In Class Notes Flashcards
What is the definition of Isometric Contraction?
No change in muscle length during contraction
Holiding a plank position or carrying a box without moving is an example of what?
Isometric Contraction
what is the definition of Isotonic contraction?
Muscles changes in length during contraction
What are the two types of isotonic contraction?
Concentric and eccentric contraction
Define defined what a concentric contraction is
It is when the muscle shorten while contracting
Lifting a dumbbell during a bicep curl is an example of what type of isotonic contraction?
Concentric contraction
Define what a eccentric contraction does
The muscle lengthens while contracting
Lowering a dumbbell during a bicep curl is an example of what isotonic contraction?
Eccentric contraction
What are the two connective tissues in muscles?
Superficial fascia and deep fascia
Where is the superficial fascia found in regarding the connective tissue?
Found just below the skin
What is the function of the superficial fascia?
Separates muscles from the skin, stores fat, and provides insulation
Where is the deep fascia found in regarding the connective tissue?
It surrounds individual muscles or groups of muscles
What is the function of the deep fascia?
It supports protects and provides roots for nerves and blood vessels
How many connective tissue layers are there?
Three
What is the function of the epimysium?
It covers the entire skeletal muscle
What is the epimysium made out of?
Dense irregular connective tissue
What is the function of the perimysium?
It’s surround fascicles
What are fascicles?
Bundles of muscle fibers
What does the perimysium contain?
Contains blood vessels and nerves
What is the endomysium function?
Surrounds each individual muscle fiber
What does the endomysium contain?
Capillaries and satellite cells
What are satellite cells?
Muscle repair
Describe what a tendon is
It is a cord like structure that connects muscle to bone
Describe what a aponeurosis is
It is a flat sheet like tendon connecting muscles to other muscles or bones
What is the sarcolemma?
It is the plasma membrane of a cell
What is the function of a sarcolemma?
Transmitting action potentials
What is the sarcoplasm?
It is the cytoplasm of muscle fibers
What does the Sarcoplasm contain
It contains glycogen and myoglobin
What does glycogen do?
It stores energy
What does myoglobin do?
Stores oxygen
Describe what a myofibril is
It is a cylindrical structure within my muscle fibers
What is the function of a myofibril?
It performs contractions
What is a myofibril composed of?
Repeating sarcomeres
Describe the sarcoplasmic reticulum
It is specialized, smooth endoplasmic reticulum in muscle cells
What is the function of the Sarcoplasmic Reticulum?
Stores and releases calcium critical for contraction
Describe what a T tubule is
They are transverse tubules that conduct action potential deep into a muscle fiber
What is the function of a T tubule
To ensure uniform contraction across the fiber
Describe what a terminal cisternae is
It is enlarged areas of the SR
Where is the terminal cisternae found in?
Adjacent to the T tubules
What is the function of the terminal cisternae?
Stores calcium ions for rapid release
How does the terminal cisternae form a triad?
They connect with T-Tubules
What is the definition of a sarcomere?
The basic functional unit of muscle contraction
How is a sarcomere marked?
By Z discs
What are the two types Of Myofilaments
Thick filaments and Thin filaments
what does thin filaments contain?
Actin Troponin tropomyosin
What is the function of actin?
it is the primary protein that forms the backbone of thin filaments
what is the function of tropomyosin?
it is a regulatory protein that blocks myosin-binding sites on actin
what is the function of the troponin?
binds calcium, by moving tropomyosin to allow contraction
what does thick filaments contain?
Myosin
describe what myosin is?
it is a motor protein with heads that form cross bridges by attaching to actin
what is the synaptic cleft?
it is a gap between the motor neuron and muscle fiber
what is acetylcholine?
it is a neurotransmitter released from motor neurons to initiate muscle contractions
what is an motor end plate?
it is part of the sarcolemma that contains ACh receptors
what is acetylcholinesterase?
it is an enzyme that breaks down Ach, stopping contraction signals
What does Black widow venom cause?
it causes excessive Ach release leading to muscle spasms
what does tetanus cause?
causes sustained contraction ex “lock Jaw”
what does Botulism/Botox cause?
It blocks Ach release, causes paralysis
what is myasthenia Gravis?
it is an autoimmune disease
what does Myasthenia Gravis do?
The Ach receptors receptors are attacked
what is Curare?
A plant toxin that blocks Ach receptors
what does Curare do?
Prevents muscle contraction
What is Duchenne Muscular Dystrophy?
It is a genetic condition that weakens muscle due to faulty dystrophin protein
name the 3 phases of a muscle twitch in order?
Latent phase contraction phase recovery phase
describe what the latent phase do?
It is a delay between the stimulation and the start of contraction
describe what the contraction phase do?
Muscle tension rises as cross bridges form
describe what the recovery phase do?
Calcium is reabsorbed, and muscle relaxes
describe what temporal summation is?
It is repeated stimuli that increases muscle contraction strength
describe what unfused tetanus is
it is incomplete relaxation between stimuli
Shivering is an example of what?
Unfused tetnus
Describe what fused tetnus is?
Sustained contraction without relaxation
Holding a heavy object is an example of what?
Fused tetnus
What is the definition of recruitment?
Activating different muscle fibers to vary force output
What are small fibers used for?
Light, percise actions
A small pat uses what?
Small fibers
What are large fibers used for?
Used for strong actions
A hard slap uses what?
Large fibers
ATP sources Creatine phosphate what does that do?
It is quick energy for short bursts. It yields 2 ATP
ATP sources Areobic respiration what does that do?
Produces 36 ATP with oxygen; supports endurance
ATP sources Anerobic Respiration what does that do?
Produces ATP without oxygen; lactic acid builds up leading to fatigue
What color are fast fibers?
White
What are the characteristics of fast fibers?
Contract quickly Fatigue rapidly Use anaerobic metabolism
Sprinting and weightlifting use what type of fibers?
Fast fibers
What color are slow fibers?
Dark
What are the characteristics of slow fibers?
Contract slower But sustain longer Use aerobic respiration
Distance running and posture maintenance use what type of fibers?
Slow fibers
What is disuse atrophy?
Loss of a muscle mass due to inactivity
What is degeneration atrophy?
Loss of muscle mass due to nerve damage
What is hypertrophy?
It is increase on muscle size due to training or resistance exercise
