Hormones

Follicle-stimulating hormone (FSH) is a glycoprotein gonadotropin secreted by the anterior pituitary in response to gonadotropin-releasing hormone (GnRH), which is released by the hypothalamus.

No, the pituitary gland does not secrete aldosterone. Aldosterone is primarily secreted by the adrenal glands, specifically by the outer layer called the adrenal cortex. The hormone aldosterone plays a key role in regulating blood pressure and electrolyte balance in the body.

The distal tubule and collecting duct are the parts of the nephron that are under the control of the hormones ADH (antidiuretic hormone) and aldosterone. These hormones regulate water reabsorption and sodium reabsorption, respectively, in these segments of the nephron.

Cortisol is a steroid produced in the adrenal cortex (top portion of the kidney). It is called a stress hormone because its production increases when a person experiences stress to elicit the fight or flight response to deal with the stressful situation.

Gastrin is a hormone produced by the stomach that stimulates the release of gastric acid, aiding in the digestion of food. It also plays a role in regulating the emptying of the stomach and the movement of food through the digestive tract. Abnormal levels of gastrin can lead to conditions like gastritis and peptic ulcers.

Oxytocin release is a positive feedback control mechanism. This means that an initial stimulus triggers the release of oxytocin, which then promotes further release of oxytocin, amplifying the response until a specific outcome is achieved, such as uterine contractions during childbirth.

Yes, antidiuretic hormone (ADH) is a peptide hormone composed of nine amino acids. It is produced in the hypothalamus and released from the pituitary gland to regulate water balance in the body by increasing water reabsorption in the kidneys.

Delta cells, also known as D cells, are responsible for producing somatostatin in the pancreas. Somatostatin is a hormone that inhibits the secretion of other hormones, such as insulin and glucagon, and has various functions in the body including regulating digestion and inhibiting the release of growth hormone.

Prostacyclin (PGI2) opposes the action of thromboxane A2. They are both derived from arachidonic acid and have opposite effects on platelet aggregation and blood clot formation. Prostacyclin acts as a vasodilator and inhibits platelet aggregation, counteracting the pro-thrombotic effects of thromboxane A2.

Adrenaline is secreted by the adrenal glands into the bloodstream in response to stress, fear, or excitement to prepare the body for the "fight or flight" response. This hormone increases heart rate, boosts energy levels, and enhances focus to help the body respond quickly to perceived threats.

Yes, oxytocin release is an example of a positive feedback control mechanism. In response to stimuli such as childbirth or breastfeeding, oxytocin is released, which leads to stronger contractions in the uterus or milk let-down reflex, further stimulating more oxytocin release. This cycle reinforces and amplifies the initial stimulus.

Glycogen is a form of stored glucose in the body, primarily found in the liver and muscles. Glucagon is a hormone that helps release glucose from glycogen when blood sugar levels are low, providing energy for the body. Think of glucagon as "glucose-gone" - it helps to release glucose when it's gone.

No, not all living organisms have insulin. Insulin is a hormone that is produced by the pancreas of vertebrates, such as humans and other mammals. Invertebrates and other non-vertebrate organisms do not have insulin as it is a hormone specific to vertebrate metabolism.

Yes insulin and glucagon are antagonistic hormones, as they antagonize, or incite a reaction, the liver into transforming glucose into glycogen when the blood sugar levels are high (insulin), and transforming glycogen into glucose when the blood sugar levels are low (glucagon).

The primary chemical affected by the renin-angiotensin-aldosterone system is angiotensin II. This hormone is involved in regulating blood pressure and electrolyte balance by causing vasoconstriction and stimulating the release of aldosterone from the adrenal glands.

No, insulin is a small protein hormone composed of two peptide chains. It is not a polymer.

When sodium ions are reabsorbed in response to aldosterone, potassium ions are often secreted into the urine to maintain electrolyte balance. Aldosterone triggers the reabsorption of sodium in exchange for the secretion of potassium in the distal tubules of the kidney. This mechanism helps to regulate blood pressure and electrolyte balance in the body.

Insulin antagonizes glucagon. Insulin is released by the pancreas in response to high blood sugar levels, and it works to lower blood sugar levels by promoting the uptake of glucose by cells and inhibiting the release of glucose from the liver. This is in contrast to glucagon, which is released when blood sugar levels are low and works to increase blood sugar levels by promoting the release of glucose from the liver.

Blood calcium levels are greater when parathyroid hormone is increased. Parathyroid hormone helps regulate calcium levels in the blood by promoting its release from bones and increasing its absorption from the intestines, leading to higher blood calcium levels.

True. The islets of Langerhans in the pancreas produce insulin and glucagon, which have opposite effects on blood glucose levels. Insulin lowers blood sugar levels by promoting glucose uptake by cells, while glucagon raises blood sugar levels by promoting the release of glucose from the liver. These hormones work together to regulate blood glucose levels.

Adrenaline, also known as epinephrine, is a hormone that triggers the body's "fight or flight" response, increasing heart rate and blood flow to muscles. Dopamine is a neurotransmitter that plays a role in regulating mood, motivation, and pleasure. While adrenaline is released in response to stress and danger, dopamine is involved in rewarding behaviors and movement control.

No, aldosterone is not a water-soluble hormone; it is a steroid hormone that is soluble in lipids (fats). Aldosterone is produced in the adrenal glands and plays a key role in regulating salt and water balance in the body.

Decreased blood pH. Aldosterone increases sodium reabsorption in the kidneys, leading to increased hydrogen ion secretion as a compensatory mechanism to maintain electrolyte balance. This can result in acidosis, leading to a lower blood pH.

Enkephalins and endorphins are neuromodulators because they can influence the activity of neurotransmitters in the brain by interacting with specific receptors, altering the cell's response to those neurotransmitters. This modulation can result in changes in pain perception, mood, and overall brain function.

Yes, oxytocin plays a key role in milk ejection during breastfeeding. When a baby suckles, oxytocin is released from the brain, causing the muscles around the milk-producing cells to contract and push milk into the ducts for the baby to feed on.