Looking for more information on this topic? Check out the Emergent Hypertension brick. If you enjoyed this episode, we’d love for you to leave a review on Apple Podcasts . It helps with our visibility, and the more med students (or future med students) listen to the podcast, the more we can provide to the future physicians of the world. Follow USMLE-Rx at: Facebook: www.facebook.com/usmlerx Blog: www.firstaidteam.com Twitter: https://twitter.com/firstaidteam Instagram: https://www.instagram.com/...
Jun 10, 20250
Glucose is the main source of energy for all forms of life, but it isn’t usually stored as individual C6H12O6 molecules. Animals use glycogen to do that job. Glycogen is a large branched polymer of glucose molecules, linked together by α-1,4 and α-1,6 glycosidic bonds. The liver and muscles break down the stored glycogen whenever the body needs an extra boost of glucose. Glycogen storage diseases are genetic defects in glycogen metabolism resulting in accumulation of glycogen. What happens when ...
Mar 04, 2025•21 min
Looking for more information on this topic? Check out the Acid-Base Disorders: Putting it all Together brick. If you enjoyed this episode, we’d love for you to leave a review on Apple Podcasts . It helps with our visibility, and the more med students (or future med students) listen to the podcast, the more we can provide to the future physicians of the world. Follow USMLE-Rx at: Facebook: www.facebook.com/usmlerx Blog: www.firstaidteam.com Twitter: https://twitter.com/firstaidteam Twitter: https...
Feb 25, 2025•37 min
Looking for more information on this topic? Check out the Adrenal Insufficiency brick. If you enjoyed this episode, we’d love for you to leave a review on Apple Podcasts . It helps with our visibility, and the more med students (or future med students) listen to the podcast, the more we can provide to the future physicians of the world. Follow USMLE-Rx at: Facebook: www.facebook.com/usmlerx Blog: www.firstaidteam.com Twitter: https://twitter.com/firstaidteam Instagram: https://www.instagram.com/...
Feb 18, 2025•25 min
Early in fetal development, the precursors of the major systems in the body are outlined. The three germ layers (endoderm, mesoderm, ectoderm) are formed during the third week of development. We’ll focus on the ectoderm, from which the entire nervous system (central and peripheral) forms. But first, let’s back up to review the anatomy of the central nervous system (CNS) and peripheral nervous system (PNS) so that we know what the end products of their development are. The CNS comprises the brain...
Jan 07, 2025•21 min
Differences in ion concentrations inside and outside a cell cause a difference in the charge of the intracellular and extracellular environments. This electrical polarization of a cell relative to its environment is referred to as cellular membrane potential. This potential serves as an energy source for a variety of cellular functions and as a way for excitable cells like muscle cells and neurons to communicate their signals. A cell controls its membrane potential by regulating the concentratio...
Dec 10, 2024•30 min
What are bullous skin disorders? Bullae are fluid-filled blisters >1 cm in diameter. They can be caused by infection, mechanical stress, or a malfunctioning immune system. In this discussion, we tackle the latter, focusing on the most common autoimmune bullous (blistering) disorders: pemphigus vulgaris, bullous pemphigoid, and dermatitis herpetiformis. Distinctly, the blisters in each of these disorders involve different layers of the skin and autoantibodies against different proteins. After ...
Dec 03, 2024•25 min
A macrovascular complication of diabetes, diabetic nephropathy is progressive, chronic kidney disease seen in patients with both type 1 and type 2 diabetes mellitus, usually after at least 10 years of hyperglycemia (high blood glucose levels). The three main lesions that are seen in the kidney in patients with diabetes are glomerular lesions, vascular lesions, and pyelonephritis. This brick will focus primarily on the first two of these three lesions; diabetic pyelonephritis is covered in a sepa...
Nov 26, 2024•20 min
It might not be the flashiest anatomical structure, but if you want to stand upright, and keep your retroperitoneal organs (like your kidneys) in place, the posterior abdominal wall is pretty important. Located at the back of the body, bounded by the lateral abdominal walls and the posterior parietal peritoneum, the posterior abdominal wall is a complex combination of muscles, bones, nerves, and vessels that provides structural support for the body and for the organs of the retroperitoneal space...
Nov 12, 2024•26 min
Epithelium is one of the four basic tissue types (the other three are muscle tissue, nerve tissue, and connective tissue). It is found throughout the body—covering it; lining organs, vessels, and cavities; and forming glands. It absorbs nutrients, transports electrolytes, secretes hormones, and regulates body temperature by producing sweat. We begin with some general principles of how epithelial tissue is organized, and then we describe its various components. After listening to this AudioBrick,...
