The Human Body

The remainder of our free online Medical Terminology course will seem a lot like anatomy and physiology.  Medical terms would have little meaning without putting them in proper perspective. If you’ve already taken our anatomy and physiology course, the rest of this course will serve as a refresher.

The human body is made up of different systems. There are different branches of science that study the human body.

Anatomy studies the composition of the human body and the relationships of its parts to each other.

Biology is the study of all living things.

Embryology studies the origin and development of life during the second to the 8th week after conception. The embryonic stage covers from week two to the end of week 8.

Histology studies the microscopic parts of the body.  These include the cells, tissue, and organs.

Pathology studies changes caused to the structures of the body by disease.

Physiology studies the normal activity and functions of the human body.

An organ is formed when two or more types of tissue work together to perform a specific function. The largest organ in the human body is the skin.  We know, we know.  Skin isn’t technically in the body but we didn’t write the rules. Skin is an organ.  The liver is an organ.  These two organs work independently of each other. A system is formed when several organs join together to perform a body function.

The chart below explains some of the major systems in the human body.

Major Systems of the Human Body
Cardiovascular System This system includes the heart and blood vessels that carry the blood throughout the human body
Endocrine System This system is made up of glands that manufacture and distribute hormones.
Gastrointestinal or Digestive System This system includes the mouth, esophagus, stomach, small intestines, and large intestines. This system digests and absorbs food, and excretes waste.
Integumentary System This system includes the skin, hair, nails, sweat glands, and oil glands.
Lymphatic System This system works in conjunction with the cardiovascular system to protect the body against diseases.
Musculoskeletal System This system includes  the bones, muscles, ligaments, and tendons that provide the frame of the body.
Reproductive System This system includes the male and female organs that provide for reproduction.
Respiratory System This system includes the lungs, bronchi, and trachea.
Sensory or Special Senses System This system includes the eyes, nose, ears, and mouth along with the nervous system composed of the brain and the spinal cord.
Urinary System This system produces and excretes urine.

In addition to the individual systems, the human body contains five cavities. These cavities help protect organs and other parts of the various systems. The chart below shows the five cavities of the body and lists the major functions associated with each cavity.

Cavities of the Human Body
Abdominal Cavity This cavity contains the stomach, liver, intestines, spleen, kidneys,  gallbladder, ureters, and pancreas.
Cranial Cavity This cavity contains the brain.
Pelvis Cavity In the female this cavity contains the urinary bladder, urethra, uterus and vagina. In both males and females, it also contains the large intestine and the rectum.
Spinal Cavity This cavity consists of the spinal column.
Thoracic or Chest Cavity This cavity contains the heart, lungs, esophagus, trachea, and aorta.

The table below lists some root words associated with the body structure and organization.

Root Words of Human Body Structure and Organization
Cyt/o cell
Epitheli/o epithelium
Fibr/o fibrous
Hist/o tissue
Lip/o fat
Myo muscle
Neur/o nerve
Organ/o organ
Viscer/o internal organs

The table below lists some of the suffixes associated with the body structure and organization.

Suffixes Associated With Body Structure and Organization
-cyte cell
-gen agent that causes (for example a disease)
-genic producing
-ologist person who studies or practices a certain field
-oma tumor or swelling
-osis abnormal condition
-pathy disease
-plasm formation or growth
-sarcoma malignant tumor