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also, do hair and finger nails continue to grow after we die? I have been told these things over time; have researched the subject, but could not find any info on the topic. Just curious.

2006-09-19 00:19:55 · 14 answers · asked by bobbie e 3 in Science & Mathematics Medicine

14 answers

The following may give you some additional information. I'm still not really sure it actually answers your question!

VIEWPOINT 1
A number of scientific studies have been conducted over the years in an attempt to answer this perplexing question. One such project found that on average, ears grow one-hundredth of an inch every year.
Many people are under that impression that our ears and nose get bigger throughout life because they are made of cartilage, which continues to grow after our bones have stopped. While this is true of the cartilage in fish that lack a bone skeleton, such as sharks, the expert at the MadSci network says it's simply not true for humans and other animals with a bone skeleton.

So what accounts for the largish ears and nose one tends to see on older folk? Some speculate that large ears somehow correlate with longer life, so those with biggish ears are simply the ones who make it to old age. And on a plastic surgery site, we read, "Nasal cartilage becomes thinner and loses its elasticity as we age, causing the tip of the nose to lengthen and droop." So maybe our nose and ears just get droopier?

Fact is, no one really knows. This smells like one of those eternally confounding scientific questions that we'll continue to hear about until someone sniffs out a satisfactory explanation.

VIEWPOINT 2
Researching this question has been a lot of fun. I looked at the web discussion you referred to(http://www2.abc.net.au/science/k2/stn- archive1/posts/topic1836.shtm). The first thing I thought about was confirmation bias: we pay more attention to information that supports our existing ideas, probably because that is where we are directing our attention. This is called a cognitive bias (see http://www.cia.gov/csi /books/19104/art12.html and just about any introductory psychology text). So maybe the person who said that older men’s ears are overly large is falling under the spell of confirmation bias.

Next, I thought about correlation and causation – they are not the same. Just because two things happen at the same time does not mean they cause each other. For instance, deaths in India are correlated with ice cream sales in America. Why? The weather. The two happen at the same time, and so are correlated, but one does not cause the other. Mathematically, a fitted regression line can be drawn by plugging in almost any real numbers to the estimated equation, that is, you can draw a pretty graph of the relationship between nearly any two things, without it meaning anything. We are so used to thinking about relationships between events that we often overestimate. (http://www.ai.univie.ac.at/archives/Psycoloquy/1999.V10/0026.html, Altman DG, Blan JM. Generalisation and extrapolation BMJ 1998;317:409-410, Kuo Y- H, Extrapolation of Correlation Between 2 Variables in 4 General Medical Journals, JAMA. 2002;287:2815-2817.)

So watching out for bias, I thought about ear and nose growth. Are they different from the rest of the body? Probably not – the outer or external ear is mostly cartilage and skin, with a little fat and muscle and a supply of blood vessels and nerves. Does cartilage and skin continue to grow throughout life? Yes and no. The cells continue to divide, grow, mature and die, just like cells in the gut, liver, bones and elsewhere. And the amount of skin and cartilage in our bodies obviously increases as we grow. But cartilage does not keep growing at the same rate throughout life, and while cartilage keeps dying and being replaced, in the vertebrates it does stop increasing in size in adulthood – which is what is usually meant by ‘keeps growing’. This information can be found in most introductory physiology text books.

(The idea that cartilage mass increases in age may come from the cartilaginous, or boneless, fishes. In the cartilaginous fishes, including sharks, the cartilage ‘skeleton’ does increase in size throughout life. Sharks get really noticeably bigger and bigger (http://www.isle-of-man.com/interests/shark/growth.htm,). This does not happen in animals with bone skeletons – the cartilage does not keep getting bigger and bigger to any known extent. We would all look very different if it did. We would get big lumps in our noses, ears, thoraxes, shoulders, wrists, knees and ankles – but at least osteoarthritis would not be such a problem! In fact, new cartilage is produced more slowly as people and sharks age (O'Driscoll SW, Saris DB, Ito Y, Fitzimmons JS. The chondrogenic potential of periosteum decreases with age. J Orthopaedic Res. 19(1):95-103, 2001, http://homepage.mac.com/mollet/VBGF/VBGF.html)

The size of the ear canal does not increase with age (Liu TC. Chen YS. Aging and external ear resonance. Audiol. 39(5):235-7, 2000.) The ear canal is defined by skin and cartilage as well as bone. That suggests that there is no overall ear cartilage growth in adulthood.

Does the pinna, or outside flappy part of the ear, grow during adulthood? Do old men really have big ears? Maybe their ears look bigger relative to their head size because they don’t have as much hair. Maybe their ears just get flabbier, and hang down more. Several studies have found that ears are larger in older people. (Ferrario VF. Sforza C. et al., Morphometry of the normal human ear: a cross-sectional study from adolescence to mid- adulthood. J Craniofacial Genetics Developmental Biol. 19(4):226-33, 1999.)

