topic 1: blood and circulation
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The circulatory system is a body-wide network of blood, blood vessels, and lymph. Powered by the heart, it is the body’s distribution system to organs with oxygen, hormones, and essential nutrients that helps it function properly
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Recall why simple, unicellular organisms can rely on diffusion for movement of substances in and out of the cell
Recall:Remember or recognize from prior learning experiences.
Recall:Remember or recognize from prior learning experiences.
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Singled celled organisms can obtain oxygen through the cellular membrane. The area of the cell's surface determines how much oxygen the organism can obtain and the volume of the cell determines how much oxygen the organism uses. Ratio for supply to demand equals the surface area over volume. Single celled organisms tend to have a higher surface are to volume ratio. This is because their surface membrane has a large enough area to supply all the oxygen the volume demands.
Explain the need for a transport system in multicellular organisms
Explain: Give a detailed account of causes, reasons or mechanisms
Explain: Give a detailed account of causes, reasons or mechanisms
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Multi-cellular organisms are too big and not all of their cells have contact with the external environment. All organisms need to exchange substances with their environment, A single cellular organism can use the processes of osmosis, diffusion and active transport to transport substances in and out of the organism. But as organisms increase in size, they need a specialized transport system to exchange substances between the internal environment and the external environment. Interestingly enough, osmosis and diffusion are still the important mechanisms at the cellular level.
Single Cell Organisms
Tiny organisms have to take in food, water, gases, and chemicals, and they have to excrete waste products. They are full of organic molecules that have to be moved around and processed. In small cells, all parts of the cell are near the cell membrane, and chemical exchanges with the environment are simplified. As single cells grow larger, the contents increase in volume, and making everything work together becomes more complex. The cell wall, the interface between the living cell and the world, does not increase in area as quickly as the volume of the cell contents. At some point, the structures and processes in the cell will become inefficient if the cell becomes too large.
Small Animals
Very small organisms have a lot of surface compared to their volumes. Small warm-blooded animals (endotherms), like mice and hummingbirds, have to eat a lot in proportion to their weights in order to keep themselves warm. In cold weather, a small animal loses heat rapidly because so much of it is in contact with the environment. It needs to eat a lot, stay in a warm area, and have good insulating fur or feathers.
Large Animals
Large animals can hold heat well, but may have trouble getting rid of body heat in very hot weather. This is an important problem, because proteins break down if the body gets too hot, and the organism may die if overheated. Many animals have developed ways of getting rid of extra heat by sweating or panting. Elephants can dissipate heat from their large, thin ears.
Single Cell Organisms
Tiny organisms have to take in food, water, gases, and chemicals, and they have to excrete waste products. They are full of organic molecules that have to be moved around and processed. In small cells, all parts of the cell are near the cell membrane, and chemical exchanges with the environment are simplified. As single cells grow larger, the contents increase in volume, and making everything work together becomes more complex. The cell wall, the interface between the living cell and the world, does not increase in area as quickly as the volume of the cell contents. At some point, the structures and processes in the cell will become inefficient if the cell becomes too large.
Small Animals
Very small organisms have a lot of surface compared to their volumes. Small warm-blooded animals (endotherms), like mice and hummingbirds, have to eat a lot in proportion to their weights in order to keep themselves warm. In cold weather, a small animal loses heat rapidly because so much of it is in contact with the environment. It needs to eat a lot, stay in a warm area, and have good insulating fur or feathers.
Large Animals
Large animals can hold heat well, but may have trouble getting rid of body heat in very hot weather. This is an important problem, because proteins break down if the body gets too hot, and the organism may die if overheated. Many animals have developed ways of getting rid of extra heat by sweating or panting. Elephants can dissipate heat from their large, thin ears.
Solve surface area to volume ratio
For a single-celled organism (or a cell in a multicellular organism's body, for that matter), the surface is a critical interface between the organism/cell and its environment. Exchange of materials often occurs through the process of diffusion, in which dissolved molecules or other particles move from areas of higher concentration to areas of lower concentration (although some exchange is mediated by cellular mechanisms). This type of exchange is a passive process, and as a result imposes constraints upon the size of a single-celled organism or cell. Materials must be able to reach all parts of a cell quickly, and when volume is too large relative to surface area, diffusion cannot occur at sufficiently high rates to ensure this.
Surface Area
Here is a cube. Each edge measures two inches long.
How do we find the area of the surface, the outside?
We multiply two touching edges together.
Each edge is 2 inches long, so the area of one flat side of the cube is
2*2 = 4 square inches.
Here is a cube. Each edge measures two inches long.
How do we find the area of the surface, the outside?
