Cardiac muscle cells are involuntarily controlled: we cannot consciously control how fast our heart beats. The muscle cells are composed of aligned sarcomeres, so they appear striated, or striped. They have intercalated discs, which allow action potentials to spread between muscle cells in the heart.

Cardiac muscle cells are not multinucleated; skeletal muscle cells, however, do have multiple nuclei.

There are three types of muscle tissue. Cardiac muscle is found in the heart, smooth muscle surrounds organs and blood vessels, and skeletal muscle is used to move the skeleton and body.

During periods of heavy exercise, it is the cardiac muscle and skeletal muscles that get worked out. Cardiac muscle is strengthened because it has to pump more oxygenated blood to the body, while skeletal muscles are the muscles we move in order to exercise.

Smooth muscle is not directly related to exercise.

Skeletal muscle is a form of striated muscle under the control of the somatic nervous system (voluntary control). Skeletal muscle is striated and contains multiple nuclei.

Smooth muscle is a component of the inner lining of different organs and blood vessels. Smooth muscle is not striated and is mononucleated.

Cardiac muscle is the muscle that allows the heart to contract, thereby pumping blood throughout the body. Cardiac muscle is striated and mononucleated.

This is the correct order because in every muscle fiber there are many myofibrils, and in every myofibril there are many myofilaments. The two main myofilaments are the proteins actin and myosin. 

The three types of muscle tissues are: skeletal, cardiac, and smooth. Epithelial tissue is another of the four tissues found in animals, and is responsible for lining body cavities, forming glands, and covering the body (skin). The two other basic animal tissue types are connective, and nervous.

Besides moving the body, muscles are also used to provide heat and stabilize the body. Certain muscles are constantly being stimulated to help maintain posture and stability, even when we are unaware of their action. When body temperature is low, muscles can contract to produce body heat. This is why we shiver when we are cold.

Though some calcium is stored in muscle cell, calcium storage and regulation is primarily accomplished by the skeletal system. Hormones are released to directly influence calcium release or uptake in bone.

There are two types of cells responsible for myelinating axons in the nervous system: oligodendrocytes and Schwann cells. They only differ by the division of the nervous system in which they are found. Oligodendrocytes myelinate axons in the central nervous system, while Schwann cells myelinate axons in the peripheral nervous system.

Ependymal cells and astrocytes are other types of neuroglia. Ependymal cells secrete cerebrospinal fluid (CSF) into the central nervous system. Astrocytes play a key role in creating the blood-brain barrier in the central nervous system.

The cerebrum is the portion of the brain above the middle of the brain, or diencephalon. The thalamus is a part of the diencephalon, and it is intimately associated with motor behaviors, such as walking or flying (in birds). The cerebrum is divides into four lobes based on location and function. The frontal lobe contains the motor cortex and pre-frontal cortex, as well as Broca's area. It is associated with thought and higher brain function. The parietal lobe contains the sensory cortex and processes tactile input. The temporal lobe contains the hippocampus and auditory cortex. The occipital lobe contains the visual cortex.

Nervous tissue contains a variety of support cells in order to preserve the neurons in the brain, known as glial cells. Microglia are similar to monocytes, a type of white blood cell. They are used to remove debris and pathogens from the central nervous system.

Schwann cells, oligodendrocytes, and astrocytes are all part of the neural glia. Schwann cells produce myelin around the axons of neurons in the peripheral nervous system, while oligodendrocytes produce myelin for the axons of neurons in the central nervous system. Astrocytes around found in the central nervous system and help create the blood-brain barrier.

Sensory neurons respond to stimuli, such as pain. Association neurons receive signals from the sensory neurons and, on the basis of that input, activate motor neurons. Motor neurons activate muscles or glands. Effectors are the muscles or glands that perform the response directed by the nervous system.

Connective tissue consists of bone, cartilage, blood, and fat and is not involved in this process. Connective neurons is a misnomer. Interneurons, however, can be used to relay signals between sensory and motor neurons in the spinal cord.