Kidneys in the context of Toxins

The urinary system, also known as the urinary tract or renal system, is a part of the excretory system of vertebrates. In humans and placental mammals, it consists of the kidneys, ureters, bladder, and the urethra. The purpose of the urinary system is to eliminate urine from the body, regulate blood volume and blood pressure, control levels of electrolytes and metabolites, and regulate blood pH. The kidneys have an extensive blood supply via the renal arteries which leave the kidneys via the renal vein. Each kidney consists of functional units called nephrons. Following filtration of blood and further processing, the ureters carry urine from the kidneys into the urinary bladder. The urethra carries urine from the bladder through the penis or vulva during urination. The female and male urinary system are very similar, differing only in the length of the urethra.

800–2,000 milliliters (mL) of urine are normally produced every day in a healthy human. This amount varies according to fluid intake and kidney function.

The adrenal glands (also known as suprarenal glands) are endocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol. They are found above the kidneys. Each gland has an outer cortex which produces steroid hormones and an inner medulla. The adrenal cortex itself is divided into three main zones: the zona glomerulosa, the zona fasciculata and the zona reticularis.

The adrenal cortex produces three main types of steroid hormones: mineralocorticoids, glucocorticoids, and androgens. Mineralocorticoids (such as aldosterone) produced in the zona glomerulosa help in the regulation of blood pressure and electrolyte balance. The glucocorticoids cortisol and cortisone are synthesized in the zona fasciculata; their functions include the regulation of metabolism and immune system suppression. The innermost layer of the cortex, the zona reticularis, produces androgens that are converted to fully functional sex hormones in the gonads and other target organs. The production of steroid hormones is called steroidogenesis, and involves a number of reactions and processes that take place in cortical cells. The medulla produces the catecholamines, which function to produce a rapid response throughout the body in stress situations.

Biomedical engineering (BME) or medical engineering is the application of engineering principles and design concepts to medicine and biology for healthcare applications (e.g., diagnostic or therapeutic purposes). BME also integrates the logical sciences to advance health care treatment, including diagnosis, monitoring, and therapy. Also included under the scope of a biomedical engineer is the management of current medical equipment in hospitals while adhering to relevant industry standards. This involves procurement, routine testing, preventive maintenance, and making equipment recommendations, a role also known as a Biomedical Equipment Technician (BMET) or as a clinical engineer.

Biomedical engineering has recently emerged as its own field of, as compared to many other engineering fields. Such an evolution is common as a new field transitions from being an interdisciplinary specialization among already-established fields to being considered a field in itself. Much of the work in biomedical engineering consists of research and development, spanning a broad array of subfields (see below). Prominent biomedical engineering applications include the development of biocompatible prostheses, various diagnostic and therapeutic medical devices ranging from clinical equipment to micro-implants, imaging technologies such as MRI and EKG/ECG, regenerative tissue growth, and the development of pharmaceutical drugs including biopharmaceuticals.

The endocrine system is a messenger system in an organism comprising feedback loops of hormones that are released by internal glands directly into the circulatory system and that target and regulate distant organs. In vertebrates, the hypothalamus is the neural control center for all endocrine systems.

In humans, the major endocrine glands are the thyroid, parathyroid, pituitary, pineal, and adrenal glands, and the (male) testis and (female) ovaries. The hypothalamus, pancreas, and thymus also function as endocrine glands, among other functions. (The hypothalamus and pituitary glands are organs of the neuroendocrine system. One of the most important functions of the hypothalamus—it is located in the brain adjacent to the pituitary gland—is to link the endocrine system to the nervous system via the pituitary gland.) Other organs, such as the kidneys, also have roles within the endocrine system by secreting certain hormones. The study of the endocrine system and its disorders is known as endocrinology.The thyroid secretes thyroxine, the pituitary secretes growth hormone, the pineal secretes melatonin, the testis secretes testosterone, and the ovaries secrete estrogen and progesterone.

Osmoregulation is the active regulation of the osmotic pressure of an organism's body fluids, detected by osmoreceptors, to maintain the homeostasis of the organism's water content; that is, it maintains the fluid balance and the concentration of electrolytes (salts in solution which in this case is represented by body fluid) to keep the body fluids from becoming too diluted or concentrated. Osmotic pressure is a measure of the tendency of water to move into one solution from another by osmosis. The higher the osmotic pressure of a solution, the more water tends to move into it. Pressure must be exerted on the hypertonic side of a selectively permeable membrane to prevent diffusion of water by osmosis from the side containing pure water.

Although there may be hourly and daily variations in osmotic balance, an animal is generally in an osmotic steady state over the long term. Organisms in aquatic and terrestrial environments must maintain the right concentration of solutes and amount of water in their body fluids; this involves excretion (getting rid of metabolic nitrogen wastes and other substances such as hormones that would be toxic if allowed to accumulate in the blood) through organs such as the skin and the kidneys.

Renin (etymology and pronunciation), also known as an angiotensinogenase, is an aspartic protease protein and enzyme secreted by the kidneys that participates in the body's renin-angiotensin-aldosterone system (RAAS)—also known as the renin-angiotensin-aldosterone axis—that increases the volume of extracellular fluid (blood plasma, lymph, and interstitial fluid) and causes arterial vasoconstriction. Thus, it increases the body's mean arterial blood pressure.

Renin is not commonly referred to as a hormone, although it has a receptor, the (pro)renin receptor, also known as the renin receptor and prorenin receptor (see also below), as well as enzymatic activity with which it hydrolyzes angiotensinogen to angiotensin I.

Perinatal asphyxia (also known as neonatal asphyxia or birth asphyxia) is the medical condition resulting from deprivation of oxygen to a newborn infant that lasts long enough during the birth process to cause physical harm, usually to the brain. It remains a serious condition which causes significant mortality and morbidity. It is also the inability to establish and sustain adequate or spontaneous respiration upon delivery of the newborn, an emergency condition that requires adequate and quick resuscitation measures. Perinatal asphyxia is also an oxygen deficit from the 28th week of gestation to the first seven days following delivery. It is also an insult to the fetus or newborn due to lack of oxygen or lack of perfusion to various organs and may be associated with a lack of ventilation. In accordance with WHO, perinatal asphyxia is characterised by: profound metabolic acidosis, with a pH less than 7.20 on umbilical cord arterial blood sample, persistence of an Apgar score of 3 at the 5th minute, clinical neurologic sequelae in the immediate neonatal period, or evidence of multiorgan system dysfunction in the immediate neonatal period. Hypoxic damage can occur to most of the infant's organs (heart, lungs, liver, gut, kidneys), but brain damage is of most concern and perhaps the least likely to quickly or completely heal. In more pronounced cases, an infant will survive, but with damage to the brain manifested as either mental, such as developmental delay or intellectual disability, or physical, such as spasticity.

It results most commonly from antepartum causes like a drop in maternal blood pressure or some other substantial interference with blood flow to the infant's brain during delivery. This can occur due to inadequate circulation or perfusion, impaired respiratory effort, or inadequate ventilation. Perinatal asphyxia happens in 2 to 10 per 1000 newborns that are born at term, and more for those that are born prematurely. WHO estimates that 4 million neonatal deaths occur yearly due to birth asphyxia, representing 38% of deaths of children under 5 years of age.

The hypothalamic–pituitary–adrenal axis (HPA axis or HTPA axis) is a complex set of direct influences and feedback interactions among three components: the hypothalamus (a part of the brain located below the thalamus), the pituitary gland (a pea-shaped structure located below the hypothalamus), and the adrenal (also called "suprarenal") glands (small, conical organs on top of the kidneys). These organs and their interactions constitute the HPA axis.

The HPA axis is a major neuroendocrine system that controls reactions to stress and regulates many body processes, including digestion, immune responses, mood and emotions, sexual activity, and energy storage and expenditure. It is the common mechanism for interactions among glands, hormones, and parts of the midbrain that mediate the general adaptation syndrome (GAS).