We multiply two touching edges together.
Each edge is 2 inches long, so the area of one flat side of the cube is
2*2 = 4 square inches.
The area of one side of the cube is 4 square inches.
A cube has 6 sides.
4 square inches * 6 sides = 24 square inches.
So now we know the surface area of the outside of the whole cube.
A cube has 6 sides.
4 square inches * 6 sides = 24 square inches.
So now we know the surface area of the outside of the whole cube.
Volume
Now let's think about the inside.
To find out the volume (how much is inside) of the cube we multiply height by width by length.
With this cube, we multiply 2*2*2 = 8 cubic inches.
So we have 24 square inches of surface to only 8 cubic inches of volume.
Is the surface always a larger number? Let's do some more cubes and see
Now let's think about the inside.
To find out the volume (how much is inside) of the cube we multiply height by width by length.
With this cube, we multiply 2*2*2 = 8 cubic inches.
So we have 24 square inches of surface to only 8 cubic inches of volume.
Is the surface always a larger number? Let's do some more cubes and see
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Recall the general structure of the circulation system to include the blood vessels to and from the heart, the lungs, the liver and the kidneys
Recall:Remember or recognize from prior learning experiences.
Recall:Remember or recognize from prior learning experiences.
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The structure of the circulatory system is a complex network of pumps and vessels that transports nutrients and oxygen throughout the body. Blood travels in a circular path through the system. The heart pumps blood to all parts of the body, and within about a minute, that blood returns to the heart to be pumped out once again. (a closed system). Blood carries a variety of materials throughout the body, including oxygen and nutrients. All cells of the body get their resources from the circulatory system, either directly or indirectly, depending on their proximity to blood vessels.
Within the structure of the circulatory system, the heart is its center. The left side of the heart carries out systemic circulation, pumping blood to the body, and the right side of the heart pumps blood to the lungs, undergoing pulmonary circulation. Each side of the heart is composed of two chambers, one above the other, connected by valves which ensure that blood only flows in one direction.
Within the structure of the circulatory system, the heart is its center. The left side of the heart carries out systemic circulation, pumping blood to the body, and the right side of the heart pumps blood to the lungs, undergoing pulmonary circulation. Each side of the heart is composed of two chambers, one above the other, connected by valves which ensure that blood only flows in one direction.
Describe the structure of the heart and how it functions
Describe: Give a detailed account
Describe: Give a detailed account
The human heart is a hollow, upside-down, pear-shaped shell. The inside of the heart is divided into four chambers, the left and right atria and the left and right ventricles, which periodically fill with blood and empty.
The two atria form the curved top of the heart. The ventricles meet at the bottom of the heart to form a pointed base which points toward the left side of the chest. The left ventricle contracts most forcefully, so the heart beat is felt most strongly on the left side of the chest.
A wall, called the septum, separates the right and left sides of the heart. A valve connects each atrium to the ventricle below it. The mitral or bicuspid valve connects the left atrium with the left ventricle. The tricuspid valve connects the right atrium with the right ventricle.
The two atria form the curved top of the heart. The ventricles meet at the bottom of the heart to form a pointed base which points toward the left side of the chest. The left ventricle contracts most forcefully, so the heart beat is felt most strongly on the left side of the chest.
A wall, called the septum, separates the right and left sides of the heart. A valve connects each atrium to the ventricle below it. The mitral or bicuspid valve connects the left atrium with the left ventricle. The tricuspid valve connects the right atrium with the right ventricle.
Explain how the factors that affect heart rate
Explain: Give a detailed account of causes, reasons or mechanisms
Explain: Give a detailed account of causes, reasons or mechanisms
There are many factors that affect your heart rate. The heart rate can speed up or slow down because of stress, exercise, medication, trauma or illness. Even breathing can cause slight fluctuations in heart rate. Most of the time a person does not really think about changes in his heart rate.
Other factors that can affect heart rate
Other factors that can affect heart rate
- Air temperature: When temperatures (and the humidity) soar, the heart pumps a little more blood, so your pulse rate may increase, but usually no more than five to 10 beats a minute.
- Body position: Resting, sitting or standing, your pulse is usually the same. Sometimes as you stand for the first 15 to 20 seconds, your pulse may go up a little bit, but after a couple of minutes it should settle down. Emotions: If you’re stressed, anxious or “extraordinarily happy or sad” your emotions can raise your pulse.
- Body size: Body size usually doesn't usually change pulse. If you’re very obese, you might see a higher resting pulse than normal, but usually not more than 100.
