Muscle contraction Flashcards
At any given time muscles are stimulated while other aren’t this causes tightened firmed muscle
Muscle tone
Types of muscle contractions
Isotonic and isometric contractions
What is an istotonic contraction
Same tone or tension and myofilaments are successful in their sliding movements the muscle shortens and movement occurs
What is an isometric contraction
Same measurement and tension of muscle keeps increasing but no movement happens
When a muscle loses its ability to contract during strenuous exercise it is referred to as what?
Fatigue
What prevents a muscle from contracting
Lowered pH as a result of accumulated lactic acid
How does a muscle cramp occur
Lack of ATP required to return calcium ions back to sarcoplasmic reticulum so muscle fibers can relax
When may oxygen deficiency occur
Strenuous exercise and lactic acid accumulates as an end product of anaerobic respiration
What stores oxygen in muscle tissue
Pigment myoglobin
What carries oxygen to the muscle
Hemoglobin in red blood cells
When is the complete breakdown of glucose enabled in the mitochondria
Early phase of cellular respiration
Energy for contraction comes from the molecules of what
Atp
What stores energy release by the mitochondria
Creatine phosphate
As atp decomposes what happens
Energy from creatine phosphate can be transferred to ADP molecules converting them back to ATp
What is a motor unit
A motor neuron and muscle fibers it controls
What does a motor unit do
When told to do so muscle fibers of motor unit contract all at once
Where do the motor neuron and muscle fiber meet
Neuromuscular junction
What does the cytoplasm of the motor neuron contain
Numerous mitochondria and synaptic vesicles storing neaurotransmitters
What do cross bridges do
Link thick and thin filaments together during contraction
What is the h zone
Center of a bands and consists of myosin filaments
What are the thick filaments
Myofilaments
What are actin filaments made up of
Protein actin
What is the sarcolemma
Cell membrane
What is sarcoplasm
Cytoplasm
What are the muscle functions
Produce movement,maintain posture,stabilize joints,and generate heat
Which two muscles are involuntary
Cardiac and smooth
Which muscle is a striated muscle with intercalated discs
Cardiac
Has no striations
Smooth
Cells are spindle shaped and have single nucleus
Smooth
Arranged in sheets or layers
Smooth
Found mainly in walls of visceral organs
Smooth
What are the functions of tendons
Anchor muscles and provide durability and conserve space
Sheath of connective tissue that encloses a muscle fiber
Endomysium
A coarse of fibrous membrane that encloses several sheathed muscle fibers
Perimysium
Bundle of fibers held together by the perimysium
Fascicle
Tough connective tissue which binds together many fascicles
Epimysium
Cords of dense fibrous tissue attaching a muscle to a bone
Tendons
Blend together to form the cordlike tendons or into sheet like aponeuroses which attach muscle indirectly to bone and cartilage
Epimysia
Skeletal muscle fibers are packed into organs called what
Skeletal muscles
Skeletal muscle is also known as what
Striated muscle