Understanding the Endocrine System: Hormones, Glands, and Functions
The Endocrine System: An Overview
The hormonal or endocrine system consists of a set of glands, organs composed of cells that produce and secrete specific substances. These glands, made of glandular tissue, release their products in different ways. Exocrine glands secrete substances outside the body or into a cavity connected to the outside, such as sweat, salivary, and intestinal glands. Endocrine glands, on the other hand, release their products, called hormones, directly into the bloodstream.
Read MoreDNA, RNA, Mediterranean Diet, Olive Oil, and Iberian Ham
DNA and RNA: The Building Blocks of Life
DNA: is formed by the union of deoxyribonucleotides. The nitrogen bases are adenine, guanine, cytosine, and thymine.
Watson-Crick Model
- Consists of two polynucleotide chains joined together along its entire length.
- The two chains are antiparallel, with the 3′ end of one facing the 5′ end of the other.
- The union between the strands is through hydrogen bonds between the nitrogenous bases: adenine forms two bridges with thymine, and guanine forms three with cytosine.
Health, Heart Disease, and Risk Factors
Health and Quality of Life
In the mid-twentieth century, the WHO defined health as a state of complete physical, mental, and social well-being. The health of a person cannot be defined only in terms of fitness; it is necessary to consider mental health. The idea of health should not merely be the absence of disease but should be more ambitious and include positive elements. Quality of life is often used to refer to this way of understanding health.
What Determines Health?
- Lifestyle: Individual behaviors
Hormones, Reproduction, Immunity, and Renal Function
Reproductive Hormones and Functions
Major Classes of Reproductive Hormones:
- Androgens – steroids
- Estrogens – steroids
- Gonadotropins – protein hormones
- Progesterones – steroids
Androgens (Masculinizing Actions)
Key Androgens: Testosterone, DHEA (dehydroepiandrosterone), Androstenedione, DHT (dihydrotestosterone).
Testosterone
- Produced by Leydig cells in testes, ovaries, adrenal gland, and placenta.
- Stimulates testes and penis function.
- Induces male secondary sex characteristics.
- Stimulates protein anabolism,
Cellular Metabolism: Energy, Reactions, and Pathways
Metabolism: Cellular Reactions and Energy
Metabolism is the set of reactions that occur within a cell, through which it gains and uses energy. These reactions maintain ionic concentrations and continuously regenerate molecules and structures. The spontaneity of a chemical reaction is measured using a thermodynamic quantity called free energy.
Exergonic Reactions (Catabolism)
Exergonic reactions occur spontaneously, releasing energy. These degradation reactions result in products with less energy than
Read MoreBacterial, Fungal, and Parasitic Infections: Symptoms and Causes
Bacterial Infections
Acne Vulgaris Pathogen: Propionibacterium acnes (Humans) Signs and Symptoms: Sebum and dead cells clog pores, leading to papule and pustule formation, scarring, and distress. Extra: More common among teenagers and young adults. Hallmark: Cystic acne – an uncommon, severe form of acne with painful pustules. | Gas Gangrene (Clostridial Myonecrosis) Pathogen: Clostridium perfringens (Soil) Signs and Symptoms: Muscle and soft tissue destruction, gas pockets in tissues compress small blood |