Krv je neuveriteľne fascinujúca tekutina, ktorá každú sekundu zachraňuje náš... Show more
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Updated Mar 31, 2026
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Krv – vlastnosti, funkcie a jej významné zložky
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Krv - zloženie a funkcia
Krv nie je len obyčajná červená tekutina - je to vlastne špeciálne tekuté tkanivo, ktoré prúdi v našich cievach ako rýchla doprava. Predstav si ju ako mestskú hromadnú dopravu, ktorá neustále rozvážá potrebné veci a odvážá odpad.
Krv sa skladá z dvoch hlavných častí: tekutej krvnej plazmy a krvných teliesok plávajúcich v nej. Každá časť má svoje dôležité úlohy a bez ktorejkoľvek z nich by sme nemohli prežiť.
Najdôležitejšie pojmy, ktoré musíš vedieť: červené krvinky (prenášajú kyslík), biele krvinky (bojujú proti chorobám), krvné doštičky (zastavujú krvácanie) a hemoglobín (červené farbivo s železom).
Tip: Zapamätaj si, że krv má päť hlavných funkcií - transport, obranu, reguláciu teploty, udržiavanie rovnováhy a zrážanie!
Zloženie krvi
Krvná plazma tvorí asi 55% krvi a vyzerá ako žltkastá tekutina. Je to vlastne naša "riekaˮ - z 90% je to voda, ale prenáša v sebe všetko potrebné: bielkoviny, glukózu, soli, hormóny aj vitamíny. Zároveň odstraňuje odpadové látky, ktoré telo nepotrebuje.
Krvné telieska tvoria zvyšných 45% a každé má svoju špeciálnu misiu. Červené krvinky sú najpočetnejšie - v jednom mililitri ich máme milióny! Majú zvláštny tvar sploštených diskov a sú plné hemoglobínu, červeného farbiva s železom.
Hemoglobín je tvoj najlepší kamarát pri dýchaní - viaže kyslík v pľúcach a rozvážia ho do celého tela. Červené krvinky žijú asi 120 dní, potom sa rozpadnú a telo si vytvorí nové.
Vedel si, že červené krvinky nemajú jadro? Vďaka tomu sa do nich zmestí viac hemoglobínu na prenos kyslíka!
Biele krvinky a krvné doštičky
Biele krvinky sú tvoji osobní bodyguardi! Je ich menej ako červených, ale sú väčšie a majú jadro. Každý deň bojujú proti baktériám, vírusom a iným škodlivinám, ktoré sa dostanú do tela.
Niektoré biele krvinky dokážu "požrať" nepriateľov (nazýva sa to fagocytóza), iné vyrábajú špeciálne zbrane - protilátky. Keď si chorý, ich počet sa zvýši, pretože telo potrebuje viac bojovníkov.
Krvné doštičky sú najmenšie a fungujú ako rýchla zásahová jednotka. Keď sa porežeš, okamžite sa zhlukujú na mieste poranenia a vytvoria krvnú zrazeninu - takú prirodzenú náplasť. Žijú len 5-9 dní, ale stačí im to na ochranu pred vykrvácaním.
Zaujímavosť: Keď máš infekciu, lekár ti môže urobiť krvný obraz - počíta biele krvinky, aby videl, ako tvoje telo bojuje!
Funkcie krvi v praxi
Krv má päť super dôležitých úloh, ktoré ti zachraňujú život každú sekundu. Transportná funkcia je najzrejmejšia - rozvážia kyslík, živiny a hormóny, zároveň odvážia odpad ako oxid uhličitý a močovinu.
Obranná funkcia znamená, že tvoje biele krvinky neustále hliadkujú a ničia všetko nebezpečné. Termoregulačná funkcia udržuje tvoju teplotu na 37°C - krv rozváža teplo po celom tele.
Krv tiež udržiava stálé vnútorné prostredie - reguluje množstvo vody, solí a pH. A samozrejme, zrážanie krvi ťa ochráni pred vykrvácaním pri každom poranení.
Praktický tip: Ak si unavený, možno ti chýba železo na tvorbu hemoglobínu. Jedz špenát, červené mäso alebo strukoviny!
