Obtočilni sistem je kot transportna mreža tvojega telesa - srce... Show more
Biologija
Matematika
Angleščina
GeografijaSign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
31
•
Updated Mar 28, 2026
•
Srčno-žilni sistem: Osnove
1 / 6
Uvod v obtočilni sistem
Predstavljaj si obtočilni sistem kot mrežo cest po katerih vozijo tovornjaki 24/7. Srce je glavna črpalka, kri so tovornjaki polni kisika in hranil, žile pa so avtoceste različnih velikosti. Brez tega sistema bi tvoje celice literally umrle od lakote in dušenja.
Glavni igralci so torej tri: srce (mišična črpalka velika kot pest), kri (rdeča tekočina polna pomembnih stvari) in krvne žile (cevi po katerih kri potuje). Vsak ima svojo specifično nalogo.
Najbolj kul je to, da sistem dela 24/7 brez da bi se ti bilo treba zavedati. Medtem ko spiš, se učiš ali tekaš, tvoje srce neutrudno črpa kri in oskrbuje cele 37 bilijonov celic v tvojem telesu.
💡 Zanimivost: Tvoje srce utripne približno 100.000-krat na dan in prečrpa okoli 7.000 litrov krvi!
Zgradba srca
Srce ni samo ena velika črpalka, ampak je razdeljeno na štiri ločene sobe. Desna stran (desni preddvor in prekat) se ukvarja z vensko krvjo, leva stran pa z arterijsko. Med njima je debela stena, ki preprečuje mešanje.
Levi prekat je pravi mocak - njegova stena je najdebelejša, ker mora potisniti kri po celotnem telesu. Desni prekat pa ima lažje delo, saj pošlje kri samo v bližnja pljuča. Srčne zaklopke delujejo kot enosmerni ventili - zagotavljajo, da kri teče vedno v pravo smer.
Ko se srce krči, se pravi sistola, nastane višji tlak. Ko se sprošča (diastola), je tlak nižji. To je razlog, zakaj imaš dva krvna tlaka - 120/80 mmHg na primer.
💡 Pomni za test: Desna stran srca = venska kri, leva stran = arterijska kri. To je ključno!
Kri - reka življenja
Kri je tvoje tekočé tkivo sestavljeno iz dveh glavnih delov. Krvna plazma (55%) je rumena tekočina, večinoma voda z raztopljenimi snovmi. Krvne celice (45%) pa so pravi delavci s specifičnimi nalogami.
Rdeče krvničke so najštevilčnejše in nimajo jedra - so kot mini blazinice polne hemoglobina. Ta rdeče barvilo veže kisik kot magnetček. Bele krvničke so tvoji osebni bodyguardi - večje so, imajo jedro in lovijo bakterije ter viruse.
Krvne ploščice niso prave celice, ampak delčki ki delujejo kot naravni obliž. Ko se porežeš, se hitro zberejo na rani in pomagajo pri strjevanju krvi.
💡 Uporabno: Če si bled, verjetno imaš premalo rdečih krvničk. Če se pogosto prezimiš, morda tvoje bele krvničke potrebujejo podporo!
Krvne žile - transportna mreža
Arterije so kot avtoceste - široke, z debelimi stenami, ker prevzemajo visok tlak iz srca. Vodijo kri OD srca proti telesu. Vene so bolj kot lokalne ceste - tanjše stene, nižji tlak, a imajo pametne zaklopke ki preprečujejo, da bi kri tekla nazaj.
Kapilare so MVP cele zgodbe. Te drobcene žilice so tanke kot en sam sloj celic, kar omogoča popolno izmenjavo. Tukaj rdeče krvničke oddajo kisik, poberejo ogljikov dioksid, celice dobijo hranila in se znebijo odpadkov.
Razlika med njimi je očitna - arterije pulzirajo z vsakim utripom srca, vene pa mirno prenašajo kri nazaj. Kapilare pa so tako majhne, da jih komaj vidiš, a brez njih bi bil ves sistem neuporaben.
