What’s the Question? Come up with some questions where the key words below are the answers: Open circulatory system Blood vessels Body cavity Ostia Low pressure Tissue fluid Lumen Endothelium Elastic fibres Smooth muscle Collagen fibres High pressure
Blood Vessels - Lesson 2 3
Dec 18, 2015
Regular exercise and a balanced diet are needed to keep the body healthy. Too little food leads to a person being underweight and prone to certain types of illness, while too much food and not enough exercise leads to a person being overweight and other types of ill health.
Nutrients
A mixture of different types of food in the correct amounts is needed to maintain health.
The main food groups are carbohydrates, fats and proteins.
This table summarises some typical sources of these nutrients and why our bodies need them.
The main food groups
Food group Found in Needed by our bodies for:
Carbohydrates
potato, banana, pasta
potatoes, pasta, bread, bananas, sugar and rice a source of energy for life processes
Fats
cheese
cheese, butter, margarine and oils a source of energy for life processes: fats are also needed to make cell membranes and to insulate our bodies
Proteins
meat
meat, fish, eggs and cheese growth and repair - building cells
Mineral ions and vitamins are also important in a healthy diet. They are needed in small amounts for healthy functioning of the body.
Imbalanced diets
An imbalanced diet causes a person to become malnourished. For example:
too little food may lead to a person being underweight
too much food may lead to a person being overweight.
A poor diet may also lead to deficiency diseases. For example, too little vitamin D in the diet can lead to rickets, which affects the proper growth of the skeleton. Type 2 diabetes is also a problem related to poor diet. Note that you do not need to know how the nutrients work or the effects of any particular deficiency in the diet for your exam.Regular exercise and a balanced diet are needed to keep the body healthy. Too little food leads to a person being underweight and prone to certain types of illness, while too much food and not enough exercise leads to a person being overweight and other types of ill health.
Nutrients
A mixture of different types of food in the correct amounts is needed to maintain health.
The main food groups are carbohydrates, fats and proteins.
This table summarises some typical sources of these nutrients and why our bodies need them.
The main food groups
Food group Found in Needed by our bodies for:
Carbohydrates
potato, banana, pasta
potatoes, pasta, bread, bananas, sugar and rice a source of energy for life processes
Fats
cheese
cheese, butter, margarine and oils a source of energy for life processes: fats are also needed to make cell membranes and to insulate our bodies
Proteins
meat
meat, fish, eggs and cheese growth and repair - building cells
Mineral ions and vitamins are also important in a healthy diet. They are needed in small amounts for healthy functioning of the body.
Imbalanced diets
An imbalanced diet causes a person to become malnourished. For example:
too little food may lead to a person being underweight
too much food may lead to a person being overweight.
A poor diet may also lead to deficiency diseases. For example, too little vitamin D in the diet can lead to rickets, which affects the proper growth of the skeleton. Type 2 diabetes is also a problem related to poor diet. Note that you do not need to know how the nutrients work or the effects of any particular deficiency in the diet for your exam.
Nutrients
A mixture of different types of food in the correct amounts is needed to maintain health.
The main food groups are carbohydrates, fats and proteins.
This table summarises some typical sources of these nutrients and why our bodies need them.
The main food groups
Food group Found in Needed by our bodies for:
Carbohydrates
potato, banana, pasta
potatoes, pasta, bread, bananas, sugar and rice a source of energy for life processes
Fats
cheese
cheese, butter, margarine and oils a source of energy for life processes: fats are also needed to make cell membranes and to insulate our bodies
Proteins
meat
meat, fish, eggs and cheese growth and repair - building cells
Mineral ions and vitamins are also important in a healthy diet. They are needed in small amounts for healthy functioning of the body.
Imbalanced diets
An imbalanced diet causes a person to become malnourished. For example:
too little food may lead to a person being underweight
too much food may lead to a person being overweight.
A poor diet may also lead to deficiency diseases. For example, too little vitamin D in the diet can lead to rickets, which affects the proper growth of the skeleton. Type 2 diabetes is also a problem related to poor diet. Note that you do not need to know how the nutrients work or the effects of any particular deficiency in the diet for your exam.Regular exercise and a balanced diet are needed to keep the body healthy. Too little food leads to a person being underweight and prone to certain types of illness, while too much food and not enough exercise leads to a person being overweight and other types of ill health.
