B4 - The Blood Flashcards
What is the human circulatory system?
- The blood, blood vessels and heart which transports substances to and from the body cells.
What is plasma?
- 55% of the blood capacity.
- Blood cells suspended in it and transports proteins and other chemicals around the body.
What are red blood cells?
- 45% of the blood capacity.
- Contains haemoglobin that binds to oxygen to transport it from the lungs to the tissues.
What are white blood cells?
- <1% of the blood capacity.
- Help to protect the body against infection.
What are platelets?
- <1% of the blood capacity.
- Cell fragments that start the clotting process at wound sites.
Characteristics of an artery.
- Small lumen, thick layer of muscle and elastic fibres and thick walls.
- Carry oxygenated blood away from the heart.
Characteristics of a vein.
- Large lumen, often have valves and relatively thin walls.
- Carry deoxygenated blood to the heart.
Characteristics of a capillary.
- Walls a single cell thick and tiny cells with narrow lumen.
- Substances diffuse in and out of the blood in the capillaries.
Why are the valves important?
- Prevent back-flow ensuring blood flows in the right direction.
Human beings circulatory system.
- They have a double circulatory system.
What are the 4 chambers of the heart?
- Left and right atriums, top of the heart.
- Left and right ventricles, bottom of the heart.
What is the function of the aorta and where is it located?
- Carries oxygenated blood around the body and is located above the left atrium.
What is the function of the pulmonary vein and where is it located?
- Brings oxygenated blood from the lungs and is located in the left atrium.
What is the function of the vena cava and where is it located?
- Brings deoxygenated blood into the heart and is located in the right atrium.
What is the function of the pulmonary artery and where is it located?
- Takes deoxygenated blood to the lungs and is located above the right atrium.
What do ventricles do?
- Pump blood out of the heart.
What does blood do when coming into the atria?
- Comes through the valves to the ventricles and then out via the arteries.
What is the heart?
- The heart is an organ that pumps blood around the body.
What are stents used for?
- To keep narrowed or blocked arteries open.
What are statins used for?
- Reduce cholesterol levels in the blood, reducing the risk of coronary heart disease.
How can damaged heart valves be replaced?
- Using biological or mechanical valves.
How is the resting heart rate controlled?
- By a group of cells in the right atrium that form a natural pacemaker.
What are artificial pacemakers?
- Electrical devices used to correct irregularities in the heart rhythm.
What are artificial hearts occasionally used for?
- To keep patient alive while they wait for a transplant or for their heart to rest as an aid to recovery.
Where are the lungs?
- The lungs are in your chest cavity protected by your ribcage and separated from your abdomen by the diaphragm.
What is the alveoli good for in gas exchange process?
- Provide a large surface area and a rich supply of blood capillaries.
- Means gases can diffuse into and out of the blood as efficiently as possible.
Order from top - bottom of tissues in the leaf.
- Upper Epidermis
- Waxy Cuticle
- Palisade Mesophyll
- Spongy Mesophyll
- Guard Cells (in the lower epidermis)
- Stomata (in the lower epidermis)
What does the epidermal tissue do in the plant?
- Covers the plant.
What does the phloem do in the plant?
- Transports dissolved foods from the leaves to the rest of the plant including the growing regions and the leaves.
What does the xylem do in the plant?
- Transports water and minerals ions from the roots to the stem and leaves.
What does the mesophyll tissue do in the plant?
- Carries out photosynthesis.
What happens in the palisade mesophyll?
- There is many chloroplasts located here for photosynthesis.
What happens in the spongy mesophyll?
- Big surface area on these cells for gas exchange.
- Big air spaces.
What does the stomata do in the plant?
- Allow gases and water to move in and out of the leaf.
What do the guard cells do in the plant?
- Control the opening and closing of the stomata.
What are plant tissues?
- Collections of cells specialised to carry out specific functions.
What is in the plant organ system?
- The roots, stem and leaves form to transport the substances around the plant.
What is transpiration?
- Loss of water vapour from the surface of plant leaves is known as transpiration.
- More rapid in hot, dry, windy, or bright conditions.
How is water lost in the plant?
- Stomata opens to let water out and carbon dioxide in for photosynthesis.
What factors increase the rate of photosynthesis which will then act on the rate of transpiration?
- Temperature, humidity, air flow and humidity.
