a search on the web gave me the following answers:
1) lighten the skull
2) help to act as shock absorbers for the head
3) aid in voice resonance
4) regulate pressure in the nose

I could not find consensus. What do you think the sinuses are for, if anything?

One link dealing with hypotheses around sinus functions in primates shallowly explores

1) hypotheses relating to an external mechanical function (different architectural factors);
2) hypotheses relating to an internal mechanical (related to a phonetic or an olfactory) function;
3) hypotheses relating to a physiological function (in relation with the production of nitric oxide);
4) to the hypothesis that frontal sinus represent simple evolutionary remains and serve no particular function in strepsirrhines.

http://www.research.unizh.ch/p3678.htm

I think it's mainly 2.

I think it's mainly 2.Why do you believe this?

pressure regulation

Why do you believe this?

I think it makes the most sense of the four. I just have a hard time seeing it initially evolving for the other three purposes.

I think it makes the most sense of the four. I just have a hard time seeing it initially evolving for the other three purposes.Thanks for going into it.
Let me try to convince you of 3).
Primates as vocal social animals depend on the ability to make sound. Communicators who can be more subtle or louder - impress more females or males, threaten more of their same sex competitors, warn their group better - are more likely to survive/mate.

This is me just speculating.

pressure regulation
And how has this been useful?

And how has this been useful?

it allows the pressure in the brain to be regulated easier by having some of the regulation done by sinuses.


Here is an analogy: you got one gun, your using it to shoot all the zombies and monsters around you...the gun is heating up from all the steaming action, the gun is so hot you can barely hold it, when voila!!! you got another gun in your left arm so you put it to action and thus the gun in your right hand has some time to cool down. Got the analogy?

At what age can a person get a sinus infection? Can an infant?

it allows the pressure in the brain to be regulated easier by having some of the regulation done by sinuses.


Here is an analogy: you got one gun, your using it to shoot all the zombies and monsters around you...the gun is heating up from all the steaming action, the gun is so hot you can barely hold it, when voila!!! you got another gun in your left arm so you put it to action and thus the gun in your right hand has some time to cool down. Got the analogy?

not really. What's the one gun? and the other? Left and right side sinuses?
is heat the metaphor for pressure?
When do our heads need pressure regulation?

When do our heads need pressure regulation?

are you kidding me?! :eek:

brain renin-angiotensin system

modulation of cardiovascular and fluid-electrolyte homeostasis, generally complementing the classical roles of the endocrine RAS. The RAS has additionally been implicated in other brain-specific functions, such as memory, cognition and stress

are you kidding me?! :eek:

brain renin-angiotensin system

modulation of cardiovascular and fluid-electrolyte homeostasis, generally complementing the classical roles of the endocrine RAS. The RAS has additionally been implicated in other brain-specific functions, such as memory, cognition and stress

Not kidding, me trying to learn.
How do the hollow cavities of the sinuses help modulate fluid pressures in the head?

Not kidding, me trying to learn.
How do the hollow cavities of the sinuses help modulate fluid pressures in the head?

from a physics perspective point of view...the hollow cavities provide extra volumetric spaces which if body needs to can be either released of the pressure by increase or decrease of blood pressure which causes the sinuses entrances to contract or expand.

Ha! Good topic. I'll tell you what sinuses are for.

Their sole purpose seems to be to cause me unending discomfort and grief since childhood. They are designed specifically to reduce breathing ability, cause incredible headaches, induce nausea by draining down the back of my throat, and harbor any type of bacteia or virus that happens by.

Fuck sinuses.

Fuck sinuses.

I agree. :p I got nose problems everday.

I agree. :p I got nose problems everday.

Did you know that millions of man-hours and billions in productivity are lost yearly due to sinus problems (usually allergy related)? It's a serious problem.

Did you know that millions of man-hours and billions in productivity are lost yearly due to sinus problems (usually allergy related)? It's a serious problem.

yup...sux

I had a CAT scan done on me for purpose of sinus scanning...they said my sinuses were larger than usual and that caused problems...duh me

Cooling of blood. Sinuses are very vascularised. Breathing through them cools blood on it's way to the brain. Very important for hunter-gatherers trotting across the blazing African plains.

Cooling of blood. Sinuses are very vascularised. Breathing through them cools blood on it's way to the brain. Very important for hunter-gatherers trotting across the blazing African plains.

yeah...what are you suggesting...I am closer to the evolution line to the African hunter-gatherers? :cool:

I am like Russian 100%....my ancestry is Russian as well, as far as 2000 years...so why is this African sinus thing? grrrr

Oh boy.

Ha! Good topic. I'll tell you what sinuses are for.

