Muscles quiz Flashcards
Layers of muscle from outside to inside
Facia- outer layer and surrounds epimysium
Epimiseum- surrounds the perimysium
Perimesium- surrounds the fascicles
Fascicles- contain muscle fibers
Muscle fibers- contain myofibrils and filaments
What happens when skeletal muscles contract
They individual sarcomeres shorten as thin filaments and slide past thicker filaments towards the center of the sarcomere.
What are the roles of actin and myosin in muscle contraction
The myosin molecule composed of twisted protein strands, attack to the actin binding sites and bend pulling the actin filament. This movement causes muscle contraction
transmission of a nerve impulse over neuromuscular junction
First the axon terminal of a neuron’s vesicles release neurotransmitters towards the receptors in the sarcolemma. After connecting to the muscle fibers are depolarized causing an charge to travel through the transverse tubules.
interaction of acetylcholine and calcium to stimulate muscle contraction
acetylcholine are the neurotransmitters and calcium binds to the Tripoli on the actin.
cross bridge
the globular head on the myosin molecule that temporarily attaches to the actin filament.
Which enzyme halts the action of acetylcholine
ACHE, nerve agents bind to ACHE molecule and build up and stop the action
How does ATP supply energy for muscle contraction
ATP synthesizes as it decomposes and provides energy, cellular respiration makes it
How does creatine phosphate supply energy for muscle contraction
Creatine phosphate is the initial source of energy that is available to regenerate ATP from ADP and phosphate. It includes a high-energy phosphate bond. It is more abundant in muscle fibers than ATP, but it cannot directly supply energy to a sell. However, it stores energy released from mitochondria. When sufficient ATP is present, an enzyme in the mitochondria promotes the synthesis of creatine phosphate, which stores the excess energy in its phosphate bond
what substance in muscle seems able to store oxygen temperarily
The substance in muscle that is able to store oxygen temporarily is myoglobin
why is oxygen necessary for muscle contraction
Hemoglobin carries oxygen from the lungs in the blood. When it reaches the muscle, the oxygen is transferred from the hemoglobin to the myoglobin in the muscle fiber. Oxygen is necessary for muscle contraction because without it there would be no aerobic reactions of cellular respiration
what is meant by oxygen debt
it is when you are doing strenuous exercise and oxygen deficiency develops and lactic acid accumulates.
