We started this week by talking about the urinary system. The urinary system consists of at least one kidney, two ureters, the urinary bladder, and the urethra. The kidneys filter the blood plasma then they return most of the water and solutes into the blood stream. The rest of the water and solutes make the urine. The urine is passed through the ureters and is then help in the urinary bladder until it is passed through the urethra and out of the body.
When you eat food, your body takes nutrients and uses them to maintain all of the bodies functions. After the body takes what it needs from the food. The rest of the waste products are left in the blood stream. The urinary system works with the lungs, skin and also the intestines. All of these excrete waste. On average, adults eliminate about one to two quarts of urine every day. This number can change depending on the amount of food and fluid that adult takes in. It also depends on how much fluid is lost during sweating and breathing. The urinary system releases a waste called urea. This comes form the blood. Urea comes from foods that contains proteins. When this food is broken down, urea is carried in the bloodstream to the kidneys.
Kidneys are about the size of your fist and they are in the shape of a bean. They are located just below the rib cage. Kidneys are responsible for removing urea from the blood using small filtering units called nephrons. A nephron has a ball formed of small blood capillaries. This ball is called a glomerulus. They also have a small tube called a renal tube.
After the kidneys, the urine travels down the ureters. These are small tubes, about 8 to 10 inches long, leading to the bladder. The muscles of the ureter constrict and relax which forces the urine down away from the kidneys. Urine is moved through the ureters to the bladder about every 10 to 15 seconds.
Your bladder is balloon shaped organ that sits in your pelvis and is held in that place by ligaments. The bladder is the organ that holds urine until you are ready to go pee and empty it. In a healthy urinary system, a bladder can hole about 2 cups of urine for about 2 to 5 hours. Sphincters are circular muscles that help keep the urine from leaking. They close tightly around the opening of the bladder into the urethra. When you urinate, the brain sends a signal to the bladder muscles which says to tighten. When tightened the urine is squeezed out of the bladder. While the brain is telling the bladder muscles to tighten, it is also telling the sphincter muscles to relax. This allows the urine to exit from the urethra.
Tuesday, May 5, 2009
Saturday, May 2, 2009
Fetal Circulation
This post is a little out of order but I thought I would talk about fetal circulation due to the fact that it was on our last test.
The fetal circulatory system works differently during pregnancy than it does after birth. During pregnancy, the fetus it attached to the placenta by the umbilical cord. The placenta is the organ that develops and implants in the uterus during pregnancy. Using the blood vessels of the umbilical cord the fetus is provided the necessary nutrition, oxygen and life support from the mother from the placenta. While these things are being moved in, there are other things making their way out of the fetus. Waste products and carbon dioxide are sent back through the umbilical cord and the placenta and moved into the mothers circulation to be released.
The blood from the mother enters the placenta and comes close to the fetal blood that has returned from the fetus to the placenta through the umbilical arteries. When the two circulations get closer in the placenta, the oxygen and nutrients such as sugar, proteins and fat molecules are able to move from maternal blood to fetal blood. While this is happening...carbon dioxide and waste products can move from the fetal blood to the maternal blood. After the fetal blood is nourished, it can return to the baby through the umbilical vein.
This vein goes to the liver and splits into three branches. One of these branches connects directly to the inferior vena cava. This branch allows the blood to reach the fetal heart and is then sent to the rest of the body.
After birth, and the umbilical cord is clamped from the placenta, the circulation changes after the baby is detached from the placenta. When the baby is removed from the placenta, the reservoir to the fetus, the baby's venous/resistance blood pressure rises. When the lungs are filled with air, the blood pressure in the lung arteries goes down.
Since the fetal lungs do not function to exchange gases and oxygenated blood is obtained from the mother, there are some important differences in the circulatory systems from adults and fetuses.
