This unit is about human anatomy and physiology which is the study of structures that make up the body and how those structures relate with each other and physiology is the study of how the body and its part work or function.



The course human anatomy and physiology for nurses is designed to help student nurses learn and understand how the human body is organized and function. Equipping the student nurse with the knowledge of anatomy and physiology will further assist the student in understanding what happens and what to do when the body is injured, diseased or placed under stress. This teaching and learning material (lecture note) for nursing students at a diploma level is prepared in line with this concept.

Therefore, the students are expected to achieve the following general educational objectives after completion of the course:

What are Anatomy and Physiology?

Anatomy: the word anatomy is derived from a Greek word “Anatome” meaning to cut up. It is the study of structures that make up the body and how those structures relate with each other.

The study of anatomy includes many sub specialties. These are Gross anatomy, Microscopic anatomy, Developmental anatomy and Embryology.

Gross anatomy studies body structure with out microscope. Systemic anatomy studies functional relationships of organs within a system whereas Regional anatomy studies body part regionally. Both systemic and regional approaches may be used to study gross anatomy

Microscopic anatomy (Histology) requires the use of microscope to study tissues that form the various organs of the body.

Physiology: the word physiology derived from a Greek word for stud of nature. Itiurana

Hence, Anatomy and physiology are studied together to give students a full appreciation and understanding of human body.


When structure and function are coordinated the body achieves a relative stability of its internal environment called homeostasis / staying the same. Although the external environmental changes constantly, the internal environment of a healthy body remains the same with in normal limits.

Under normal conditions, homeostasis is maintained by adaptive mechanisms ranging from control center in the brain to chemical substances called hormones that are secreted by various organs directly into the blood streams. Some of the functions controlled by homeostasis mechanisms are blood pressure, body temperature, breathing and heart rate.

Level of structural organization of the body

The human body has different structural levels of organization, starting with atoms molecules and compounds and increasing in size and complexity to cells, tissues, organs and the systems that make up the complete organism.

Levels of structural organization of the body


Atoms molecules and compounds: – At its simplest level, the body is composed of atoms. The most common elements in living organism are carbon, hydrogen, oxygen, nitrogen phosphorus and sulfur.

Atoms → Molecule → Compounds.

Cell: The smallest independent units of life. All life depends on the many chemical activities of cells. Some of the basic functions of cell are: growth, metabolism, irritability and reproduction.

Tissue: tissue is made up of many similar cells that perform a specific function. The various tissues of the body are divided in to four groups. These are epithelial, connective, nervous and muscle tissue.

Epithelial tissue:Found in the outer layer of skin, lining of organs, blood and lymph vessels and body cavities. Connective tissue: – Connects and supports most part of the body. They constitute most part of skin, bone and tendons.

Muscle tissue: – Produces movement through its ability to contract. This constitutes skeletal, smooth and cardiac muscles.

Nerve tissue: – Found in the brain, spinal cord and nerves. It responds to various types of stimuli and transmits nerve impulses.

Organ: – Is an integrated collection of two or more kinds of tissue that works together to perform specific function. For example: Stomach is made of all type of tissues.

System: Is a group of organs that work together to perform major function.

For example: Respiratory system contains several organs.

Organism level: – The various organs of the body form the entire organism.

Anatomical Terminologies

The language of anatomy will probably be unfamiliar to you at first. But once you have understood the basic word roots, combining word forms, prefixes and suffix you will find that anatomical terminologies are not as difficult as you first imagined.

Anatomical Position.

Anatomical positions are universally accepted as the starting points for positional references to the body. In anatomical position the subject is standing erect and facing the observer, the feet are together, and the arms are hanging at the sides with the palms facing forward the body.

Relative directional terms of the body.



Relative Directional terms

Standardized terms of reference are used when anatomists describe the location of the body part. Relative means the location of one part of the body is always described in relation to another part of anatomy and physiology.


Body parts Regions

The body can generally be described to have areas of:

Axial body part: – It is the part of the body near the axis of the body. This includes head, neck, thorax (chest), abdomen, and pelvis.

Appendicular body part: – It is the part of the body out of the axis line. This includes the upper and lower extremities.

It is customary to subdivide the abdominal area into nine regions or more easily in to four quadrants.

Abdominal sub divisions


Body planes and sections

Body planes are imaginary surfaces or planes lines that divide the body in to sections. This helps for further identification of specific areas.

Sagittal plane:

divides the body into right and left half.

Mid sagittal plane: – divides body into equal left and right


– Para sagittal plane: – divides body into unequal left and right

Frontal plane: – divides the body into asymmetrical antererior and posterior sections.

Transverse plane: – divides the body into upper and lower body section.

Oblique plane: – divides the body obliquely into upper and lower section.

 Body planes


Body Cavities

The cavities of the body house the internal organs, which commonly referred to as the viscera. The two main body cavities are the larger ventral (anterior) and the smaller, dorsal (posterior) body cavity.

The ventral body cavity constitutes the thoracic cavity and the abdomino-pelvic body cavity.

The Thoracic cavity houses lung and heart. It is protected by the rib cage & associated musculature and the sternum anteriorly. It consists of the right and left pleural cavities and mediastinum (the portion of tissues and organs that separates the left and right lung).

Abdomino-pelvic Cavity extends from the diaphragm inferior to the floor of the pelvis. It is divided into superior abdominal and inferior pelvic cavity by imaginary line passing at upper pelvis.

Abdominal cavity contains the stomach, intestine, liver, spleen and gallbladder.

The pelvic cavity contains urinary bladder, rectum, and portions of the reproductive organs.

The dorsal body cavity: it constitutes the cephalic cavity containing brain and the vertebral canal containing the spinal cord.

Body cavities and membranes




SEE ALLAdd a note
Add your Comment