Learn with Iqra Zaman

  Sexual reproduction  In sexual reproduction, the genetic information of the descendants is made up of the genetic contribution of both parents, through the fusion of sexual cells or gametes;[13]​ that is, sexual reproduction is a source of genetic variability.  Sexual reproduction requires the interaction of a chromosome, generating both male and female gametes or two individuals, being of different sexes, or also hermaphrodites. The offspring produced as a result of this biological process will be the result of the combination of the DNA of both parents and, therefore, will be genetically different from them. This form of reproduction is the most common in complex organisms. Two haploid cells originated by meiosis, the gametes, participate in this type of reproduction, which will join together during fertilization. Disadvantages  Normally requires the presence of a second individual. To avoid this problem, parthenogenesis, multiplication from eggs without a pa...

Reproduction Reproduction is a biological process that can be sexual or asexual, which allows the formation of new individuals, being a common property of all known forms of life, with the purpose of preserving the species. Self-perpetuation  One of the fundamental characteristics of living beings is the ability to reproduce, to generate new living beings with characteristics similar to them.  The strategies and structures that living beings use to fulfill the reproductive function are diverse. Within this wide range of strategies, it is possible to find sexually reproducing species that produce a huge number of eggs, like most fish, in order to ensure that some reach adults. Other species, such as the albatross or the whale, generate a single offspring for each reproductive stage, which they care for intensely for long periods of time. This reduces the chances of death and increases the chances of continuity of the species.  In nature, we can find groups of specimens t...

  Nephron   The nephron or nephron is the basic structural and functional unit of the kidney, responsible for blood purification. Its main function is to filter waste from the blood to regulate water and soluble substances, reabsorbing what is necessary and excreting the rest as urine. It is located mainly in the renal cortex. Discription The nephron is the functional unit of the renal parenchyma. In humans, each kidney contains around 800,000 to 1,000,000 nephrons.[1] The structure of the nephron is complex, it is composed of a renal corpuscle in communication with a renal tubule. The Malpighian renal corpuscle is a spheroidal structure, made up of Bowman's capsule and the capillary ball contained inside or glomerulus. The capsule, lined internally by a flattened epithelium, has two openings: the vascular pole, through which the afferent arteriole penetrates and the efferent arteriole emerges, and the urinary pole, which communicates with the renal tubule. The urinary s...

Cranial Nerves   The cranial nerves, also called cranial nerves, are 12 pairs of nerves that arise directly from the brain or at the level of the brainstem to distribute through the foramina at the base of the skull in the head, neck, thorax and abdomen. The International Anatomical Nomenclature includes the terminal nerve as a cranial nerve, despite it being atrophic in humans and being closely related to the olfactory nerve. Cranial nerves have an apparent origin that is the place where the nerve exits or enters the brain. The real origin is different according to the function they fulfill. The fibers of the cranial nerves with motor function (efferent) originate from cell groups found deep in the brain stem (motor nuclei) and are homologous to the cells of the anterior horn of the spinal cord. The fibers of the cranial nerves with sensory or sensory (afferent) function have their cells of origin (first-order nuclei) outside the brain stem, usually in ganglia that are homolog...

  Lungs The lungs are anatomical structures belonging to the respiratory system, they are located in the thoracic cage, on both sides of the mediastinum. Due to the space occupied by the heart, the right lung is larger than its left counterpart. They have three faces; mediastinal, costal and diaphragmatic, it is irrigated by the bronchial arteries and the pulmonary arteries carry blood for oxygenation. Embryologically it is derived from the endoderm. The lungs are the organs in which the blood receives oxygen from the inspired air and releases carbon dioxide, which passes into the expired air. This exchange occurs through simple diffusion of gases thanks to the difference in partial pressures of oxygen and carbon dioxide between the blood and the alveoli. Anatomy   The lungs are located inside the thorax and on both sides of the heart. They are protected by the ribs and separated from each other by the mediastinum. They are covered by a double membrane called the pleura...

  Stomach :   The stomach is a muscular sac in the upper left part of the abdomen that plays a fundamental role in digestion. The stomach develops from the foregut and connects the esophagus to the duodenum. Structurally, the stomach is J-shaped and forms a greater and lesser curvature and is roughly divided into regions: cardia, fundus, body and pylorus. At the microscopic level, the stomach wall has several layers, including mucosa, submucosa, muscularis, and serosa. The stomach is filled with glands that secrete a variety of substances involved in the digestive process. The arterial supply to the stomach comes mainly from the vessels that originate from the celiac trunk. General description  The stomach is a muscular sac in the upper abdomen that plays a critical role in digestion.   Stomach functions  Food storagei Digestion Mechanically breaks down food Mixes food with gastric secretions to produce chymeSlow/controlled emptying of chyme into the s...

  Nephrology   Nephrology is the medical specialty, branch of internal medicine, concerned with the study of kidney structure and function, both in health and disease, including the prevention and treatment of kidney diseases. The word nephrology derives from the Greek word νεφρός (nephrós), which means kidney, and from the suffix -logy (study, treatise). Definition  Nephrology can be defined as the clinical specialty that deals with the study of the anatomy, physiology, pathology, health promotion, prevention, clinical, therapeutic and rehabilitation of diseases of the urinary system in its entirety, including the urinary tract that affects the renal parenchyma. Unlike urology, this is not a surgical specialty.  The doctor specializing in nephrology is called a nephrologist. Nephrology should not be confused with urology, which is the surgical specialty of the urinary system and the male genital system. Scope of the specialty  Nephrology refers to the diagno...