Muscles

Cardiac muscle is not voluntary.

This muscle (part of the pelvic floor) has two parts to its name: origin is on the pubis (pubic bone); insertion is to the coccyx. Choice B is named “whimsically”, choice C is named according to location and direction of muscle fibres and choice D is named according to location and appearance.

Troponin causes tropomyosin (which covers the binding site of actin) to be shifted away.

Smooth muscle is not striated, and it is involuntary and has one nucleus.

“Costa” refers to rib. There are internal intercostal muscles, so the external intercostals are more superficial. The muscles in choices B and C lie on the femur and radius bones, respectively.

Aerobic means that oxygen must be an input. Respiration must result in energy being produced, hence D.

The term “carpi” refers to the carpal bone (the eight bones of the wrist), so this muscle extends the wrist.

“Extensor” refers to the action of extension (increasing the angle between the hand and fingers), while “digitorum” refers to the digits (fingers).

The hamstrings are in the thigh. “Femoris” refers to the femur bone. Biceps femoris is one of the three hamstring muscles. Choices A and C are on the arm (from “brachii”).

The origin is on the sternum and clavicle (sternocleido-), while the insertion (on the “moving bone”) is to the mastoid process of the temporal bone.