The fetal circulatory system works differently during pregnancy than it does after birth. During pregnancy, the fetus it attached to the placenta by the umbilical cord. The placenta is the organ that develops and implants in the uterus during pregnancy. Using the blood vessels of the umbilical cord the fetus is provided the necessary nutrition, oxygen and life support from the mother from the placenta. While these things are being moved in, there are other things making their way out of the fetus. Waste products and carbon dioxide are sent back through the umbilical cord and the placenta and moved into the mothers circulation to be released.
The blood from the mother enters the placenta and comes close to the fetal blood that has returned from the fetus to the placenta through the umbilical arteries. When the two circulations get closer in the placenta, the oxygen and nutrients such as sugar, proteins and fat molecules are able to move from maternal blood to fetal blood. While this is happening...carbon dioxide and waste products can move from the fetal blood to the maternal blood. After the fetal blood is nourished, it can return to the baby through the umbilical vein.
This vein goes to the liver and splits into three branches. One of these branches connects directly to the inferior vena cava. This branch allows the blood to reach the fetal heart and is then sent to the rest of the body.
After birth, and the umbilical cord is clamped from the placenta, the circulation changes after the baby is detached from the placenta. When the baby is removed from the placenta, the reservoir to the fetus, the baby's venous/resistance blood pressure rises. When the lungs are filled with air, the blood pressure in the lung arteries goes down.
Since the fetal lungs do not function to exchange gases and oxygenated blood is obtained from the mother, there are some important differences in the circulatory systems from adults and fetuses.
Friday, May 1, 2009
The digestive system!!!!!
This week in class we started talking about the digestive system. We discussed the GI tract. The GI tract goes from the oral cavity to the anal cavity. This GI tract is made up of four different layers of tissues. The four layers are mucosa, submucose, muscularis, and serosa. That is the order of the layers from the deepest to the most superficial.
The mucosa :: This is the inner lining of the GI tract. It is a mucous membrane that is composed of a layer of epithelium. This epithelium in the mouth, pharynx, esophagus, and the anal canal, is a mostly nonkeratinized stratified squamous epithelium. This functions as a protector. In the stomach and intestines is a simple columnar epithelium layer that functions in secretion and absorption. The mucosa also has a layer of areolar connective tissue known as the lamina propria. This layer has many blood and lymphatic vessels. These vessels are the routes in which nutrients that have been absorbed into the GI tract reach the other tissues of the body. This layer is responsible for supporting the epitelium and binding it to the muscularis mucosae. The third layer of the mucosa is the muscularis mucosae. This is a layer of smooth muscle fibers. This layer creats a fold in the mucous membrane of the stomach and small intestine. This helps to boost the surface area for digestion and absorption. This layer is avascular and has no blood supply.
The submucosa :: The submucosa layer has areolar connective tissue that helps bind the mucosa to the muscularis. It has many blood and lymphatic vessels that receive the absorbed food molecules. The submusocsa may have glands and lymphatic tissue. In this layer there is also an extensive network of neurons know as the submucosal plexus. This layer is highly vascular. It has clusters of white blood cells to recognize pathogens.
The muscularis :: The muscularis in the mouth, pharynx, and superior and middle parts of the esophagus has skeletal muscle. This muscle produces voluntary swallowing. This skeletal muscle also makes up the external anal sphincter. This permits voluntary control of defercation. For the rest of the tract, the muscularis has smooth muscle that is found in two sheets. There is a sheet of circular fibers and and outer sheet of longitudinal fibers. The food is broken down by the invouluntary contractions of the smooth muscle. The food is then mixed with digestive secretions. It is propeled along the rest of the tract.
The serosa :: The serosa is a serous membrane containing areolar connective tissues and simple squamous epithelium. This layer secretes a slippery/watery fluid that allows the tract to glide easily against the other organs. The serose inferior to the diaphragm, is known as the visceral peritoneum. This is becuase it forms a portion of the peritoneum.
Some other important words that we talked about are the following. The esophagus is what directs food to the stomach. The pyloric region leads to the small intestine. The true sphincter contains smooth or skeletal muscle cells that control the opening. The stomach is a "mixing bag" that works to mechanically digest food particles.
