Health Definitions 1 - Gut and HPA

Question 1

5-alpha-reductase

Answer 1

An enzyme that is primarily known for converting testosterone to DHT, most commonly found on the face and scalp.

Question 2

Acetyl-CoA

Answer 2

Acetyl-CoA is a molecule that participates in many biochemical reactions in protein, carbohydrate, and lipid metabolism. Its main function is to deliver the acetyl group to the citric acid cycle to be oxidized for energy production.

Question 3

Adipocyte

Answer 3

An adipocyte is a cell specialized for the storage of fat, primarily found in connective tissue.

Question 4

Adiponectin

Answer 4

Adiponectin is a hormone that’s produced and secreted by fat cells, or adipocytes. It plays a crucial role in regulating glucose levels and breaking down fatty acids in the body. Higher levels of adiponectin are linked to a lower risk of developing type 2 diabetes and heart disease. It’s also involved in controlling inflammation. Unlike many hormones, adiponectin levels are typically lower in people with more body fat, which is part of why obesity can lead to health problems.

Question 5

Adrenocorticotropic hormone (ACTH)

Answer 5

Adrenocorticotropic hormone (ACTH) is produced by the pituitary gland. Its key function is to stimulate the production and release of cortisol from the cortex (outer part) of the adrenal gland.

Question 6

Aetiological

Answer 6

Aetiological refers to causing or contributing to a disease or condition.

Question 7

Allostasis

Answer 7

Allostasis is the process by which the body responds to stressors in order to regain homeostasis.

Question 8

Allostatic load

Answer 8

Allostatic load is often described as “the wear and tear on the body” which accumulates as an individual is exposed to repeated or chronic stress.

Question 9

Apoptosis

Answer 9

Apoptosis is the death of cells which occurs as a normal and controlled part of an organism’s growth or development.

Question 10

Cellular respiration

Answer 10

Cellular respiration is the process by which cells convert nutrients, primarily glucose, into energy in the form of adenosine triphosphate (ATP) to fuel cellular activities.

Question 11

Corticotropin-releasing hormone

Answer 11

Corticotropin-releasing hormone (CRH) is the central regulator of the hypothalamic-pituitary-adrenal (HPA) axis, which is the main organizer of the body’s response to stress. It is secreted by the paraventricular nucleus of the hypothalamus which, among other functions, releases hormones.

Question 12

Endocrine glands

Answer 12

Endocrine glands are glands that secrete substances directly into the bloodstream, including adrenal, pituitary, and thyroid glands.

Question 13

Enteroendocrine cells

Answer 13

Enteroendocrine cells are responsible for the regulation of appetite, digestion, intestinal absorption, and motility.

Question 14

Enzyme

Answer 14

Enzymes are proteins that speed up chemical reactions in our bodies. They act like a key to a lock, binding to specific molecules, called substrates, to carry out their jobs. Enzymes help with various functions, such as breaking down food in digestion or building DNA in cells. Without enzymes, these reactions would be too slow to support life.

Question 15

Exocrine glands

Answer 15

Exocrine glands are glands that secrete substances onto a surface such as the skin, but not into the bloodstream.

Question 16

Glands

Answer 16

Glands are cells or groups of cells that secrete substances for use by the body.

Question 17

Glucocorticoids

Answer 17

Glucocorticoids are steroid hormones secreted by the adrenal glands to produce powerful anti-inflammatory and metabolic effects. They block CRH and ACTH release, among other functions.

Question 18

Gut peptides

Answer 18

Gut peptides, also known as gastrointestinal peptides, are a group of hormones secreted by cells in the gastrointestinal (GI) tract. They play crucial roles in regulating a variety of functions including digestion, absorption of nutrients, gut motility, and appetite. Some well-known gut peptides include ghrelin, which stimulates appetite, and cholecystokinin (CCK), which promotes digestion and suppresses hunger.

Question 19

Luminal contents

Answer 19

Luminal contents refer to food particles, enzymes, etc., present in the space inside a small intestine. The nature of luminal contents can influence various physiological processes, including the activation of digestive enzymes and the signaling pathways involved in nutrient sensing.

Question 20

Holocrine secretion

Answer 20

Holocrine secretion is a method characterized by the purposeful self-destruction of the sebaceous gland’s primary cellular unit, the sebocyte, in order to produce sebum.

Question 21

Hypothalamic-pituitary-adrenal axis (HPA)

Answer 21

The hypothalamic-pituitary-adrenal axis (HPA) is best known as the primary regulator of the body’s stress response, connecting three hormone-secreting glands.

Question 22

Hypothalamus

Answer 22

The hypothalamus is a small neuroendocrine structure that regulates hormone secretion in the pituitary gland.

