Tag: Biology

Primary Essential Hypertension vs Secondary Hypertension: Causes and Health Effects of High Blood Pressure [Biology, MCAT, USMLE]

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In this quick, easy-to-understand lesson, we learn about secondary hypertension for USMLE and medicine. Secondary hypertension is defined as high blood pressure (>140/90 or >130/80) caused by an underlying disease, medical condition, or drugs. While primary essential hypertension comprises of the majority of hypertension cases (90%), only 10% of patient cases is secondary hypertension.

Direct Hernia vs Indirect Hernia

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Direct vs Indirect Hernia: What is the difference between direct and indirect inguinal hernias? In this easy-to-understand lesson, we explore the differences between direct inguinal hernias and indirect inguinal hernias. Overall, an inguinal hernia is a medical condition, where protrusion or bulge of abdominal contents into the groin area and/or inguinal canal. There are two types of inguinal hernias: 1) direct inguinal hernia and 2) indirect inguinal hernia.

Embryogenesis: Definition, Stages, and Development [MCAT]

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Sonic Hedgehog Gene. CNS development and Limb development. In embryology and developmental biology, embryogenesis is the development of an animal or plant embryo, starting with fertilization of an egg cell by a sperm cell. After fertilization, the ovum becomes a diploid zygote. orms forebrain, separates right and left brain, and establishes midline. f there’s a mutation, then we have a whole brain with no separation of right and left, which is bad. This is called holoprosencephaly. Left and right hemispheres fail to separate. There are also facial abnormalities, cleft lip/palate and even severe cyclopia (single eye like a cyclops).

Psychology 101 and the Brain: Stress – Definition, Symptoms, and Health Effects of the Fight-or-Flight Response

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The “fight or flight” response is in response to impending danger. For example, the stress responses kicks in when seeing a snake slithering towards you or running away from a bear in the woods. Homeostasis is the normal equilibrium of body function, so stress can be induced by belief that homeostasis might be interrupted. In this guide, we share the effects of stress on the human body system, psychology, immune system, and long-term health effects of chronic stress.

Biology 101: Microfilaments vs Microtubules in Cell Biology

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Microfilaments and microtubules are both important elements of the cytoskeleton, maintaining the structure and integrity of the cell, but there are several differences between microfilaments and microtubules. In this article, we share this information on microfilaments versus microtubules.

Microfilament and Microtubulues are made from different individual subunits. Microfilaments are made from ACTIN, while microtubules are made from TUBULIN.

Arthropods 101: Insects, Evolution, Classes, and Examples of Arthropods

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Making up around 75% of all animal species in the world, arthropods are are a vast phylum of the kingdom Animalia. The name comes from the Greek words “arthro”, meaning joint, and “podos”, meaning legs. While they all share segmented bodies with joined legs, members in this phylum vary wildly, from butterflies and millipedes, to scorpions and lobsters. They are also all invertebrates, which means that they do not have backbones. Instead, they use hard exoskeletons to protect themselves, which are made out of chitin. Because these exoskeletons are relatively inflexible, arthropods molt as they grow larger, which means they shed their exoskeletons.

Cardiology 101 – Atrial Fibrillation (USMLE) : Causes, Symptoms, Diagnosis, and Treatments

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In this quick easy-to-understand lesson, we learn about atrial fibrillation, causes, symptoms, diagnoses, and treatments for USMLE medicine. Atrial fibrillation is the most common type of cardiac arrhythmia. This means the heart beat has an irregularly irregular rhythm. Symptoms can include fatigue, dyspnea (difficulty breathing), and heart palpitations in the chest. You diagnose atrial fibrillation via EKG. It can be treated with medications or surgically.

Immunology 101: Innate Immunity vs. Adaptive Immunity

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Innate vs Adaptive Immunity: What are the differences between innate and adaptive immunity? The human body has two protective immunological systems against pathogens: the innate immunity and the adaptive immunity. In this quick and easy lesson, we will explain the differences between the innate and adaptive immunity. The innate immunity and adaptive immunity differ based on the type of components that are used to protect the human body. For example, the innate immunity consists of neutrophils, dendritic cells, natural killer cells, macrophages, complements, physical barriers. On the other hand, the adaptive immunity contains components such as T cells, B cells, and antibodies to protect us from viruses, bacteria, and other pathogens.

Cardiac Arrhythmias: Definition, Types, Symptoms, and Prevention

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The heart’s function is to consistently move the blood in the body for the blood to spread nutrients to other body parts or to be replenished with oxygen and nutrients from other respective organs. The heartbeat is a way to understand the pace at which the blood is moving and how quick the heart is pumping itself. A heartbeat changes based on its environment. Running and high-intensity movement causes the heart to increase its number of beats whereas resting may lead to a lower heartbeat for the low amount activity that does not require as much oxygen. Depending on the difficulty and intensity of each activity, the heart accommodates via changing its pace to fit the body’s needs. In certain cases, however, a cardiac arrhythmia occurs and can lead to different cardiac issues that may or may not be harmless. Cardiac arrhythmia has affected millions of people in a multitude of forms. This article explains the basics of this condition such as heart block and bradycardia. The article is solely for educational purposes and not to diagnosis. What is a Cardiac Arrhythmia?

Taxonomy: History, Definition, Classification, and Taxonomy Mnemonic

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Cougar. Mountain Lion. Puma. What do these animals all have in common? Believe it or not, they are actually all names for the same animal! Because this feline spans such a large area, different areas call it different names. As you might think, this could get confusing if scientists try to discuss the same animal, so what do they do? They use taxonomy.
Taxonomy is the science and process of organizing organisms into categories and naming them. Every species of animal has a unique taxonomic, or scientific, name. A species is a group of organisms that reproduce among itself and produce offspring. The scientific name is used by scientists all over the world for ease of communication. After all, it is very important to be specific in science. For example, the scientific name of the cougar/mountain lion/puma is Puma concolor. The name cougar/mountain lion/puma refers to the animal’s common name. Organisms can have many common names used by the public, but when scientists are referring to them, they use the scientific name. Domain Kingdom Phylum Class Order Family Genus Species

Circulatory System: Heart Structures and Functions

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Circulatory System: Heart Structures and Functions; Blood flows through the heart in the following order: body –>inferior/superior vena cava –> right atrium –> tricuspid valve –> right ventricle –> pulmonary arteries –> lungs –> pulmonary veins –> left atrium –> mitral valve –> left ventricle –> aortic valve –> aorta –> body…

Eyes 101: Top 25 Most Common Eye Problems, Diseases, and Disorders

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Common eye problems, diseases, and disorders – Quick and easy to learn diagram, definitions, and explanations for common eye diseases. In this article, we explore the top 25 most common eye problems, diseases, and disorders, including diagrams,  definitions, and explanations for common eye diseases. The eye is a small but unique organ of the human body with the ability to visualize a lifetime of events.