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...

  Anatomy of Brain  The cerebrum makes up most of the brain. It is located inside the skull. The brain is made up of two hemispheres (left and right) and five lobes. All lobes, except one, are named according to the bone of the skull on which they rest: frontal, parietal, temporal, occipital and, the exception we mentioned, insular. The insula lobe is hidden beneath the frontal, temporal, and parietal lobes. “Insula” means island; Indeed, the insula is an “island” of gray matter hidden beneath the surface of the brain.  You can probably find the term “limbic lobe” in some text, however, this is not actually a lobe. It is a functional group of interconnected brain regions that together control emotions, memory, and spatial perception; therefore, we refer to it as the “limbic system.” The brain, together with the hippocampus, amygdala, olfactory bulb, and basal ganglia, make up the telencephalon.  The most superficial layer of the brain is the cerebral co...

Respiratory system   Definition   "The respiratory system allows oxygen to enter the body, as well as carbon dioxide to escape." Mechanism   To stay alive, the body needs to produce enough energy. This energy is produced by the combustion of nutrient molecules, which are oxidized when they combine with oxygen. Oxidation involves the combination of carbon and hydrogen with oxygen to form carbon dioxide and water. The consumption of oxygen and the production of carbon dioxide is an essential process for life. Consequently, the human body needs an organic system specialized in the elimination of carbon dioxide from the circulating blood and the absorption of oxygen from the atmosphere, at a speed appropriate to the needs of the organism and even at the moment of maximum effort. The respiratory system allows oxygen to enter the body, as well as carbon dioxide to escape. Anatomy    The respiratory system begins in the nose and mouth and continues through the a...

Spleen Organ that is part of the lymphatic system.  The spleen produces lymphocytes, filters blood, stores blood cells, and destroys old blood cells.  It is located on the left side of the abdomen, near the stomach. Anatomy of the lymphatic system.  The lymphatic vessels and some lymphatic organs (lymph nodes, tonsils, thymus, spleen and bone marrow) are observed.  Lymph (clear fluid) and lymphocytes move through the lymphatic vessels to the lymph nodes, where the lymphocytes destroy harmful substances.  Lymph enters the blood through a large vein near the heart. The spleen is an organ present in almost all vertebrates. It is part of the lymphatic system and is the center of activity of the immune system, it facilitates the destruction of old or expired red blood cells and platelets and during the fetal period it participates in the production of new red blood cells (hematopoiesis). The human spleen is flattened and oval in shape, it is located in the upper lef...

Organ that is part of the lymphatic system. The spleen produces lymphocytes, filters blood, stores blood cells, and destroys old blood cells. It is located on the left side of the abdomen, near the stomach. Anatomy of the lymphatic system. The lymphatic vessels and some lymphatic organs (lymph nodes, tonsils, thymus, spleen and bone marrow) are observed. Lymph (clear fluid) and lymphocytes move through the lymphatic vessels to the lymph nodes, where the lymphocytes destroy harmful substances. Lymph enters the blood through a large vein near the heart.

 Human Stomach  The stomach (from the Latin stomăchus, derived from the Greek στόμαχος [stomachos], from the prefix στόμα [stoma], "mouth") is the portion of the digestive tract located between the esophagus and the intestine. In humans, it is located in the upper left region of the abdomen, below the diaphragm. It is a chamber in which the ingested food is mixed and stored and is emptied in small intervals towards the duodenum thanks to peristaltic movements. Complete gastric emptying requires several hours after a large meal. The stomach is very distensible, so it varies considerably in size depending on whether it is full or empty. It is divided into four main regions, which are called: cardia, which joins it to the esophagus, fundus, body, and pylorus, which connects it to the intestine. It secretes several substances that are collectively called gastric juice, formed mainly by hydrochloric acid and pepsin, a proteolytic enzyme that divides proteins into smaller frag...

 Human Liver The liver is an organ that is present in both humans and other vertebrate animals. The human liver has an average weight of 1500 g,[1]​ it is located in the upper right part of the abdomen, below the diaphragm, it secretes bile, essential for the digestion of fats, it also has many other functions,[2 ]​ among them the synthesis of plasma proteins, storage of vitamins and glycogen and detoxifying function. Its main cells are hepatocytes and one of its most characteristic features is that it has the ability to regenerate. The liver is responsible for eliminating different substances from the blood that may be harmful to the body, including alcohol, converting them into harmless ones. The absence of a liver or its lack of functioning is incompatible with life. Etymology  The word "liver" does not derive from its Latin homonym jecur, nor from the Greek hepatos. It comes from the Latin expression ficatum jecur which literally means “liver fattened with fi...

What is the digestive system?  The digestive system is made up of the gastrointestinal tract, also called the digestive tract, and the liver, pancreas, and gallbladder.  The gastrointestinal tract is a series of hollow organs joined together in a long, twisted tube that runs from the mouth to the anus.  The hollow organs that make up the gastrointestinal tract are the mouth, esophagus, stomach, small intestine, large intestine, and anus.  The liver, pancreas and gallbladder are the solid organs of the digestive system.  The small intestine has three parts.  The first part is called the duodenum.  The jejunum is in the middle and the ileum is at the end.  The large intestine includes the appendix, cecum, colon, and rectum.  The appendix is ​​a small finger-shaped sac attached to the cecum.  The cecum is the first part of the large intestine.  The colon is next.  The rectum is the end of the large intestine.  Bacteria in the...

SOLAR SYSTEM  The Solar System is a group of astronomical objects that orbit, due to gravity, around a star, the Sun, from which its name comes.  That star, which concentrates 99.75% of its mass[2], is the only one of the objects that it emits, through the combustion of hydrogen and its transformation into heli by nuclear fusion: light  Among the objects that orbit directly around the Sun, the eight largest are the planets that form, together with it, the planetary system;  The rest, some of which orbit directly around the Sun and others around the other of the objects that orbit around that star, fall into three categories: nano planets, comets, asteroids and the other small objects of the Solar System. (SSSBs, small Solar System bodies) The Solar System formed 4.6 billion years ago as a result of the gravitational collapse of a giant molecular cloud. The vast majority of the system's mass is in the Sun, and the remainder mostly in Jupiter. The four planets located ...