There are many things you can do to make sure you have and can maintain a healthy digestive system. Some of those things include eating healthy, exercising regularly and reduce or manage stress levels. Everything you eat and even drink needs to be broken down. The molecules are to big to just go trough the body.
The mucosa :: This is the inner lining of the GI tract. It is a mucous membrane that is composed of a layer of epithelium. This epithelium in the mouth, pharynx, esophagus, and the anal canal, is a mostly nonkeratinized stratified squamous epithelium. This functions as a protector. In the stomach and intestines is a simple columnar epithelium layer that functions in secretion and absorption. The mucosa also has a layer of areolar connective tissue known as the lamina propria. This layer has many blood and lymphatic vessels. These vessels are the routes in which nutrients that have been absorbed into the GI tract reach the other tissues of the body. This layer is responsible for supporting the epitelium and binding it to the muscularis mucosae. The third layer of the mucosa is the muscularis mucosae. This is a layer of smooth muscle fibers. This layer creats a fold in the mucous membrane of the stomach and small intestine. This helps to boost the surface area for digestion and absorption. This layer is avascular and has no blood supply.
The submucosa :: The submucosa layer has areolar connective tissue that helps bind the mucosa to the muscularis. It has many blood and lymphatic vessels that receive the absorbed food molecules. The submusocsa may have glands and lymphatic tissue. In this layer there is also an extensive network of neurons know as the submucosal plexus. This layer is highly vascular. It has clusters of white blood cells to recognize pathogens.
The muscularis :: The muscularis in the mouth, pharynx, and superior and middle parts of the esophagus has skeletal muscle. This muscle produces voluntary swallowing. This skeletal muscle also makes up the external anal sphincter. This permits voluntary control of defercation. For the rest of the tract, the muscularis has smooth muscle that is found in two sheets. There is a sheet of circular fibers and and outer sheet of longitudinal fibers. The food is broken down by the invouluntary contractions of the smooth muscle. The food is then mixed with digestive secretions. It is propeled along the rest of the tract.
The serosa :: The serosa is a serous membrane containing areolar connective tissues and simple squamous epithelium. This layer secretes a slippery/watery fluid that allows the tract to glide easily against the other organs. The serose inferior to the diaphragm, is known as the visceral peritoneum. This is becuase it forms a portion of the peritoneum.
Some other important words that we talked about are the following. The esophagus is what directs food to the stomach. The pyloric region leads to the small intestine. The true sphincter contains smooth or skeletal muscle cells that control the opening. The stomach is a "mixing bag" that works to mechanically digest food particles.
There are many things you can do to make sure you have and can maintain a healthy digestive system. Some of those things include eating healthy, exercising regularly and reduce or manage stress levels. Everything you eat and even drink needs to be broken down. The molecules are to big to just go trough the body.
Wednesday, April 29, 2009
Inflammation!!!!!
Inflammation is a response of the body when there is damage done to tissue. There are many things that can cause inflammation. Some of those things include pathogens, abrasions, chemical irritations, disturbances to cells and also extreme temperatures. It is fairly easy to identify inflammation. Some of the obvious clues are redness, swelling, pain and heat. When tissues are damaged and inflammation occurs, some functions can be lost in that area. This depends on the location and also the extent of the injury. Inflammation is a way to dispose of microbes, toxins and foreign materials at the injured area. This helps prevent the spread to other tissues. It also helps to prepare the site of injury for tissue repair and restore homeostasis in the tissue.
The inflammatory response consists of three different stages. The first stages is vasodilation and increased permeability of blood vessels. The second stages is the movement of phagocytes from the blood to the interstitial fluid. The final stage is the tissue repair.
