The study of the normal function of living organisms and the means by which it is achieved.

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8
votes
2answers
84 views

What is the convention for log notation in biology?

I'm reading through some oldish (1980s) papers on length-weight relationships in fish and crustaceans. Many report log-log relationships without specifying whether this is natural log, base 10, etc. ...
6
votes
1answer
67 views

Why is the brain dependent on glucose?

The strict dependence of the (human) brain on glucose has always been puzzling to me. While ketones can substitute for a portion of the brain's energy needs, it cannot substitute completely: blood ...
1
vote
1answer
21 views

Are there fish with a double circulatory system?

Our courseware materials say there are such fish, but the internet suggests fish only have a single circulatory system. Thanks!
4
votes
0answers
22 views

What are those visual and auditory reflex controlled by the midbrain?

The midbrain is a centre for certain visual and auditory reflexes. But what are those reflexes exactly? My study book says that these reflexes are, e.g., responsible for moving the eyes to view ...
3
votes
2answers
47 views

Determining how much energy a plant takes in?

I asked a question on WorldBuilding.SE, "Are diamond berries possible?". This led to asking a question on Chemistry.SE about the amount of energy required to burn a 1 ct. diamond (โˆ’6.527kJ). The ...
2
votes
1answer
23 views

Where does the exudate comes from during inflammation?

During inflammation transudate and exudate is formed by vessels. I would like to make sure if it comes from arterioles, venules, or both, and the reason why.
1
vote
0answers
49 views

Why can we control our breath rate but not our heart rate? [closed]

Even though we cannot survive for more than few minutes if we stop breathing or if our heart stops, why is it so that our heart beat is controlled involuntarily while breathing can be voluntarily ...
1
vote
0answers
41 views

How many mitotic divisions do haploid cells undergo before fertilization?

Background This question is about human physiology and gametogenesis. A spermatozoid is not necessarily the direct "offspring" of diploid cell. Stated differently, a spermatozoid cell can be the ...
-5
votes
1answer
56 views

Why do fingers swell during cold winters?

When exercising, tissue in the hands may swell. This may be caused by the muscles generating heat, which leads to blood being pushed to the vessels closest to the surface of your body to dissipate the ...
10
votes
4answers
641 views

How can we differentiate between respiration and breathing?

I am a student of 10th grade, and I eagerly want to learn biology. What is the difference between respiration and breathing?
2
votes
3answers
65 views

Why Doesnโ€™t Hypercalcemia Cause Muscle Spasms?

If you have more calcium in the cell, wouldnโ€™t more attach to troponin and initiate muscle contraction? Why does hypercalcemia cause muscle weakness instead of spasms?
1
vote
1answer
27 views

Does creatine-phosphate (CP) supplementation regenerate NADH?

I have the following facts: It is possible to convert ATP <-> creatine vice-versa. (ref - non scientific) CP supplementation protects against metabolic syndrome. ref1 ref2 Fructose digestion ...
2
votes
1answer
50 views

Does breathing air containing 3% carbon dioxide gives you a headache?

As far as I know, breathing air containing relatively high levels of CO2 may get you a headache. I also know that CO2 level in the fruit bodies of peppers can reach levels as high as 3% at certain ...
2
votes
2answers
75 views

Difference between facilitated diffusion and secondary active transport in cells

Specifically, what is the difference between facilitated diffusion carrier processes (passive transport) and secondary active transport co-transport processes (active transport)? They seem to be the ...
1
vote
1answer
42 views

How is ATP involved in muscle contraction?

The sliding filament mechanism as explained by my text does not elaborate on how ATP is involved in the cross bridge binding and contraction process. How does muscle contraction utilize ATP? In my ...
0
votes
1answer
95 views

Why should or shouldn't we allow the human body to take its natural course? [closed]

For example, when you are sick but don't feel thirsty, this could be due to baroreceptor reflex that is attempting to readjust salt and water balancing. Why shouldn't a patient be left thirsty and ...
4
votes
1answer
89 views

Question about epinephrine

In my class we were told that adrenaline (or epinephrine) causes vasoconstriction. My question was I had always thought that people took this via an EpiPen when they were having an allergic reaction. ...
3
votes
1answer
105 views

Why do people in the scientific community use terminology such as renal, hepatic, cardiac instead of kidney, liver and heart? [closed]

Why is there the need to map these everyday words into another set of words, it seems to complicate matters. Is it done mostly out of tradition or is there some logical basis to it?
0
votes
0answers
24 views

What is the difference between specific and nonspecific stress response?