Nutrients
A mixture of different types of food in the correct amounts is needed to maintain health.
The main food groups are carbohydrates, fats and proteins.
This table summarises some typical sources of these nutrients and why our bodies need them.
The main food groups
Food group Found in Needed by our bodies for:
Carbohydrates
potato, banana, pasta
potatoes, pasta, bread, bananas, sugar and rice a source of energy for life processes
Fats
cheese
cheese, butter, margarine and oils a source of energy for life processes: fats are also needed to make cell membranes and to insulate our bodies
Proteins
meat
meat, fish, eggs and cheese growth and repair - building cells
Mineral ions and vitamins are also important in a healthy diet. They are needed in small amounts for healthy functioning of the body.
Imbalanced diets
An imbalanced diet causes a person to become malnourished. For example:
too little food may lead to a person being underweight
too much food may lead to a person being overweight.
A poor diet may also lead to deficiency diseases. For example, too little vitamin D in the diet can lead to rickets, which affects the proper growth of the skeleton. Type 2 diabetes is also a problem related to poor diet. Note that you do not need to know how the nutrients work or the effects of any particular deficiency in the diet for your exam.
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Transcript
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Whats the Question?Come up with some questions where the key words below are the answers:Open circulatory systemBlood vesselsBody cavityOstiaLow pressureTissue fluidLumenEndotheliumElastic fibresSmooth muscleCollagen fibresHigh pressure
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Blood, Tissue Fluid and Lymph
By the end of the lesson you will be able to: Explain the differences between blood, tissue fluid and lymph. (E)Describe how tissue fluid is formed from plasma. (C)Explain how effective blood pressure determines the direction of fluid movement. (A)
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Key definitionBlood is the liquid held in our arteries, veins & heart. Tissue fluid bathes the cells of individual tissuesLymph is held within the lymphatic system
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Blood composition
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Plasma -55%RBC-40%WBC-5%
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Tissue fluidBathes the cells of a tissue (hence the name!)Similar to blood (plasma) but without the cells or plasma proteins.Its job is to transport oxygen and nutrients to the cells from the blood and carbon dioxide and other wastes back to the blood from the cells.
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Artery linked to a vein by acapillary bed
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How is tissue fluid formed?Blood flows into a capillary in an organThe blood is under high pressure at the arteriole end of the capillary bedThis is hydrostatic pressureThis tends to push the blood fluid out of the capillaries through tiny gaps in the wallThe fluid consists of plasma with dissolved oxygen and nutrientsRBC & WBC are too large to be pushed out-as are plasma proteinsExchange of gases and nutrients takes place across plasma membranes by diffusion or facilitated diffusion
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Artery linked to a vein by acapillary bed
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A single capillary showing the relative hydrostatic and osmotic (water potential) forcesTherefore fluid pushed out of capillaryEffective HP = 4.3 1.1 = 3.2kPaEffective SP = -3.3 (-1.3)= -2kPaEffective blood pressure = 3.2 2 = 1.2kPaArteriole End Worked Example
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How does fluid return to the blood?The hydrostatic pressure of the blood is not the only force acting on the fluid. The fluid itself has some hydrostatic pressure.This tends to push the fluid BACK into the capillaries.Both the blood and tissue fluid contain solutes giving them a negative water potential.The water potential of the tissue fluid is less negative than that of the blood.Therefore water moves back into the blood from the fluid by OSMOSIS.
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Now calculate the effective blood pressure and direction of flow for the venous end: Venous End Values (kPa): In capillary: HP = 1.6 SP = -3.3 In tissue fluid: HP = 1.1 SP = -1.3
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A single capillary showing the relative hydrostatic and osmotic (water potential) forcesTherefore fluid pushed into the capillaryEffective HP = 1.6 1.1 = 0.5kPaEffective SP = -3.3 (-1.3)= -2kPaEffective blood pressure = 0.5 2 = -1.5kPaVenous End Worked Example
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Formation of lymphNot all tissue fluid is returned to the blood capillariesExcess fluid drains into the lymphatic systemEventually the lymph rejoins the bloodIt is similar in composition but with less oxygen and fewer nutrients, and fatty material that has been absorbed from the intestinesLymph contains lymphocytes which are produced at lymph nodes and which filter bacteria from the fluidThis is part of our immune system which protects against infection
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