Transport Systems Flashcards
Main types of blood vessels
Artery
Capillary
Vein
Artery structure
Thick layer of muscles
Narrow lumen
Artery (5)
Arteries carry blood away from the heart
Almost all arteries carry oxygenated blood except for pulmonary artery
Have thick muscular walls containing elastic fibres
Have narrow lumen
Blood flows through at a high pressure
Structure related to function: artery
The thick muscular wall of the arteries help to withstand high blood pressure.
The wall of the arteries contain elastic fibres allowing the arteries to stretch and recoil maintaining high blood pressure.
The narrow lumen also helps to maintain high pressure
Capillary structure
Lumen
Capillary
Capillaries connect arteries to vein.
The primary function of capillaries is the exchange of materials between the blood and tissue cells.
Structure related to function: capillary
It has a very narrow lumen, so RBC can move in a single file, increasing their SA during exchange of materials.
Capillary have walls that are one cell thick (short diffusion distance) so materials can be diffused quickly.
Contain microscopic pores on their walls allowing plasma to leak through them forming tissue fluid.
Vein structure
Thin wall with less muscles and elastic fibres
Large lumen
Vein
Veins carry blood towards heart
Most veins carry deoxygenated blood except for pulmonary artery
The pressure is much lower in veins than arteries
Veins (valves)
The skeletal muscles contract to propel the blood in the veins towards the heart.
The semilunar valves prevent backflow of blood in the vein.
Structure related to function: Veins
Veins have wide lumen allowing large volume of blood to flow without resistance
Veins have semilunar valves that prevents the backflow of blood
Plasma contains (7)
Urea
Carbon dioxide
Nutrients
Protein (fibrinogen)
Water
Antibodies
Hormones
Plasma transport
Digested food products
Excretory products
Chemical messages
Plasma does
Maintains steady body temperature
Acts as a buffer
Blood cells
Red blood cells
White blood cells
Platelets
Red blood cells: made
Made in the bone marrow
Red blood cells: contain
Haemoglobin that carries oxygen and give their red color
Red blood cells: function
Transports oxygen from lungs to all cells
Red blood cells: adaptations
Biconcave disc shape - provides large SA/V ratio so oxygen can diffuse rapidly.
They are packed with haemoglobin which bonds with oxygen.
No nucleus - leaves more space for haemoglobin to carry oxygen
Platelets: made
Made in the bone marrow
Platelets: function
Involved in blood clotting
White blood cells: made
Made in the bone marrow
White blood cells: function
Protect the body against invasion by pathogens
White blood cells
Phagocytes
Lymphocytes
Phagocytes
They defend the body by engulfing and digesting the pathogen
Lymphocytes
They defend the body by producing antibodies
Phagocytes structure
Lobed nucleus
Contains granules
Pulmonary
Lungs
Hepatic
Liver
Renal
Kidney
Coronary
Heart
Why don’t unicellular organisms need specialised transport systems for the exchange of substances?
Unicellular organisms don’t not need specialised transport systems because they have a very large surface area to volume ratio. This allows diffusion at the cell surface to meet the organism’s needs
Why unicellular organisms do not need transport systems
Unicellular organisms are made up of only one cell so the diffusion distance is relation. This short diffusion distance means that a transport system is not needed
Why do multicellular organisms need transport systems
Multicellular organisms need transport systems because they contain many layers of cells which increases the diffusion distances involved in the movement of substances. Diffusion alone would take too long to reach all of the cells
Phloem
Where does phloem transport occur
From the photosynthesising leaves to the rest of the plant
What is the vascular tissue of plants
Phloem and xylem together make up the vascular tissue in plants. This vascular tissue is the plant transport system
In what form are sugars transported in the phloem vessels
In the form of sucrose
Xylem
How are root hair cells adapted to aid the absorption of water and mineral ions?
They have a large surface area
They contain mitochondria which releases energy for active transport
How do minerals move into the root hair cells
By active transport
Only water
Can move by osmosis
Transpiration
Is the loss of water vapour from the leaves of the plant by evaporation
What is the role of spongy mesophyll cells in transpiration?
Water vapour evaporates from the surface of spongy mesophyll cells and enter air spaces. From here water vapour diffuses out of the leaf
How does transpiration stop when the guard cells close the stomata
Guard cells can cause the stomata to close preventing water vapour from exiting the lead and stopping transpiration
Transpiration involves the loss of water from
The xylem of plants
By what process does water vapour exit the leaf air spaces
By diffusion
What factors affect the rate of transpiration in plants
Humidity
Wind speed/air movement
Temperature
Light intensity
What happens to transpiration rate as light intensity increases
Transport rate increases
Why does transpiration rate increase at high light intensity
It increases with light intensity because the stomata opens at high light intensities to enable gas exchange for photosynthesis
What happens to transpiration as temperature decreases
transpiration rate decreases
Why does transpiration rate increase at higher temperatures
At higher temperatures water molecules have more kinetic energy and are more likely to diffuse out the stomata
As wind speed increases
Transpiration rate increases
Why do transpiration occur faster on a windy day?
Transpiration is faster on a windy day because wind blows water vapors away from the surface of leaves maintaining a water vapor concentration gradient between the inside and outside of leaves
Increasing humidity
Decreases the rate of transpiration
What are the coronary arteries responsible for?
The coronary arteries supply the heart with oxygenated blood
CHD
Coronary heart disease
How does coronary heart disease occur
It occurs when fatty deposits (plaque) build up inside the coronary arteries reducing blood flow and depriving the heart muscles of oxygen
How does plaque/fatty deposits buildup in the coronary artery
Plaque buildup narrows the arteries reducing blood flow and causing a lack of oxygen to the heart muscle. This can lead to angina (chest pain) or a heart attack
Risk factors for CHD
Smoking
High blood pressure
Obesity
High cholesterol
