An Unconditioned Stimulus

question 78

Multiple Choice

An unconditioned stimulus:

• A) automatically triggers a physiological reflex
• B) requires conscious effort
• C) is paired with a conditioned response
• D) is acquired through practice

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Definitions:

Sarcomere Contraction

The process of muscle fibers shortening, caused by the sliding of actin and myosin filaments within the sarcomere, the fundamental unit of muscle contraction.

Myosin

ATP-dependent motor protein; makes up the thick filaments in a sarcomere.

Actin

A globular protein that forms filaments, which are vital components of the cytoskeleton in all eukaryotic cells, involved in cell movement and structure.

Cross Bridge

A myosin projection on a muscle cell that connects with actin to contract muscle fibers, fundamental in muscle contraction.