GAS EXCHANGE in TERRESTRIAL INSECTS: tracheal system & how insects reduce water loss.A Level Biology

[@leoweicker9253]

EVERYONE KEY MISTAKE MADE AT 5:50 MINUTE MARK!!! The movement of water from the tracheoles into the cells decreases the volume of WATER it does not decrease the volume in the tracheoles. In fact it increases the volume of the tracheoles as the water is now gone. More volume therefore lower pressure and oxygen drawn in. And another KEY MISTAKE SAID a lower volume causes a higher pressure not a lower pressure!!!

[@leoweicker9253]

@MissEstruch very important to change that as this slightly wrong detail will lose people marks in the exam. Everything else very good keep it up!

[@MissEstruchBiology]

Hello, thanks for the comment. Watching it I see I said it correctly initially, but the PowerPoint is wrong so I need to edit that bit. Thank you.

[@TheGuyThatEnjoysArguments]

Thanks dude!

[@lightonkalumba]

My teacher kept wondering how i was the highest in the circulatory system test......not knowing i watched your videos which made me pass

[@MissEstruchBiology]

😄 Congrats on the test result!! Great to hear the videos helped you so much

[@alisalis1568]

I'm a bit confused in my text book it says that when o2 used up during respiration this creates a diffusion gradient and causes o2 to diffuse FROM the atmosphere ALONG trachea. But in this video you say having o2 used up creates a conc gradient FROM THE TRACHEOLES TO THE ATMOSPHERE.

[@MissEstruchBiology]

it will be both the trachea and tracheoles compared to the atmosphere 😊

[@cecylishilling6837]

when you say volume decreases and pressure decreases, wouldn't the pressure increase if the volume decreases?

[@cecylishilling6837]

oh i have just seen that you replied to a similar comment, sorry! so does hte volume increase then? as pressure moves from high to low?

[@MissEstruchBiology]

Hello, When discussing the volume I'm referring to the volume of gas rather than the volume of the insects abdomen. So as the volume of gas decreases so does the pressure.

[@shraddhasheth2023]

Hi, you know how you said that as volume decreases pressure decreases, why is that as we are always taught that as volume decreases pressure increases as more particles are hitting surfaces in the same amount of space?

[@MissEstruchBiology]

At what point do I say this? If I have said that, then it is incorrect and I need to correct it. Pressure does increase as volume decreases

[@shraddhasheth2023]

@@MissEstruchBiology Yes, you mentioned it somewhere in the video, thanks for clarifying.

[@r0byncw]

@@MissEstruchBiology 5:44 is where you say this

[@srooely7929]

Where does the water in the tracheoles come from or is it naturally occurring? Also does lactate lower the water potential?

[@MissEstruchBiology]

Some will be as a product of aerobic respiration. Yes, lactate lowers the water potential 😊

[@srooely7929]

@@MissEstruchBiology Thank You so much!!!

[@lizziebiology]

From 5:31 I don't understand your explanation. If volume decreases then pressure INCREASES. That is a fundamental scientific idea surrounding ventilation. Does the volume decrease when the water is drawn into the cells? Hmm

[@lizziebiology]

Just seen some of oyur other responses... So does that mean that the water moving out of the tracheoles causes a decrease in pressure in them and so air moves in?

[@MissEstruchBiology]

hey, in the video I'm referring to the volume of gas decreases, not the volume of the tubes. Hope that helps 😊

[@MissEstruchBiology]

yup, that's it exactly!

[@ChiriloCholChol]

How illustrates between trachea and tracheal

[@tobiii5318]

Why do insects have a small surface area to volume ratio if they have smaller organism

[@ammaralado5930]

liquid moves from the tracheoles into the tissue provide lower pressure in the tracheole, how do the tracheoles regain their original pressure, how this could go on in a cyclical manner in an insect that flies long distance like butterfly, thank you very much.

[@theprovenpilot007]

In long-distance flight, the air pressure gradient is constantly maintained as oxygen is continuously used up in aerobic respiration. This is established since oxygen is always being used up whilst carbon dioxide is always being released into the environment which maintains the pressure gradient. Eventually, water will build up in the tracheoles as a product of aerobic respiration which will decrease the volume within the tracheoles and, as a result, increase the pressure gradient closer to the pressure of the atmosphere. Any lactic acid formed prior can be broken down during aerobic respiration. The insect will then be forced to respire anaerobically due to less oxygen in the tracheoles, forming lactic acid. The lactic acid formed creates a steep concentration gradient of water between the tracheoles and the respiring cells. As a result, water will diffuse into these cells via osmosis. This lowers the air pressure gradient within the tracheoles, creating a steep pressure gradient between the tracheoles and the environment. The cycle repeats. Any wrong assumptions that I made feel free to correct. hope this helps Edit: I'm unsure of the effects on the insect caused by oxygen debt due to anaerobic respiration or whether it is even relevant so this information might not be completely accurate - I only applied knowledge about the gas exchange systems in insects.

