A stroke occurs when the blood supply to part of the brain is interrupted or reduced, preventing brain tissue from getting oxygen and nutrients.
Explain why reducing the transport of oxygen to brain cells (neurons) will make them unable to transmit nerve impulses and may eventually kill them.
Brain tissue is highly vascularized with a dense network of capillaries. Explain two ways the structure of a capillary is adapted to help maximize the exchange of oxygen and nutrients with brain cells.
55 exam-style questions on Edexcel IGCSE Biology Transport. Each one has a worked solution and a mark scheme showing where the marks go.