Structure of Muscles

Question 1

Voluntary muscle

Answer 1

Skeletal (attached to bone) - controlled by voluntary nervous system. Move bones and joints. Fibres are multi-nucleate and striated. Contraction is quick and powerful but fatigues quickly.

Question 2

Involuntary muscle

Answer 2

Smooth (in blood vessels, iris of eye and gut) - controlled unconsciously by autonomic nervous system. Control diameter of arterioles/bronchi/pupil and peristalsis. Cells are unstriated and uninucleate. Contraction is slow but muscles tire slowly.

Question 3

Cardiac

Answer 3

Myogenic but can be speed up by sympathetic or slowed down by parasympathetic nervous systems. Striated, uninucleate and branched. Joined by intecalated discs. Contraction is quick and powerful and muscle doesn’t fatigue.