MYTUTOR SUBJECT ANSWERS

2123 views

Explain the relationship between the structure and function of arteries, capillaries and veins.

Arteries have a thick outer layer of longitudinal collagen and elastic fibers to avoid leaks and bulges. They have a thick wall, which is essential to withstand the high pressures.

They also have thick layers of circular elastic fibres and muscle fibres to help pump the blood through after each contraction of the heart.

In addition the narrow lumen maintains the high pressure inside the arteries.

 

Veins are made up of thin layers with a few circular elastic fibres and muscle fibres. This is because blood does not flow in pulses and so the vein walls cannot help pump the blood on.

Veins also have thin walls which allows the near by muscles to press against them so that they become flat. This helps the blood to be pushed forwards towards the heart. There is only a thin outer layer of longitudinal collagen and elastic fibres as there is low pressure inside the vein and so little chance of bursting. Finally, a wide lumen is needed to accommodate the slow flowing blood due to the low pressure. They have valves to prevent blood pooling at extremities (arteries do not have valves).

 

Capillaries are made up of a wall that is only one cell layer thick and results in the distance for diffusion in and out of the capillary being very small so that diffusion can occur rapidly. Capillaries are involved with material and gas exchange with the surrounding body tissue

They also contain pores within the their wall which allow some plasma to leak out and form tissue fluid à aid the transport of material. Phagocytes can also pass through these pores to help fight infections.

In addition, the lumen of the capillaries is very narrow. This means that many capillaries can fit in a small space, increasing the surface area for diffusion.

Zana Katarina L. IB Biology tutor, IB Maths tutor, IB Psychology tutor

2 years ago

Answered by Zana Katarina, an IB Biology tutor with MyTutor


Still stuck? Get one-to-one help from a personally interviewed subject specialist

26 SUBJECT SPECIALISTS

£22 /hr

Victoria T.

Degree: Biomedical Sciences (Bachelors) - Queen Mary, London University

Subjects offered: Biology, Japanese+ 1 more

Biology
Japanese
French

“Hi, my name is Victoria. I was born in France and moved to London to study Biomedical Sciences. Having been in an international school, I am bilingual in French and English and learnt other languages like Japanese. Alongside, I was ab...”

£20 /hr

Emily T.

Degree: Biomedical Science (Bachelors) - Durham University

Subjects offered: Biology, Psychology+ 1 more

Biology
Psychology
Chemistry

“About Me:Hello, I reading Biomedical Sciences at Durham University. I am always been interested in the reason behind biological and chemical mechanisms of the world around us!I was a Student Leader in a Theatre Company in Hong Ko...”

MyTutor guarantee

£22 /hr

Anna W.

Degree: Medicine (Other) - Edinburgh University

Subjects offered: Biology, Physics+ 6 more

Biology
Physics
Maths
Dutch
Chemistry
.UKCAT.
-Personal Statements-
-Medical School Preparation-

“Who am I? My name is Anna and I am currently studying medicine at the University of Edinburgh. Previously I have rounded off the International Baccalaureate (IB) and during those years, I have been doing many extracurricular activitie...”

About the author

£20 /hr

Zana Katarina L.

Degree: Psychology (Bachelors) - Durham University

Subjects offered: Biology, Psychology+ 1 more

Biology
Psychology
Maths

“Top tutor from the renowned Russell university group, ready to help you improve your grades.”

MyTutor guarantee

You may also like...

Posts by Zana Katarina

Describe one example of transient polymorphism.

Discuss the relative importance of genetic and cultural evolution in the recent evolution of humans.

Analyze the changes in concentration of atmospheric carbon dioxide using historical records.

Behaviour can be innate because it is genetically based and can be inherited.

Other IB Biology questions

Define sex linkage

Describe one example of transient polymorphism.

Explain the energy flow in a food chain.

Explain how sound is perceived by the ear, including the roles of the eardrum, bones of the middle ear, oval and round windows, and the hair cells of the cochlea.

View IB Biology tutors

Cookies:

We use cookies to improve our service. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok