Yea I don’t know im sorry
exhalation results mainly from our brain telling our lungs the exhale the Co2 and add more oxygen in our lungs.
If we pick small intestine as and organ we can observe its large the surface area/volume ratio. The ration between surface and volume is important, because it impact the function of the organ. In this case, small intestine absorbs the nutrients more efficiently. The surface of the small intestine is increased due to finely wrinkled internal surface and convoluted surface composed of the microvilli (cellular membrane extensions for better absorption).
Answer:
Negative feedback loop
Explanation:
When the blood calcium level is low, the receptors of the parathyroid gland sense it and increase the production of cAMP. The increased cAMP levels stimulate the secretion and release of parathyroid hormone from the parathyroid gland into the blood.
The increased parathyroid hormone levels stimulate the number and activity of osteoclasts and speed up the process of bone resorption resulting in the release of calcium ions from bone into the blood to raise the blood calcium levels.
Here, the response (increased blood calcium level) reverse the stimulate and hence, the process is under the regulation of negative feedback loop
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<h2>Urea </h2>
Explanation:
Urea is a small nitrogenous compound which is the main end product of protein catabolism in mammals
- Urea is a nitrogen-containing substance normally cleared from the blood by the kidney into the urine
- It is made predominantly in the liver from ammonia and bicarbonate and is one of the main components of urine
- The rate of synthesis varies from 300 to 600 mmol/day depending on the protein intake
- All of this urea eventually finds its way into the urine
- Because urea makes up a large part of the obligatory solute excretion, its osmotic pressure requires significant volumes of water to carry the urea
- Urea passively crosses biological membranes, but its permeability is low because of its low solubility in the lipid bilayer
- Some cells speed up this process through urea transporters, which move urea by facilitated diffusion
- Urea is passively reabsorbed in the proximal tubule, but its route of transport is not clear
- Urea transporters have not yet been identified for the proximal tubule