The events of inflammation can be summarized in about seven steps. * Microbes, or bacteria, enter the area of injury. * Vasodilation of the microcirculation. This results in an increased blood flow. * An increase in vascular permeability to protein. * Filtration of fluid into the tissue. This is what causes the swelling. * Exit of neutrophils and later monocytes, from the blood vessels to the tissues. * Phagocytosis and destruction of the microbes. * Tissue repair.
When the small blood vessels constrict, they quickly dilate. When this dilation occurs, it slows the blood flow this what causes the redness and heat at the injury site. White blood cells move through the blood vessels and move into the injured area. While they are there...they have to job to clean up the micro-organisms and the dead tissue. When protein and water are moved from the blood vessels is when the swelling occurs. With water and protein comes other substances that start the clotting process. One of these substances is fibrin. Fibrin is what is responsible for deaths that can occur in diphtheria.
Inflammation is a necessary process. When you have a wound, it has to go through the inflammation process before the wound healing process an start. When tissue is injured, chemical reactions are started which in turn started the inflammatory process.
The inflammatory response consists of three different stages. The first stages is vasodilation and increased permeability of blood vessels. The second stages is the movement of phagocytes from the blood to the interstitial fluid. The final stage is the tissue repair.
The events of inflammation can be summarized in about seven steps. * Microbes, or bacteria, enter the area of injury. * Vasodilation of the microcirculation. This results in an increased blood flow. * An increase in vascular permeability to protein. * Filtration of fluid into the tissue. This is what causes the swelling. * Exit of neutrophils and later monocytes, from the blood vessels to the tissues. * Phagocytosis and destruction of the microbes. * Tissue repair.
When the small blood vessels constrict, they quickly dilate. When this dilation occurs, it slows the blood flow this what causes the redness and heat at the injury site. White blood cells move through the blood vessels and move into the injured area. While they are there...they have to job to clean up the micro-organisms and the dead tissue. When protein and water are moved from the blood vessels is when the swelling occurs. With water and protein comes other substances that start the clotting process. One of these substances is fibrin. Fibrin is what is responsible for deaths that can occur in diphtheria.
Inflammation is a necessary process. When you have a wound, it has to go through the inflammation process before the wound healing process an start. When tissue is injured, chemical reactions are started which in turn started the inflammatory process.
Wednesday, April 22, 2009
Arteries
Arteries are what carry blood away from the heart. They carry the blood to the other organs of the body. The wall of arteries has three coats. The coats are the tunica interna, the tunica media and the tunica externa. The innermost coat is the tunica interna, it is composed of a lining of simple squamous epithelium called endotherlium, a basement membrane and a layer of elastic tissue called the internal elastic lamina.The endothelium is a continuous layer of cells that line the inner surface of the entire cardiovascular system. The tunica interna is the closest layer to the lumen. The lumen is the hollow space in which the blood flows. The tunica media is the middle coat. The coat contains elastic fibers and smooth muscle fibers. These fibers are arranged in rings around the lumen. The tunica externa is composed of mostly of elastic and collagen fibers. The walls of arteries normally can stretch easily without tearing when there is an increase in pressure.
ELASTIC ARTERIES: Elastic arteries, sometimes called conducting arteries, are the arteries with the largest diameter. The contain a lot of elastic fibers in their tunica media. They help propel blood onward while ventricles are relaxing. When blood is moved into elastic arteries, the walls stretch and the elastic fibers store mechanical energy. When the ventricles are relaxing, the fibers within the artery walls recoil and this forces blood towards the smaller arteries.
MUSCULAR ARTERIES: The medium sized arteries are called the muscular arteries. These arteries have more smooth muscle and less elastic fibers than the elastic arteries. These arteries are capable of greater vasoconstriction and vasodilation, allowing them to adjust to the rate of blood flow. Muscular arteries cn also be called distributing arteries. This is because they distribute blood to a variety of areas of the body.