Their sole purpose seems to be to cause me unending discomfort and grief since childhood. They are designed specifically to reduce breathing ability, cause incredible headaches, induce nausea by draining down the back of my throat, and harbor any type of bacteia or virus that happens by.

Fuck sinuses.

And you are not alone. So here we have a ripe little environment for invading organisms. IOW a disadvantage. So what is offsetting this disadvantage. I mean, no offense, but early primates having a stuffed and painful head etc. had to cut down on mating possibilties.

yeah...what are you suggesting...I am closer to the evolution line to the African hunter-gatherers? :cool:

I am like Russian 100%....my ancestry is Russian as well, as far as 2000 years...so why is this African sinus thing? grrrr

Convergent ev.
I am sure there are also very tall and very short Russians, also.
Not sure why you took it as an insult though.

Agreed. Clearly their evolutionary advantage outweighs thier occasional malfunctions. I think it's the cooling effect that I mentioned before.

Agreed. Clearly their evolutionary advantage outweighs thier occasional malfunctions. I think it's the cooling effect that I mentioned before.
I thought I'd do some searching to find back up for your vote:

googling sinuses and cooling I got this

Physiology: A function for guttural pouches in the horse

Keith E. Baptiste1,5, Jonathan M. Naylor1, Jeremy Bailey2, Ernest M. Barber3, Klass Post1 & Jim Thornhill4
Top of page
Abstract

Athletic animals must keep their brains cool during exertion because this organ can be damaged irreversibly by hyperthermia. But how horses do this has remained a mystery, as they don't appear to have thermoregulatory dervices like those found in other animals. They do, however, have a unique anatomical arrangement of their internal carotid arteries, which supply blood to the brain: these are enveloped by a pair of air-filled guttural pouches. Here we show that horses use their guttural pouches to cool these important arteries during exercise, keeping the brain from overheating.

and

Selective brain cooling seems to be a mechanism leading to human craniofacial diversity observed in different geographical regions .

which I would need to pay to read.

Perhaps the sinuses have several functions.

sowhatifit'sdark are you being specific to sinuses of the nose or of all sinuses in the body?

In bioscience we are taught that its where nerves and blood vessles get into the bone so that the bones can have a blood surplie (because bone isnt good at transfering neturents through the tissues)

I agree. :p I got nose problems everday.

Have you tried rinsing your nose?
Like they suggest here:
http://allergies.about.com/od/noseandsinusallergies/a/nasalsalineirr.htm
http://www.npr.org/templates/story/story.php?storyId=7108546
http://209.85.135.104/search?q=cache:rxBwZC2udqwJ:www.mentsa.com/SaltWaterRinsefortheNose.pdf
-?

I haven't yet, and I'm uncomfortable about pouring or sticking anything into my nose.
I have nose problems too. :(

I haven't yet, and I'm uncomfortable about pouring or sticking anything into my nose.
I have nose problems too. :(

I tried it...and I did it...and at first it worked...

but it always comes back. I figured that the best thing against it is to eat an apple a day or some fruit with vitamin C, it works seriously :) Also take antihistamines works too.

Perhaps the sinuses have several functions.

What if they also serve as temporary storage room for mucus?
Consider - all that air and everything in it that goes through the nose - it is to be expected that infections will occur relatively frequently, and that there will frequently be lots of mucus.

If the mucus would run out of the nose as quickly as it would be produced, we would be drooling idiots, literally. Instead, we have some control over excreting it - by blowing our nose or spitting.

Similarly as we have a bladder - otherwise we'd drip urine little by little as it gets produced.

There seems to be an evolutionary advantage in excreting certain things at will.

sowhatifit'sdark are you being specific to sinuses of the nose or of all sinuses in the body? Sinuses of the head.

In bioscience we are taught that its where nerves and blood vessles get into the bone so that the bones can have a blood surplie (because bone isnt good at transfering neturents through the tissues)
Another theory!
thank you.

I mean it is interesting how many hypotheses there are.

not really taught AS a theory, its taught as basic A&P

Old woman farts
An old woman came into her doctor's office and confessed to an embarrassing
problem. "I fart all the time, Doctor Johnson, but they're soundless, and
they have no odor. In fact, since I've been here, I've farted no less than
twenty times. What can I do?"

"Here's a prescription, Mrs. Harris. Take these pills three times a day for
seven days and comeback and see me in a week."

Next week an upset Mrs. Harris marched into Dr. Johnson's office. "Doctor, I
don't know what was in those pills, but the problem is worse! I'm farting
just as much, but now they smell terrible! What do you have to say for
yourself?".

