Organ system in the context of Dysautonomic

Physiology (/ˌfɪziˈɒlədʒi/; from Ancient Greek φύσις (phúsis) 'nature, origin' and -λογία (-logía) 'study of') is the scientific study of functions and mechanisms in a living system. As a subdiscipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out chemical and physical functions in a living system. According to the classes of organisms, the field can be divided into medical physiology, animal physiology, plant physiology, cell physiology, and comparative physiology.

Central to physiological functioning are biophysical and biochemical processes, homeostatic control mechanisms, and communication between cells. Physiological state is the condition of normal function. In contrast, pathological state refers to abnormal conditions, including human diseases.

The human body is the entire structure of a human being. It is composed of many different types of cells that together create tissues and subsequently organs and then organ systems.

The external human body consists of a head, hair, neck, torso (which includes the thorax and abdomen), genitals, arms, hands, legs, and feet. The internal human body includes organs, teeth, bones, muscle, tendons, ligaments, blood vessels and blood, lymphatic vessels and lymph.

Alcoholism is the continued drinking of alcohol despite it causing problems. Some definitions require evidence of dependence and withdrawal. Problematic alcohol use has been mentioned in the earliest historical records. The World Health Organization (WHO) estimated there were 283 million people with alcohol use disorders worldwide as of 2016. The term alcoholism was first coined in 1852, but alcoholism and alcoholic are considered stigmatizing and likely to discourage seeking treatment, so diagnostic terms such as alcohol use disorder and alcohol dependence are often used instead in a clinical context. Other terms, some slurs and some informal, have been used to refer to people affected by alcoholism such as tippler, sot, drunk, drunkard, dipsomaniac and souse.

Alcohol is addictive, and heavy long-term use results in many negative health and social consequences. It can damage all organ systems, but especially affects the brain, heart, liver, pancreas, and immune system. Heavy usage can result in trouble sleeping, and severe cognitive issues like dementia, brain damage, or Wernicke–Korsakoff syndrome. Physical effects include irregular heartbeat, impaired immune response, cirrhosis, increased cancer risk, and severe withdrawal symptoms if stopped suddenly.

In a multicellular organism, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a function. Tissues of different types combine to form an organ which has a specific function. The intestinal wall for example is formed by epithelial tissue and smooth muscle tissue. Two or more organs working together in the execution of a specific body function form an organ system, also called a biological system or body system.

An organ's tissues are broadly classified into parenchyma, the functional tissue, and stroma, the structural tissue with supportive, connective, or ancillary functions. For example, the gland tissue that produces hormones is the parenchyma, while the stroma includes the nerves that innervate the parenchyma, the blood vessels that oxygenate and nourish it and remove metabolic wastes, and the connective tissues that provide structure, placement, and anchoring. The primary tissues that form an organ generally have common embryologic origins, often arising from the same germ layer. Organs are present in most multicellular organisms. In single-celled organisms such as eukaryotes, the functional analogue of an organ is an organelle. In plants, there are three main organs.The number of organs in any organism depends on the definition used. There are approximately 79 organs in the human body; the exact number remains debated.

The human musculoskeletal system (also known as the human locomotor system, and previously the activity system) is an organ system that gives humans the ability to move using their muscular and skeletal systems. The musculoskeletal system provides form, support, stability, and movement to the body.

The human musculoskeletal system is made up of the bones of the skeleton, muscles, cartilage, tendons, ligaments, joints, and other connective tissue that supports and binds tissues and organs together. The musculoskeletal system's primary functions include supporting the body, allowing motion, and protecting vital organs. The skeletal portion of the system serves as the main storage system for calcium and phosphorus and contains critical components of the hematopoietic system.

In vertebrates, the circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the body. It includes the cardiovascular system, or vascular system, that consists of the heart and blood vessels (from Greek kardia meaning heart, and Latin vascula meaning vessels). The circulatory system has two divisions, a systemic circulation or circuit, and a pulmonary circulation or circuit. Some sources use the terms cardiovascular system and vascular system interchangeably with circulatory system.

The network of blood vessels are the great vessels of the heart including large elastic arteries, and large veins; other arteries, smaller arterioles, capillaries that join with venules (small veins), and other veins. The circulatory system is closed in vertebrates, which means that the blood never leaves the network of blood vessels. Many invertebrates such as arthropods have an open circulatory system with a heart that pumps a hemolymph which returns via the body cavity rather than via blood vessels. Diploblasts such as sponges and comb jellies lack a circulatory system.

Smooth muscle is one of the three major types of vertebrate muscle tissue, the others being skeletal and cardiac muscle. It can also be found in invertebrates and is controlled by the autonomic nervous system. It is non-striated, so-called because it has no sarcomeres and therefore no striations (bands or stripes). It can be divided into two subgroups, single-unit and multi-unit smooth muscle. Within single-unit muscle, the whole bundle or sheet of smooth muscle cells contracts as a syncytium.

Smooth muscle is found in the walls of hollow organs, including the stomach, intestines, bladder and uterus. In the walls of blood vessels, and lymph vessels, (excluding blood and lymph capillaries) it is known as vascular smooth muscle. There is smooth muscle in the tracts of the respiratory, urinary, and reproductive systems. In the eyes, the ciliary muscles, iris dilator muscle, and iris sphincter muscle are types of smooth muscles. The iris dilator and sphincter muscles are contained in the iris and contract in order to dilate or constrict the pupils. The ciliary muscles change the shape of the lens to focus on objects in accommodation. In the skin, smooth muscle cells such as those of the arrector pili cause hair to stand erect in response to cold temperature and fear.

The reproductive system of an organism, also known as the genital system, is the biological system made up of all the anatomical organs involved in sexual reproduction. Many non-living substances such as fluids, hormones, and pheromones are also important accessories to the reproductive system. Unlike most organ systems, the sexes of differentiated species often have significant differences. These differences allow for a combination of genetic material between two individuals, which allows for the possibility of greater genetic fitness of the offspring.

Dysautonomia, autonomic failure, or autonomic dysfunction is a condition in which the autonomic nervous system (ANS) does not work properly. This condition may affect the functioning of the heart, bladder, intestines, sweat glands, pupils, and blood vessels. Dysautonomia has many causes, not all of which may be classified as neuropathic. A number of conditions can feature dysautonomia, such as Parkinson's disease, Long COVID, multiple system atrophy, dementia with Lewy bodies, Ehlers–Danlos syndromes, autoimmune autonomic ganglionopathy and autonomic neuropathy, HIV/AIDS, mitochondrial cytopathy, pure autonomic failure, autism, and postural orthostatic tachycardia syndrome.

Diagnosis is made by functional testing of the ANS, focusing on the affected organ system. Investigations may be performed to identify underlying disease processes that may have led to the development of symptoms or autonomic neuropathy. Symptomatic treatment is available for many symptoms associated with dysautonomia, and some disease processes can be directly treated. Depending on the severity of the dysfunction, dysautonomia can range from being nearly symptomless and transient to disabling and/or life-threatening.

A skin condition, also known as a cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of this system is to act as a barrier against the external environment.

Conditions of the human integumentary system constitute a broad spectrum of diseases, also known as dermatoses, as well as many nonpathologic states (like, in certain circumstances, melanonychia and racquet nails). While only a small number of skin diseases account for most visits to the physician, thousands of skin conditions have been described. Classification of these conditions often presents many nosological challenges, since underlying causes and pathogenetics are often not known. Therefore, most current textbooks present a classification based on location (for example, conditions of the mucous membrane), morphology (chronic blistering conditions), cause (skin conditions resulting from physical factors), and so on.