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5

It contains white blood cells (leukocytes) and cells from the inner lining of the mouth (buccal epithelial cells). The DNA obtained from these cells is the basis of DNA profiling based on saliva samples. Source: Salimetrics


1

The term tumor is used in the medical definition of inflammation. However it just denotes a temporary swelling that goes down once the inflammation subsides. This swelling is due to edema (accumulation of fluid). You have to understand that in practice no one uses the term tumor to denote an inflammatory swelling. So the term “tumor” denoting edematous ...


2

A PlOS One study notes drinking coffee (aka moderate caffeine intake) doesn't necessarily lead to hydration. They note coffee has hydrating qualities akin to water. Further empirical studies found no substantial fluid loss in caffeinated beverages. EDIT: Make note we're talking normal doses and moderate intake, though source 2 goes into diminishing effect ...


1

Replicated from comment section: "Tumor," latin root Tumere is for swelling. If you're looking at a modern definition though, you have to consider the abnormal tissue growth. Yes, injuries may produce a thrombus, embolus, etc. however when you get injured and it swells, that isn't really a tumor. Injury swelling is just a biochemical response, but isn't ...


5

The answer is both. Different women experience menstruation differently depending on the levels of different hormones in their body, personal medical conditions, medications, on their age, and the activities they do in their lives. Bleeding is due to the sloughing off of the highly vascularized endometrial lining of uterus which is no longer receiving the ...


2

These drinks contain minor diuretics. Caffeine is the diuretic found in tea and coffee. Alcohol is the diuretic in beer. Diuretic substances increase the amount of urine produced i.e causes dehydration.


4

For several reasons, I seriously doubt that this has been studied extensively. There is a good reason to study absorption through oral mucosa because a drug or glucose can be held there by people who needing rapid absorption of a drug (e.g. sublingual nitroglycerine) or by people who may be unable to swallow (e.g. a hypoglycemic individual who has lost ...


1

The most important features are the eyes, followed by the nose and mouth, respectively. An elaborate answer can be found on a duplicate question on Cognitive Sciences SE: http://cogsci.stackexchange.com/questions/8393/are-some-facial-features-more-important-than-others-in-human-facial-recognition/8906#8906


1

Hot spots on the human body caused by cell phones are caused by the EMF/RF (ElectroMagnetic Frequency/Radio Frequency) emitted from the phones (or any mobile wireless device). (There is much conjecture about the safety of these frequencies and whatnot... That is not what I am here to talk about). In this case, the term hot spot does not refer to you being ...


4

An example case would be retinal implants wearers. Retinal implants like the Argus II consist of a set of electrodes placed onto the degenerate retina of blind folks. Electrical stimulation of the electrode array elicits flashes of light (phosphenes). Visual input is provided via a head-mounted camera, and the device translates the camera images into ...


2

Height This is just a single example, but "height" has received a lot of GWAS (genome-wide association study) attention, and last year the GIANT consortium published results of an analysis on 250,000 people looking at the genetic influences of height [1]. Using just 2,000 genetic variants they could statistically account for 20% of the phenotypic ...


1

This is just a guess, but maybe it's cheaper to masturbate than to maintain the additional machinery to quickly re-absorb or otherwise dispose of the unused/old sperm. Assuming that fresher sperm will be more likely to fertilise the egg, selection will favour those with a larger proportion of fresher sperm per ejaculation. So individuals who have recently ...


0

Unfortunately at this time, there are no known glucosepane breakers which can feasibly be used in a living organism. There is a small (very small) amount of research being done on the topic by Yale university in cooperation with the SENS foundation, but the focus is extremely early stage - nothing more than synthesis and detection of artifical glucosepane ...


2

Welcome to Biology.SE. First off, .. I'm assuming insects are at an earlier evolutionary stage than humans It is not the core of your question but still I want to point to this sentence. What is an evolutionary stage? Does it really mean something to you? What is sure is that a given insect individual or a given human both have evolved for exactly the ...


3

The first thing that comes to mind would be eosinophils numeration. It is a specific type of white blood cell that handles parasitic infections. So in most cases, a blood sample would show an increase in this type of cell.


0

It is my understanding that the dark-adapted eye can perceive single photons. Those have a well-defined range of energies in the visible spectrum. Also, as others have pointed out, light is very directional and localized: if you are not looking at the source, it will not be perceived. Sound comes to the ears from all directions at all times. The waves are so ...


2

Succinycholine, as its name might suggest, is a cholinergic agonist indeed. It acts on the neural plate of skeletal muscles, where it activates the muscle cholinergic receptors. Phase 1 block due to succinylcholine thus occurs by activating so many receptors at once, that the whole muscle gets desensitized and therefore paralyzed. A corollary of that is ...


