Page 1 Anatomy and Physiology Study Guide for the HESI® exam

Anatomy and physiology are perhaps the most fundamental areas for a nurse to study. Anatomy is the area of study in between biology and medicine that considers the structure of the body. Physiology is the scientific study of how the body and its organs and cells work. Understanding the location of parts of the human body is critical. A nurse must understand how each part of the body works in order to deliver the best patient outcome. Simply knowing where the heart is located is not enough; you must understand how the heart works and how the other systems that depend on it work in conjunction.

Here is a basic review of the different systems of the body, their parts and function:


The endocrine system of the body is made up of glands that secrete hormones into the bloodstream. Through the circulatory system, these hormones travel to work on different target organs in other parts of the body. The hormones the endocrine system produces help regulate many different bodily functions, including growth and development, reproduction, metabolism, and stress response. The endocrine system is considered a “slow” system compared to others (such as the nervous system) in that its initiation and effects are often prolonged and may last hours or days.

Primary Endocrine Glands and Hormones

Hypothalamus ― dopamine, thyrotropin-releasing hormone (TRH)

Pituitary Gland:

Anterior lobe ― growth hormone, thyroid-stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), prolactin, follicle-stimulating hormone (FSH), luteinizing hormone

Posterior lobe ― oxytocin, vasopressin

Pineal Gland ― melatonin

Thyroid Gland ― triiodothyronine (T3), thyroxine (T4), calcitonin

Parathyroid Gland ― parathyroid hormone (PTH)

Adrenal Gland:

Medulla ― adrenaline, noradrenaline, dopamine

Cortex ― androgens, aldosterone, cortisol

Pancreas ― insulin, glucagon

Testes (males) ― testosterone

Ovaries (females) ― estrogen, progesterone

There are also “secondary” endocrine glands that are not considered endocrine glands but do have endocrine functions. They are the kidneys, bone, liver, gonads, and heart.

Problems with the Endocrine System

Problems can occur in the endocrine system at any point in the gland-circulatory system-target tissue loop.

The gland itself may secrete too much or too little hormone, which may cause a decreased or increased response in the body.

Circulatory issues may cause a delayed or diminished response if the hormones are not brought to the target organ as intended.

If the receptors on the organs are not fully functional, the organ may not be able to interpret and respond to the “message” the hormone is trying to send.

Common disease associated with endocrine dysfunction include diabetes, Addison’s Disease, Graves’ Disease, obesity, and osteoporosis.