💡 Preprosta razlaga: Arterije = OD srca, Vene = V srce, Kapilare = izmenjava!
Krvna obtoka
Tvoja kri potuje po dveh ločenih krogih, ki se začneta in končata v srcu. Veliki obtok oskrbuje celotno telo, mali obtok pa samo pljuča. Oba sta kritična za preživetje.
V velikem obtoku levi prekat pošlje arterijsko kri po aorти v celotno telo. V kapilarah kri odda kisik celicam in pobere odpadke, nato se po venah vrne v desni preddvor kot venska kri. To je kot dostava po vsej državi.
Mali obtok je specializiran za pljuča. Desni prekat pošlje vensko kri v pljuča, kjer se v kapilarah okrog alveol odloči ogljikovega dioksida in naloži s svežim kisikom. Arterijska kri se potem vrne v levi preddvor.
💡 Pazljivo: Pljučna arterija nosi vensko kri, pljučne vene pa arterijsko! To je edina izjema pri žilah.
Ključni pojmi za test
Arterijska kri je svetlo rdeča in polna kisika - kao premium gorivo za celice. Venska kri je temno rdeča in polna ogljikovega dioksida - izrabljeno gorivo, ki ga je treba obnoviti. To je osnovna razlika, ki jo moraš obvladat.
Krvni tlak meriš z dvema vrednostma - višja nastane ob krčenju srca (sistola), nižja ob polnjenju (diastola). Normalen je nekje 120/80 mmHg. Srčni utrip v mirovanju je 60-80 utripov na minuto.
Najpogostejše bolezni obtočil so visok krvni tlak, poapnenje žil in srčni infarkt. Večina je posledica slabega življenjskega sloga - malo gibanja, slaba prehrana, kajenje.
💡 Za ponavljanje: Srce = 4 dele, kri = plazma + celice, žile = arterije/vene/kapilare, obtoka = veliki/mali!
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 Biologija
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
Srčno-žilni sistem: Osnove
Obtočilni sistem je kot transportna mreža tvojega telesa - srce je črpalka, kri so tovornjaki in žile so avtoceste. Ta sistem skrbi, da vsaka celica dobi kisik in hranila ter se znebì odpadkov.
Uvod v obtočilni sistem
Predstavljaj si obtočilni sistem kot mrežo cest po katerih vozijo tovornjaki 24/7. Srce je glavna črpalka, kri so tovornjaki polni kisika in hranil, žile pa so avtoceste različnih velikosti. Brez tega sistema bi tvoje celice literally umrle od lakote in dušenja.
Glavni igralci so torej tri: srce (mišična črpalka velika kot pest), kri (rdeča tekočina polna pomembnih stvari) in krvne žile (cevi po katerih kri potuje). Vsak ima svojo specifično nalogo.
Najbolj kul je to, da sistem dela 24/7 brez da bi se ti bilo treba zavedati. Medtem ko spiš, se učiš ali tekaš, tvoje srce neutrudno črpa kri in oskrbuje cele 37 bilijonov celic v tvojem telesu.
💡 Zanimivost: Tvoje srce utripne približno 100.000-krat na dan in prečrpa okoli 7.000 litrov krvi!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Zgradba srca
Srce ni samo ena velika črpalka, ampak je razdeljeno na štiri ločene sobe. Desna stran (desni preddvor in prekat) se ukvarja z vensko krvjo, leva stran pa z arterijsko. Med njima je debela stena, ki preprečuje mešanje.
Levi prekat je pravi mocak - njegova stena je najdebelejša, ker mora potisniti kri po celotnem telesu. Desni prekat pa ima lažje delo, saj pošlje kri samo v bližnja pljuča. Srčne zaklopke delujejo kot enosmerni ventili - zagotavljajo, da kri teče vedno v pravo smer.
Ko se srce krči, se pravi sistola, nastane višji tlak. Ko se sprošča (diastola), je tlak nižji. To je razlog, zakaj imaš dva krvna tlaka - 120/80 mmHg na primer.
