Transport And Excretion Flashcards
What is Xylem?
Carry water and minerals salts
Roots to shoots
In transpiration stream
What is Phloem?
Transport sugars, like sucrose and amino acids
From leaves to the rest of the plant
List the 4 components of the blood
Red blood cells
Plasma
Platelets
White blood cells
What’s plasma
Liquid part of blood Carries: Hormones Platelets Blood cells Carbon dioxide Digested food Urea Heat energy
What are platelets?
Small fragments that help blood to clot
Stops pathogens entering
Prevents blood loss
Held together by a mesh of the protein fibrin
How are red blood cells adapted?
Small and biconcave shaped
They have no nucleus
This all gives them more room to transport haemoglobin and oxygen
What are phagocytes
Phagocytes engulf then ingest pathogens
They are non specific
What are lymphocytes?
Lymphocytes produce antibodies
In presence of a foreign antigen, they produce antibodies (which are specific)
Memory cells can also be produced afterwards
Which side of the heart caries deoxygenated blood?
The right carries deoxygenated blood
What keeps blood traveling through the heart in one direction?
Valves (eg semi-lunar)
What factors increase risk of coronary heart disease?
Inactivity- leads to blood pressure being high
Smoking- increase blood pressure
Poor diet- saturated fats cause fatty deposits
Describe the structure of arteries
HIGH PRESSURE
Strong elastic walls
Elastic fibres allow expansion
Walls are thick compared to lumen
Describe the structures of capillaries
Permeable wall that’s one cell thick for diffusion
Supply food and oxygen, take away CO2
Describe the structure of veins
LOWER PRESSURES
Walls not as thick
Bigger lumen allows blood flow
Have valves to keep blood flow in one direction
Circulation system on Pg 41 diagram in CGP guide
Look at diagram
