structure and function of blood vessels

Danielle Cope
Flashcards by Danielle Cope, updated more than 1 year ago
Danielle Cope
Created by Danielle Cope about 5 years ago


Eduqas - pg 184-185 theory booklet class - pg 5-6

Resource summary

Question Answer
Arteries STRUCTURE epithelial cells 1-outer coat (TUNICA EXTERNA) THICK layer of connective tissue-collagen fibres (to resist high pressure and over-stretching) 2- (TUNICA MEDIA) MIDDLE layer of tissue is thick (composed of: smooth muscle, elastic tissue) - arteries SWELL as blood enters and ELASTIC RECOIL helps to maintain the pressure (smaller artrioles have MORE muscles to control flow of blood to capillaries) 3- endothelium (single cell layer to make smooth vessel lining - minimise resistance to blood flow - and short diffusion pathway) surrounded by TUNICA INTIMA 4- LUMEN is narrow ( to maintain pressure)
Capillaires - lined with a SINGLE CELL layer (endothelium) on the basement membrane >site of exchange>short diffusion pathway to the tissue fluid surrounding cells - PORES between the cells make the capillary walls PERMIABLE (water, solutes like glucose) so exchange of materials between the blood and tissues takes place - LUMEN diameter is slightly smaller than a red blood cell so that the ERYTHROCYTES have to squeeze through >slowing flow> allowing more time for diffusion
Veins 1- outer coat (TUNICA EXTERNA) made of connective tissue thinner than in arteries (low pressure) 2- (TUNICA MEDIA) smooth muscle and elastic tissue (layer is smaller than in arteries due to low pressure) 3- endothelium (single cell layer to give smooth lining to vessels reducing friction and minimises resistance to blood flow; and short diffusion pathway) surrounded by TUNICA INTIMA 4- wide LUMEN (so flow of blood is not impeded)
Arteries - carry blood at HIGH pressure - carry blood away from heart - branch into smaller vessels called arterioles that further sub divide into capillaries -BASE of aorta and pulmonary artery - valves
Capillaires - forms a vast network that penetrates all the tissues and organs of the body - LARGE SURFACE AREA for diffusion - blood from the capillaries collects into venules, which take blood into veins, RETURNING it to the heart
Veins - larger diameter lumen than arteries - semi- lunar VALVES prevent back flow - THINNER walls (less connective tissue, muscle and elastic tissue) -carry blood under LOW pressure and lower flow rate -veins above heart (blood returns to heart by gravity) - blood moves through other veins by pressure from surrounding muscle
effect of faulty valves the faulty functioning of valves can contribute to varicose veins and heart failure
Show full summary Hide full summary


Biology AQA 3.1.3 Osmosis and Diffusion
Biology AQA 3.2.5 Mitosis
GCSE AQA Biology - Unit 2
James Jolliffe
Biology AQA 3.1.3 Cells
Biology- Genes, Chromosomes and DNA
Laura Perry
Using GoConqr to study science
Sarah Egan
GCSE AQA Biology 1 Quiz
Lilac Potato
Biology- Genes and Variation
Laura Perry
Enzymes and Respiration
I Turner
Cells and the Immune System
Eleanor H
GCSE Biology AQA