Príklady z reálneho života
Keď sa porežeš, uvidíš krv v akcii! Krvné doštičky sa okamžite zhluknu, vytvoria zrazeninu s bielkovinami z plazmy a zastavia krvácanie. Neskôr sa z toho stane chrasta, pod ktorou sa rana zahojí.
Anémia (chudokrvnosť) vznikne, keď máš málo železa. Telo nedokáže vyrobiť dostatok hemoglobínu, červené krvinky prenášajú menej kyslíka a ty si unavený a slabý. Preto je železo v strave také dôležité!
Keď zješ niečo pokazené a dostanú sa ti do tela baktérie, biele krvinky okamžite zasahjú. Fagocyty "požerú" škodlivé baktérie a lymfocyty vytvoria protilátky na ich zničenie.
Zaujímavé: Tvoje telo vyrobí nové červené krvinky každé 3-4 mesiace - kostná dreň pracuje nonstop!
Rýchly súhrn na test
Krv = krvná plazma (55%) + krvné telieska (45%). Plazma je žltkastá tekutina s vodou, bielkovinami a živinami. Krvné telieska majú tri typy s rôznymi úlohami.
Červené krvinky (erytrocyty) obsahujú hemoglobín s železom a prenášajú kyslík. Biele krvinky (leukocyty) sú obrancovia proti chorobám. Krvné doštičky (trombocyty) zastavujú krvácanie.
Päť funkcií krvi: transport látok, obrana pred chorobami, regulácia teploty, udržiavanie rovnováhy a zrážanie. Bez ktorejkoľvek z týchto funkcií by sme nemohli prežiť.
Na záver: Každá kvapka krvi obsahuje milióny buniek, ktoré pre teba pracujú 24/7 - oceň si túto úžasnú tekutinu!
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Most popular content in Biológia
Most popular content
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.6/5
App Store
4.7/5
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Krv – vlastnosti, funkcie a jej významné zložky
Krv je neuveriteľne fascinujúca tekutina, ktorá každú sekundu zachraňuje náš život! Bez nej by naše bunky nemohli dýchať a bojovať proti chorobám. Poďme sa pozrieť na to, z čoho sa skladá a ako funguje táto životne dôležitá súčasť nášho tela.
Krv - zloženie a funkcia
Krv nie je len obyčajná červená tekutina - je to vlastne špeciálne tekuté tkanivo, ktoré prúdi v našich cievach ako rýchla doprava. Predstav si ju ako mestskú hromadnú dopravu, ktorá neustále rozvážá potrebné veci a odvážá odpad.
Krv sa skladá z dvoch hlavných častí: tekutej krvnej plazmy a krvných teliesok plávajúcich v nej. Každá časť má svoje dôležité úlohy a bez ktorejkoľvek z nich by sme nemohli prežiť.
Najdôležitejšie pojmy, ktoré musíš vedieť: červené krvinky (prenášajú kyslík), biele krvinky (bojujú proti chorobám), krvné doštičky (zastavujú krvácanie) a hemoglobín (červené farbivo s železom).
Tip: Zapamätaj si, że krv má päť hlavných funkcií - transport, obranu, reguláciu teploty, udržiavanie rovnováhy a zrážanie!
Sign up to see the contentIt's free!
Access to all documents
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Join milions of students
Zloženie krvi
Krvná plazma tvorí asi 55% krvi a vyzerá ako žltkastá tekutina. Je to vlastne naša "riekaˮ - z 90% je to voda, ale prenáša v sebe všetko potrebné: bielkoviny, glukózu, soli, hormóny aj vitamíny. Zároveň odstraňuje odpadové látky, ktoré telo nepotrebuje.
Krvné telieska tvoria zvyšných 45% a každé má svoju špeciálnu misiu. Červené krvinky sú najpočetnejšie - v jednom mililitri ich máme milióny! Majú zvláštny tvar sploštených diskov a sú plné hemoglobínu, červeného farbiva s železom.
