Muscle Types & Characteristics
Type of muscle found in the heart, limbs, head, and torso
What is striated muscle?
The area between two Z discs (or Z lines) i.e. the smallest unit of contraction.
What is a sarcomere?
This sends nerve signals to skeletal muscle
What is a motor neuron?
A motor neuron and the muscle fibers it innervates
What is a motor unit?
Type of muscle found in the respiratory, circulatory, excretory, and digestive systems
What is smooth muscle?
This occurs when myosin heads interact with actin filaments
What is the cross-bridge formation?
The type of tissue that wraps around whole muscle groups and muscle bundles
What is connective tissue? (Bonus points if they said epimysium and endomysium)
This depends on the number of motor units activated in each time frame
What is a muscle’s force output?
Muscle protein types found in striated and smooth muscle
What are actin & myosin?
The effect of ATP binding to myosin
What is the detachment of the myosin head from actin?
The neurotransmitter released by motor neurons at the motor endplate
What is acetylcholine?
This structure is apparent when looking at the cross-section of a myofibril, and the arrangement of actin and myosin (which helps illustrate why muscle fibers are so strong)
What is a hexagonal lattice?
Major characteristics of a striated muscle cell, or muscle fiber you could see using a microscope
What are multiple nuclei, hundreds of myofibrils, lots of mitochondria, innervated by efferent motor neurons?
The effect of ATP hydrolysis on myosin
What is the cocking back of myosin heads?
This causes troponin to interact with tropomyosin, exposing myosin-binding sites and triggering muscle contraction.
What is Ca2+ binding (Ca++ release from the sarcoplasmic reticulum)?
This conducts a depolarization into the muscle cell, where it affects the sarcoplasmic reticulum
What is a t-tubule?
Major components of a whole muscle, from smallest to largest or vice versa
What are myofibrils, muscle fibers or cells, muscle bundles, and muscles?
The effect of ADP + Pi releasing from myosin
What is the “power stroke” (the thin filament sliding relative to the thick filament under the action of myosin heads)?
This happens when acetylcholine is reabsorbed, Ca2+ is actively transported back to the sarcoplasmic reticulum, and tropomyosin again blocks myosin-binding sites
How does skeletal muscle relax?
This causes the release of calcium ions from the sarcoplasmic reticulum
What is the muscle cell firing an action potential?