Friday, May 21, 2010
Monday, May 17, 2010
iv. Human Papillomavirus (HPV)
You can use the Visible Thinking Tool – Generate questions on the transmission of these infections. The questions may include:
i. What causes the infections?
ii. How the transmission occurs?
iii. What are the signs and symptoms?
iv. What is the treatment?
v. How can this infection be prevented?
Monday, May 10, 2010
Sunday, May 9, 2010
i. What is the cause of the disease?
Septicemia is a systemic infection, usually caused by bacteria of various types contaminating a person’s blood. Infections of the mouth or teeth, when untreated by antibiotics, can cause septicemia. How? One serious complication can occur if a dentist initiates treatment of affected teeth, and there is an additional development of bacterial endocarditis (BE), which is a strep infection. The strep enters the blood stream and then cultivates inside the cardiac tissues creating blockages.
Infections of cuts or surgical wounds both carry a risk or developing septicemia. With a large cut or surgical wound, one has a slightly increased risk of septicemia, because blood loss lowers the body’s natural immunities.
Burns are another major causal factor in septicemia. Third degree burns are particularly vulnerable to infection, and the larger the burn, the greater the chance of infection. Often third degree burns damage the nerve endings of skin, causing people not to initially feel pain at the site of the burn. People may not notice initial infection of burns without visual inspection.
Another possible cause of septicemia is internal injury, such as a stomach injury after a car accident. Intestinal rupture, gall bladder disease and rupture of the appendix or spleen are indicated in septicemia as well. These ruptures very often are treated with antibiotics from the onset, since the blood is immediately exposed to high and dangerous bacteria levels. This is particularly of issue with intestinal perforations, which spill bowel contents into other parts of the body, causing almost immediate septicemia.
A partial miscarriage, or missed miscarriage can also result in septicemia, if pregnancy remains stay in the uterus and become infected. Virtually any internal infection more readily can become septicemia because of direct contact with blood cells.
Those who have autoimmune disorders are more prone to infections of all kinds, since they have weakened immune systems. People with diabetes tend to exhibit an overall higher risk for septicemia because they also lack the ability to heal from cuts. Diabetics with foot injuries are asked to be particularly watchful, as these injuries or even small cuts can be very susceptible to infection.
ii. How does the component of blood/ blood vessel affected in the disease?
Septicemia is a disease that originates from a severe penetration of micro-organisms or their toxic products into the blood.
Many germs are quite innocuous for human body if they remain on the surface or skin of the body. They are even beneficial to the body in some cases. But if they enter the blood stream, they may impose serious threat to the body by developing infection. When they enter the blood stream, they multiply and cause severe infection until the body’s immune or defense system itself counter and kill them.
When patient experiences low blood pressure leading to less amount of blood transportation into the organs, the condition is termed as Septic Shock.
The penetration of these germs or micro-organisms into the blood stream happens when any other infection in any body parts acts as an entry point for the germs. In other cases, inappropriate surgical procedures, knife or other wounds can become a pathway towards the infection.
- What is the function of the blood component/ structure in circulatory system?
Red blood cells:A major function of the red blood cells is to carry oxygen to all the tissues from the lungs. The red blood cells than transport the carbon dioxide from the cells because of breaking down the nutrients.
white blood cells:They defend the body against bacteria and other enemies. The name white blood cells can be very misleading. The white blood cells are colorless. White blood cells come in many varieties. Each fights the body enemies in a different way. Some white blood cells produce antibodies, detoxify foreign substances, and digest bacteria.
Platelets:They are small fragments of cells that clump together and stick to inner surface of blood vessels to plug up leaks. The platelets release a substance for clotting of blood. The platelets cause the injured site to shrink and seal off.
- How does this blood component/ structure differ from the rest in the circulatory system?
Platelet:help to clot blood to prevent excessive blood loss
Red Blood Cells:carry oxygen from the lungs to the tissues around the body
White Blood Cells: leave the blood vessels and enter the surrounding tissue by chemotactically attracting these white blood cells to the infection site and by triggering neutrophils to release killing agents for extracellular killing
- How will the absence of the blood component / structure affect the health of the patient?
Absence of Red blood cells - The patient will not be able to do major physical activities like running, swimming because he or she cannot take in much oxygen due to the deficiency of red blood cells
Absence of White blood cells - The patient will be sick for short intervals and long period of time as white blood cells kill foreign particles like bacteria, viruses and germs.
Absence of Platelets - The patient will have a great loss of blood when wounded or have a small cut because platelets help in clotting blood at wounded areas.
- How technology is used to facilitate the analysis of one’s state of health and improve one’s lifestyle?
For people living in the past, whenever someone has something stuck in his or her body, sometimes even the doctors themselves cannot decipher where exactly is that object. But now, technology is more advanced and we have the x-ray machine. Just a scan and you can tell where that particular object is. Not only an x-ray machine. Now, we can tell the pulse of the patient when he or she is in coma or having an operation. It makes our lifestyle much easier than in the past.