According to traditional Chinese medicine, the kidney (Chinese: 腎: shèn) refers to either of the two viscera located on the small of the back, one either side of the spine. As distinct from the Western medical anatomical formative definition of kidneys, the TCM concept is a functional and energetic way of describing a set of interrelated parts. In TCM, the kidneys are associated with Ming Men 命門, the gate of vitality. A famous Chinese doctor named Zhang Jie Bin (approximately 1563-1640) wrote "there are two kidneys, (kidney yin and yang), with the Gate of Vitality between them. The kidney is the organ of water and fire, the abode of yin and yang, the sea of essence, and it determines life and death."

The abdominopelvic cavity is a body cavity that consists of the abdominal cavity and the pelvic cavity. The upper portion is the abdominal cavity, and it contains the stomach, liver, pancreas, spleen, gallbladder, kidneys, small intestine, and most of the large intestine. The lower portion is the pelvic cavity, and it contains the urinary bladder, the rest of the large intestine (the lower portion), and the internal reproductive organs.

There is no membrane that separates out the abdominal cavity from the pelvic cavity, so the terms abdominal pelvis and peritoneal cavity are sometimes used.

Inorganic ions in animals and plants are ions necessary for vital cellular activity. In body tissues, ions are also known as electrolytes, essential for the electrical activity needed to support muscle contractions and neuron activation. They contribute to osmotic pressure of body fluids as well as performing a number of other important functions. Below is a list of some of the most important ions for living things as well as examples of their functions:

• Ca – calcium ions are a component of bones and teeth. They also function as biological messengers, as do most of the ions listed below. (See Hypocalcaemia.)
• Zn - zinc ions are found in very small concentrations in the body, and their main purpose is that of an antioxidant; the zinc ions act as antioxidants both generally and for liver specific pro-oxidants. Zinc ions can also act as an antioxidant-like stabilizer for some macro-molecules which bind zinc ions with high affinity, especially in cysteine-rich binding sites. These binding sites use these zinc ions as a stabilizer to protein folds, making these protein motifs more rigid in structure. These structures include zinc fingers, and have several different conformations.
• K – potassium ions' main function in animals is osmotic balance, particularly in the kidneys. (See Hypokalemia.)
• Na – sodium ions have a similar role to potassium ions. (See Sodium deficiency.)
• Mn- manganese ions are seen being used as stabilizer for varying protein configurations. However, manganese ion overexposure is linked to several neurodegenerative diseases such as Parkinson's disease.
• Mg – magnesium ions are a component of chlorophyll. (See Magnesium deficiency (plants))
• Cl – inability to transport chloride ions in humans manifests itself as cystic fibrosis (CF)
• CO
  ₃ – the shells of sea creatures are calcium carbonate. In blood approximately 85% of carbon dioxide, is converted into aqueous carbonate ions (an acidic solution), allowing a greater rate of transportation.
• Co- cobalt ions are present in the human body in amounts from 1 to 2 mg. Cobalt is observed in the heart, liver, kidney, and spleen, and considerably smaller quantities in the pancreas, brain, and serum. Cobalt is a necessary component of vitamin B₁₂ and a fundamental coenzyme of cell mitosis. Cobalt is crucial for amino acid formation and some proteins to create myelin sheath in nerve cells. Cobalt also plays a role in creating neurotransmitters, which are vital for proper function within the organism.
• PO
  ₄ – adenosine triphosphate (ATP) is a common molecule which stores energy in an accessible form. Bone is calcium phosphate.
• Fe/Fe – as found in haemoglobin, the main oxygen carrying molecule has a central iron ion.
• NO
  ₃ – source of nitrogen in plants for the synthesis of proteins.

A diuretic (/ˌdaɪjʊˈrɛtɪk/ ) is any substance that promotes diuresis, the increased production of urine. This includes forced diuresis. A diuretic tablet is sometimes colloquially called a water tablet. There are several categories of diuretics. All diuretics increase the excretion of water from the body, through the kidneys. There exist several classes of diuretic, and each works in a distinct way. Alternatively, an antidiuretic, such as vasopressin (antidiuretic hormone), is an agent or drug which reduces the excretion of water in urine.