Depression (physiology)

	Depression (physiology) In physiology and medicine, depression refers to a lowering, in particular a reduction in a specific biological variable or the functions of an organ. It is the opposite of elevation. For example, it is possible to refer to "depressed thyroid function" or to a depression of blood flow in a particular area. Further examples: * Depression of the central nervous system of an animal may be expressed as drowsiness or sleep, lack of coordination and unconsciousness. * Respiratory depression or hypoventilation Hypoventilation (also known as respiratory depression) occurs when ventilation is inadequate (''hypo'' meaning "below") to perform needed respiratory gas exchange. By definition it causes an increased concentration of carbon dioxide (hypercapni .... References Medical terminology {{med-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Physiology Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the 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 Nobel Prize in Physiology or Medicine is awarded by the Royal Swedish Academy of Sciences for exceptional scientific achievements in physiology related to the field of medicine. Foundations Cells Although there are differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Medicine Medicine is the science and practice of caring for a patient, managing the diagnosis, prognosis, prevention, treatment, palliation of their injury or disease, and promoting their health. Medicine encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness. Contemporary medicine applies biomedical sciences, biomedical research, genetics, and medical technology to diagnose, treat, and prevent injury and disease, typically through pharmaceuticals or surgery, but also through therapies as diverse as psychotherapy, external splints and traction, medical devices, biologics, and ionizing radiation, amongst others. Medicine has been practiced since prehistoric times, and for most of this time it was an art (an area of skill and knowledge), frequently having connections to the religious and philosophical beliefs of local culture. For example, a medicine man would apply herbs and say prayers for healing, o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Organ (biology) In biology, 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 can be broadly categorized as parenchyma, the functional tissue, and stroma, the structural tissue with supportive, connective, or ancillary functions. For example, the gland's tissue that makes the hormones is the parenchyma, whereas the stroma includes the nerves that innervate the parenchyma, the blood vessels that oxygenate and nourish it and carry away its metabolic wastes, and the co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Thyroid The thyroid, or thyroid gland, is an endocrine gland in vertebrates. In humans it is in the neck and consists of two connected lobes. The lower two thirds of the lobes are connected by a thin band of tissue called the thyroid isthmus. The thyroid is located at the front of the neck, below the Adam's apple. Microscopically, the functional unit of the thyroid gland is the spherical thyroid follicle, lined with follicular cells (thyrocytes), and occasional parafollicular cells that surround a lumen containing colloid. The thyroid gland secretes three hormones: the two thyroid hormones triiodothyronine (T3) and thyroxine (T4)and a peptide hormone, calcitonin. The thyroid hormones influence the metabolic rate and protein synthesis, and in children, growth and development. Calcitonin plays a role in calcium homeostasis. Secretion of the two thyroid hormones is regulated by thyroid-stimulating hormone (TSH), which is secreted from the anterior pituitary gland. TSH is regula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Hemodynamics Hemodynamics or haemodynamics are the dynamics of blood flow. The circulatory system is controlled by homeostatic mechanisms of autoregulation, just as hydraulic circuits are controlled by control systems. The hemodynamic response continuously monitors and adjusts to conditions in the body and its environment. Hemodynamics explains the physical laws that govern the flow of blood in the blood vessels. Blood flow ensures the transportation of nutrients, hormones, metabolic waste products, oxygen, and carbon dioxide throughout the body to maintain cell-level metabolism, the regulation of the pH, osmotic pressure and temperature of the whole body, and the protection from microbial and mechanical harm. Blood is a non-Newtonian fluid, and is most efficiently studied using rheology rather than hydrodynamics. Because blood vessels are not rigid tubes, classic hydrodynamics and fluids mechanics based on the use of classical viscometers are not capable of explaining haemodynamics. The st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Central Nervous System Depression Central nervous system (CNS) depression is a physiological state that can result in a decreased rate of breathing, decreased heart rate, and loss of consciousness possibly leading to coma or death. It is the result of inhibited or suppressed brain activity. Causes Depression of the central nervous system is generally caused by the use of depressant drugs such as ethanol, opioids, barbiturates, benzodiazepines, general anesthetics, and anticonvulsants such as pregabalin used to treat epilepsy. Drug overdose is often caused by combining two or more depressant drugs, although overdose is also possible by consuming a large dose of one depressant drug. Central nervous system depression can also be caused by the accidental or intentional inhalation or ingestion of certain volatile chemicals such as butanone (contained in plastic cement) or isopropyl alcohol. Other causes of central nervous system depression are metabolic disturbances such as hypoglycaemia. Comparison In a stud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Unconsciousness Unconsciousness is a state in which a living individual exhibits a complete, or near-complete, inability to maintain an consciousness, awareness of self and environment or to respond to any human or environmental Stimulus (physiology), stimulus. Unconsciousness may occur as the result of traumatic brain injury, Cerebral hypoxia, brain hypoxia (inadequate oxygen, possibly due to a brain infarction or cardiac arrest), severe intoxication with drugs that Depressant, depress the activity of the central nervous system (e.g., Alcohol (drug), alcohol and other hypnotic or sedative drugs), severe fatigue, pain, Anesthesia, anaesthesia, and other causes. Loss of consciousness should not be confused with the notion of the Unconscious mind, psychoanalytic unconscious, cognitive processes that take place outside awareness (e.g., implicit cognition), and with altered states of consciousness such as sleep, delirium, hypnosis, and other altered states in which the person responds to stimuli, in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Hypoventilation Hypoventilation (also known as respiratory depression) occurs when ventilation is inadequate (''hypo'' meaning "below") to perform needed respiratory gas exchange. By definition it causes an increased concentration of carbon dioxide (hypercapnia) and respiratory acidosis. Hypoventilation is not synonymous with respiratory arrest, in which breathing ceases entirely and death occurs within minutes due to hypoxia and leads rapidly into complete anoxia, although both are medical emergencies. Hypoventilation can be considered a precursor to hypoxia and its lethality is attributed to hypoxia with carbon dioxide toxicity. Causes Hypoventilation may be caused by: A medical condition such as stroke affecting the brainstem Voluntary breath-holding or underbreathing, for example, hypoventilation training or the Buteyko method. Medication or drugs, typically when taken in accidental or intentional overdose. Opioids and benzodiazepines in particular are known to cause respiratory depress ... [...More Info...] [...Related Items...] OR:* [Wikipedia] [Google] [Baidu]