Oct 22, 2024•39 min
What do you know about prokaryote structure and the gram stain? Bacteria are members of a unique taxonomic kingdom consisting of prokaryotic unicellular organisms. Prokaryote is a term from ancient Greek meaning “before the kernel.” The kernel in this case is a nucleus, which prokaryotes lack. Prokaryotes also do not have any membrane-bound organelles. In fact, many of the organelles found in eukaryotes—like an endoplasmic reticulum, mitochondria, Golgi apparatus, lysosomes, and peroxisomes—are ...
Oct 08, 2024•35 min
What Is Global Health? In our increasingly interconnected world, health challenges transcend national boundaries and demand global solutions. Global health is an interdisciplinary field of study and practice that seeks to improve the health and well-being of populations worldwide, focusing on the health challenges that require global and national action in every country. It encompasses epidemiology, public health, medicine, environmental health, anthropology, sociology, health policy, and econom...
Sep 10, 2024•27 min
How do we survive in a complex environment filled with harmful organisms that thrive on colonizing us? Our heroic defender is the immune system, a network of organs and cell lines that exist with the mission of protecting the body from harm. While we often recognize the pathogen-fighting capabilities of the system, we can sometimes forget that the immune system is also crucial in ensuring the body is kept safe from itself, as in when our cells transform into cancer cells. On the dark side, somet...
Sep 03, 2024•27 min
In the fed state, glucose is used by almost all the cells in the body to generate energy. But even when we are not fueling it with food, our bodies still run well, such as during sleep. Gluconeogenesis is the process of synthesizing glucose from noncarbohydrate precursors. The major substrates (substances that enzymes act on) are the glucogenic amino acids, lactate, glycerol, and propionate. The liver and kidneys are the major sites where gluconeogenesis occurs; the kidneys may contribute up to ...
Aug 27, 2024•28 min
When you hear the word blood, what do you picture in your mind? Most likely, your brain conjures up an image of thick, red liquid. But what would blood look like if you removed all the red cells? You’d be left with a murky yellowish liquid that would clear up once you removed the white cells and platelets. This lovely, clear, straw-yellow, liquid portion of blood is known as plasma. So let’s talk about plasma composition. After listening to this AudioBrick, you should be able to: Define blood pl...
Aug 20, 2024•17 min
Hemophilia is a bleeding disorder resulting from defects in factors of the coagulation cascade. There are two primary types of hemophilia: A and B. Both types of hemophilia are rare, with only a combined frequency of about 1 in 5000 live births. Of the two types, hemophilia A is about four times more common. In the intrinsic arm of the coagulation cascade, factor VIII serves as a cofactor for factor IX. They cooperate to activate factor X, leading to the formation of fibrin. After listening to t...
Aug 13, 2024•15 min
Pain is a sensation that warns of potential injury and alerts the person to avoid or treat it. For example, if you touch a hot object, you will feel pain and immediately remove your hand from that object, protecting your hand from further damage. As much as pain can burden and torment, ultimately it is an essential part of our bodies’ mechanisms of self-preservation. Pain can be mild or severe, constant or intermittent, sharp or dull. Sometimes it can even be hard to describe the uncomfortable s...
Jul 16, 2024•23 min
As we eat, our gastrointestinal (GI) system releases a host of both local and distant regulators to control the process of digestion. We will begin with the primary hormones, then cover some of the secondary hormones, and lastly discuss how our body senses its intraluminal contents and then subsequently integrates all of the various stimuli it receives. After listening to this AudioBrick, you should be able to: Identify the location, cell type, release stimulus to the endocrine cells, and functi...
Jul 09, 2024•29 min
Headaches are an unavoidable fact of life and often are nothing more than the result of sitting through one too many lectures. However, they can become debilitating and get in the way of daily life, especially when they become recurrent. Although some headaches have symptoms other than head pain, we typically think of headache pain relative to its location, how intense it is, and how long it lasts. After listening to this AudioBrick, you should be able to: Compare and contrast the clinical featu...
Jul 02, 2024•28 min
he ductus arteriosus (DA) is a structure that allows blood pumped from the right side of the heart to bypass the lungs while the fetus is developing in utero. Normally, the DA closes shortly after birth and becomes the ligamentum arteriosum. When the DA fails to close (remains open, or patent) after birth, it is known as patent ductus arteriosus (PDA). This acyanotic congenital heart defect causes abnormal blood flow from the left to the right side of the heart and can lead to heart failure and ...
