Describe how the following would change if you were to extend your arm at the elbow (that is, stretch the biceps). a) the length of the muscle spindles in the biceps muscle
b) the firing of muscle-spindle afferents from the biceps muscle
c) the firing of alpha motor neurons that project to biceps muscle extrafusal fibers (assume you are trying to hold your arm in place.)

a. The biceps would relax causing it to increase in length

b. The firing of the muscle-spindle afferents from the biceps would decrease.

c. The alpha motor neurons would contract or decrease.

Explanation:

The skeletal joints in the human or animal body are controlled by muscles. Examples of these muscles are the biceps and triceps found in the human arm. They control the elbow joint with the biceps in front and triceps at the back of the elbow.

When the arm is extended from the elbow, the biceps relaxes or extends while the triceps contracts. This increases the length of the biceps and reduces the triceps length.

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.