Muscular System Flashcards
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What are Type 1 muscle fibers?
Slow twitch muscle fibers
What are Type 2a muscle fibers?
Fast twitch oxidative
What are Type 2b muscle fibers?
Fast twitch glycolytic
What is an example of a sport for Type 1 muscle fibers?
Marathon running
What are examples of sports for Type 2a muscle fibers?
800m or 400m
What are examples of sports for Type 2b muscle fibers?
100m sprint and high jump
What is the function of muscles in producing movement?
Muscles contract and relax to pull on bones, creating movement.
What is the function of muscles in maintaining essential bodily functions?
Refers to the body’s ability to regulate processes like heart rate, respiration, and temperature during physical activity
What is the function of muscles in maintaining posture?
Muscles make continuous small adjustments to maintain posture
What is the function of muscles in stabilizing joints?
Tendons of muscles expand over joints to contribute to stability
What is the function of muscles in generating heat?
Heat is a by-product of any muscular activity
What is smooth muscle?
Involuntary muscle found in internal organs helping move substances around
What is cardiac muscle?
Involuntary muscle responsible for pumping blood around the body, found in the heart
What is skeletal muscle?
Voluntary muscle attached to bones responsible for movement, controlled consciously
What is excitability in muscle function?
Ability to receive and respond to a stimulus from the brain
What is contractility in muscle function?
Ability for muscle to shorten
What is extensibility in muscle function?
Ability for muscle to be stretched
What is elasticity in muscle function?
Ability to resume resting length
What is the all or none principle in muscle contraction?
Once a motor unit receives an impulse that reaches the required threshold, all of the muscle fibers will contract at maximum force
What is disinhibition in the context of contractility?
CNS sends signals to excite or inhibit muscular activity during exercise
How does muscle contraction occur in terms of contractility
When more excitatory than inhibitory signals are sent, muscular contraction will occur
How can disinhibition reduce the likelihood of injuries?
Prevents excitatory signals from exceeding the limit during exercise
What does increased firing rate of motor units indicate?
Faster messages from the brain lead to faster muscle fiber contraction
What does improved synchronization of firing rate mean?
When motor units fire at the same time, the force produced will increase
What does improved technique and muscle coordination result in?
Results in better performance and strength through improved coordination
Where are the triceps located?
Located on the back of the upper arm
What is the gluteus maximus?
The large muscle in the buttocks
What are the hamstrings?
The muscles at the back of the thigh
What is the gastrocnemius?
The large calf muscle at the back of the lower leg
What is the soleus?
A muscle under the gastrocnemius in the lower leg near the Achilles tendon
What is the latissimus dorsi?
A large muscle in the back, extending from the lower spine to the upper arms
What is the adductor group?
Muscles in the inner thigh that help bring the leg together
Where are the pectorals located?
Located in the upper chest
What is the trapezius?
A large muscle in the upper back and neck
What is the deltoid?
The shoulder muscle in the upper back and neck
Where are the biceps located?
The muscle on the front of the upper arm
What are the quadriceps?
The large muscles on the front of the thigh
What are abdominal muscles?
The core muscles in the stomach area
What are hip flexors?
A group of muscles in the front of the hip that help lift the leg
What is the tibialis anterior?
The muscle on the front of the lower leg, near the shin
What are isometric contractions?
Tension increases but there is no change in muscle length or joint angle
What are concentric contractions?
Shortening of a muscle while under tension (isotonic)
What are eccentric contractions?
Lengthening of a muscle while generating force (isotonic)
What are isotonic contractions?
Movement where the muscle changes length while maintaining mostly constant tension
What are isokinetic contractions?
Change in muscle length against a varying load (special equipment needed)
What is an example of an isotonic contraction?
Bicep curl
What is an example of an isometric contraction?
Gripping a tennis racket
What is an example of an isokinetic contraction?
Riding on a stationary bike
What is the Z Line in a sarcomere?
A disk-like structure for actin filament attachment; anchors them in place
What is the I Band in a sarcomere?
Consists of only actin filaments
What is the A Zone in a sarcomere?
The length of the Myosin filaments
What is the H Zone in a sarcomere?
The center of each A band, only contains myosin
What is the M Line in a sarcomere?
In the middle of the H zone, consists of delicate fibers that anchor myosin filaments
