Final answer:
Neuromuscular irritability and repetitive muscle spasms can be caused by hypocalcemia, which is characterized by abnormally low levels of calcium. Hypocalcemia can affect various body systems and its symptoms range from muscle twitching to paralysis with potential fatal consequences.
Step-by-step explanation:
Neuromuscular irritability and repetitive muscle spasms can be caused by abnormally low levels of calcium, known as hypocalcemia. When blood calcium levels are low, membrane permeability to sodium increases, which can result in muscle twitching, cramping, spasms, or convulsions. Severe deficits can paralyze muscles, including those involved in breathing, and can be fatal. Hypocalcemia can have an adverse effect on various body systems, including circulation, muscles, nerves, and bone.