Questions tagged [human-physiology]
For questions on the biochemical, physical, and mechanical functioning of humans in good health including their organs and cells.
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Viability of argon-oxygen atmosphere
Can humans breathe an Argon-Oxygen atmosphere, where Argon substitutes the inert Nitrogen gas which currently populates our atmosphere? I didn't quite know which forum to stick this one in; I put it ...
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Plant vs animal protein digestibility?
The protein scoring methodologies ( https://en.wikipedia.org/wiki/Protein_Digestibility_Corrected_Amino_Acid_Score) rate plant proteins of a lower quality than animal proteins. Now I can understand ...
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What is the function of the Hyoepiglottic ligament?
The hyoepiglottic ligament (ligamentum hyoepiglotticum) is an elastic band that connects the epiglottis to the hyoid bone.
Although I can find information about the clinical significance of this ...
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Contribution of major nutrients to energy in the human body
What is the contribution of the major nutrients -- glucose, fat and protein -- to the human body's energy requirements, in normal conditions?
For some tissues, the fuel preference is known ...
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Is it possible to have sleep paralysis while sleepwalking?
At least from a conceptual level, these two disorders don't conflict. The effect of sleep paralysis is being conscious while having the inability to consciously direct motor functions. Sleepwalking is ...
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Immune response to shock
I am studying nursing and have a question regarding the physiological response to shock (decreased perfusion). In lecture notes supplied by the lecturer, he indicates that there is a neural, hormonal ...
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What is the difference between tissue engineering and 3D bioprinting?
3D bioprinting is the modified version of the tissue engineering but when we want to describe the both terms, what are the basic criteria or points to make difference between these?
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Protein food eating tendency
As I understand human love fatty food as they taste good because it has more energy which was good when we were primitive and food was scarce and unreliable,
Is there same urge for protein food too? ...
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Could humans breathe if the average methane content of the atmosphere increased to 1%?
Below is a table of atmospheric composition. Could humans breathe if the average methane content of the atmosphere increased to 1%?
Table 7a-1: Current Average composition of the atmosphere up to ...
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Why does the amount of adipose tissue contribute the most to the total body water amount in humans?
I don't quite get this concept. An obese individual will have a greater fat content in their body, and thus will have 45% water in their bodies (for example), versus a slim person that will have 75% ...
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What is the minimum caloric intake for a truly starving adult
What is the minimum caloric intake for an adult? I'm not talking about a healthy diet. There's plenty of advice on that. I'm wondering what the absolute limits of H. sapiens are. When there's a ...
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Myopia & the Blur Effect
I know myopia is caused by elongation of the eyeball. When the eye is too long, light entering the eye balls falls in front of the retina instead of on it.
However I do not quite understand how this ...
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What is the structural/chemical difference leading to different shapes in facial/head/pubic hair?
Different hairs have different shapes, thicknesses, properties.
What exactly is different between these types of hairs? a previous post implies that the root of the differing length (pun intended) ...
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Reference for most up to date sport physiology
I currently have
Exercise Physiology Nutrition Energy And Human Performance, 7th Edition, 2012, McArdle et al.
as my reference book for Exercise physiology. However, based on a question I ...
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Why does the ova remain viable for only a day after ovulation?
The ova remains viable for approximately 24 hrs after ovulation to be fertilised by a sperm.
...chances of becoming pregnant increase dramatically if you have sex during the 5 days before ovulation ...
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Do humans produce rennin?
At school, we've been taught that human infants produce rennin/chymosin (which aids in the digestion of milk). More specifically, it is the peptic cells in the stomach which secrete prorennin, the ...
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What are the most efficient heat exchange sites on the human body?
Where on the body would be the best place to achieve the greatest cooling effect with a "cooling undergarment"? Concentrated over the kidneys, groin, inside the wrists, back of the neck?
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Role of neuraminidase in preventing polyspermy in humans
Neuraminidase is a hydrolytic enzyme present in the acrosome of human sperm. It removes neuraminic acid (salic acid) from glycoproteins. I have read in a book that due to this reason it (the enzyme) ...
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Small Pimple like structure in lips? [closed]
Is this some kind of disease ? I saw this in one of my family member
Usually it is totally not visible but whenever the lips are stretched they are seen
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Ejaculation without orgasm: is this possible to do it at will without external stimulation?
I know that ejaculation without orgasm is possible for human males with external stimulations, e.g. prostate massage.
My question is, can a human male perform full ejaculation without reaching orgasm ...
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Effects on body without fitting routine to external time (non 24 hour Circadian clock) [closed]
Often I find myself trying to fit my daily routines to factors such as those of the external time, e.g. to light levels outside, and those that others around me live by.
However this often seems ...
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Can pheromones be received other than by odor?
I'm trying to understand how deodorants affect pheromones in humans.
Wiki states:
Axilla
In humans, the formation of body odor happens mostly in the axillary
region. These odorant substances ...
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Empty room, Room full with stuffs & Auditory adaptation to reflection of sounds
Background
When a room is full with stuffs like furniture, electronic utilities, books etc. it's hard to hear reflections of sounds made by us (talking, playing an instrument, sound from falling ...
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Cooperativity of haemoglobin and oxygen dissociation curve of haemoglobin
Haemoglobin shows positive cooperativity with oxygen. When an oxygen atom binds to one of hemoglobin's four binding sites, the affinity to oxygen of the three remaining available binding sites ...
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What are the absolute facial features which features sexual dimorphism in humans?
Apart from beard and moustache, is there any facial feature that would help to distinguish between men and women?