Question 23

Immunoglobulin A (IgA)

Answer 23

Immunoglobulin A (IgA) is an antibody blood protein that’s part of your immune system. It’s found in mucous membranes, mainly in the respiratory and digestive tracts, as well as in saliva, tears, and breastmilk. It plays a critical role in mucosal immunity. It functions by binding to pathogens and toxins, preventing them from entering or infecting the cells of the host organism. IgA exists mainly in two forms: serum IgA circulating in the blood and secretory IgA (sIgA) present in secretions on mucosal surfaces.

Question 24

Interleukin 8 (IL 8)

Answer 24

Interleukin 8 (IL-8) is a type of protein in our bodies called a cytokine. It plays a crucial role in the immune system’s response to inflammation and infection. IL-8 is produced by various cells, including immune cells and tissue cells, in response to an inflammatory signal. It attracts neutrophils, a type of white blood cell, to the site of inflammation to help fight against invading pathogens. However, if produced excessively, IL-8 can contribute to chronic inflammation and diseases, including some types of cancer.

Question 25

Keratinocyte

Answer 25

Keratinocytes are the primary cell type found in the epidermis, the outer layer of the skin. They produce keratin, a protein that provides strength and protection to the skin, hair, and nails. As keratinocytes mature, they move from the basal layer of the epidermis toward the surface, becoming flattened and eventually shedding off in a process known as desquamation.

Question 26

Kinase

Answer 26

Kinase is a type of enzyme (a protein that speeds up chemical reactions in the body) that adds chemicals called phosphates to other molecules, such as sugars or proteins. This may cause other molecules in the cell to become either active or inactive. Kinases are a part of many cell processes.

Question 27

Lipogenesis

Answer 27

Lipogenesis refers to the conversion of fatty acids and glycerol into fats, or a metabolic process through which acetyl-CoA is converted to triglyceride for storage in fat.

Question 28

Mast cells

Answer 28

Mast cells are a type of white blood cell residing in various tissues, predominantly in connective tissues and near blood vessels and nerves, playing a central role in immune responses. They contain granules rich in histamine and heparin and are involved in the inflammatory response, where they release these and other mediators in response to pathogens and allergens. While they are crucial in defending against pathogens, their activation can also contribute to allergic reactions and chronic inflammatory diseases.throughout the body.

Question 29

Paracrine signaling

Answer 29

Paracrine signaling is a method of cellular communication by which the cell secretes signaling molecules only to the nearby cells that have the relevant receptors, ultimately altering the behavior of those cells.

Question 30

Parasympathetic nervous system

Answer 30

The parasympathetic nervous system is the part of the autonomic nervous system that calms down the body, in contrast to the sympathetic nervous system which activates the fight-or-flight response.

Question 31

Pituitary gland

Answer 31

The pituitary gland is a hormone-secreting gland that sits just below the hypothalamus.

Question 32

Reactive oxygen species (ROS)

Answer 32

Reactive oxygen species (ROS) are chemically reactive molecules containing oxygen that are generated as by-products of various metabolic processes, primarily during cellular respiration in the mitochondria. ROS include free radicals, such as superoxide anion (O2•-), hydroxyl radical (•OH), and non-radical molecules like hydrogen peroxide (H2O2). At low to moderate levels, ROS play essential roles in cellular signaling, immune function, and other physiological processes. However, when ROS levels become too high, they can cause damage to cellular components, such as proteins, lipids, and DNA. This damage is known as oxidative stress.

Question 33

Sebocytes

Answer 33

Sebocytes are sebum-producing epithelial cells within the sebaceous gland.

Question 34

Stratum corneum

Answer 34

The stratum corneum is the top layer of the epidermis.

Question 35

Sympathetic nervous system

Answer 35

The sympathetic nervous system is the part of the autonomic nervous system that controls the fight or flight response in reaction to stressors.

Question 36

Toll-like receptors (TLRs)

Answer 36

Toll-like receptors (TLRs) are proteins that play a key role in the immune system. They’re found on the surface of certain cells, like immune cells, and help these cells recognize and respond to invading pathogens, like bacteria and viruses. When a TLR identifies the molecular patterns of a pathogen, it triggers an immune response. This includes the release of chemicals that promote inflammation and attract additional immune cells to the site of infection.

Question 37

Triglyceride

Answer 37

Triglyceride is the most common type of fat in the body.

Question 38

Urocortin

Answer 38

Urocortin is a peptide closely related to corticotropin releasing factor (CRF), which is a hypothalamic hormone regulating the secretion of corticotropin and the synthetic/secretory activity of the adrenal cortex.

