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2

Haemophiliac females are rare but they can survive just like affected males do. However, the case is slightly more complicated in women because of menstruation. I could not find an article from any medical journal but this site seems authentic enough for a reference.


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It's all about chemical reactions in your body triggered by your brain. Lot's of researches and documents confirmed this is what happens when you face a stressful situation. Stress -> hypothalamus -> sympathetic nerves -> Epinephrine (Adrenaline) -> more urine flow Domino neural connectivity (Thinking) => Domino Chemistry (Body reaction = stress and ...


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You might need to demote your single-celled 'lords' to 'squires'. They're not essential to an individual's life. You wouldn't die (dispensing with the "how" right off the bat.) You'd be just fine if no bacteria reentered your body. Your fecal output would be greater; you would derive somewhat less nutrition from your food, you would need to take vitamin K, ...


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Assuming you mean organism, not organisation, it's not entirely false that cravings can be driven by deficiencies. In the case of the eating disorder pica, where a person eats non-food items like dirt and clay, can be caused by iron deficiency (Source). However, that article also suggests the possibility that pica causes iron deficiency by causing the person ...


-1

It is unneccessary for a mammal to breath in CO2, though our bodies are able to expel unneeded gasses easily. However, if there were no CO2 in the atmosphere, animals would all die, as no oxygen could be produced by plants. In other words, we don't need to breath in CO2, but we need it to be plentiful.


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Not really a conventional source, but SCUBA divers use tanks that consist of only oxygen and nitrogen, no CO2 needed http://www.lakesidepress.com/pulmonary/books/scuba/sectionl.htm


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No, mammals need not take in CO2 from atmosphere. The body's homeostatic function will maintain its composition by checking the amount of CO2 released out by lungs. So certainly animals would survive if put in a CO2 free atmosphere.


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ANF (Atrial Natriuretic Factor more commonly known as ANP - atrial natriuretic peptide) squeezes (vasoconstricts) the efferent arteriole. This means the pressure in the glomerulus is higher (like if you squeeze the end of a hose) and so more fluid is squeezed out i.e. the glomerular filtration rate (GFR) is higher. It also dilates the afferent which means ...


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I found an interesting article that dealt with anxiety and micturition. There are no proven or accepted view on this. There are a few theories as to how this happens. I am quoting it: There are several beliefs for what causes frequent urination from anxiety, and the likelihood is that all of these factors play a role: Muscle Tension – This is one ...


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Given the hypothetical 70 kg man, let him be separated into components: Blood: 7% (70 kg x .07 = 4.9 kg) Of that, 60% is plasma, so (4.9 kg x .4 = 1.96 kg blood cell weight.) Therefore of a 70 kg male, ~ 2 kg is blood cells Tissue and bone: 93% of body weight (70 kg x .93 = 65kg) Of that, 27% is extracellular fluid, so (65 kg x .73 = ~ 47.5 kg cell ...


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The human body has about $3.72 × 10^{13}$ cells according to Bianconi et al. 2013, although this is disputed. It also has about 5 liters of blood, which is made approximately 40-45% of erythrocytes. Let's assume 2.5 liters = 2500 $cm^3$ of red blood cells (RBC). Assuming a mean value of 5 millions RBC per $mm^3$ there should be in total $5 \cdot 10^6 \cdot ...


2

Yes it is possible but in most cases it will not occur as the body simply halts production. The most infamous manifestation of this is in adrenal insufficiency. That's where when we take glucocorticoids (e.g. prednisolone used in management of lots of inflammatory diseases like asthma and autoimmune diseases) for a prolonged period at high dose. This causes ...


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Mostly no. For example, if a non-diabetic person were to be injected with a small amount of insulin, the pancreas would halt its own production of insulin and, if the dose was too large, begin producing glucagon, which stimulates the liver to produce more glucose to match the dose of insulin. If these periodic doses continue, the size of the islets in the ...


3

The pectoralis muscle attaches to the top to the inner half of the clavicle, just underneath the biceps on the inner part of your arm and the breastbone (a.k.a the sternum) which is found in the middle of your ribs. See below: So taking that in account the pectoralis muscle helps bring your arm closer to your body (adducts your arm), pulling it forward in ...


3

Preamble. There is a lot of misunderstood science here and you are more than right for questioning the lecturers interpretation of these energy values; something the other answers do not discuss. The problem arises from a dodgy reference and a lot of conjecture. In summary. Light and sound cannot be compared energetically in a biological context. Our ears ...


2

No it isn't necessary to breathe in CO2 from the atmosphere. For the buffer system your brain detects the amount of CO2 (H+ which is an indicator of excess or too little CO2) and adjusts your breathing automatically to compensate so that your blood's pH stays normal. No outside CO2 is needed. Your kidneys also play a similar role but the lungs are what ...


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Some people burn more calories than others, in the default mode. Just sitting in a chair, I warm the seat much more than some other members of my family. That heat has to come from somewhere. That's a different metabolism. But, that's not something you can order and install. It's not a pill. Your doctor is right to focus on what you can control, and ...


3

In BACK INJURIES IN THE YOUNG ATHLETE, a paper by three Harvard Medical School/Children's Hospital orthopedic surgeons in the Division of Sports Medicine, there is more than enough evidence that back pain is common in young athletes of both sexes: Back injuries in the young athlete are a significant phenomenon, estimated to occur in 10% to 15% of ...