Hemoglobín je tvoj najlepší kamarát pri dýchaní - viaže kyslík v pľúcach a rozvážia ho do celého tela. Červené krvinky žijú asi 120 dní, potom sa rozpadnú a telo si vytvorí nové.
Vedel si, že červené krvinky nemajú jadro? Vďaka tomu sa do nich zmestí viac hemoglobínu na prenos kyslíka!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Biele krvinky a krvné doštičky
Biele krvinky sú tvoji osobní bodyguardi! Je ich menej ako červených, ale sú väčšie a majú jadro. Každý deň bojujú proti baktériám, vírusom a iným škodlivinám, ktoré sa dostanú do tela.
Niektoré biele krvinky dokážu "požrať" nepriateľov (nazýva sa to fagocytóza), iné vyrábajú špeciálne zbrane - protilátky. Keď si chorý, ich počet sa zvýši, pretože telo potrebuje viac bojovníkov.
Krvné doštičky sú najmenšie a fungujú ako rýchla zásahová jednotka. Keď sa porežeš, okamžite sa zhlukujú na mieste poranenia a vytvoria krvnú zrazeninu - takú prirodzenú náplasť. Žijú len 5-9 dní, ale stačí im to na ochranu pred vykrvácaním.
Zaujímavosť: Keď máš infekciu, lekár ti môže urobiť krvný obraz - počíta biele krvinky, aby videl, ako tvoje telo bojuje!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Funkcie krvi v praxi
Krv má päť super dôležitých úloh, ktoré ti zachraňujú život každú sekundu. Transportná funkcia je najzrejmejšia - rozvážia kyslík, živiny a hormóny, zároveň odvážia odpad ako oxid uhličitý a močovinu.
Obranná funkcia znamená, že tvoje biele krvinky neustále hliadkujú a ničia všetko nebezpečné. Termoregulačná funkcia udržuje tvoju teplotu na 37°C - krv rozváža teplo po celom tele.
Krv tiež udržiava stálé vnútorné prostredie - reguluje množstvo vody, solí a pH. A samozrejme, zrážanie krvi ťa ochráni pred vykrvácaním pri každom poranení.
Praktický tip: Ak si unavený, možno ti chýba železo na tvorbu hemoglobínu. Jedz špenát, červené mäso alebo strukoviny!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Príklady z reálneho života
Keď sa porežeš, uvidíš krv v akcii! Krvné doštičky sa okamžite zhluknu, vytvoria zrazeninu s bielkovinami z plazmy a zastavia krvácanie. Neskôr sa z toho stane chrasta, pod ktorou sa rana zahojí.
Anémia (chudokrvnosť) vznikne, keď máš málo železa. Telo nedokáže vyrobiť dostatok hemoglobínu, červené krvinky prenášajú menej kyslíka a ty si unavený a slabý. Preto je železo v strave také dôležité!
Keď zješ niečo pokazené a dostanú sa ti do tela baktérie, biele krvinky okamžite zasahjú. Fagocyty "požerú" škodlivé baktérie a lymfocyty vytvoria protilátky na ich zničenie.
Zaujímavé: Tvoje telo vyrobí nové červené krvinky každé 3-4 mesiace - kostná dreň pracuje nonstop!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Rýchly súhrn na test
Krv = krvná plazma (55%) + krvné telieska (45%). Plazma je žltkastá tekutina s vodou, bielkovinami a živinami. Krvné telieska majú tri typy s rôznymi úlohami.
Červené krvinky (erytrocyty) obsahujú hemoglobín s železom a prenášajú kyslík. Biele krvinky (leukocyty) sú obrancovia proti chorobám. Krvné doštičky (trombocyty) zastavujú krvácanie.
Päť funkcií krvi: transport látok, obrana pred chorobami, regulácia teploty, udržiavanie rovnováhy a zrážanie. Bez ktorejkoľvek z týchto funkcií by sme nemohli prežiť.
Na záver: Každá kvapka krvi obsahuje milióny buniek, ktoré pre teba pracujú 24/7 - oceň si túto úžasnú tekutinu!
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
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Students love us — and so will you.
4.6/5
App Store
4.7/5
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user