💡 Pomni za test: Desna stran srca = venska kri, leva stran = arterijska kri. To je ključno!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Kri - reka življenja
Kri je tvoje tekočé tkivo sestavljeno iz dveh glavnih delov. Krvna plazma (55%) je rumena tekočina, večinoma voda z raztopljenimi snovmi. Krvne celice (45%) pa so pravi delavci s specifičnimi nalogami.
Rdeče krvničke so najštevilčnejše in nimajo jedra - so kot mini blazinice polne hemoglobina. Ta rdeče barvilo veže kisik kot magnetček. Bele krvničke so tvoji osebni bodyguardi - večje so, imajo jedro in lovijo bakterije ter viruse.
Krvne ploščice niso prave celice, ampak delčki ki delujejo kot naravni obliž. Ko se porežeš, se hitro zberejo na rani in pomagajo pri strjevanju krvi.
💡 Uporabno: Če si bled, verjetno imaš premalo rdečih krvničk. Če se pogosto prezimiš, morda tvoje bele krvničke potrebujejo podporo!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Krvne žile - transportna mreža
Arterije so kot avtoceste - široke, z debelimi stenami, ker prevzemajo visok tlak iz srca. Vodijo kri OD srca proti telesu. Vene so bolj kot lokalne ceste - tanjše stene, nižji tlak, a imajo pametne zaklopke ki preprečujejo, da bi kri tekla nazaj.
Kapilare so MVP cele zgodbe. Te drobcene žilice so tanke kot en sam sloj celic, kar omogoča popolno izmenjavo. Tukaj rdeče krvničke oddajo kisik, poberejo ogljikov dioksid, celice dobijo hranila in se znebijo odpadkov.
Razlika med njimi je očitna - arterije pulzirajo z vsakim utripom srca, vene pa mirno prenašajo kri nazaj. Kapilare pa so tako majhne, da jih komaj vidiš, a brez njih bi bil ves sistem neuporaben.
💡 Preprosta razlaga: Arterije = OD srca, Vene = V srce, Kapilare = izmenjava!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Krvna obtoka
Tvoja kri potuje po dveh ločenih krogih, ki se začneta in končata v srcu. Veliki obtok oskrbuje celotno telo, mali obtok pa samo pljuča. Oba sta kritična za preživetje.
V velikem obtoku levi prekat pošlje arterijsko kri po aorти v celotno telo. V kapilarah kri odda kisik celicam in pobere odpadke, nato se po venah vrne v desni preddvor kot venska kri. To je kot dostava po vsej državi.
Mali obtok je specializiran za pljuča. Desni prekat pošlje vensko kri v pljuča, kjer se v kapilarah okrog alveol odloči ogljikovega dioksida in naloži s svežim kisikom. Arterijska kri se potem vrne v levi preddvor.
💡 Pazljivo: Pljučna arterija nosi vensko kri, pljučne vene pa arterijsko! To je edina izjema pri žilah.
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Ključni pojmi za test
Arterijska kri je svetlo rdeča in polna kisika - kao premium gorivo za celice. Venska kri je temno rdeča in polna ogljikovega dioksida - izrabljeno gorivo, ki ga je treba obnoviti. To je osnovna razlika, ki jo moraš obvladat.
Krvni tlak meriš z dvema vrednostma - višja nastane ob krčenju srca (sistola), nižja ob polnjenju (diastola). Normalen je nekje 120/80 mmHg. Srčni utrip v mirovanju je 60-80 utripov na minuto.
Najpogostejše bolezni obtočil so visok krvni tlak, poapnenje žil in srčni infarkt. Večina je posledica slabega življenjskega sloga - malo gibanja, slaba prehrana, kajenje.
💡 Za ponavljanje: Srce = 4 dele, kri = plazma + celice, žile = arterije/vene/kapilare, obtoka = veliki/mali!
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.
2
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Mock Exam
Quiz
Flashcards
Essay
Most popular content in Biologija
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