Transport In Humans Flashcards
Arteries
- Carry blood away from the heart.
- blood is pumped out at high pressure, so the arteries have thick muscular and elastic walls to withstand this.
- small lumen
Capillaries
- one cell thick
- Carry blood to the body cells.
- flow through every tissue and connect arteries to veins. Deliver and remove substances from cells.
- Thin and permeable walls allowing the exchange of gases
- Tiny vessel with narrow lumen
- Relatively thin walls
Veins
- Carry blood back toward the heart.
- These vessels have a large lumen, allowing them to carry a large amount of blood.
- The valves within the vein prevent the blood, which is at a low pressure, from flowing the wrong way.
White blood cells fight
Disease
Simple unicellular organisms can rely of diffusion for movement of substances in and out of the cell because..
They have a large surface area: volume ratio and therefore it is easier to diffuse across because it is shorter.
Why do multicellular systems need a transport system?
Because they have a small surface area: volume ratio and it is harder to diffuse across.
Need a transport system to deliver materials and remove waste products
How do red blood cells adapt to transport oxygen?
Their shape aids their function, they have a biconcobe shape and a larger surface area for haemoglobin.
what makes up blood?
plasma
red blood cells
white blood cells
platelets
plasma
carries: dissolved food, urea, hormones, carbon dioxide ,heat energy and antibodies
why do we need blood to circulate around our bodies
so that oxygen and glucose can get to our working muscles.
because it removes co2 and waste materials (Urea)
What structures in the heart keep the blood flowing in one direction?
The valves in the main blood vessels (in the heart and veins)
red blood cell
made in the bone marrow
length of life- 120 days
no nucleus
main function- transporting oxygen around the body
most common blood cells, they have several adaptations that make them efficient at transporting oxygen. Their shape aids their function.
E.G. biconcove shape (8)
larger surface area for haemoglobin
what are the types of white blood cells?
phagocytes
lymphocytes
phagocyte
made in the bone marrow
length of life- a few days
lobed nucleus
main funtion- kill pathogens by engulfing and then digesting them
Lymphocyte
made in the bone marrow
length of life- weeks/months/years
large nucleus
main funtion- produces chemicals called antibodies