wellness c)Increased life expectancy

The benefits of exercise include which of the following? Select all that apply.

Moment Arm of Resistance Force

The distance between the resistance force (load) and the fulcrum is known as the:

true

The fixed point which a lever revolves around is known as a fulcrum.

neural control

The frequency of action potential generation in a motor neuron •Frequency increases when more force is required

agonist.

The primary muscles that work together to bring about a movement are called ________.

inverse

The relationship between force and velocity during a concentric contraction is __________.

true

True or False: There is always overlap between actin and myosin.

Perform the powerstroke

What does ATP allow myosin heads to do?

They turn into fat and connective tissue

What happens to muscles that are not activated on a regular basis (months or years)?

Capacity of muscle to return to its normal resting length after a stretch

What is the definition of elasticity?

cardiac and skeletal

What type of muscles are striated? Select all that apply.

Running fast Lifting relatively heavy weight Jumping

What types of activities can be done to prevent atrophy of skeletal muscles, and specifically, type II fibers?

isotonic

When a concentric contraction occurs and the muscle shortens, which type of muscle contraction is occuring?

eccentric contraction

When a muscle lengthens as it contracts, this is known as a:

isotonic concentric

When a person stands up out of a chair, the agonist muscles involved include the quadriceps, gluteals, and hamstrings, which are contracting in which type of muscle action? Select all that apply.

isotonic and concentric

When a person stands up out of a chair, the agonist muscles involved include the quadriceps, gluteals, and hamstrings, which are contracting in which type of muscle action? Select all that apply.

Force of resistance Moment arm of resistance force

When calculating the torque of resistance, what 2 variable are multiplied together?

Moment arm length Force

When calculating torque, what 2 variables do you multiply?

third class lever

Which class of lever, by definition will have a longer moment arm of resistance (MRF)?

T = Force x Moment arm

Which of the following correctly identifies the equation for torque?

Decreased actin and myosin synthesis

Which of the following does not describe a muscle adaptation to exercise?

Excitability

Which of the following functional characteristics of muscle is shared with nervous tissue?

fulcrum force

Which of the following is NOT a component of a lever system?

Elbow flexion with a biceps curl

Which of the following is an example of a third-class lever?

Type I Type IIA Type IIB

Which of the following muscle fiber types would be recruited for jumping on a trampoline? Select all that apply.

Type I

Which of the following muscle fiber types would be recruited for sitting?

Fulcrum - Applied Force - Resistance Force Resistance Force - Applied Force - Fulcrum

Which of the following places the components of a lever in the correct order for a 3rd class lever? (may or may not be more than one answer)

-Transformation within muscle fiber subtypes has been demonstrated. -Type I to Type II transitions¸ and vice versa¸ appear less probable. -Even if fiber types do not change¸ every person can improve in aerobic endurance¸ strength¸ and power.

Which of the following statement(s) is/are true regarding altering characteristics of muscle fiber types? Select all that apply.

second-class

Which type of lever provides the greatest mechanical advantage?

Breast-Fast-twitch Leg/neck-Slow-twitch

With this example and muscle color types in mind, what parts of a chicken are fast-twitch and which parts are slow-twitch?

a46 in-lbs. b50 in-lbs. c47 in-lbs. d100 in-lbs.

You are trying to take apart an Ikea desk to move back home for the summer. You are attempt to get out a screw from the desk. If the resistance torque of the screw is 45 in-lbs., which of the following effort torques would cause the screw to be dislodged? (check all that apply)

first class lever

applied and resistant forces on opposite sides of the fulcrum fulcrum in the middle

Distribution of Type I versus Type II muscle

depends on the demands on that particular muscle.

Functional characteristics of skeletal muscle

excitability, contractility, extensibility, elasticity

Type II muscle fibers

fast twitch inefficient fatigue easily low aerobic capacity produce force more rapidly

third class lever

force is applied between the resistance and the fulcrum

progressive overload

gradual adaptation to increased stress on muscles from exercise

three specific muscle adaptations

growth, fiber type transition and biochemistry

plasticity

muscle's ability to constantly adapt to stretching.

insertion

muscle's distal attachment

origin

muscle's proximal attachment

first class lever

neck rotation is an example of?

second class lever

resistance lies between (in the middle of) the applied force and the fulcrum

Type I muscle fibers

slow twitch efficient resistant to fatigue high capacity for aerobic energy supply produce force less rapidly

smooth

what type of muscles produce the most force per fiber size

fiber recruitment

which and how many motor units are involved in a muscle contraction -Type I fibers are recruited first for any given movement -Type II fibers are recruited second, if needed

Calf raise is a 2nd class lever The moment arm of the applied force is longer than the moment arm of the resistance force

why can you calf raise your body weight, but can't bicep curl your body weight?

To increase the length of the moment arm of applied force More mechanical advantage

why would applying an effort force (applied force) to the far end of the lever generate the maximum amount of torque?

joints create levers

•A lever is a simple machine •Bones, muscle, and joints constitute a lever system

contractility

•Ability of muscle to shorten and produce tension at its ends •Pulls on tendons

concentric contractions (isotonic)

•Contractile force is greater than external load •Muscle shortens ex: elbow flexion (lifting barbell)

eccentric contractions (isotonic)

•Contractile force is less than external load •Muscle lengthens ex: elbow extension

aerobic training muscle adaptations

•Increased aerobic capacity of skeletal muscle •Increased maximal aerobic power •Increased size of Type I muscle fibers due to their increased recruitment •Increased size and number of capillaries and mitochondria

fiber types (muscle adaptation)

•Type IIb can transition to Type IIa with aerobic endurance or high intensity resistance training •Type I to II transitions (or vice versa) are less likely


Ensembles d'études connexes

Erikson's Theory of Psychosocial Development and 8 stages

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