Transport Flashcards
🪼In jellyfish oxygen diffuses into body then to respiring cells.
🪼Each cell gets an adequate amount of oxygen.(bc they are not far from surface)
Why do mammals have greater requirements for oxygen than other animals?
because they use respiration to generate heat inside their bodies, to help to keep their body temperature constant.
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The pressure in systemic circulation is considerably higher than in pulmonary circulation
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the mammalian transport system may be able to deliver more oxygen more quickly to the tissues than the fish’s transport system
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Fish don’t regulate their temperature
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Aorta by 2.5cm diameter is the largest artery
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Arteries near the heart have especially large numbers of elastic fibres in the middle layer. In other parts of the body, the middle layer contains less elastic tissue and more smooth muscle.
Capillaries form a network through every tissue in body except…..
Brain
Cornae(قرنیه)
Cartilage غضروف
Suggest why there are no blood capillaries in the cornea of the eye. How might the cornea be supplied with oxygen and nutrients?
Blood cells and hemoglobin would cause scattering پراکندگیand absorption of light before it reaches the retina. The aqueous supplies زلالیهthe cornea with its requirements
Are valves present in arteries, veins and capillaries? What’s the function of it?
It only exists in veins. These prevent the low- pressure blood from flowing backwards.
Systemic circulation:
the part of the circulatory system that carries blood from the heart to all of the body except the gas exchange surface, and then back to the heart
Pulmonary circulation:
the part of the circulatory system that carries blood from the heart to the gas exchange surface and then back to the heart
Artery:
vessel with thick, strong walls that carries high-pressure blood away from the heart
Vein:
vessel with relatively thin walls that carries low-pressure blood back to the heart
Arteriole:
Venule:
Small artery
Small vein
Capillaries:
Linking arterioles and venules, taking blood close to almost every cell in the body, are tiny vessels called capillaries. smallest blood vessel, whose role is to deliver oxygen and nutrients to body tissues, and to remove their waste products
Endothelium:
a tissue that lines the inner surface of a structure such as a blood vessel
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resistance to blood flow, causing it to slow down, which provides extra time for exchange of gases and nutrients as the blood flows through the capillaries in the tissues.
Vasoconstriction:
The walls of arterioles have a nerve supply. Nerve impulses from the brain can cause their smooth muscle to contract, narrowing the arteriole. This is called vasoconstriction.
Vasodilation :
When the muscle relaxes, the diameter of the arteriole widens.
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As blood enters a capillary from an arteriole, it may have a pressure of around 35 mmHg or 4.7 kPa; by the time it reaches the far end of the capillary, the pressure will have dropped to around 10 mmHg or 1.3 kPa.
Semilunar valve:
a half-moon shaped valve, such as the ones in the veins and between the ventricles and arteries. These valves allow blood to move towards the heart, but not away from it. So, when you contract your leg muscles, the blood in the veins is squeezed up through these valves, but cannot pass down through them.
Many of the plasma proteins are made in….
Liver
Tissue fluid :
the almost colourless fluid that fills the spaces between body cells; it forms from the fluid that leaks from blood capillaries
A-edema:
blood pressure is too high, too much fluid is forced out of the capillaries and may accumulate in the tissues.
This build-up of fluid is called a edema
Which item avoids the a edema?
One of the roles of arterioles is to reduce the pressure of blood that enters the capillaries in order to avoid this
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As well as substances in solution, blood plasma transports heat around the body. You will remember that water has a high heat capacity, which allows it to absorb a lot of heat energy without altering its temperature very much.
As tissue fluid is formed from blood plasma, it also contains a high percentage of water. The high heat capacity of the water in tissue fluid helps the whole body to maintain a relatively constant temperature.
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Red blood cells do not live very long. Old ones are broken down in the liver, and new ones are constantly made in the bone marrow.
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red blood cells are very flexible. some capillaries are even narrower than the diameter of a red blood А
cell. The cells are able to be squashed so that they can pass through these vessels. This is possible because the cells have a specialised cytoskeleton made up of a us mesh-like network of protein fibres. This allows them to be squashed into different shapes but then spring back to produce the normal biconcave shape.
White blood cells like red blood cells are made in…
Bone marrow
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All white blood cells have nucleus
Most white blood cells are larger than red blood cells although one type……….. may be slightly smaller.
Lymphocytes
White blood cells can be divided into two groups:
Phagocytes and lymphocytes
The common type of phagocyte is called a……that can be recognized by its …..nucleus and……..cytoplasm
Neutrophil
Lobed
Granular
Monocytes:
the largest type of white blood cell; it has a bean-shaped nucleus; monocytes can leave the blood and develop into a type of phagocytic cell called a macrophage
Macrophages:
phagocytic cell found in tissues throughout the body; they act as antigen-presenting cells (APCs)
Lymphocytes:
a white blood cell with a nucleus that almost fills the cell, which responds to antigens and helps to destroy the antigens or the structure that is carrying them
Bohr shift:
The presence of a high partial pressure of carbon dioxide causes haemoglobin to release oxygen. This is called the Bohr shift,
Chloride shift:
movement of chloride ions into red blood cells from blood plasma, to balance the movement of hydrogencarbonate ions into the plasma from the red blood cells
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If the chloride shift did not happen, the inside of the red blood cell would develop an overall positive charge, because hydrogen ions (from the dissociation of carbonic acid would accumulate. Hydrogen ions cannot leave the cell, because its cell membrane is not permeable to them. The influx of chloride ions therefore helps to prevent the overall charge inside the cell from becoming too positive.
The blood transports carbon dioxide in three different ways:
1)As hydrogen carbonate ions in the blood plasma
(One product of the dissociation of dissolved carbon dioxide is hydrogencarbonate ions, HCO;. These are formed in the cytoplasm of the red blood cell, because this is where the enzyme carbonic anhydrase is found. Most of the hydrogencarbonate ions then diffuse out of the red blood cell into the blood plasma, where they are carried in solution. About 85% of the carbon dioxide transported by the blood is carried in this way.)
2)As dissolved carbon dioxide molecules in the blood plasma
(Some carbon dioxide remains as carbon dioxide molecules and some of these simply dissolve in the blood plasma, About 5% of the total is carried in this form.)
3)As carbaminoheamoglobin
(Other carbon dioxide molecules diffuse into the red blood cells but do not undergo the reaction catalysed by carbonic anhydrase. Instead, they combine directly with the terminal amine groups (-NH,) of some of the haemoglobin molecules.)10%
Most carbon dioxide is transported in solution in the blood plasma.
❌❌❌solution 75%of co2 is transported in red blood cells and 25% in plasma
The strong walls if arteries pump blood around the body .
❌❌❌they help to give blood a further push and not pumping and its only due to elasticity not muscle contraction
Myogenic:
a word used to describe muscle tissue that contracts and relaxes even when there is no stimulation from a nerve
Sinoatrial node(SAN):
a patch of cardiac muscle
in the right atrium of the heart which contracts and relaxes in a rhythm that sets the pattern for the rest of the heart muscle
Atrioventricular node(AVN):
a patch of tissue in the septum of the heart which transmits the wave of excitation from the walls of the atria and transmits it to the Purkyne tissue
Purkyne tissue:
a bundle of fibres that conduct the wave of excitation down through the septum of the heart to the base (apex) of the ventricles
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For the right ventricle, the force produced must be relatively small, because the blood goes only to the lungs,
which are very close to the heart. If the pressure developed was too high, (lung capillaries could be damaged and tissue fluid would accumulate in the lungs, hampering gas exchange
