NCLEX-RN

This content has been developed to support nursing students preparing for the National Council Licensing Examination for Registered Nurses (NCLEX-RN). Videos and questions will be added to this collection throughout the summer and fall of 2014. All of this content has been created under the direction of Khan Academy and has been reviewed under the direction of the the American Association of Colleges of Nursing (AACN). This content is intended to be a supplemental resource for nursing graduates, not a program of study for the NCLEX-RN exam. The NCLEX-RN is administered by the National Council of State Boards of Nursing (NCSBN). For more information on the NCLEX-RN, visit: https://www.ncsbn.org/nclex.htm
Community Questions

NCLEX-RN practice questions

A collection of questions from content covered on the NCLEX-RN.

Circulatory system physiology

Your heart sits in the middle of your chest and pumps blood from about 4 weeks after conception until the day that you die. It never stops, and over your lifetime it will pump ~175 million liters of blood. To visualize that, imagine the amount of water that falls over Niagara falls in a few minutes. Remarkable! This little pump is the size of your clenched fist and in an adult can weigh about 300 grams. Watch these videos to learn more about how the heart works, blood flow in arteries and veins, blood pressure, and lymphatics.

Circulatory system diseases

With the heart pumping 24 hours a day, 7 days a week, it’s absolutely vital to make sure things are flowing smoothly (pun intended!). Unfortunately, this isn’t always the case, and different parts of the circulatory system can cause problems: your heart, your blood vessels, and even the fluid in your tissues and blood itself can be the issue. To further complicate things, the underlying reasons for circulatory system problems vary from your genes (nature) to your lifestyle habits (nurture). An understanding of how different diseases can affect your circulatory system is important to combat this growing problem in the world.

Respiratory system physiology

Place your hand on your ribs and inhale deeply. You’ll notice that your chest expands and your back straightens. As this occurs, air is rushing through your windpipe and branches off to either your left or right lung. After 20 to 30 more branch points, oxygen in the air ends up in the alveoli where it diffuses into the liquid that surrounds the alveoli, and slips into the blood. This microscopic gas exchange occurs rapidly, oxygen is taken into the body and carbon dioxide is removed from the body, and then you exhale. Learn more about the intricate and fascinating respiratory system in these videos!

Respiratory system diseases

Our lungs are composed of a bronchial tree (think of an upside down tree with millions of leaves), blood vessels bringing blood in and out, and a protein-rich fluid that forms a matrix holding everything together! If any part of this well-balanced organ isn’t working properly, a person can be left feeling short of breath. The lungs are also exposed to the outside environment, making them prone to infections. To counter infections, the lungs are lined with cells that have tiny protein bristles which wave back and forth and can literally sweep away dangerous bacteria. Learn more about diseases of the lungs and how modern medicine helps to keep them healthy!

Hematologic system diseases

Blood is incredibly important in combating disease and the healing process after an injury. It acts as a highway for medicine, stops bleeding, fights infections, controls cells from multiplying too fast, and so much more. But things can go wrong with blood too! What if your blood couldn’t clot and stop you from bleeding, or started to clot uncontrollably? What if your red blood cells or white blood cells suddenly disappeared? Blood contains many different types of tissues doing very different jobs, making diseases of the blood produce a variety of symptoms, including continuously feeling tired and bone pain. Learn about the different blood diseases, how they are diagnosed, and the cool ways health professionals treat these conditions.

Endocrine system physiology

When you’re nervous before an important speech, or asking someone out on a date, you might feel butterflies in your stomach. This is actually the result of your endocrine system releasing hormones! You can’t really point to any single organ as “the endocrine system”, because it’s actually a family of glands that secrete hormones into the body. Hormones seep into the blood (imagine putting a tea bag into hot water), and as the blood flows around the body, it carries with it these important hormone molecules that interact with specific target cells and organs. This signaling system helps to keep the entire body well-balanced and on the same page.

Endocrine system diseases

Lymphatic system physiology

Your heart pumps roughly 20 L of blood throughout the day to your tissues. The plasma component of blood (not containing blood cells) leaks out through capillaries (the tiniest of blood vessels) and is mostly reabsorbed. However, about 3L of the plasma is left behind in fluid surrounding tissues, and it is the job of the hard-working lymphatic system to bring back this fluid to the circulatory system. The lymphatic system moves fluid in one direction, but without the force of a pump like the heart.