1

Gigantism is caused by too much growth hormone (GH) and causes increased growth in kids (healthline website). After adulthood, increased GH leads to acromegaly which leads to continuing growth of fingers, feet, forehead, jaw, nose, and lips (UCLA Health website). Note that structures like the nose and ears also keep on growing in healthy folks. Hence, GH ...


0

High carbohydrate meals will undoubtedly increase the relative levels of insulin, increase the shuttling of glucose from the blood to the cells, and leave you fatigued in wake of that. See reactive hypoglycemia. Reducing carbohydrate consumption should, to some level, reduce this effect. Caffeine should just as likely increase blood glucose levels by ...


1

The answer is, in part, it depends. Let's think of the PI3K/AKT pathway. Akt actively phosphorylates BAD which abrogates the Bax/Bak apoptosis pathway. RTK's at the plasma membrane activate this pathway when bound with survival factors. In the absence of survival factors, Akt would become dephosphorylated and you'd have a net movement toward apoptosis. In a ...


0

One event that comes to mind is the use of radiation on cancer patients. Radiation is an external event that can trigger apoptosis in humans 1. When cancer patients receive radiation, the treatment is localized. The brain isn't telling the cells to die it is the radiation effects on the cell. Ionizing radiation can also induce apoptosis via the ...


1

You mentioned something odd in the tittle "adipocyte count", this was likely a mistake, but I will address it anyway. I recall something about liposuction not being preventative for diabetes: You can have more adipocytes with less lipids in each cell, or fewer adipocytes with more lipid in each cell. Hypertrophy vs hyperplasia, just like in the ...


4

To put it in very simple words the reason for isovolumetric contaction and relaxation is to make the necessary pressure changes that is necessary to allow blood to flow into or flow out of the ventricles. The basic formula you need to remember to understand this is:- Fluids flow from high pressure area to low pressure area along the pressure gradient ...


5

Period of Isovolumic (Isometric) Contraction:Immediately after ventricular contraction begins, the ventricular pressure rises abruptly, as shown in Figure causing the A-V valves to close. Then an additional 0.02 to 0.03 second is required for the ventricle to build up sufficient pressure to push the semilunar (aortic and pulmonary) valves open against the ...


1

I think that Carl Sagan said it best: The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of starstuff. The current view of cosmology is that every atom that isn't hydrogen, helium, or lithium was created in the fusion furnace in the hearts ...


3

The reason is that X-inactivation is not complete (Carrell & Willard, 2005; Ahn & Lee, 2008), and as many as 15-25% of X-linked genes escape silencing (Carrell & Willard, 2005; Cheng et al, 2005). This means that some genes on the Barr body are expressed in XX-females, although often at lower levels compared to the active X-chromosome, and this ...


4

No, this is not true. The only "organ" (if you will) that needs to "sleep" is the brain, and even then it is still quite active. The body needs to rest. When blood is needed in a prioritized manner in certain areas of the body - for example, during a marathon the muscles and the heart need more oxygen - mechanisms are in place to shunt some of the blood ...


4

To measure cardiac output by the so-called “indicator dilution method,” a small amount of indicator, such as a dye, is injected into a large systemic vein or, preferably, into the right atrium. This passes rapidly through the right side of the heart, then through the blood vessels of the lungs, through the left side of the heart and, finally, into the ...


5

Drs. Swan and Ganz developed a direct method of measuring cardiac output by thermodilution. They invented a multilumen catheter with a thermal resistor on the end (a Swan Ganz catheter) which could be advanced into the pulmonary artery. Through another lumen, a cold saline solution of known temperature and volume is injected into the right atrium. Using a ...


2

An interesting question! I am attaching the picture from Boron & Boulpaep, Medical Physiology, 2nd Ed, p921 here to clarify the details left out in the hand drawn picture. The flow of the digestive pancreatic enzymes increase mainly during food consumption. This is brought about by a number of redundant systems. The fasting secretion of pancreatic ...


6

To say that there is a cutoff of one minute at which time shocking becomes ineffective is incorrect. The best way to defibrillate a heart within one minute of VFib onset is with electric shock. In fact, short of certain drugs in certain instances, it's the only way to defibrillate Vfib, regardless of the amount of time that has passed. If the one minute ...


2

Between at least the endocardial and epicardial regions, I believe the transient outward current is facilitated much more in epicardial cells. This article demonstrates the differences in Ito between the two cell types in dogs. I'm also recommending the following article about Ito phenotypes: "Transient outward potassium current, ‘Ito’, phenotypes in the ...


0

Very interesting question! And I don't think either that the linked Wikipedia article answers the question. Unfortunately I do not know the answer for sure, but I might have some relevant information to add. So, from my studies I know that Barr-bodies are not totally inactive, they, in fact, do have some very limited transcriptional activity. It might be ...


6

Unless defibrillated within 1 minute after fibrillation begins, the heart is usually too weak to be revived by defibrillation because of the lack of nutrition from coronary blood flow. However, it is still possible to revive the heart by preliminarily pumping the heart by hand (intermittent hand squeezing) and then defibrillating the heart later. In this ...