When muscular arteries divide into smaller arteries, those smaller arteries then divide into even smaller arteries. The smallest arteries are called arterioles. These arterioles delivers blood to capillaries. They play an important role in regulating the blood flow from arteries to capillaries by regulating the opposition to blood flow. When the diameter of an artery is smaller, the friction is greater. Arterioles are also known as resistance vessels. This is because relaxation and contraction of the smooth muscle in the walls can change the diameter. The contraction of the smooth muscle of an arteriole causes vasoconstriction. When this occurs, the resistance is increased and the blood flow into the capillaries is decreased. During relaxation, resistance is decreased and the blood flow into the capillaries is increased. This is called vasodilation.
The diameter of arteries can also affect someone's blood pressure. vasoconstriction increases blood pressure while vasodilation decreases blood pressure. While veins are moving blood from tissues to the heart, arteries are transferring blood from the heart to the tissues. The circulatory system is extremely important for sustaining life. Its proper functioning is responsible for the delivery of oxygen and nutrients to all cells, as well as the removal of carbon dioxide and waste products, maintenance of optimum pH, and the mobility of the elements, proteins and cells of the immune system.
ELASTIC ARTERIES: Elastic arteries, sometimes called conducting arteries, are the arteries with the largest diameter. The contain a lot of elastic fibers in their tunica media. They help propel blood onward while ventricles are relaxing. When blood is moved into elastic arteries, the walls stretch and the elastic fibers store mechanical energy. When the ventricles are relaxing, the fibers within the artery walls recoil and this forces blood towards the smaller arteries.
MUSCULAR ARTERIES: The medium sized arteries are called the muscular arteries. These arteries have more smooth muscle and less elastic fibers than the elastic arteries. These arteries are capable of greater vasoconstriction and vasodilation, allowing them to adjust to the rate of blood flow. Muscular arteries cn also be called distributing arteries. This is because they distribute blood to a variety of areas of the body.
When muscular arteries divide into smaller arteries, those smaller arteries then divide into even smaller arteries. The smallest arteries are called arterioles. These arterioles delivers blood to capillaries. They play an important role in regulating the blood flow from arteries to capillaries by regulating the opposition to blood flow. When the diameter of an artery is smaller, the friction is greater. Arterioles are also known as resistance vessels. This is because relaxation and contraction of the smooth muscle in the walls can change the diameter. The contraction of the smooth muscle of an arteriole causes vasoconstriction. When this occurs, the resistance is increased and the blood flow into the capillaries is decreased. During relaxation, resistance is decreased and the blood flow into the capillaries is increased. This is called vasodilation.
The diameter of arteries can also affect someone's blood pressure. vasoconstriction increases blood pressure while vasodilation decreases blood pressure. While veins are moving blood from tissues to the heart, arteries are transferring blood from the heart to the tissues. The circulatory system is extremely important for sustaining life. Its proper functioning is responsible for the delivery of oxygen and nutrients to all cells, as well as the removal of carbon dioxide and waste products, maintenance of optimum pH, and the mobility of the elements, proteins and cells of the immune system.
Wednesday, March 18, 2009
Blood
Recently, we started talking about the cardiovascular system. The cardiovascular system includes three components. Those three components are blood, the heart and blood vessels. Blood is a connective tissue that has a liquid portion called plasma and a cellular portion that consists of many cells and cell fragments. Blood is the life maintaining fluid that circulates throughout the body’s heart, arteries, veins and capillaries. While circulating throughout the body, the blood carries difference substances. Some of these substances include nourishment, hormones and antibodies. While those substances are being carried to the body, waste matter and carbon dioxide are carried by blood out of the body. Oxygen and nutrients that are being transported by the blood diffuse into the interstitial fluid ( the fluid found between body cells ).
Blood has three main functions. Those three functions are transportation, regulation and protection.
Transportation:: Blood transports different substance throughout the body. It moves oxygen from the lungs to the cells throughout the body and it carries carbon dioxide from the cells to the lungs. Oxygen and carbon are not the only substances that are carried by blood. It is also responsible for carrying substances from the gastrointestinal tract to cells and at the same time it moves heat and waste products away from cells. It also moves hormones from endocrine glands to other cells.
