Flashcards in Chapter 3 - Muscle Structure And Function Deck (81):
Human body consists of _____ muscles
Muscle makes up ___-___% (in women) and ___-___ (in men) of body mass
30-35 in women and 42-47 in men
What are the 3 basic types of muscle?
What is another name for skeletal muscle?
Skeletal muscle connects the various parts of the skeleton through one or more connective tissue structures called _______
During muscle _______ skeletal muscle shortens and moves various parts of the skeleton
How can the required smoothness and speed of muscles be achieved?
Through the graded activation of muscles
Are skeletal muscles under voluntary or involuntary control?
Under voluntary control
________ involves the assessment of movement and the sequential pattern of muscle activation that that move body segments
What is most skeletal muscle attached to?
What is skeletal muscles contraction responsible for?
Supporting and Moving the skeleton
List 4 spots u can find smooth muscle.
1) blood vessels
2) respiratory tract
3) iris of the eye
4) gastro-intestinal tract
Are the contractions of smooth muscle slow and uniform?
What are the functions of the smooth muscle?
To alter the activity of various body parts to meet the needs f the body at that time
Smooth muscle is fatigue _______
Activation of smooth muscle is ________
Swallowing food in the esophagus uses wave like movements called _____
What kind of muscle has characteristics of both skeletal and smooth
What are the functions of cardiac muscle
To provide the contractile activity of the heart
Contractile activity can be ______ (like skeletal muscle)
Is very fatigue _______
Activation of cardiac muscle is ________ (like smooth muscle)
What are the 4 components of skeletal muscle?
1) muscle belly
2) muscle fiber bundle
3) muscle fiber
4) filament proteins
What is the muscle belly? (Of skeletal muscle)
The "whole" of the muscle is the muscle belly
What is the muscle fiber bundle? (Of skeletal muscle)
Muscle fiber bundle is a bunch of fibers bundled together
What are muscle fibers? (Skeletal muscle)
Muscle fibers are the individual muscle fibers that make up the bundle
Where are filament proteins found in skeletal muscle?
Inside the myofibril
Muscle fibers are ______ shaped cells that make up the skeletal muscle
Each muscle fiber is made up of a nber of _________
Muscle fibers are surrounded by a connective tissue sheath (membrane) called __________
Many muscle fibers are enclosed by connective tissue sheath called _______ to form a bundle of fibers
What 2 things does each muscle fiber contain?
1) contractile machinery
2) cell organelles
Muscle fibers are activated through nerve impulses via ____ ____ ____
Motor end plate
What is a group of muscle fibers activated via the same nerve called?
Each muscle fiber has _______ that supply nutrients and eliminate waste
What is the agonist (prime mover)?
The muscle or group of muscles producing a desired effect
Eg. The bicep when lifting an object
What is the antagonist?
The muscle or group of muscles opposing the action
Eg. The triceps relax when the bicep is working
What is the synergist?
The muscles surrounding the joint being moved
What are the fixators?
The muscle of group of muscles that steady joints closer to the body axis so that the desired action can occur
Muscles that stabilize so you don't dislocate
Eg. If you are carrying 45 pounds of weight in your hand your shoulder would pop out if not for the shoulder fixator muscles
Sarcomeres are ________ units
What are the 2 types of protein myofilaments in sarcomeres?
What are actin
What are myosin
Each myosin is surrounded by ___ actin filaments
Projecting from each myosin are tiny contractile _______ _______.
What is cross bridge formation?
- a signal comes from the motor nerve activating the fiber
-the heads of the myosin filaments temporarily attach themselves to the actin filaments
- active action coming from the brain
Motor nerve activates fiber causing the myosin to attach to actin
What is cross bridge movement?
- similar to the stroking of the para and movement of rowing shell
- movement of myosin filaments in relationn to actin filaments
- shortening of the sarcomere
- shortening of each sarcomere is additive
Sarcomeres should be _____ distance apart
What happens if the sarcomeres are stretched farther apart than optimal distance?
Then fewer cross bridges can form which means less force is produced
What happens if the sarcomeres are too close together?
Cross bridges then interfere with one another as they form which means less force is produced
Maximal force occurs at what 2 things?
Optimal muscle length and joint angle
Optimal joint angle occurs at ______ ______ ______
Optimal muscle length
The distance between sarcomeres needs to be optimal for what to occur
Maximum exertion of force
What are the 2 types of muscle fibers?
Slow twitch fibers and fast twitch fibers
Slow twitch fibers
- slow oxidative (type 1)
- continuous repition but slowly
- suited for repeated contractions during activities requiring a force output of less than 20-25% of max force output
- examples: lower power activities, endurance events
- have less capacity to generate force
Fast twitch fibers
- fast glycolytic (type lla)
- fast oxidative glycolytic (type llb)
- explosive fibers
- for maximum utilization
- significantly greater force and speed generating capability than slow twitch fibers
- well suited for activities involving high power, low endurance
- examples: sprinting, jumping, throwing
- you want explosiveness
Give a comparison example between fast twitch and slow twitch
Jumping on the spot would be slow twitch while jumping distance would be fast twitch
Nervous system can be divided into what 2 parts?
Central nervous system (CNS)
Peripheral nervous system (PNS)
What 2 functions can the nervous system be divided into?
Motor and sensory activity
Collects info from the various sensors located throughout he body and transmits the info to the brain
Conducts signals to activate muscle contraction
Most f what happens in our eyes is _______
Hot receptors cold receptors pressure receptors are all examples of ______
Motor nerves extend from where to where
From the spinal cord to the muscle fibers
How is each muscle fiber activated by motor nerves?
Through impulses delivered via the motor end plate
A group of fibers activated via the same nerve
True or false: all muscle fibers of one particular motor unit are always of the same fiber type
What do muscles that need to perform precise movements generally consist of?
A large number of motor units and new muscle fibers
What do muscles who need to perform less precise movements generally consist of?
Fewer motor units with many fibers per unit
All or none principle
Whether or not a motor unit activates upon the arrival of an impulse depends upon the so called all or none principle
What is required to cause the inner cared fibers to contract?
An impulse of a certain magnitude (or strength)
Every motor unit has a special _______ that much be reached for such activation to occur
What is intra muscle coordination
The capacity to apply motor units simultaneously
How much of their available muscle fibers can highly trained power athletes (weightlifters, wrestlers and shot putters) activate up to? Vs an untrained person?
85% vs 65%
The difference between assisted and voluntarily generated maximal force
Inter muscle coordination
The interplay between muscles that generate movement through contraction (agonists) and muscles responsible for opposing movements (antagonists)
The greater the participation of muscles and muscle groups the higher the what?
The higher the importance of inter muscle coordination
Prime mover is controlled by ______
The greater the participation, the greater the _________
Individuals performance improvements occur through a process of _________ _________ which is reflected on the body's increased strength