Question 39

Vagus nerve

Answer 39

The vagus nerve is the main parasympathetic nerve of the body, transmitting signals from the gut and heart to the brain to modulate immune and inflammatory responses.

Question 40

Histamine

Answer 40

Histamine is a chemical messenger produced by mast cells that mediates:
-inflammatory reactions
-allergic reations
-gastric acid secretion
-limited neurotransmitter action in the brain

Question 41

Central nervous system

Answer 41

This consists of the brain and the spinal cord. It is the main processing center for the nervous system where it receives information, processes it, and then orchestrates responses based on the perceived information.

Question 42

Peripheral nervous system

Answer 42

This encompasses all the nerves outside of the CNS and connects the CNS to limbs and organs. It is further divided into the somatic nervous system, which controls voluntary movements, and the autonomic nervous system, which controls involuntary functions like heartbeat and digestion. The autonomic system is further divided into the sympathetic and parasympathetic nervous systems, which have opposing effects on the body’s organs and help to maintain homeostasis.

Question 43

Somatic nervous system

Answer 43

The somatic nervous system is a component of the peripheral nervous system that is responsible for voluntary movements and the perception of sensory information. It contains motor neurons that control skeletal muscles, allowing for actions such as walking and lifting, and sensory neurons that convey information from the sensory receptors (like those in the skin, muscles, and joints) to the central nervous system. This sensory-motor system is crucial for responding to the external environment and facilitating interactions with it through conscious control of muscles and the processing of sensory information.

Question 44

autonomic nervous system

Answer 44

The autonomic nervous system (ANS) is a division of the peripheral nervous system that controls involuntary and automatic bodily functions, such as heart rate, digestion, respiratory rate, and pupil dilation. Includes both the sympathetic and parasympathetic nervous systems.

Question 45

Diamine oxidase

Answer 45

Diamine oxidase (DAO) is an enzyme that is involved in the breakdown and metabolism of histamine, a molecule that plays roles in the immune system, digestive system, and the central nervous system. The enzyme helps in the catabolism of histamine and other amines in the gut, thereby regulating the levels of histamine in the body. Adequate levels of DAO are necessary to maintain histamine balance and prevent symptoms of histamine intolerance, which can include headaches, skin irritation, and digestive issues.

Question 46

Angiogenesis

Answer 46

Angiogenesis is the biological process by which new blood vessels form from pre-existing ones. This process is essential for growth, development, and wound healing, but it is also involved in the progression of diseases like cancer, where tumors stimulate the formation of new blood vessels to supply them with nutrients and oxygen. Various signaling molecules, such as vascular endothelial growth factor (VEGF), are crucial for the regulation of angiogenesis, and therapies that inhibit angiogenesis are used in treating certain types of cancer and other conditions.

Question 47

Tryptase

Answer 47

Tryptase is an enzyme primarily found in mast cells, which play a role in the immune system. Tryptase is released during an allergic reaction or inflammation and is involved in breaking down protein molecules. It is often measured in blood tests as an indicator of mast cell activation or allergic responses.

Question 48

de novo

Answer 48

from scratch

Question 49

in vivo vs. in vitro

Answer 49

In Vivo: This Latin term means “within the living” and refers to experiments or observations made in living organisms, such as animals or humans. In vivo studies provide comprehensive insights into biological processes in a natural, complex biological system, but they are usually more time-consuming and costly.

In Vitro: This Latin term means “in glass” and pertains to experiments conducted outside of living organisms, typically in a controlled environment like a test tube or petri dish. These studies are generally simpler, faster, and less expensive but may not fully capture the complexity of living systems.

Question 50

TLR-2

Answer 50

TLR-2 (Toll-like receptor 2) is a protein that plays a crucial role in the immune system as a part of the Toll-like receptor family. It is primarily found on the surface of immune cells like macrophages and dendritic cells, where it recognizes specific microbial components, such as lipoproteins and peptidoglycans from bacteria. Activation of TLR-2 triggers intracellular signaling pathways that ultimately result in the release of inflammatory cytokines and type I interferons, helping to initiate an immune response against the invading pathogens.

Question 51

Thyroid gland

Answer 51

The thyroid gland is a butterfly-shaped endocrine gland located in the front of the neck, below the Adam’s apple. It produces thyroid hormones, primarily thyroxine (T4) and triiodothyronine (T3), which regulate metabolism, growth, and development.

Question 52

glutathione

Answer 52

Glutathione is a powerful antioxidant produced in cells, composed of three amino acids—glutamine, cysteine, and glycine—that helps reduce oxidative stress and plays a key role in cellular detoxification processes.