- How technology is used to save lives with respect to the disease investigated?
Septicemia is a serious condition that requires a hospital stay. You may be admitted to an intensive care unit (ICU).
Fluids and medicines are given by an IV to maintain the blood pressure.
Oxygen will be given. Antibiotics are used to treat the infection.
Plasma or other blood products may be given to correct any clotting abnormalities.
Pictures and Videos
Done by: Carisa, Su En, Shamemi, Jaime, Priyanka, Pei Shan, Yi Lin, Teoh Yun.
Friday, May 7, 2010
i. What is the cause of the disease?
ii. How does the component of blood/ blood vessel affected in the disease?
iii. What is the function of the blood component/ structure in circulatory system?
iv. How does this blood component/ structure differ from the rest in the circulatory system?
v. How will the absence of the blood component / structure affect the health of the patient?
vi. How technology is used to facilitate the analysis of one’s state of health and improve one’s lifestyle?
vii. How technology is used to save lives with respect to the disease investigated?
We will be discussing the following diseases in the next lesson (Friday): Leukopenia, Thrombocytopenia, Coronary Heart Disease & Septicemia. You can do some research and read in advance to facilitate the discussion :) You can use the above questions to guide your research and readings
Saturday, April 17, 2010
Try playing & learn at the same time :)
Thursday, April 15, 2010
Sunday, April 11, 2010
Red Blood Cells
Introduction to Red Blood Cells.
Red blood cells are also known as RBCs, red blood corpuscles (an archaic term), haematids, erythroid cells or erythrocytes (from Greek erythros for "red" and kytos for "hollow", with cyte translated as "cell" in modern usage). The capitalized term Red Blood Cells is the proper name in the US for erythrocytes in storage solution used in transfusion medicine.
Information on Red Blood Cells.
Human erythrocytes are produced through a process named erythropoiesis, developing from committed stem cells to mature erythrocytes in about 7 days. When matured, these cells live in blood circulation for about 100 to 120 days. At the end of their lifespan, they become senescent, and are removed from circulation.
-Life cycle (Erythropoiesis)
Erythropoiesis is the development process in which new erythrocytes are produced, through which each cell matures in about 7 days. Through this process erythrocytes are continuously produced in the red bone marrow of large bones, at a rate of about 2 million per second in a healthy adult. (In the embryo, the liver is the main site of red blood cell production.) The production can be stimulated by the hormone erythropoietin (EPO), synthesised by the kidney. Just before and after leaving the bone marrow, the developing cells are known as reticulocytes; these comprise about 1% of circulating red blood cells.
This phase lasts about 100–120 days, during which the erythrocytes are continually moving by the blood flow push (in arteries), pull (in veins) and squeezing through microvessels such as capillaries as they compress against each other in order to move.
Relating to what we have learned- embryonic stem cells
-Artificially grown red blood cells
In 2008 it was reported that human embryonic stem cells had been successfully coaxed into becoming erythrocytes in the lab. The difficult step was to induce the cells to eject their nucleus; this was achieved by growing the cells on stromal cells from the bone marrow. It is hoped that these artificial erythrocytes can eventually be used for blood transfusions.
-How it looks like
-Red Blood Cell in the human blood
- Red Blood Cell in the blood vessel.
The artery that enters any organ divides and thins six to eight times before becoming an arteriole, the capillaries' control valve. Subsequently, the arteriole itself will branch two or three times, reducing its diameter to just 9 microns, and will continue on as a capillary. Some of these capillaries are so small that they cannot let even some large blood cells pass through them. Even red blood cells pass through such capillaries in single file, or else by distorting their shape.
The blood proceeding along the arteries at 1.5 kilometers an hour (0.93 miles per hour) slows down by a thousandth of that rate when it enters the capillaries. Every region of the body has been penetrated by an extraordinarily wide ranging network of capillaries. The capillaries in just one single person could stretch from one end of the USA to the other.109 This incomparable mechanism is brought into being to nourish all the cells in the body. In fact, a cell can be no further than 20 to 30 microns from a capillary—a distance of 0.02 millimeters (0.0007874 inch), which is sufficient to grasp the scale of this magnificent network that visits 100 trillion cells.
How does waste from the red blood cell goes into the lungs and how does oxygen molecules enters the red blood cell from the alveoli (tiny air sacs in the lungs where the exchange of oxygen and carbon dioxide takes place)
-Function of Red Blood Cells
Red blood cells (also referred to as erythrocytes) are the most common type of blood cell and the vertebrate organism's principal means of delivering oxygen (O2) to the body tissues via the blood flow through the circulatory system. They take up oxygen in the lungs or gills and release it while squeezing through the body's capillaries.
-What are the organelles found in the cell?
The organelles found in red blood cells include a plasma membrane and the cells' cytoplasm is rich in hemoglobin, an iron-containing biomolecule that can bind oxygen and is responsible for the blood's red color.
green = heme groups
red & blue = protein subunits
-List the structural features of the cell.
