The only type of muscle tissue that can be controlled voluntarily is skeletal muscle tissue. Both skeletal and cardiac muscle tissue have the sarcomere as the functional unit, and only skeletal muscle has multinucleated cells. Smooth muscle does not have troponin, and therefore does not require calcium in order to contract.

The first requirement of this question is that the muscle type be striated. Striated muscle can be identified by the presence of alternating dark and light bands, caused by the repetition of sarcomeres, the basic muscle units composed of actin and myosin. Both cardiac and skeletal muscle types are striated.

The second requirement is that the muscle type must be multinucleate, meaning that individual cells have fused to form larger units with more than one nucleus. The only muscles with multinucleate cells are skeletal muscles, so that is our solution.

Cardiac muscle and skeletal muscle are both composed of sarcomeres. This layout gives both muscle types a striated appearance, alternating dark bands of myosin with lighter bands of actin. Only cardiac muscle has intercalated discs and skeletal muscle is the only type that is multinucleated. No muscle type is attached directly to bone, but skeletal muscle is linked to bone via tendons.

Cardiac muscle is organized into sarcomeres, giving it a striated appearance, and cardiac contraction is strongly dependent on calcium concentrations and release. While the heart is capable of beating without nervous innervation, autonomic regulation via the parasympathetic nervous system mediates the frequency of cardiac stimulation from the sinoatrial (SA) node.

Signals from the parasympathetic nervous system travel to the cardiac muscle via chemical synapses, by use of a neurotransmitter. Signals from one cardiac fiber to another are transmitted via electrical synapses, or gap junctions, the allow proliferation of the signal without a chemical intermediate.

Smooth muscle is involuntarily controlled, and is used to regulate the autonomic functions in the body. When stimulated by the sympathetic nervous system, contracting smooth muscle cells will shrink the diameter of arterioles and arteries, causing vasoconstriction.

Both cardiac and skeletal muscle is striated, however, cardiac muscle is mononucleated, whereas skeletal muscle in multinucleated. Smooth muscle is not striated. The student is observing muscle that is both striated and mononucleated, meaning it must be cardiac muscle.

Smooth muscle: mononucleated with no striations

Skeletal muscle: multinucleated with striations

Cardiac muscle: mononucleated with striations

All muscle types play some role in helping to move blood through the body. The heart actively pumps blood through the circulatory system. Smooth muscle in the arteries and arterioles works to constrict or dilate various shunts and pathways to direct blood flow. Skeletal muscle contractions alter the shape of the muscle, pushing blood in various directions to affect its flow.

You can test this principle by making a tight fist with one hand; when you release the fist, look at the color of your palm compared to your hand that remained open. The hand that made a fist pushed blood away from the surface due to the change in shape, causing your palm to look white.

White fibers have less myoglobin than red fibers. White fibers have less mitochondria than red fibers. White fibers fatigue more quickly than red fibers. 

White fibers primarily use anaerobic respiration (red primarily uses aerobic). Remember that red fibers are active over long periods of sustained stress, while white fibers are more explosive. Red fibers require oxygen from respiration and myoglobin to maintain activity.

The two main types of muscle fibers are red and white fibers. Also known as slow twitch and fast twitch fibers, respectively, red fibers are used for high endurance activities, such as long distance running, while white fibers are used for quick movements, such as jumping. We expect red fibers to have more mitochondria and myoglobin, as these are essential to extended aerobic respiration and fatigue prevention.

Type I muscle cells, or red muscle cells, use aerobic respiration, whereas type II muscle cells, or white muscle cells, use anaerobic respiration. Aerobic respiration requires oxygen; therefore, myoglobin must be present to carry oxygen within type I muscle cells. Aerobic respiration occurs in mitochondria. This means that type I cells must have more mitochondria and myoglobin to facilitate aerobic respiration.

Calcium ions from the sarcoplasmic reticulum are essential for muscle contraction, and are found in equal amounts in both cell types.