"Calm down, Mrs.Harris," said the doctor soothingly. "Now that we've fixed
your
sinuses, we'll work on your hearing." :D

Thanks for going into it.
Let me try to convince you of 3).
Primates as vocal social animals depend on the ability to make sound. Communicators who can be more subtle or louder - impress more females or males, threaten more of their same sex competitors, warn their group better - are more likely to survive/mate.

This is me just speculating.

Well, if we knew what other animals have sinuses we'd be a step closer to the truth. I thought at least all mammals had sinuses..

Hmm I was under the impression Sowhat meant the frontal sinuses specifically..

http://www.cityallergy.com/images/Sinuscilia.jpg

Sinueses definitely only have one function. Just like dicks are only for pissing or fucking, but not both.

You guys are so inane.

Hmm I was under the impression Sowhat meant the frontal sinuses specifically..

http://www.cityallergy.com/images/Sinuscilia.jpg

Nice image, thanks. Those were the ones I was primarily thinking of.

Sinueses definitely only have one function. Just like dicks are only for pissing or fucking, but not both.

You guys are so inane.

This made me laugh, but since it is the internet I was left wondering which argument you were backing up. It's sad. I should be able to assume you were pointing out that sinuses have or could certainly have more than one function - which I believe - but who knows.

Well, if we knew what other animals have sinuses we'd be a step closer to the truth. I thought at least all mammals had sinuses..

Despite intensive research efforts in the past, hypotheses seeking to explain the function of the paranasal sinuses found in some but not all species of primates have remained largely speculative.

this was taken from one of the links I included earlier. I am assuming that paranasal refers to the sinuses in the image you posted. So it seems like these are not present in, even, all primates. They do occur in many primates and they occur in horses. This much I know. So far I cannot find a comprehensive breakdown of their occurance in mammals.

J Appl Physiol. 1998 Aug ;85 (2):405-10 9688712 (P,S,E,B) Low nitric oxide concentrations in exhaled gas and nasal airways of mammals without paranasal sinuses.

[My paper] K Lewandowski, T Busch, H Lohbrunner, S Rensing, U Keske, H Gerlach, K J Falke
Klinik für Anästhesiologie und operative Intensivmedizin, D-13353 Berlin, Germany.
To investigate whether relevant levels of nasal nitric oxide (NO) are produced in the absence of paranasal sinuses, we studied 17 healthy baboons, mammals without any paranasal sinuses. The animals were anesthetized with ketamine hydrochloride and breathed spontaneously. While the baboons breathed through a face mask (mouths closed) connected to a respirator, NO concentrations in exhaled gas were sampled from the expiratory limb and analyzed by chemiluminescence. While the animals were breathing ambient air, nasal gas was sampled via a thin plastic tube and analyzed for NO concentrations by chemiluminescence. Mean NO concentration in the exhaled gas was 1.00 +/- 0.59 parts/billion, and NO release was 4.28 +/- 2.72 nl/min. A NO concentration of 4.79 +/- 2.08 parts/billion was found in the nasal gas (NO release: 7.18 +/- 3.13 nl/min). An age-dependent increase in nasal NO levels was not observed. Exhaled and nasal NO concentrations in baboons were markedly lower than in mammals with paranasal sinuses, suggesting that paranasal sinuses might be an anatomic requirement for production of relevant nasal NO levels.
Mesh-terms: Animals; Chemiluminescence; Female; Male; Nasal Cavity :: physiology; Nitric Oxide :: analysis; Nitric Oxide :: metabolism; Papio :: physiology; Paranasal Sinuses :: physiology; Skull :: anatomy & histology; Skull :: radiography; Support, Non-U.S. Gov't;

Can anyone explain the importance of nitrous oxide release?

um in what context (sorry im not sure where you started discussing it or if its a new line)

It actually came up in today's lecture as a possable means of comunication relating to I BELIVE (i will have to check this) the andiotensin 2 cycle (relating to the kidneys)

Found a potential answer to my question:

Nitric oxide (NO), a substance produced in the paranasal sinuses, is thought to defend against pathogens among other functions. High levels of NO increase mucuciliary activity. NO levels in both the nasal cavity and the maxillary sinus seem to depend on the size of the paranasal ostia [i.e., the openings of the sinuses into the nasal cavity]: As ostia [sic] size increases, NO levels decrease. It has been hypothesized that the purportedlarge sinuses of Neandertals are a consequence of their need for high NO production to support a vigorous way of life (Rae and Koppe 2004:216).

I had never heard this NO issue before I started this thread. I never knew that I was producing NO in my own head. I have to say this seems important and interesting and something that should be more widely known.

^So sinuses have a function in dealing with infections.


BTW, how come nobody commented on my "drooling idiots" hypothesis? Being able to do things at will is an important part of being human, wouldn't you agree?