My book states that given any stressor, the body will response by providing a specific response to that stressor and a non-specific response that is triggered no matter what the stressor is (fear, ...
0
votes
0answers
18 views

Can you feel cortisol release?

Cortisol release is pretty well studied but I am curious as to why there are so many pulses throughout the day but yet I do not feel any of it. More curious is that I experience focus and energy at ...
2
votes
2answers
80 views

When glucose production is low, the brain turns into keto acid as an energy source, how does this work?

Can someone very generally describe how the brain consumes keto acid when blood sugar has been completely depleted?
1
vote
1answer
22 views

What is the so called “hepatic glucose production”

I came across this term in my readings but I do not understand how this works. Can someone direct me to some reference as to what this "hepatic" glucose production is all about?
1
vote
1answer
42 views

Given an EC50 value, how do I reproduce the sigmoidal curve from which this was calculated?

All-trans retinoic acid (atRA) is a potent ligand for a nuclear receptor called retinoic acid receptor alpha (RARa). The concentration of atRA at which RARa is half maximal is 19nM. The dose-response ...
3
votes
1answer
36 views

Liver - Regeneration in Cirrhosis

Liver is the most resilient of the human organ (on par with or next to skin). A very interesting experiment on liver regeneration is here. Even if two-thirds of the liver is removed, the remaining ...
4
votes
0answers
31 views

Case Study and speculations of Edward Mordake

I am very interested in the case of the man named Edward Mordake who lived in the 19th century. In particular, he had two faces. If you have not heard of this man, please, search this up as there are ...
3
votes
0answers
25 views

Blood as newtonian flow and Poiseuille law [closed]

For a prep exam: A healtly pacient has a carotid with the following characteristics: intern ratio: ๐‘…= 2.8 mm, ๐‘ƒ2 = 89 ๐‘š๐‘š๐ป๐‘”, ๐‘ƒ1 = 90 ๐‘š๐‘š๐ป๐‘”, ๐œ‡blood = 3.5 cp, ๐ฟ=10.0 cm. Using the ...
2
votes
1answer
46 views

How to define drug-resistant or -sensitive cell line when knowing the IC50 values?

I have got the IC50 data for a drug on different cell lines. How to define if the cell line is sensitive or resistant towards this drug? Could anyone tell me how to define this?
2
votes
1answer
18 views

How is circadian rhythm of gastric acid secretion regulated?

Gastric acid secretion shows a circadian rhythm where acid production in the morning is minimal and it reaches a maximum towards the evening. How is this process regulated?
2
votes
2answers
42 views

What is the difference between meristem and bud?

Keep reading both terms quite frequently while studying plant physiology. I did some research trying to establish their differences and I learnt that meristems are undifferentiated cells that can ...
1
vote
2answers
359 views

Why can newborns swim?

I am wondering for someone to discuss the phenomena that newborn babies (humans) are able to submerge underwater up until a few months where that ability is lost again? What is the explanation for ...
3
votes
1answer
70 views

What is the impact of stress on the human body?

Can stress trigger any changes in the human body? I'd like to know more about things less commonly known than, for example: sweating and tiredness. What are the long term risks of chronic stress? Do ...
8
votes
2answers
132 views

Should we induce fever to assist healing?

I am currently reading "The Fundamentals of Anatomy Physiology" 10th edition, and have found it an incredibly interesting book. I have just been reading about the lymphatic system, and the various ...
0
votes
1answer
103 views

Similarity between a heart attack and a spasm

When someone is having a heart attack, could it be considered , in some situations, a spasm? Below, I have written how I believe the process may work. The heart is basically a muscle working ...
6
votes
5answers
85 views

Is the amount of blood that flows through every vein and artery per minute really a constant?

