17
votes
Accepted
Why do you die if you cannot breathe?
Short answer
This is a difficult question to answer. As far as I am aware, asphyxiation results in excitotoxicity, which causes unconsciousness, brain damage and eventually, death.
Background
...
- 52.2k
10
votes
Accepted
Darwinism and the idea of being too successful
Photosynthesis.
early photosynthesizers, which would have been adapted for a reducing atmosphere, drove themselves extinct as they dumped oxygen into the atmosphere as a waste product. They were ...
- 13.9k
9
votes
Why do we get sleeply after we eat?
After we have eaten... the maximum blood supply is transferred towards the digestive system so that digestion is done, and therefore the brain to does not get adequate blood supply. Am I right about ...
- 24.7k
8
votes
What biological functions does crying serve?
Lets break this question into parts and answer them one by one.
Do tears really save us from harm?
Well, yes. Tears, mucus and saliva contain an enzyme lysozyme that breaks down the cell wall of ...
- 14.1k
6
votes
Accepted
What is enantiostasis?
Both are ways for an organism to adapt to the environment, but enantiostasis focuses on maintaining functionality while homeostasis focuses on maintaining a stable internal environment.
For example, ...
- 176
6
votes
Accepted
Why antipyretics do not bring the body-temperature below normal?
Antipyretics doesn't work by reducing the body temperature but blocking pathways that make it higher.
For paracetamol/acetaminophen the mechanisms implied are not currently completely clear (as ...
- 180
5
votes
Accepted
why do our eyes not go red in response to body temperature?
Skin turns red when light skinned people flush because it contains few absorbers, so photons diffuse through it long distances. During this time green and blue light is absorbed as photons encounter ...
- 952
5
votes
Is lemon water an alkalizing agent in the body?
The excellent answers from Chris and One Face have already written about why the claim is wrong, so I'm going to add a hypothesis for how this sort of nonsense could even originate in the first place.
...
- 360
4
votes
How can hyperthyroidism induce osteoporosis?
T3 stimulates osteoclast formation. Osteoclasts are cells that break down bone tissue. They are essential for bone growth in children, because they allow bone remodelling. However, elevated ...
4
votes
Why don't cats have to pant?
Transpiring and panting are ways to regulate body temperature. When sweat evaporates, it cools the skin, and panting releases heat through the mouth. Horses, humans and even plants transpire for this ...
- 52.2k
4
votes
Accepted
Regulation of the TCA cycle and glycolysis by adenine nucleotides
Summary
Glycolysis and the tricarboxylic acid cycle (TCA cycle) are distinct processes which are not necessarily linked sequentially. It is therefore not surprising that their modes of regulation are ...
- 23.8k
3
votes
Accepted
At what calcium concentration does the Sodium-Calcium Exchanger (NCX) "turn on"?
I could not find the $K_d$ of NCX proteins in KEGG BRITE, BRENDA, SuperTarget, DrugBank, Uniprot, or PDSP Ki databases...
(Also, I cannot understand the use of the word 'relevant' in the question you ...
- 606
3
votes
Accepted
Can oral baking soda effect tumor cells in mice
What can oral baking soda do?
If your question is (which I don't think it is):
Does baking soda cure cancer?
The answer is that there is no support for that statement.
If your question is:
Can oral ...
- 8,741
3
votes
Accepted
Can tardigrades survive being eaten?
In there natural state no, tartigrade have absolutely no way to survive the acidic content of stomachs and are fragile.
In their cryptobiosed form (extremely resilient form) there has been no ...
- 858
3
votes
Accepted
Osmolarity vs. Tonicity
You're correct that tonicity needs two solutions to define.
Osmolarity (or osmotic concentration) is the measure of solute concentration, defined as the number of osmoles of solute per litre (L) of ...
- 176
2
votes
Accepted
Blood pH at Higher Altitudes
The following chemical equation explains why pH decreases with increased $CO_2$:
$CO_2 + H_2O \rightleftharpoons H^+ + HCO^{-3}$
pH changes are the reason why oxygen binds to hemoglobin in you ...
- 519
2
votes
How does the brain regulate its temperature?
From what I can make up from your question is that you assume the blood in the brain is a bad thing in terms of temperature control. It is not. On the contrary, blood circulation is crucial in ...
- 52.2k
2
votes
Accepted
How do poiklotherms survive at different temperatures even though enzymes work at specific temperature?
Instead of viewing poikilotherms as having the same temperature as the environment, view them as lacking an internal thermoregulatory system. Poikilotherms indeed suffer from not having the ability to ...
- 4,669
2
votes
Darwinism and the idea of being too successful
Going exinct hardly counts for being successful. Let us, take, e.g., Ebola - a virus that is efficiently transmitted and quickly replocates, but ends up killing most of the hosts. It quickly goes ...
- 3,812
1
vote
Hypothalamus and posterior pituitary gland in ADH production
Your second hypothesis is correct.
Hypothalamus secretes vasopressin (ADH), transports it along the axons and stores it in the posterior pituitary, thereby when hypothalamus senses the stimuli(osmotic ...
- 132
1
vote
Accepted
Why don't cats have to pant?
Cats are smaller and hotter than dogs and humans, with a temperature between 100.4°F and 102.5°F (38.1°C to 39.2°C).
Smaller animals have a higher surface-to-volume ratio and so radiate excess heat ...
- 2,836
1
vote
Are there any benefits/disadvantages/traits from having a permanent lower core temperature?
Yes absolutely. Body temperature is associated with basal metabolic rate which is linked to life-span/body mass. Keeping your body at temperature is responsible for the majority of your caloric burden ...
- 226
1
vote
Accepted
Role of the Hypothalmus in the control of Blood Sugar
Your question doesn’t make it clear whether you think that the pancreas must be under the control of the hypothalmus, or whether you are asking whether it has an influence on the pancreas in relation ...
- 23.8k
1
vote
Why do endotherms need more food than ectotherms?
Here's a (hopefully) simple answer:
Ectotherms eat, and convert most of the energy in their food into new biomass (i.e. producing more tissue and growing). Between meals their metabolism (all the ...
- 11
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