- Medication use: Meds that block your adrenaline (beta blockers) tend to slow your pulse, while too much thyroid medication or too high of a dosage will raise it
- Digestion : In a digestive process, the intestines would require additional blood circulation and therefore a possible heart rate increase can be seen
Describe the structure of arteries, veins and capillaries and understand their roles
Describe: Give a detailed account
Describe: Give a detailed account
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Describe the composition of the blood: red blood cells, white blood cells, platelets and plasma
Describe: Give a detailed account
Describe: Give a detailed account
The composition of blood is actually quite complex. Blood is the medium in which dissolved gases, nutrients, hormones and waste products are transported. .
Blood is composed of a straw-colored liquid called plasma which contains suspended cells. The different specialized cells found in blood are:
Approximately 90% of plasma is water with the rest composed of dissolved substances, primarily proteins (e.g. albumin, globulin, fibronogen). Plasma typically accounts for 55% by volume of blood and of the remaining 45% the greatest contribution is from the red blood cells
Blood is composed of a straw-colored liquid called plasma which contains suspended cells. The different specialized cells found in blood are:
- red blood cells
- white blood cells
- platelets
Approximately 90% of plasma is water with the rest composed of dissolved substances, primarily proteins (e.g. albumin, globulin, fibronogen). Plasma typically accounts for 55% by volume of blood and of the remaining 45% the greatest contribution is from the red blood cells
State the role of plasma in the transport of carbon dioxide, digested food, urea, hormones and heat energy
State: Give a specific name, value or other brief answer without explanation or calcualtion
State: Give a specific name, value or other brief answer without explanation or calcualtion
Plasma is a pale-yellowish, watery solution that suspends all of the other parts of the blood. It makes up about 55% of the total volume of our blood. Plasma itself is made up of 91.5% water. It acts as a solvent for important proteins, nutrients, electrolytes, gases, and other substances essential to life.
Plasma is made mostly of water. This allows our blood to flow freely through our blood vessels, transporting a variety of substances throughout our entire body. We can think of plasma as the river upon which particles can travel and be delivered where needed. Red blood cells, white blood cells, and platelets are carried in the current of the plasma, transporting oxygen, providing an immune response, and delivering clotting agents when we have a cut.
Plasma is made mostly of water. This allows our blood to flow freely through our blood vessels, transporting a variety of substances throughout our entire body. We can think of plasma as the river upon which particles can travel and be delivered where needed. Red blood cells, white blood cells, and platelets are carried in the current of the plasma, transporting oxygen, providing an immune response, and delivering clotting agents when we have a cut.
Explain how adaptations of red blood cells, including shape, structure and the presence of haemoglobin, make them suitable for the transport of oxygen
Explain: Give a detailed account of causes, reasons or mechanisms
Explain: Give a detailed account of causes, reasons or mechanisms
The oxygen carried in your red blood cells is stored in a special protein known as hemoglobin. A single hemoglobin molecule is made of four identical sub-units. Each sub-unit has a heme component, aglobin chain and an iron atom bound to the heme section. Red blood cells are completely lacking in most other common cellular parts, such as a nucleus with DNA, or mitochondria.
Oxygen is able to bind to each of the iron atoms, meaning that a single hemoglobin molecule is able to carry up to four oxygen molecules at its maximum capacity. Interestingly, the structure of hemoglobin makes it such that the more oxygen that is bound to one of the sub-units, the more other oxygen molecules are attracted to the remaining iron atoms.
Oxygen is able to bind to each of the iron atoms, meaning that a single hemoglobin molecule is able to carry up to four oxygen molecules at its maximum capacity. Interestingly, the structure of hemoglobin makes it such that the more oxygen that is bound to one of the sub-units, the more other oxygen molecules are attracted to the remaining iron atoms.
Describe how the platelets are involved in blood clotting
.Describe: Give a detailed account
.Describe: Give a detailed account
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Platelets are not only the smallest blood cell, they are the lightest. Therefore they are pushed out from the center of flowing blood to the wall of the blood vessel. There they roll along the surface of the vessel wall, which is lined by cells called endothelium. The endothelium is a very special surface, like Teflon, that prevents anything from sticking to it. However when there is an injury or cut, and the endothelial layer is broken, the tough fibers that surround a blood vessel are exposed to the liquid flowing blood. It is the platelets that react first to injury. The tough fibers surrounding the vessel wall, like an envelop, attract platelets like a magnet, stimulate the shape change that is shown in the pictures above, and platelets then clump onto these fibers, providing the initial seal to prevent bleeding, the leak of red blood cells and plasma through the vessel injury.
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Describe how the immune system responds to disease using white blood cells, illustrated by phagocytes ingesting pathogens and lymphocytes releasing antibodies specific to the pathogen
Describe: Give a detailed account.
