what is the mechanism of hair to be brittle?and its relation with cell division?
350533
In short, nutrition (improper or lack of it), hygiene and natural aging process causes hair to be brittle. \n\nThe complete cycle and how it is related to cause brittle hair (just the aging part) can be found in this link without too much technicalities.\n\nhttp://mens-health.health-cares.net/hair-life-cycle.php\n\nHope this helped.
774081
That will do it. Also, hair contains di-sulphide bridges (S-S bonds). Breaking these will make the hair straighter. The compounds that break disulphide linkages are foul smelling (mercaptains, etc) so aren't as popular .
291856
Formation of a cell wall is a characteristic feature of all plant cells.Its formation in angiosperms does not differ much from its formation in other plants cells.\n After the nuclear division is over (end of karyokinesis)only then the division of cytoplasm(cytokinesis) begins.\n A number of microtubules are laid across the original cell, equidistant from the two recently formed daughter nuclei. They fuse to form middle lamella.This is the first dividing boundery between the two cells. Deposition of cellulose now begins on this middle lamella from either side and the wall formation is completed. Thus, a cell wall in plant cells is by and large made up of a complex carbohydrate called cellulose and in between the two layers of cellulose there is a layer called middle lamella.It is like butter sandwich. Just as the layer of butter holds the two slices of bread together or just as the layer of cement holds two adjecent bricks together and forms a wall; like wise the middle lamella holds the cells together and helps to form a tissue.
71620
BooooooYaaaaaaaah\n\nThis is a normal thing... Why do you have flakes after you got a haircut? It is bcoz your hair is adjusting...\n\nIt caused by testosterone. Testosterone is the most biologically active male hormone, produced primarily in the testicles as well as in the adrenal glands. Testosterone is responsible for male secondary sexual characteristics such as voice and beard. Testosterone masculinizes the brain in male fetuses and plays a major role in the sexual desire and drive of both sexes.\n\nFrom menshealth:\nThe Cause of Male Pattern Baldness\nMost men are genetically predisposed to male pattern baldness. It is the effect of hormones on the hair follicle that produces male pattern baldness. Testosterone, a hormone that is present in high levels in males after puberty, is converted to dihydrotestosterone (DHT) by an enzyme called 5-alpha reductase. DHT has an adverse affect on the hair follicles. Acting on a hormone receptor on the hair follicle it slows down hair production and produces weak, shorter hair, sometimes it stops hair growth from the follicle completely. This process gradually depletes your stock of hair and is normal hair loss.\n\nThat article may help you...
819440
The growth of human hair\n\nEach human head carries roughly 100,000 hair follicles. \nEach follicle can grow many hairs over a lifetime: on average, each grows a new hair around twenty times. \nNot all these follicles are actively growing hairs at any one time. From the moment when it is first formed, each follicle undergoes repeated cycles of active growth and rest. The length of the cycle varies with the individual, and also with the part of the body on which the hair is growing. \nThe hairs on an adult scalp do not grow in unison, as they do in an unborn baby. They are 'out of cycle' with each other. If this were not so, everyone would go temporarily bald from time to time. \nThe growing and shedding of hair as a whole seems to happen at random, but for each hair follicle the process is precisely controlled. No one knows for certain, however, exactly how the body controls these cycles. \nPlucking a hair from a follicle brings forward the next period of hair growth in that follicle\nOver the years, the number of follicles capable of growing hair declines naturally. The decline is especially noticeable on the top of the head. Some follicles increasingly produce only fine, short non-pigmented hairs that look more like vellus hairs than terminal hairs. In older women, this leads to a general thinning of hair. In men it tends to lead to common baldness. If you look at a bald scalp you will see these fine, poorly pigmented hairs.
80750
Stress could cause hair loss. If you're not eating right, you could be losing hair due to malnutrition also.
161032
It can be drying, can weaken hair strands, make them snap and break easily.
82701
There are special cells called melanocytes at the base of each hair shaft.  These cells produce a pigment called melanin that gives hair its color.\n\nAs we age, the melanocytes in the hair slow down and then stop producing pigment.  Lacking pigment, the hair shaft is clear, which appears white when in a headful of hair.
193548
I love my natural texture. I wear my hair in locs, and the only regret I have about it is that I didn't do it sooner. Yes, I have good hair, just like all of us unless we perm it, thereby damaging it.
760529
Damage to the cuticle\nIllness\nStress\nNutritional deficiencies\nCertain conditions such as psoriasis
345988
Cancer is uncontrolled, disorganized cell growth, usually at a rate more rapid than normal cell growth/repair. Chemotherapy works by targeting the most rapidly dividing cells. Unfortunately, this is not a perfect method. There are some cells in the body which normally divide in a controlled manner at a rapid rate. These cells include the hair follicles, cells lining the gastrointestinal tract, and blood cells. These cells are often mistakenly affected by chemotherapy, which causes hair loss, diarrhea, and low blood counts.
364658
Well, there can be a lot of reasons. If you process your hair by dying or perming, you can be overprocessing it and it can be getting so damaged that it is breaking off and coming out. Time for a deep conditioner.\n\nYou could be getting older and it is just genetics starting to work on you.\n\nYou could have a disease that is stressing your body and causing your hair to fall out - or from not getting the right nourishment.\n\nYou could also loose your hair from stress - stress can affect the body in lots of ways. If it is coming out in clumps, maybe you should go see a doctor.
975998
Hair is not repaired after being broken, but if removed it will regenerate, assuming that the folicle hasnt been damanged. The entire hair is composed of dead cells.
478094
Yup and mine are danceing on my head\n\nofcourse not\n\nHair consists 90% of a biological polymer, α-keratin, and about 10% water, which modifies its mechanical properties. This α-helically coiled protein is further wound into supermolecular coiled-coil microfibrils, many of which are held together with a protein glue to form long macrofibrils, which are packed inside dead hair cells about 100 µm long by 3 µm across. Several of these associate to form one strand of hair, which is covered with tiny surface scales. The ends of individual keratin chains are high in the amino acids proline (an α-helix breaker) and cysteine. Adjacent keratin chains are held together by many disulfide bonds bridging their cysteines. These links are very robust; virtually intact hair has been recovered from ancient Egyptian tombs. Different parts of the hair have different cysteine levels, leading to harder or softer material.
836985
Dead stuff doesn't grow. Instead, what is perceived as "growth" is acually the surrounding tissues receding, or shrinking, as a result of moisture loss from the once living surrounding tissue. Hair and nails are mostly protein (keratin) and contain very little moisture (in comparison to skin cells) and thus don't shrink.
866207
the cell dividing force lol. theres no such force. it's a spontaneous occurence
469294
Hair is an interesting biological structure. What we usually think of as 'hair' is really just the part we see... that's the hair shaft, which contains pigment (a chemical that gives color to things). There is also a hair follicle, which is a multi-cellular structure inside the skin of our scalp that creates the hair strand (making it grow), and also is responsible for the pigmentation. Some of the cells in the follicle make the chemical melanin, which is a skin and hair pigment in many species on our planet. \n\nHair turns grey when the pigment cells in the hair follicle stop making melanin. When this happens due to aging, it's mostly under the control of the genes we inherit. Long periods of constant stress may also contribute, but a big shock won't turn hair grey overnight.