It is said that men have square, rectangular or oblong face and women have oval,...
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Is starch and glycogen digestion intra or extracellular?
Do humans have the enzyme for starch intracellular digestion?
Also, do plants have the ability to digest Glycogen? Intra or extracellular, or both?
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Renorenal Reflex
According to this:
The kidney contains afferent sensory nerve fibers that are located primarily in the renal pelvic wall where they sense stretch.
I think the stretch is due to urine. If I am ...
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Are 'homeothermic' and 'endothermic' synonymous?
I got this question from the comments below this answer. So, do homeothermic and poikilothermic have the same meaning as endothermic and ectothermic, respectively?
A user also suggested that the ...
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Human's capacity to withstand extreme heat in dry air [duplicate]
What is the maximum temperature a human can withstand for short periods of time in an environment with dry air (e.g. oven @+300F, other confined spaces) and what would be the immediate risk of being ...
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Why does an increased heart rate mean increased blood pressure?
Say a person starts exercising. If their cardiac volume remains the same but their heart rate increases so that the overall result is an increase in cardiac output, will their blood pressure increase ...
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Pee Shiver: Any reliable research about this phenomenon?
I came across 2 webpages about the science of pee shiver.
Link 1
Link 2
I wonder if there any reliable scientific research about this phenomenon. The 2 webpages I have hyperlinked attribute this to ...
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Does osmosis require a protein channel?
Earlier today, I undertook an exam which featured a question regarding the stickiness of mucus in a person diagnosed with CF's. We had to explain why they had stickier mucus than a 'normal' person, ...
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How can heart disease cause excessive sweating?
According to google:
What can cause sudden sweating?
Excessive Sweating. A person with
excessive sweating has a condition called hyperhidrosis. ... In
adults, the most common cause of ...
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Why don't we feel hungry after waking up?
Yesterday, I was fasting (drinking only water until I had dinner at 9 pm). After dinner, I went back to my lab (I am a Master's student) and worked till 1:30 AM. By 1 o' clock, I was feeling quite ...
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Which variables are controlled in the mammalian womb to ensure a healthy environment?
Recently, researchers have had some success with artificial wombs. Which aspects of the womb are difficult to replicate through technology?
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Why does Edema occur in Kwashiorkor?
Edema in lower leg and face is a symptom of Kwashiorkor. It is the most distinguishing feature of it which distinguishes it from Marasmus. Why would decrease in amount of proteins cause Edema? Why ...
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What will happen if there is high concentration of both calcitonin and PTH in blood?
What will happen if there were a high concentration of both calcitonin and PTH (parathyroid hormone) in the blood? In that case, will calcium resorption from bone occur, or absorption from intestine, ...
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Medical term for "holding urine for a long time"
Sometimes I get/feel pain in my stomach because of holding urine for long time. Is there any medical terminology describing: "holding urine for a long time", or pain associated with this activity?
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Excessive sweating in dry heat [closed]
It's pre-monsoon season here in India. The temperatures in the Northwest of the country really take a spike around mid April. Apparently the heatwave-like conditions seem to have announced themselves ...
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Can you bleed from your bones?
I was talking to my science teacher about the body specifically the red bone marrow.
She said that blood is created in the red bone marrow. Does that mean that if you were to cut a fresh bone open ...
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Why do human females have periods?
Why do human women have periods when most animals don't? It is known that the unfertilized egg needs to be shed from the uterus. But why shed the whole endometrium? Why didn't evolution put ...
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More *total* oxygen absorbed by breathing fast or slow?
I have heard that human lungs capture/absorb/process more oxygen by breathing slower.
A) Is the above true?
B) If so, if my primary concern was absorbing the most total oxygen (not most efficient), ...
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Why heart beats increase when we are in a state of tension even though it is a disadvantage?
Suppose a poisonous snake bites you; this will likely cause hypertension, and it will result in your heart rate increasing dramatically.
Because of the high rate of heart beats, your body will make ...
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Digestion of milk in humans
The intial step in the digestion of milk in humans is carried out by which of the following enzymes?
A) lipase.
B) trypsin.
C) rennin.
D) pepsin.
I'm confused between the C and D option. as it'...
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What happens to apetite hormones like ghrelin and leptin when a person in coma?
Don't coma individuals feel hungry? If so, how does the brain senses this condition (as coma is caused by neural death or damage) and switches off gene expression of ghrelin and leptin.
Is there any ...
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How is the Force of Contraction Applied to the Tendons by the Muscle's Individual Fibers?
Image and question have been updated for clarity!
The image above is a side view of a semi-transparent skeletal muscle. The dark red lines represent individual fibers, the blue lines represent ...
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Are hormone secretion variations the same for a pair of monozygotic twins?
I have recently read a paper about how stress affects morning salivary cortisol levels in an individual. I am conducting a study on monozygotic twins and was wondering if cortisol levels would ...
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Sex and human's sexual urge.
Why is it necessary for humans to feel pleasure while having sex? Why is it that other animals don't need to experience it? Is it evolutionary ? Why do we mate for pleasure when it's so energy wasting/...
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Physiological effects of electrical shocks on human body depending on the energy
When discussing safety of electricity, one usually considers a constant DC or AC current with constant amplitude over a longer time. It is easy to find tables in books or in the web which lists ...
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How can we move our lips even though they don't have any bones? [closed]
How can we move our lips even though they don't have any bones?
We can move everything if it is attached to the bones. Example: Legs & Arms.
otherwise we can't move it.
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