Describe: Give a detailed account.
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The immune system is the body's defense against infectious organisms. Through a series of steps called the immune response, the immune system attacks organisms that invade the body systems and cause disease. These organisms are called pathogens.
The immune system is made up of of cells, tissues, and organs that work together to protect the body. The cells involved in the immune system are called white blood cells or leukocytes The white blood cells come in two basic types that seek out and destroy the pathogens.
Leukocytes are produced or stored in many locations in the body, including the thymus, spleen, and bone marrow. For this reason, they're called the lymphoid organs. There are also lymphoid tissue,, primarily the lymph nodes, that store the leukocytes.
The leukocytes circulate through the body between the organs and nodes via lymphatic vessels and blood vessels. In this way, the immune system works in a coordinated manner to monitor the body for germs or substances that might cause problems.
The two basic types of leukocytes are:
The immune system is made up of of cells, tissues, and organs that work together to protect the body. The cells involved in the immune system are called white blood cells or leukocytes The white blood cells come in two basic types that seek out and destroy the pathogens.
Leukocytes are produced or stored in many locations in the body, including the thymus, spleen, and bone marrow. For this reason, they're called the lymphoid organs. There are also lymphoid tissue,, primarily the lymph nodes, that store the leukocytes.
The leukocytes circulate through the body between the organs and nodes via lymphatic vessels and blood vessels. In this way, the immune system works in a coordinated manner to monitor the body for germs or substances that might cause problems.
The two basic types of leukocytes are:
- phagocytes, cells that chew up invading organisms
- lymphocytes, cells that allow the body to remember and recognize previous invaders and help the body destroy them
Describe how vaccinations result in the manufacture of memory cells.
Describe: Give a detailed account.
Describe: Give a detailed account.
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Vaccines help develop immunity by imitating an infection. This
type of infection, however, does not cause illness, but it does cause
the immune system to produce T-lymphocytes and antibodies.
Sometimes, after getting a vaccine, the imitation infection can cause
minor symptoms, such as fever. Such minor symptoms are normal
and should be expected as the body builds immunity.
Once the imitation infection goes away, the body is left with a
supply of “memory” T-lymphocytes, as well as B-lymphocytes that
will remember how to fight that disease in the future. However, it
typically takes a few weeks for the body to produce T-lymphocytes and B-lymphocytes after vaccination. Therefore, it is possible that a person who was infected with a disease just before or just after vaccination could develop symptoms and get a disease, because the vaccine has not had enough time to provide protection.
type of infection, however, does not cause illness, but it does cause
the immune system to produce T-lymphocytes and antibodies.
Sometimes, after getting a vaccine, the imitation infection can cause
minor symptoms, such as fever. Such minor symptoms are normal
and should be expected as the body builds immunity.
Once the imitation infection goes away, the body is left with a
supply of “memory” T-lymphocytes, as well as B-lymphocytes that
will remember how to fight that disease in the future. However, it
typically takes a few weeks for the body to produce T-lymphocytes and B-lymphocytes after vaccination. Therefore, it is possible that a person who was infected with a disease just before or just after vaccination could develop symptoms and get a disease, because the vaccine has not had enough time to provide protection.
Outline the issues of childhood vaccinations
Outline: Give a brief account or summary
Outline: Give a brief account or summary
The number of young children who are not fully vaccinated for preventable diseases has been steadily increasing over the last decade. More and more, parents are claiming nonmedical exemptions from routine vaccinations — leaving their children, their children's classmates, and other children in their communities vulnerable to diseases.
With growing evidence that vaccinations may actually be causing chronic health problems and the attendant realization that the right to informed consent is being denied, a growing number of parents and concerned individuals are demanding that questions about safety and appropriateness be addressed.
With growing evidence that vaccinations may actually be causing chronic health problems and the attendant realization that the right to informed consent is being denied, a growing number of parents and concerned individuals are demanding that questions about safety and appropriateness be addressed.
