Which substance does not leave the nephrons by active transport?
a)Potassium ions
b)Water
c)Calcium ions
d)Phosphate ions
e)glucose
I think its either water or glucose...
Another question..
Two strategies- negative feedback and antagonistic hormones- have evolved to maintain a dynamic equilibrium within the body of a mammal. Describe how these two strategies maintain homeostatsis.
help pleaseee
the female ovary is analogous to the male
To determine which substance does not leave the nephrons by active transport, let's break down each option and understand the process involved:
a) Potassium ions: Potassium ions are actively reabsorbed in several segments of the nephron, particularly the proximal tubule and the ascending limb of the loop of Henle. Therefore, it is not the correct answer.
b) Water: Water is reabsorbed passively in the nephrons, primarily through osmosis. It follows the osmotic gradient established by the active transport of solutes such as sodium and chloride ions. Therefore, it does not leave the nephrons by active transport, making it a potential correct answer.
c) Calcium ions: Calcium ions are actively reabsorbed in the proximal tubule and the thick ascending limb of the loop of Henle. Therefore, it is not the correct answer.
d) Phosphate ions: Phosphate ions are reabsorbed in the proximal tubule through mostly passive mechanisms, including solvent drag and electrostatic attraction to sodium ions. Therefore, it is not the correct answer.
e) Glucose: Glucose is actively reabsorbed in the proximal tubule through sodium-glucose cotransporters. Therefore, it is not the correct answer.
Based on the above analysis, the correct answer is b) Water.
Regarding your second question about how negative feedback and antagonistic hormones maintain homeostasis, here's an explanation:
Negative feedback is a regulatory mechanism that responds to changes in the body and works to counteract or reverse those changes. For example, in thermoregulation, if body temperature rises above the set point, negative feedback mechanisms are activated to lower it. This can involve processes like dilating blood vessels to release heat, sweating, or reducing metabolic activity.
Antagonistic hormones, on the other hand, are hormones that have opposing effects and act to maintain balance. For instance, insulin and glucagon are antagonistic hormones that regulate blood glucose levels. When blood glucose is high, insulin is released to facilitate glucose uptake and storage. Conversely, when blood glucose is low, glucagon is released to stimulate glycogen breakdown and increase blood glucose.
Both negative feedback and antagonistic hormones play crucial roles in maintaining homeostasis by continuously monitoring and adjusting physiological processes to keep them within an optimal range. They work together to stabilize various body parameters such as body temperature, blood glucose levels, blood pressure, and pH levels, ensuring the body functions effectively.