In July 1993, 19 members of the south east Thames faculty of the Royal College of General Practitioners gathered at Bore Place, in Kent, to consider how best to encourage ordinary general practitioners to carry out research. Someone said, "Why do old men have big ears? Some members thought that this was obviously true--indeed some old men have very big ears--but others doubted it, and so we set out to answer the question "As you get older do your ears get bigger?" 206 patients were studied (mean age 53.75, range 30-93, median age 53 years). The length of the left external ear was measured from the top to the lowest part with a transparent ruler; the result (in millimetres), together with the patient's age, was recorded. The mean ear length was 675 mm (range 520-840 mm), and the linear regression equation was: ear length=55.9+(0.22 x patient's age) (95% confidence intervals 0.17 to 0.27). It seems therefore that as we get older our ears get bigger (on average by 0.22 mm a year). (James A Heathcote BMJ 1995;311:1668, 23December)

But there are other reasons than continued growth that could explain this. Maybe fewer people who are old now had plastic surgery for large ears when they were young, and lots of young people are having plastic surgery for large ears. These are alternative explanations. One of the things that does happen is that skin loses elasticity as we age, so it stretches. Ear lobes tend to increase in length with age. “Another interpretation may be that big ears predict survival: men with smaller ears may die selectively at younger ages. Ear size or pattern, or both, may be a marker of some biological process related to health. However, I don't think that I would go as far as my grandmother, whom I remember admonishing me in early childhood to stretch my ears daily to ensure long life” (Khaw, K-T. Why do old men have big ears? The Chinese believe that long ears predict longevity. BMJ 1996;312:582, 2 March). “An alternative interpretation of the findings is that a secular trend towards smaller ears has occurred during most of the present century. Have the senior citizens in the sample had big ears all their adult lives, and will the younger members keep their smaller ones? If so, what environmental factors, presumably operating during childhood or adolescence, might have been responsible? I wonder whether there has been a steady decline in the boxing or scrubbing of children's ears, or whether big ears are simply another result of passive smoking. This interpretative doubt seems to call for extended pinnametric research: the question can be resolved only by a lifelong follow up study of a cohort of young patients” (Hardisty RM. Lifelong follow up study of young people is needed BMJ;312:582 2 March 1996.)

James A Heathcote went on to say "Why ears should get bigger when the rest of the body stops growing is not answered by this research. Nor did we consider whether this change in a particular part of the anatomy is a marker of something less easily measurable elsewhere or throughout the body."

“All medical research is carried out on selected individuals. . . . . The usefulness of research lies primarily in the generalisation of the findings rather than in the information gained about those particular individuals. . . . .The extent to which it is wise or safe to generalise must be judged in individual circumstance. . . . Many studies use regression analysis to derive a model for predicting an outcome from one or more explanatory variables. The model, represented by an equation, is strictly valid only within the range of the observed data on the explanatory variable(s). When a measurement is included in the regression model it is possible to make predictions for patients outside the range of the original data (perhaps inadvertently). This numerical form of generalisation is called extrapolation. It can be seriously misleading. . . . . To take an extreme example, a linear relation was found between ear size and age in men aged 30 to 93, with ear length (in mm) estimated as 55.9+0.22×age in years. The value of 55.9 corresponds to an age of zero. A baby with ears 5.6 cm long would look like Dumbo.” (Kuo Y-H, Extrapolation of Correlation Between 2 Variables in 4 General Medical Journals, JAMA. 2002;287:2815-2817.)

So do ears keep growing? Who knows. But, thanks to Welsh scientist William Linnard, I know the Celtic words for flap eared: clustlaes. (Prominent ears: a Celtic perspective BMJ 1996;312:582, 2March).

2006-09-19 00:33:13 · answer #1 · answered by »»» seagull ««« 3 · 7 0

Do Ears Stop Growing

2016-10-15 06:15:03 · answer #2 · answered by Anonymous · 0 0

Noses and ears stay the same size but the rest of us shrinks a bit with age thus making noses and ears appear larger.
Hair and fingernails continue to grow for some time after we die, this has given rise to many 'vampire' or 'undead' stories.

2006-09-19 00:25:26 · answer #3 · answered by Courage 4 · 1 2

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2016-05-02 02:15:33 · answer #4 · answered by ? 3 · 0 0

No your ears and nose do not continue to grow but your hair and fingernails do continue to grow after you die for a few months.

2006-09-19 00:29:10 · answer #5 · answered by Anonymous · 2 1

everything grows larger as we age but as we age, we experience physical problems (esp. necrosis, hypertension and anything related to blood) and that's why some of our body parts shrinks, also, some other body parts stop growing when we reach the age of 18... unless we die, nails n hairs will never stop growing...our eyes r the only organ in the body that remains it's shape since birth

2006-09-19 01:17:39 · answer #6 · answered by enlightened_osiris 2 · 2 1

Both are very true! It's easy to see when you compare photos of someone that it's true and yes, hair and nails are dead cells so they continue to grow for some reason.

2006-09-19 00:27:42 · answer #7 · answered by Anonymous · 0 2

i haven't heard of ears and noses if you lie maybe lmao
but i have heard of hair to keep growing. but who really knows don't want to be the one to find out

2006-09-19 00:31:30 · answer #8 · answered by avbb2006 2 · 0 1

(Arnold accent): YES!, that is all I have to say! Look at Jimmy Durante! no further questions!

Did not see u write about hairs and nails, (YOU SNUCK THAT IN!--Arnold accent) NO to hairs and nails, Not sure if ears and nose continue to grow after death, (hmm have to think about--Arnold accent)

2006-09-19 02:41:48 · answer #9 · answered by Courageous Capt. Cat 3 · 0 1

i don't think so...probably the face shrinks and the nose/ears appear larger

2006-09-19 01:12:07 · answer #10 · answered by KingRichard 6 · 3 0

Yes strangely enough they do. And when a person dies and is buried their hair and fingernails and toenails continue to grow until the calcium is all used up. Scary huh.

2006-09-19 06:43:17 · answer #11 · answered by marge8710 2 · 1 2

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