Key Terms:
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surface area
SA:Volume ratio pulmonary systemic atria atrioventricular tricuspid valve bicuspid valve pathogen white blood cell |
heart
blood vessels arteries veins septum AV node arterioles innervated vaccination blood clot |
capillaries
blood plasma cardiac muscle oxygenated deoxygenated platelets red blood cells fibrinogen gibrin |
cardiac cycle
systol diastole coronary arteries erythrocytes haemoglobin oxyhaemoglobin phagocytosis secondary immune response |
medulla
ventricle vena cava aorta pseudopodia lymphocytes antibodies antigen memory cell immune |
Classroom Materials:
Surface Area to Volume ratio worksheet
Size Matters worksheet
Osmosis and Diffusion review
Comparing Human Circulation System with other species reading activity
Circulatory System (study notes)
The Heart Coloring activity
Diagram of the Heart
Exercise practical (in class design)
Heart Dissection practical
The Circulatory System Cloze activity
Blood Vessels Worksheet
Anatomy of the blood
Circulatory System Review
Surface Area to Volume ratio worksheet
Size Matters worksheet
Osmosis and Diffusion review
Comparing Human Circulation System with other species reading activity
Circulatory System (study notes)
The Heart Coloring activity
Diagram of the Heart
Exercise practical (in class design)
Heart Dissection practical
The Circulatory System Cloze activity
Blood Vessels Worksheet
Anatomy of the blood
Circulatory System Review
Part 1 Circulatory System Overview
Part 2 The Heart
Part 3 The Vessles
Part 4 The Blood
Useful Links:
Circulation from BBC Bitesize
Video clip on Heart Circulation
Active Book animation on page 55
Video clip on Heart Disease
PBS presentation on Circulation
Immunity animation from McGraw Hill
A nice review of the Circulatory System from KScience
Another KScience animation to help practice Labeling the Heart
Measles and the anti-vaccine 'debate' , BBC News
Video Clips:
Circulation from BBC Bitesize
Video clip on Heart Circulation
Active Book animation on page 55
Video clip on Heart Disease
PBS presentation on Circulation
Immunity animation from McGraw Hill
A nice review of the Circulatory System from KScience
Another KScience animation to help practice Labeling the Heart
Measles and the anti-vaccine 'debate' , BBC News
Video Clips:
This video shows how Paramecium eat. Paramecium is a genus of unicellular ciliate protozoa, commonly studied as a representative of the ciliate group. Its shape resembles that of a grain of rice. The cell ranges from about 50 to 350 �m in length (more or less one tenth of a millimetre) and is covered with simple cilia, allowing the cell to move at speeds of approximately 12 body lengths per second. The cilia act like oars and move in one direction.There is a deep oral groove containing inconspicuous tongue-like compound oral cilia (as found in other peniculids) used to draw food inside. In general, they feed on bacteria and other small cells, making them heterotrophs. Osmoregulation is carried out by a pair of contractile vacuoles, which actively expel water from the cell absorbed by osmosis from its surroundings.[1] They are relatively large protists and can easily be seen with a medium-power microscope.
Paramecia are widespread in freshwater environments, and are especially common in scums. Recently, some new species of Paramecium have been discovered in the oceans.
Certain single-cell eukaryotes such as Paramecium are examples for exceptions to the universality of the genetic code: in their translation systems a few codons differ from the standard ones.
Paramecia are widespread in freshwater environments, and are especially common in scums. Recently, some new species of Paramecium have been discovered in the oceans.
Certain single-cell eukaryotes such as Paramecium are examples for exceptions to the universality of the genetic code: in their translation systems a few codons differ from the standard ones.
For most of history, scientists weren't quite sure why our hearts were beating or even what purpose they served. Eventually, we realized that these thumping organs serve the vital task of pumping clean blood throughout the body. But how? Edmond Hui investigates how it all works by taking a closer look at the heart's highly efficient ventricle system
Hank takes us on a trip around the body - we follow the circulatory and respiratory systems as they deliver oxygen and remove carbon dioxide from cells, and help make it possible for our bodies to function.
3D How the Heart Works
Hank tells us about the team of deadly ninja assassins that is tasked with protecting our bodies from all the bad guys that want to kill us - also known as our immune system.
This amazing video shows aWhite Blood Cell Chases Bacteria. Video by David Rogers, Vanderbilt University
The first ever vaccine was created when Edward Jenner, an English physician and scientist, successfully injected small amounts of a cowpox virus into a young boy to protect him from the related (and deadly) smallpox virus. But how does this seemingly counterintuitive process work? Kelwalin Dhanasarnsombut details the science behind vaccines
Seth Berkley explains how smart advances in vaccine design, production and distribution are bringing us closer than ever to eliminating a host of global threats -- from AIDS to malaria to flu pandemics
Vaccine-autism claims, "Frankenfood" bans, the herbal cure craze: All point to the public's growing fear (and, often, outright denial) of science and reason, says Michael Specter. He warns the trend spells disaster for human progress.
Tal Golesworthy is a boiler engineer -- he knows piping and plumbing. When he needed surgery to repair a life-threatening problem with his aorta, he mixed his engineering skills with his doctors' medical knowledge to design a better repair job.
This amazing device could 'eat' bad cholesterol in your arteries.