I was listening lectures from Mark Saltzman via Open Yale Courses. Now, if I did not understand him wrong, he said that the amount of blood that travels through every vein and artery in our bodies per ...
5
votes
1answer
59 views

Is hands-only CPR as effective as traditional CPR?

Is hands-only CPR as effective as traditional CPR ? Wouldn't 30 chest compressions + 2 rescue breaths be more effective if the person doesn't have a pulse AND not breathing? From my understanding ...
6
votes
2answers
144 views

What physiological processes within a muscle cause the latent period in a muscle fiber?

This is a lab question I cant find the answer in the lab manual or in the text book. What physiological processes in a muscle cause the latent period in a muscle fiber? Please help. Edit: The latent ...
2
votes
1answer
42 views

Is Norway spruce (Picea abies (L.) Karst.) isohydric or anisohydric species?

Question from a thesis defense list ask me this. But I can't find the exact answer on the internet or in books. In my thesis, I described isohydric plants, for example maize, lupin, pea, poplar. This ...
1
vote
0answers
26 views

how food moves in horizontal coils of small intestines [duplicate]

This is a very very basic question, and I am looking at it more from point of view of physics. The small intestine is a highly coiled structure, which means it has horizontal coils as well. I can ...
2
votes
1answer
39 views

Detailed mechanism of the cause of diabetes mellitus type 1?

I have read in some texts that diabetes mellitus type 1 is caused by degeneration of beta cells due to our body's own immune reaction.Is it true? Can you explain further how are such types of immune ...
1
vote
1answer
40 views

How does ANF increase GFR?

ANF as we know reduce the Na+ uptake and K+ removal in the distal tubules and it also functions as a Vasodialator (?) But again it says that ANF increases the Glomerular filtrate ? But if it is acting ...
3
votes
0answers
32 views

Normal ECG/EKG Measurement?

I'm getting started using ECG using a 3 lead system by iWorx. I have place the leads on my two wrists and the ground on my ankle and have recorded some data into the provided LabScribe 3 software ...
1
vote
3answers
93 views

Does the necessary Carbon Dioxide need to be in the atmosphere for mammals?

In the answers to this question, we've learnt that carbon dioxide is necessary for mammalian life, but is it necessary in the atmosphere/to breathe it in? Or does the act of respiration give a ...
2
votes
1answer
47 views

Genetic abscence of backpain among teen girls? [closed]

I heard a study somewhere (I can't remember where) that claimed that teenage girls are genetically absent to experience high degrees of backpain, specifically from rigorous exercise. Strangely, of ...
9
votes
2answers
93 views

Why can good music raise goosebumps?

Listening to really good music right now, I was wondering why it raises goosebumps. Is there any physiological reason for this reaction to specific wavelengths or something? EDIT: Due sometimes ...
4
votes
1answer
177 views

Relationship between nerves and axons

I just wanted to get a realistic viewpoint of our nervous system. I understand arteries and veins, but I wanted to know how similar our nervous system is to that? I understand we have neurons ...
3
votes
0answers
79 views

What's Incomplete atrioventricular heart block (AV)? [closed]

This is unclear for me and I can not understand differences between complete and incomplete atrioventricular heart block.also I want an electrocardiograph of incomplete atrioventricular heart block.
11
votes
2answers
231 views

Why do we urinate more when we are nervous?

This question is a result of my personal experience... But I guess that is common for many of us. My school timing is 8:00 am to 1:30 pm (usually). During normal school days I typically urinate one ...
2
votes
1answer
63 views

Biphasic T wave caused by digitalis toxicity

Digitalis is a drug that can be used during coronary insufficiency to increase the strength of cardiac muscle contraction. But when overdosages of digitalis are given, depolarization duration ...
2
votes
1answer
86 views

What happens to our umbilical cord internally as we age?

I was always curious as to if or how much of the internal structure or workings of the umbilical cord are still in existence as we age. What happens to it over time? The wikipedia article naval ...
0
votes
1answer
76 views

Why is pericardium muscle repolarizated earlier than endocardium? [closed]

I was reading about heat muscle contraction and I read: The endocardium depolarization happens earlier than pericardium , but pericarduim repolarization happens earlier, therefore the T wave in ...