Topic 6C Homeostasis Flashcards
What is homeostasis?
Homeostasis is the maintenance of a stable internal environment within the body, despite changes in external conditions, to ensure optimal functioning of cells and organs.
Why is homeostasis important for organisms?
Homeostasis is essential because it ensures that internal conditions, such as temperature, pH, and glucose concentration, remain within a range suitable for enzyme activity and other cellular processes.
What are the key components of a homeostatic system?
A homeostatic system consists of receptors (detect changes), control centers (process information and decide response), and effectors (carry out responses to restore balance).
What is blood glucose concentration?
Blood glucose concentration refers to the amount of glucose present in the blood, which is important for providing energy to cells.
How does the body control blood glucose levels?
Blood glucose levels are controlled by insulin and glucagon, hormones secreted by the pancreas that lower and raise blood glucose levels, respectively.
How does insulin lower blood glucose levels?
Insulin promotes the uptake of glucose by cells, especially muscle and liver cells, where it can be stored as glycogen, thereby lowering blood glucose levels.
How does glucagon raise blood glucose levels?
Glucagon stimulates the liver to break down glycogen into glucose and release it into the bloodstream, raising blood glucose levels.
What is glycogen?
Glycogen is a polysaccharide stored in the liver and muscles, used as a reserve of glucose when blood glucose levels drop.
What is diabetes?
Diabetes is a condition where the body cannot properly regulate blood glucose levels, either due to insufficient insulin production (Type 1) or insulin resistance (Type 2).
What is the role of the kidneys in homeostasis?
The kidneys help maintain homeostasis by filtering blood to remove waste products, regulating water and electrolyte balance, and controlling blood pressure.
What is ultrafiltration in the kidneys?
Ultrafiltration is the process by which blood is filtered in the kidney’s glomerulus, allowing small molecules like water, glucose, and urea to pass into the renal capsule while retaining large molecules like proteins.
What is selective reabsorption?
Selective reabsorption is the process in which essential substances such as glucose, amino acids, and water are reabsorbed from the filtrate in the nephron back into the blood.
What is the role of the loop of Henle in the kidneys?
The loop of Henle helps concentrate urine and maintain water and salt balance by creating a concentration gradient in the medulla of the kidney.
What is ADH (antidiuretic hormone) and how does it affect the kidneys?
ADH is a hormone released by the pituitary gland that increases the permeability of the collecting ducts in the kidneys, allowing more water to be reabsorbed and concentrated urine to be produced.
What is blood water potential?
Blood water potential is the potential energy of water in the blood, which is influenced by the amount of water and solutes, such as salts and proteins, in the bloodstream.
How does the body regulate blood water potential?
Blood water potential is regulated by the kidneys, which adjust the amount of water reabsorbed and the concentration of urine, influenced by hormones like ADH and the body’s hydration status.
How does ADH control blood water potential?
ADH helps to regulate blood water potential by promoting water reabsorption in the kidneys’ collecting ducts, decreasing water excretion in urine when blood water potential is low.
What happens when blood water potential is too high?
If blood water potential is too high (too diluted), less ADH is released, causing the kidneys to excrete more water in urine to restore the balance.
What happens when blood water potential is too low?
If blood water potential is too low (too concentrated), more ADH is released, causing the kidneys to reabsorb more water and produce more concentrated urine.
What is Homeostasis?
The process of maintaining a stable internal environment in the body to ensure optimal functioning of cells and organs.
What is Blood Glucose Concentration
The level of glucose in the blood, which is regulated by hormones like insulin and glucagon to provide energy for cells.
What is insulin?
A hormone produced by the pancreas that lowers blood glucose levels by promoting glucose uptake and storage as glycogen in cells.
What is Glucagon?
A hormone produced by the pancreas that raises blood glucose levels by stimulating the liver to release glucose from glycogen stores.
What is Glycogen?
A polysaccharide that serves as a storage form of glucose in the liver and muscles.
What is diabetes?
A condition where the body cannot properly regulate blood glucose levels due to insulin deficiency (Type 1) or insulin resistance (Type 2).
What are Kidneys?
Organs that filter waste products from the blood, regulate water and electrolyte balance, and help control blood pressure.
What is Ultrafiltration?
The process by which blood is filtered in the kidneys, allowing small molecules to pass into the renal capsule while retaining large molecules.
What is Selective Reabsorption?
The process in which essential substances such as glucose, amino acids, and water are reabsorbed from the nephron filtrate back into the blood.
What is the Loop of Henle?
A part of the nephron that helps concentrate urine by creating a concentration gradient in the kidney medulla, enabling water and salt reabsorption.
What is ADH (Antidiuretic Hormone)?
A hormone released by the pituitary gland that regulates water reabsorption in the kidneys, helping control blood water potential.
What is Blood Water Potential?
The potential energy of water in the blood, influenced by solutes like salts and proteins, and regulated by the kidneys to maintain balance.