[@y.3.y.3edits41]

How come there was no mention of Air Sacs? I’m a little confused as to where these take a role in this topic. Thanks

[@xylema.]

Air sacs are alveoli found in the lungs, which are involved in Human Gas Exchange. It's not involved in the tracheal system, as terrestial insects lack lungs

[@queenbless7787]

I thought insects have a high surface area to volume ratio

[@MissEstruchBiology]

They have an exoskeleton which precens diffusion across their surfaces, that's why they have a special ventilation system

[@kiran4078]

can a decreased water potential gradient result in less evaporation, if so, why? (:

[@kiran4078]

in relation to plants, I didn't realise this video was about insects, sorry pahah

[@MissEstruchBiology]

If two areas have the same water potential ( no gradient) then there is no movement of water . The bigger the difference in water potential between two areas (the steeper the gradient) the more water will move. so in terms of transpiration , if its really wet and humid around the stomata, this reduces the gradient so less water moves(evaporates). Hope that helps 😊

[@kiran4078]

@@MissEstruchBiology yes, it does! thank you :)

[@ellamountain3087]

great thank you :)

[@MissEstruchBiology]

You're very welcome ☺

[@ksdogg]

Hi, why does the use of oxygen cause the pressure gradient to decrease when at the same time the cells are pumping out CO2, I would think it would equalise it? Thanks

[@y.3.y.3edits41]

Different tracheoles probably transport different gases, so that they can be transported in different directions without interfereing with one another (hence the decrease in pressure in tracheoles due to diffusion of O2 into repairing cells, allowing more O2 diffuse in from atmosphere)

[@AG-ql1sy]

hello can you clarify the bit at around 6 minute mark where water moves in by osmosis please! what happens to the volume and pressure? i got a bit confused. im assuming for air to move in, the pressure inside the cells/tracheoles has to be lower (for pressure gradient of high to low) for air to move in , so wouldn't the water moving into the cells by osmosis INCREASE the volume to decrease the pressure? because the final bullet point says that water moving in DECREASES the volume. nice video btw hopefully you can clear up the confusion :)

[@MissEstruchBiology]

Hello, The pressure gradient is only for the tracheole, not into the cells. The comparison is the tracheole compared to the atmosphere, as this is where the air flows in/out... air only moves into cells by diffusion, not due to pressure gradients. So as the water moves into the cells the volume in the tracheole decreases so the pressure in the tracheole is lower compared to the atmosphere and therefore more air moves into the tracheole. Hope that helps.

[@atmo1o]

@@MissEstruchBiology hi, I thought decreasing volume increases pressure? How does decreasing the volume of the tracheoles decrease the pressure compared to the atmosphere?

[@atmo1o]

@@MissEstruchBiology or by volume do you mean volume of water in the tracheoles?

[@melissacurtis7207]

@@atmo1o HI i don't know if this is helpful or correct but i heard it as the volume of water in the tracheoles decreasing rather than the volume of the tracheoles themselves, like you said. i think the decrease in pressure is because the natural/usual pressure of the tracheoles is the pressure with the water inside them (5:30), so as the water moves into the surrounding cells the pressure decreases from the norm for the tracheoles and is now lower than the atmospheric pressure --> air moves down pressure gradient from atmosphere into tracheoles. no idea if this helps at all lol

[@atmo1o]

@@melissacurtis7207 yes this helps a lot thank you!

[@Lakshmi445]

How is water loss prevented by having a waterproof exoskeleton? It should be good as some insects can absorb it such as earthworms

[@NanyunjaMiriaByateesa-b4h]

An earthworm is not an insect

[@Hgghging]

because when something is water proof it means water can’t pass through it

[@elliesmith7518]

Watching them all before my exam in 4h

[@MissEstruchBiology]

Ahh good luck!!!!

[@thierrytrevorbusinge8186]

Who needs BS and FA when there is you

[@jessicalau4040]

Hi, is it trachea, and not tracheae in insects? My teacher specified that it would be tracheaE, is that correct? thanks

[@MissEstruchBiology]

Hello, Yes your teacher is correct.

[@mohid0786]

Hey, I seen you mention words such as "abdominal" & "abdomen" throughtout the video - do these basically mean inner/deep ?

[@MissEstruchBiology]

This is referring to the middle section of the insects.

[@EbubechiAmadi]

I was finding hard to understand a concept but thank you for explaining it in simpler terms. I truly appreciate, GOD bless you.

[@MissEstruchBiology]

aw thanks you and I'm so pleased it has helped you 😊

[@sunahangrai9115]

good i like it

[@MissEstruchBiology]

thanks 😊