Immune system physiology

Chances are, you’ve had a fever or a cough at least once in your life (unless you live in a bubble, in which case you should probably go out more!) Have you ever wondered why your body reacts this way? Your body has a deadly arsenal of weapons against microbial invaders, ranging from bacteria and viruses to protozoans and fungi. We have specialized cells that destroy foreign bodies through mechanisms such as consumption, expulsion, and degradation. You will become acquainted with the interplay of the numerous soldiers in your body’s army and how they keep you healthy!

Renal system physiology

If you want to learn more about the renal system, then urine the right place! (Pun aside, the kidneys are about more than just making urine). Every thirty minutes, your kidneys filter the entire blood supply in your body. Imagine a dirty pool filled with algae. Placing a filter in this pool will cause the algae to be flushed out, and after a time you’ll have a clean, crisp blue pool to enjoy. Just like the filter for a pool, our kidneys filter the blood and remove toxic wastes. These paired organs are key to maintaining electrolyte and water homeostasis in your body.

Gastrointestinal system physiology

Do you live to eat, or eat to live? Folks fall on both sides of this question, but who can deny the powerful role that food and water play in our everyday lives. If we were cars, food and water would be the gasoline. Eating keeps us moving, laughing, playing, and learning. The energy from food is carefully extracted through a process of ingestion, digestion, and absorption, and requires one long (very long!) tube with a couple of key organs (liver, pancreas) sprouting off of it. Go ahead and grab a bite to eat before we get started…

Muscular-skeletal system physiology

How do our muscles work? When we decide to kick a ball or shake a leg, how do we get our bodies to do that? Which muscles do we control? Which muscles control us? Learn how our muscles work at the smallest, most cellular level. Then see how nature scales up those microscopic processes into a kick or a dance move. Finally, learn how our brain tells muscle to contract and how that helps us respond to changes in temperature or even a lion chasing us.

Muscular-skeletal diseases

Nervous system physiology

3A: The very fact that you are able to understand this sentence means that neurons in your brain (85 billion in total) are talking to each other. Neurons are the living substance of the nervous system, which extends beyond the brain to the spinal cord and peripherally, allows you to think and process, make decisions, stand up straight, maintain your heart rate, rest and digest. You will come to appreciate the structure and function of the nervous system as we delve into its anatomy and physiology, from the gray and white matter to the cerebellum to the neurons.

Nervous system diseases

Integumentary system physiology

3B: There is really more than meets the eye with skin. Yes, it does make us look nicer than a bag of bones, muscles, and organs. But it also serves other important purposes which range from guarding the body against infection to sensation to allowing for metabolism of vitamin D. We will explore the structure and function of skin from the macroscopic to the microscopic level in this tutorial.

Reproductive system physiology

Renal system physiology

If you want to learn more about the renal system, then urine the right place! (Pun aside, the kidneys are about more than just making urine). Every thirty minutes, your kidneys filter the entire blood supply in your body. Imagine a dirty pool filled with algae. Placing a filter in this pool will cause the algae to be flushed out, and after a time you’ll have a clean, crisp blue pool to enjoy. Just like the filter for a pool, our kidneys filter the blood and remove toxic wastes. These paired organs are key to maintaining electrolyte and water homeostasis in your body.
Community Questions
All content in “Renal system physiology”

Renal system introduction

3B: If you want to learn more about the renal system, then urine the right place! (Pun aside, the kidneys are about more than just making urine). Every thirty minutes, your kidneys filter the entire blood supply in your body. Imagine a dirty pool filled with algae. Placing a filter in this pool will cause the algae to be flushed out, and after a time you’ll have a clean, crisp blue pool to enjoy. Just like the filter for a pool, our kidneys filter the blood and remove toxic wastes. These paired organs are key to maintaining electrolyte and water homeostasis in your body.

Renal regulation of blood pressure

In addition to fluid and electrolyte balance, the kidneys play an essential role in regulating blood pressure. When the nephron, the functional unit of the kidney, senses that it is not receiving much blood flow, it knows something is up. So begins a cascade which allows the nephron to reabsorb more fluid from the urine, in attempt to fill up the perceived dip in blood volume. Here you will learn the mechanism of ADH and the renin-angiotensin-aldosterone system in sustaining this homeostasis.