Question 53

methylation

Answer 53

Methylation is a biochemical process in which a methyl group (CH3) is added to molecules, notably DNA, playing a critical role in regulating gene expression and maintaining DNA integrity. This process influences various bodily functions, from cell growth and repair to brain function and immune response, making it essential for overall health and well-being.

Question 54

lipase

Answer 54

Lipase is an enzyme that plays a critical role in the digestion of fats. It is primarily produced by the pancreas and secreted into the small intestine, where it breaks down dietary fats (triglycerides) into smaller molecules like fatty acids and glycerol, making them easier to absorb. Lipases are also found in other areas of the body, like the stomach and certain cells, where they assist in various metabolic processes involving fats. Insufficient lipase production can lead to difficulties in digesting and absorbing fats, leading to symptoms like diarrhea and nutritional deficiencies.

Question 55

hydrolyze

Answer 55

To “hydrolyze” means to chemically break down a compound by reacting it with water. In this process, a water molecule (H2O) is used to break chemical bonds, typically resulting in the fragmentation of a larger molecule into smaller components. Hydrolysis is a common reaction in biology and chemistry, playing a key role in many physiological processes, such as the digestion of food where macromolecules like proteins, fats, and carbohydrates are hydrolyzed into their constituent parts (amino acids, fatty acids, and sugars, respectively) for absorption and use by the body.

Question 56

Pregnenolone

Answer 56

It seems you might be referring to “Pregnenolone,” which is a precursor steroid hormone. Pregnenolone is synthesized from cholesterol and serves as the foundational compound from which all other steroid hormones are produced, including progesterone, cortisol, aldosterone, estrogen, and testosterone. It’s produced in the adrenal glands, gonads, and brain, and plays a role in the functioning of the central nervous system, potentially influencing mood and memory. As a precursor to various hormones, its levels and balance are crucial for overall hormonal health.

Question 57

factors that influence enzyme secretion

Answer 57

Localization: Many enzymes are confined to specific cells or compartments. For example, digestive enzymes like lipases and proteases are secreted into the digestive tract where they encounter their substrates (fats and proteins).

Regulation: Enzyme activity is tightly controlled by various mechanisms. This includes factors like pH level, the presence of co-factors or inhibitors, and the concentration of substrate. For instance, pepsin, a digestive enzyme in the stomach, is only active in acidic conditions.

Transportation and Secretion: Enzymes are often synthesized in one location and then transported or secreted to the site of action. For example, the pancreas produces digestive enzymes and releases them into the small intestine.

Signal Response: Enzymatic activity can be triggered by specific signals. For example, the presence of food in the stomach triggers the release of digestive enzymes.

Question 58

humoral signals

Answer 58

Humoral signals refer to the transmission of information in the body through substances in the blood or other bodily fluids. These substances, often hormones or other chemical messengers, are secreted by glands or tissues and travel through the bloodstream to target organs or cells, where they exert specific effects. This type of signaling is crucial for coordinating complex bodily functions, such as metabolism, growth, and immune responses.

Question 59

neuropeptide

Answer 59

A neuropeptide is a small protein-like molecule used by neurons (nerve cells) to communicate with each other. These molecules are similar to neurotransmitters, but are typically longer and have more complex structures. Neuropeptides are involved in a wide range of brain functions, such as pain perception, reward, food intake, metabolism, reproduction, social behaviors, learning, and memory. They are synthesized and released by neurons and act by binding to specific receptors on the surface of target cells, often with longer-lasting effects than neurotransmitters. Examples of neuropeptides include endorphins, which are involved in pain relief and feelings of pleasure, and substance P, involved in the pain response.

Question 60

SP+ nerves

Answer 60

“SP+ nerves” typically refers to nerves that contain Substance P, a neuropeptide. Substance P is involved in the transmission of pain and other sensory messages to the brain and is found in specific neurons of the central and peripheral nervous systems. These SP+ neurons play a crucial role in pain perception and the inflammatory response. Substance P is often studied in the context of pain, itch, and their regulation, and it can also influence other processes like mood, anxiety, nausea, and the stress response.

Question 61

prolactin

Answer 61

Prolactin is a hormone produced by the pituitary gland, and in men, it plays a role in modulating immune functions and possibly influencing reproductive health. While its functions in men are not as well understood as in women, high levels of prolactin in men can lead to decreased libido and erectile dysfunction. Factors that can cause elevated prolactin levels include stress, certain medications (like antipsychotics and antidepressants), pituitary tumors (prolactinomas), and conditions affecting the hypothalamus.

Question 62

nucleic acid

Answer 62

Nucleic acids are large molecules essential for storing and transmitting genetic information. DNA (deoxyribonucleic acid) carries genetic blueprints in cells, while RNA (ribonucleic acid) helps in protein synthesis based on those blueprints.