They are biconcave discs, having a depressed center on both sides. These depressed centers allow the cells to have more cell membrane surface which can be exposed to diffusing oxygen while transiting the lungs. This structure also allows them to be more flexible with the ability to twist and bend through the blood vessels.
-What are the functions of these organelles?
Hemoglobin facilitates transportation of oxygen and the plasma membrane keeps the hemoglobin in the cell.
-Why are these functions of the organelles important to the living cell?
Hemoglobin helps in transportation in oxygen so without hemoglobin, the cell will not carry oxygen so it would be useless and die. The person would also die.
Plasma membrane keeps the hemoglobin inside the cell if not it would be all round our blood.
-Diseases involving the red blood cells
- Anemias (or anaemias) are diseases characterized by low oxygen transport capacity of the blood, because of low red cell count or some abnormality of the red blood cells or the hemoglobin.
- Iron deficiency anemia is the most common anemia; it occurs when the dietary intake or absorption of iron is insufficient, and hemoglobin, which contains iron, cannot be formed
- Sickle-cell disease is a genetic disease that results in abnormal hemoglobin molecules. When these release their oxygen load in the tissues, they become insoluble, leading to mis-shaped red blood cells. These sickle shaped red cells are rigid and cause blood vessel blockage, pain, strokes, and other tissue damage.
Affected by Sickle-cell disease, red blood cells alter shape and threaten to damage internal organs.
- Thalassemia is a genetic disease that results in the production of an abnormal ratio of hemoglobin subunits.
- Spherocytosis is a genetic disease that causes a defect in the red blood cell's cytoskeleton, causing the red blood cells to be small, sphere-shaped, and fragile instead of donut-shaped and flexible.
- Pernicious anemia is an autoimmune disease wherein the body lacks intrinsic factor, required to absorb vitamin B12 from food. Vitamin B12 is needed for the production of hemoglobin.
- Aplastic anemia is caused by the inability of the bone marrow to produce blood cells.
- Pure red cell aplasia is caused by the inability of the bone marrow to produce only red blood cells.Hemolysis is the general term for excessive breakdown of red blood cells. It can have several causes and can result in hemolytic anemia.
- Hemolysis is the general term for excessive breakdown of red blood cells. It can have several causes and can result in hemolytic anemia.
- The malaria parasite spends part of its life-cycle in red blood cells, feeds on their hemoglobin and then breaks them apart, causing fever. Both sickle-cell disease and thalassemia are more common in malaria areas, because these mutations convey some protection against the parasite.
- Polycythemias (or erythrocytoses) are diseases characterized by a surplus of red blood cells. The increased viscosity of the blood can cause a number of symptoms.
- In polycythemia vera the increased number of red blood cells results from an abnormality in the bone marrow.
- Hemolytic transfusion reaction is the destruction of donated red blood cells after a transfusion, mediated by host antibodies, often as a result of a blood type mismatch.
- Some other diseases have been removed as it is too difficult to understand. Those who are interested to know the hard ones can go to
Information: http://web.buddyproject.org/web019/web019/blood.html and
Picture (Capillaries drawn):
Definition of alveoli: New Oxford American Dictionary.
Hemoglobin diagram: http://en.wikipedia.org/wiki/File:1GZX_Haemoglobin.png
Most information obtained from http://en.wikipedia.org/
Christopher, Carisa, Yi Lin, Jaime, Pei Shan, Priyanka
Thursday, April 8, 2010
Red blood cells are also called erythrocytes.
Firstly there are three parts in the cell that contain organelles. The nucleus, the cytoplasm and the surface. In the nucleus there are chromosomes, a nuclear membrane and a nucleolus. In the cytoplasm there are centrioles, chloroplast (plant cell), cytoskeleton, endoplasmic reticulum, golgi apparatus, lyosome, mitochondria, ribosomes and vacuoles. In the surface there are cell wall (plant cell) and cell membrane (plasma membrane).
There are other parts of organelles
It has a regular shape due to the cell wall and it also has a rectangular shape with many different looking and types of organelles.
The nucleus is the control center of the cell that dictates what all of the other organelles do. The nucleus also stores the DNA.The endoplasmic reticulum (ER) is where most chemical reactions take place. The cell makes lipids and other chemicals, and it sometimes has ribosomes attached.Ribosomes are the only organelle that every cell has, including bacteria. They take information from the DNA and use it to make proteins.The golgi apparatus is essential in packaging different products from the ER and the ribosomes into their final form. If it is a product that needs to be sent to other cells, the golgi apparatus packs them and sends them out.Mitochondria are often referred to as the powerhouses of the cell. This is because they take in sugar and create ATP, the type of energy your cell needs to function.The plasma membrane, or cell membrane, is not just the covering of the cell. It also plays a vital role in getting nutrients into the cell and sending waste products out.Chromosomes are normally in the form of chromatin. It contains genetic information. It is also composed of DNA.Moreover it is thickened for cellular division.There is a set number per species (i.e. 23 pairs for human)
They each have a specific function that helps the cell perform its function.