A: The Integumentary system, also known as the skin, accounts for approximately 16% of the
human body. In the average adult, the skin alone weighs approximately 20 pounds. While this
system is also referred to as the skin, it is important to note that the hair, nails, and sweat and oil
glands are also included in this system. Within this system, particularly in the skin, lie sense organs
that allow a person to feel temperature, pain, and pressure. This main function of the
Integumentary system is to provide protection to the other organs and tissues in the body, as well
as to serve as temperature regulator and a means to synthesize various chemicals.
2. B: The Skeletal system is composed of 206 bones that provide the structure and support for the
human body. In addition to the bones, within this system are tissue, cartilage, and ligaments that
provide the connections and support for the bones themselves. Within the skeletal system, there
are two main parts, which include the axial skeleton and the appendicular skeleton. The Axial
skeleton includes the bones of the skull, the ribs, and the neck and spine. The appendicular skeleton
includes the bones in the shoulder, arm and hands, pelvis, legs, and feet. These two divisions of the
skeletal system are attached at the pectoral girdle, the group including the scapula and the clavicle.
3. D: The Muscular system is made up of three different muscle types including the smooth muscles,
cardiac muscles, and voluntary muscles. The smooth muscles also referred to as involuntary
muscles can be found in the colon, stomach, and eyes. These muscles work constantly and do not
require conscious thought to perform. Voluntary muscles also referred to as skeletal muscles, take
conscious effort in order to be put into action. These muscles are found on the skeleton and assist in
movement. Cardiac muscles are found in the heart and are involuntary.
4. C: The nervous system includes the brain, spinal cord, and the nerves. This system serves a
number of functions including communication from the brain to the body, control, and integration.
All processes completed by the nervous system are completed through nerve impulses that move
quickly through the body to the brain, relaying various messages. These messages will depend on
which stimuli are present. For example, if you touch something hot, the nerves in your hand will
relay a message to the brain based on the stimuli, the brain will process and response by sending
nerve impulses back to the hand, telling the hand that it is hot.
5. D: The Endocrine system functions much like the nervous system in that it communicates,
integrates, and controls. The way this system accomplishes these functions is by secreting
hormones throughout the body through a series of ducts and glands. Some of the main activities the
endocrine system controls and regulates include growth, metabolism, reproduction, etc. Glands
within this system are ductless and are located throughout the body. For examples, in the brain are
the pituitary gland and the hypothalamus, in the neck are the thyroid and the parathyroid glands,
the thymus gland in the thoracic cavity, and just below in the abdominal cavity are the adrenal
glands and the pancreas.