1

Short Answer: There was an interesting paper that dealt with the pH of urine when citric acid was consumed. The summary was: There was no increase in urinary pH or total nitrogen in 24 hours collection of urine. What This Means: The food we take does not affect the blood pH directly. Acidic food will cause increased secretion of alkaline components into ...


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He may have extreme acuity, or he may even have an extra cone type that allows him to see extra colors (and more color attunement may allow easier reading of those particular plates). But, you won't know anything for sure by asking on here. Take him to an ophthalmologist and let us know what the doc says! If you aren't 40+ and have 20/20 vision and he's ...


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The "normal" visual acuity in the Anglosphere is the 20/20 vision which means that on a Snellen chart characters with 8,86 mm height can be read conveniently from a distance of approximately 6 m. Now there are many known people who have very sharp eyes, having the doubled acuity of 20/10. This means they can discern characters of only 4,43 mm height from ...


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Short answer Visual acuity decreases with age. Your son's age is within the age range that visual acuities are best. Acuity starts to decrease from about age 45. Background Visual acuity (visual resolution) first increases from birth up until around 4-6 years. Note that in the following graph better acuities are represented by lower numbers (logMAR ...


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Digitalis (which was by the way originally synthesized from Digitalis Purpurea) has two mechanisms of action: The action by which digoxin improves contractility appears to be inhibition of the sarcolemmal Na$^+$K$^+$-ATPase "pump", normally responsible for maintaining transmembrane Na$^+$ and K$^+$ gradients The major therapeutic electrical effect ...


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You might expect identical twins to have the same fingerprints as twins have virtually indistinguishable DNA. The distinguishing nature of physical characteristics of a person is due to both the inherent individual genetic diversity within the human population as well as the random processes affecting the development of the embryo. The same would then be ...


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The hippocampus helps to solidify the pattern of connections that form a memory but the memory itself depends on the solidification of connections between the individual brain cells". This refers to the phenomenon called Long Term Potentiation which regulates synaptic strength between neurons. Certain patterns of firing (high frequency) causes the post ...


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A gene being dominant does not necessarily imply the gene is also common. An easy counterexample is Huntington's disease. The gene is dominant, and only one mutant allele of huntingtin would result in development of the disease. However, the allele prevalence of the mutant is low in the general population. In the absence of a selective advantage of green ...


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Overdiagnosis and overtreatment are intertwined. There is debate about how to best describe the problem, but narrowly defined, overdiagnosis occurs when increasingly sensitive tests - or changing definitions - identify abnormalities that are minor, non-progressive, or likely to resolve on their own, and that, if left untreated, will not cause symptoms or ...


1

Screening is the process of testing the population enmasse to check for the presence of risk factors for a disease or to detect the early form of a disease. Usually the tests that are used in screening are not highly effective in excluding people who do not have the disease (low negative predictive value). Instead the goal of screening is to identify as ...


3

According to the Mayo Clinic website: As you age, the tissue structures and muscles supporting your eyelids weaken. The skin may start to sag, and fat that is normally confined to the area around the eye (orbit) can move into the area below your eyes. Also, the space below your eyes can accumulate fluid, making the under-eye area appear puffy or ...


1

A quick search through the Internet, as well as any textbook, will reveal that the lining of the uterus (endometrium) created thickened during every menstruation cycle is rich in nutrients, and requires a constant blood supply, in order to accommodate a fetus. Therefore, maintaining the lining would be more costly to the body than rebuilding it every month; ...


3

The lighter crescent-shaped part at the base of the nail is called the lunula. It is a normal part of the nail matrix, and indicates nail growth. The faster your fingernails grow, the more obvious the lunula. Absence of the lunula without any other abnormalities of the nail is not uncommon, and while it can indicate anemia or malnutrition, it is often ...


1

It sounds to me as though you have misunderstood something about the chromosomes that make up a human genome. on a different chromosome [..] at the same location is not the same location at all. There is no surprise in finding 2 genomes to differ in one place, and not at another unrelated place. edit If this is a mis-reading of your question, and you ...


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The answer is of interest not only in sleep but also the perceptions of patients under anesthesia, comatose states, etc. Our senses aren't 'dimmed' in sleep. There is no effective way to turn off our senses. The best way to explain what happens in sleep is that at some point (the last point, actually), our cognitive processing of sensations changes. That ...


1

There are several working definitions of species depending on the lineages we look at. For sexual lineages (which is the case of humans) the common definition of species is based on the concept of reproductive isolation. Two lineages are different species if they can't reproduce. In consequence of the definition of what is a species there is absolutely no ...


2

The thunder chimp's answer summarized the answer very well. To try to pull things together a bit, if you have seven minutes, check out this video. It shows a man chasing down a kudu. They both run for 8 hours, until the kudu literally collapses and the man calmly walks up to it and slays it. The video shows the evolutionary adaptions that the man has - he ...


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If your first question means: why is later-life ageing usually a long and painful process of degradation (rather than why do we have existential agony) with diseases of ageing like osteoporosis, heart disease, dementia - then I can offer one answer. There is an absence (almost) of any selection pressure after reproductive age. Once individuals are past ...



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