1

When haemoglobin takes on oxygen the colour will shift from blue to red. the reason for this is a change in orientation of the Nitrogen ligans of the haemoglobin molecule. The red cells pass through the veins in the lung(s) to the aevioli; the blue haem (pH~7.2) exchanges CO2 for O2 (now pH~7.4) 98% saturation and goes from blue to red. We see the ...


0

Definitely, yes. This is called pain shock. In absence of anesthetics death rate becomes very high when threatening the wounded.


2

Alloys have completely different chemical properties than their component elements. Elemental mercury is liquid, and is toxic, but when alloyed into amalgam with silver, tin, and some other elements it is perfectly safe, and has been used in dental fillings for a very long time with no negative effects. The same is true of cobalt and chromium alloys - they ...


6

I will provide an answer in 2 parts. The first part is a theoretical approach based on the absolute possible minimum (my original answer). The second part focuses on experiments in the peripheral auditory system (added edited answer). PART I: Absolute theoretical minimum (original answer) As you inquire about electrical signals in the auditory human system ...


-1

The average human auditory range is between $20$ Hz to $20$ kHz [1]. How this relates to time is by the definition of frequency. $$ f = \frac{1}{\text{time in sec}} = \frac{\omega}{2\pi} $$ where $\omega$ is angular frequency. So if a human can hear a sound frequency of $18$ kHz, then $$ (18\cdot 1000)^{-1} = 0.000056\text{ sec} $$ where $18$ kHz is $18000$ ...


11

Thank you for the fascinating question! It was tough to research but very worthwhile. LDL is actually not such a bad molecule. It is formed from VLDL/IDL after VLDL/IDL distribute triglycerides, phospholipids, cholesterol and cholesterol esters to peripheral cells. With less to give, LDL subsequently tries to be helpful by providing any needy peripheral ...


1

The important point is that your voice is influenced by airflow, and your vocal cords. When we're sick, and it depends on what it is, a number of factors change the sound of your voice by influencing the two of these, either: By changing airflow due to respiratory tract swelling or fluid buildup, or by damage/swelling/alterations to the vocal cords. In a ...


7

The problem is that box jellyfish doesn't specify one jellyfish but a group of different jellyfish. Some of these are highly venomenous - I pick here Chironex fleckeri, as this is often called "the most venemous jellyfish in the world". Chironex fleckeri has long tentacles which are covered with millions of explosive cells called Cnidocytes which inject a ...


2

Oxytocin It has been shown that oxytocin signaling helps in muscle regeneration by activating MAP Kinase/ERK pathway in skeletal muscles.[1] Oxytocin is also known to promote adult neurogenesis.[2] Myostatin It is a paralog of GDF and like GDF prevents hypertrophy of cardiac muscles.[3] Leptin Though leptin is not really connected to ageing but it ...


0

Salt will cause high blood pressure, but only under certain circumstance. physiologic hormonal compensations for increased blood volume: Atrial natriuretic peptide -- increases sodium excretion, hence this is increased with high blood volume Antidiuretic horomone -- ADH increases water reabsorption in the kidney, hence this will be decreased with high ...


3

Note: This is based on literature searches I've done a while ago out of general curiosity. I'm in no way an expert on human reproduction. First, I'm not sure if you are asking about evolutionary reasons or the developmental causes for for a difference in sex ratio. Here, I will focus on the developmental causes. There is much evidence for a male bias in ...


2

As salt accumulates in thebody, it also indirectly increases the extracellular fluid volume for two basic reasons: 1. When there is excess salt in the extracellular fluid,the osmolality of the fluid increases, and this in turn stimulates the thirst center in the brain, making the person drink extra amounts of water to return the extracellular salt ...


3

There is an article in the Journal of Popular Science from 1885. However, I do know there is at least one more recent article floating around some where since I read it. At the moment, I can't find it but will update if or when I do. The article goes on to state that during times of scarcity the number of male births outweighs the number of females whereas ...


2

Remember that except for the concluding pathway through the A-V bundle, the atrial muscle mass is separated from the ventricular muscle mass by fibrous tissue. Therefore, ventricular fibrillation. The mechanism of atrial fibrillation, except that the process occurs only in atrial muscle mass instead of the ventricular mass. A frequent cause of atrial ...


1

Think about it statistically. If you cut your hair short and it grows out, it's because the length you cut it to was shorter than the average length that any strand of hair is likely to grow to before it falls out. As your hair grows out, it approaches that length. (This is a simplification but is illustrative of the process.)


6

There are legitimate case reports in credited journals of hyperdontia, or the condition of having supernumerary teeth. Such cases are often associated with congenital syndromes-- cleft lip and palate, trichorhinophalangeal syndrome, cleidocranial dysplasia, and Gardner's syndrome. I included a case report and a comprehensive review for you below. Case ...



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