Acetylcholine
synaptic cleft, where neurotransmitters are released by the synaptic terminal and bind to receptors on the muscle fiber to trigger a muscle contraction.
Nicotien or anything chemical which stimulates the Nicotinic receptors.
Calcium ions
No, an egg is not released when a girl has an orgasm. Orgasms are part of the sexual response cycle and involve muscle contractions and release of tension, but they do not trigger the release of an egg from the ovaries.
Muscle contractions would be prevented, causing paralysis.
Sarcolema receptors
When the leg is straight, the muscle spindle receptors in the quadriceps muscle are not stretched enough to stimulate a reflex response. The reflex occurs when the muscle is quickly lengthened, activating the sensory receptors in the muscle and sending a signal to the spinal cord to trigger a reflexive contraction of the quadriceps muscle.
Isometric muscle contractions happen when the muscle stays the same length, concentric contractions occur when the muscle shortens, and eccentric contractions occur when the muscle lengthens.
acetylcholine as far as i know is a neurotransmitter that ativates the mscle cells.
Vesicare (solifenacin) works by blocking certain receptors in the bladder, called muscarinic receptors. By doing so, it reduces bladder muscle contractions and helps to control symptoms of overactive bladder, such as frequent urination, urgency, and incontinence.
Isotonic contractions involve muscle actions where the muscle length changes as it contracts against a constant load. There are two types: concentric contractions (shortening of the muscle during contraction) and eccentric contractions (lengthening of the muscle during contraction).
There are at lest 3 types of beta receptors and they are found in different organs. Beta-1 (β1) receptors are found in the heart, eye, and kidneys while beta (β2) receptors are found in the lungs, gastrointestinal tract, liver, uterus, blood vessels, and skeletal muscle. The third type, beta (β3) receptors are found in fat cells.