Jun 19, 2024•20 min
In typical reproductive system development, recall that the intermediate mesoderm forms the mesonephric (Wolffian) and paramesonephric (Müllerian) ducts and the indifferent gonads; primitive germ cells migrate into the indifferent gonads. These are the structures that become the internal organs of the reproductive systems. After listening to this AudioBrick, you should be able to: Describe the normal development of male and female reproductive systems. Compare and contrast anomalies of the uteru...
Jun 11, 2024•28 min
Substance use disorder (SUD) refers to a pattern of substance use—be it nicotine, cannabis, cocaine, or something else—that causes significant impairment or distress to the user. SUD is prevalent and growing in the United States and around the world. People of any age may be at risk for developing a substance use disorder. But exposure to and experimentation with alcohol and drugs usually begins in early adolescence. Many adolescents experiment with substances and then taper down or stop using t...
Jun 04, 2024•21 min
Stimulant medications are drugs that increase alertness and attention. They also elevate heart rate, blood pressure, and respiratory rate. Stimulants are used to treat many conditions, including attention-deficit/hyperactivity disorder (ADHD), chronic lethargy, narcolepsy, and obesity. Examples of stimulants include caffeine, amphetamines (such as dextroamphetamine), methylphenidate, and modafinil. Cognitive-enhancing drugs serve a similar purpose, increasing memory, alertness, and attention. Th...
May 21, 2024•15 min
If you’ve studied the hematopoietic system malignancies—all the leukemias, lymphomas, and plasma cell disorders—you probably feel like you’ve been hit with the good old medical school fire hose. Now’s a good time to take a step back from all the details, make sure that you remember the underlying framework, and pull together some information that connects several different diseases. In this brick, we’ll revisit some of the hematopoietic diseases that we often talk about in pairs: acute vs chroni...
May 14, 2024•21 min
Substance use disorder (SUD) refers to a pattern of substance use—be it nicotine, cannabis, cocaine, or something else—that causes significant impairment or distress to the user. SUD is prevalent and growing in the United States and around the world. People of any age may be at risk for developing a substance use disorder. But exposure to and experimentation with alcohol and drugs usually begins in early adolescence. Many adolescents experiment with substances and then taper down or stop using t...
May 07, 2024•21 min
Megaloblast. Now there’s a word you don’t hear every day. The root -blast (from the Greek blastos , meaning germ or bud) may be somewhat familiar since we talk about blast cells (very young hematopoietic precursor cells) in hematology. And megalo- (from the Greek megas , meaning large or great) is also used fairly frequently, as in splenomegaly (enlargement of the spleen). So does “megaloblast” just mean a large, immature cell? We’ll answer this question, and many more, in this discussion of meg...
Apr 30, 2024•25 min
Blood glucose is proof that you can have too much of a good thing. While glucose serves a critical role as fuel for many of our bodily functions, it must remain in a very tightly controlled range. If the level goes too low, you can fall into a coma. If glucose is too high, damage to tissues throughout the body can occur. When blood glucose is consistently too high and the mechanisms that return it to the normal range fail, this is called diabetes mellitus. Nearly 10% of the US population has a f...
Apr 23, 2024•26 min
Gallstones are the hardened precipitates—“stones”—of the substrates found in bile. The liver makes bile to help digest fats, and the bile is stored in the gallbladder. When there is an excess of a particular substance in the bile (eg, cholesterol or unconjugated bilirubin), gallstones form in the gallbladder. Gallstones can be as small as a grain of sand, as large as a golf ball, or any size in between. Gallstones are very common and usually do not cause any symptoms. But not all gallstones stay...
Apr 16, 2024•29 min
Normal blood pressure keeps us alive. It’s the force that moves blood throughout our circulatory system, ensuring that oxygen and nutrients reach our organs and tissues and that waste products are eliminated. When we hear the word hypertension—high blood pressure—we know this describes the blood flow exerting too much force against blood vessel walls. Pulmonary hypertension describes high blood pressure in the vessels of the lung. Specifically, pulmonary hypertension is an elevated mean arterial...
Apr 09, 2024•20 min
Macroscopic Skin Lesions A thorough skin examination should be performed annually to assess for new or changing macroscopic skin lesions. It is critically important to be able to identify and describe normal and abnormal skin and to note your findings carefully, because a change in an existing skin lesion is the most common sign of skin cancer, including deadly ones like melanoma. In this discussion, we will describe the specific ways in which you document skin lesions, using a vocabulary that o...
Mar 12, 2024•16 min
