Muscles for Movement and so Much More Quiz

Answer:

There are basically three types of muscle in the human body: striated (or skeletal) muscle, smooth muscle and cardiac muscle. Striated muscle is under voluntary control, whereas smooth muscle and cardiac muscle are not. Smooth muscle contraction is under the control of the autonomic nervous system, hormones, and intrinsic factors in the organ where it is located. Cardiac muscle is found exclusively in the heart, where it makes up the thick middle layer of the heart (myocardium). It is under the control of the autonomic nervous system.

Sartorius, sternocleidomastoid, masseter, tongue and diaphragm are all examples of striated muscle. Sartorius is the longest muscle in the body, spanning both the hip and knee joints. Masseter is a muscle of mastication and is considered the strongest muscle in the body. The tongue is actually more than one muscle and is unique in that it is only attached to bone (hyoid) at one end. The diaphragm is the major muscle of respiration. It contracts rhythmically and involuntarily in response to signals from the brain, which are in turn controlled by CO2 levels, but it can also be controlled voluntarily, as in holding your breath or changing the speed of your breathing. Sternocleidomastoid (also called sternomastoid) is a neck muscle.

The iris, urinary bladder, gall bladder, oesophagus and uterus are all organs containing smooth muscle. The cremaster muscle is composed of thin layers of striated and smooth muscle located in the inguinal canal and scrotum of the human male. It is responsible for the cremasteric reflex that raises and lowers the testicles. The iris is a sphincter muscle in the coloured part of the eye that regulates the amount of light let in by the the pupil. It reacts to the ambient level of brightness and is controlled by the parasympathetic nervous system. The urinary bladder, gall bladder, oesophagus and uterus are all important muscular structures not under voluntary control.

The red herrings are all bones. Stapes is an ossicle in the ear; hyoid (already mentioned above) attaches to the tongue; navicular is a wedge-shaped bone in the midfoot that articulates with five tarsal bones; pisiform is a sesamoid bone (located within a tendon) in the wrist; trapezoid (not to be confused with trapezius, which is a muscle in the back) is a quadrilateral-shaped bone in the wrist.