Related Concept Videos

Lipids: Dietary Sources and Requirements01:18

Lipids: Dietary Sources and Requirements

Lipids are an essential component of a balanced human diet. Triglycerides, which make up the majority of dietary lipids, are found in both saturated fats—commonly present in meat, dairy products, and certain tropical plants like coconut, and hydrogenated oils such as margarine and baking shortenings (trans fats)—and unsaturated fats, which are abundant in seeds, nuts, olive oil, and most vegetable oils. The main sources of cholesterol include egg yolks, various meats and organ...
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Oogenesis02:07

Oogenesis

In human women, oogenesis produces one mature egg cell or ovum for every precursor cell that enters meiosis. This process differs in two unique ways from the equivalent procedure of spermatogenesis in males. First, meiotic divisions during oogenesis are asymmetric, meaning that a large oocyte (containing most of the cytoplasm) and minor polar body are produced as a result of meiosis I, and again following meiosis II. Since only oocytes will go on to form embryos if fertilized, this unequal...
70.3K
Development of Immunocompetence01:22

Development of Immunocompetence

The initiation of cell-mediated immunity can be observed as early as the third month of fetal growth, with active antibody-mediated immunity following approximately one month later.
The initial cells that migrate from the fetal thymus settle within the skin and epithelial tissues lining the mouth, digestive tract, and in females, the uterus and vagina. These cells, including skin-based dendritic cells, serve as antigen-presenting cells, playing a key role in T cell activation.
Subsequent T...
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Allergic Reactions02:06

Allergic Reactions

Overview
32.6K
Nondisjunction01:21

Nondisjunction

Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate correctly and move to the opposite poles of the cells. This produces daughter cells with abnormal chromosome numbers.  Nondisjunction is common during anaphase I or anaphase II of meiosis.  Mutations in synaptonemal complex proteins that attach homologous chromosomes increase the chances of nondisjunction in anaphase I of meiosis I. In contrast, mutations in topoisomerases and condensins that hold...
5.2K
Allergic Reactions: Anaphylaxis01:30

Allergic Reactions: Anaphylaxis

Anaphylaxis is a severe, life-threatening hypersensitivity reaction mediated by Immunoglobulin E (IgE) antibodies. When IgE binds to allergens, it triggers the release of mediators– histamine, leukotrienes, and prostaglandins from mast cells and basophils. These mediators cause vasodilation, edema, and inflammation, leading to various symptoms.The primary allergens causing anaphylaxis include food items (e.g., peanuts, shellfish), drugs (e.g., penicillin, asparaginase, corticotropin,...
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