B4 Organising Animals and Plants Flashcards
What are the components in the blood?
Plasma, white blood cells, red blood cells and platelets
What is blood plasma?
A yellow-like liquid which tranfers blood cells and other substances around your body
What are red blood cells?
Cells that carry oxygen around the body
What are the adaptations of red blod cells?
- They are biconcave, giving them a bigger surface area
- They are full of a red pigment called ‘Haemoglobin’ which binds with oxygen
- They have no nucleus, making more space for haemoglobin
Haemoglobin + oxygen is a ……. reaction
Reversible
What are the functions of platelets?
Helps the blood clot
What is the function of the arteries?
Transports oxygenated blood from the heart to the other organs and lungs (double cirulatory system)
What is the function of the veins?
Transports deoxygenated blood to the heart
What is the function of the capillaries?
It is a vast network of microscopic vessels that connects the veins and arteries.
- Because they are small and delicate, oxygen and glucose can easily transfer from the blood and into the cells
What is a double circulatory system?
When one transport system send blood from the heart to the lungs, whilst one send it to the other organs
What are the main types of blood vessels?
Arteries, veins and capillaries
The valves prevent backflow which means…..
The blood flows in right direction
Circulatory system tranports…
Useful substances (such as glucose,oxygen, amino acids) towards cells and waste products away from cells.
In open circulatory systems…..
heart pumps blood away into blood vessels then blood leaves the vessels
In closed cirulatory systems…..
blood is always enclosed in blood vessels
How does blood flow in a single cirulated system?
Once
How many chambers are in the heart?
Four
Top chambers are atria
Bottom chambers are ventricles
What is the outer layer of the arteries?
It’s made up of a types of protien called collagen which provides strength and mantains the shape
Adaptations of the arteries
- Thick elastic layer stretches and recoils to withstand high pressure.
- Arteries have a smaller lumen to maintain high blood pressure.
- Arteries carry oxygenatad blood, except the pulmonary artery.
Adaptations of veins :
- Thinner layer of smooth muscles due to lower pressure
- Thinner layer of elastic fibres as there is no need of stretching and recoiling.
- Veins have valves to prevent backflow of blood
Adaptatipns of capillaries :
- Walls are one cell thick to provide short diffusion paths
- The lumen is only large enough to allow red blood cells to travel through in single file to increases contact of red blood cells with capillary walls
What is coronary heart disease?
C.H.D is a condition in which the coronary arteries constrict or get blocked.