Regulation:: Blood circulating helps to maintain homeostasis in all body fluids. Blood helps to maintain body temperature. This is with the help of the heat absorbing and coolant properties of the water in the blood.
Protection:: The blood has the ability to clot when there is an injury. This can be helpful in a way because it protects the body from losing too much blood. Also, white blood cells help to protect against disease by carrying phagocytes. Along with phagocytes, blood proteins such as antibodies, interferons can help to protect against disease as well.
Blood is stickier than water and also more dense. The temperature of blood is typically 30 degrees celsius. Blood counts for about 8 percent of body weight. In an average sized male there is about 5 to 6 liters of blood. In an average adult woman there is about 4 to5 liters.
Blood contains blood plasma, which is a watery liquid. This liquid is composed of dissolved substances. Blood also has formed elements. These elements are cells and cell fragments.
Blood plasma is a straw colored liquid that is about 91.5 percent water, 7 percent proteins and 1.5 percent solutes, that are not proteins. Plasma proteins are proteins in the blood. The most plentiful plasma proteins are the albiums. (about 54 percent of all plasma proteins)
Blood has three main functions. Those three functions are transportation, regulation and protection.
Transportation:: Blood transports different substance throughout the body. It moves oxygen from the lungs to the cells throughout the body and it carries carbon dioxide from the cells to the lungs. Oxygen and carbon are not the only substances that are carried by blood. It is also responsible for carrying substances from the gastrointestinal tract to cells and at the same time it moves heat and waste products away from cells. It also moves hormones from endocrine glands to other cells.
Regulation:: Blood circulating helps to maintain homeostasis in all body fluids. Blood helps to maintain body temperature. This is with the help of the heat absorbing and coolant properties of the water in the blood.
Protection:: The blood has the ability to clot when there is an injury. This can be helpful in a way because it protects the body from losing too much blood. Also, white blood cells help to protect against disease by carrying phagocytes. Along with phagocytes, blood proteins such as antibodies, interferons can help to protect against disease as well.
Blood is stickier than water and also more dense. The temperature of blood is typically 30 degrees celsius. Blood counts for about 8 percent of body weight. In an average sized male there is about 5 to 6 liters of blood. In an average adult woman there is about 4 to5 liters.
Blood contains blood plasma, which is a watery liquid. This liquid is composed of dissolved substances. Blood also has formed elements. These elements are cells and cell fragments.
Blood plasma is a straw colored liquid that is about 91.5 percent water, 7 percent proteins and 1.5 percent solutes, that are not proteins. Plasma proteins are proteins in the blood. The most plentiful plasma proteins are the albiums. (about 54 percent of all plasma proteins)
Friday, March 13, 2009
Hormones
This past week we talked about hormones. What are hormones anyway? Hormones carry messages from glands to cells to preserve chemical levels in the bloodstream. Hormones move around in the bloodstream waiting to be recognized by a target cell. Each target cell has a receptor that can be activated by only a specific hormone. Once the target cell is activated it then knows to start it's function.
The concentration of hormones depends on three factors. The rate of production, the rate of delivery and the rate of degradation and elimination. Rate of production :: Synthesis and secretion of hormones are the most highly regulated feature of endocrine control. The management of the rate of production is controlled by both positive and negative feed back circuits. The rate of delivery :: An example of delivery would be the blood flow to an organ or a group of target cells. When there is a high blood flow more hormone is delivered and when there is a low blood flow it is the opposite. Meaning there is less amount of hormone delivered. Rate of degradation or elimination :: All hormones have featured rates of decay and are eliminate through one of several different routes. When the secretion of a hormone that has a short half-life gets shut off, the hormone concentration drops. However, when the half-life is long effective concentrations continue for more time after the secretion ceases.
We talked about the two major hormone categories. Those two groups are protein and steroidal hormones. These two groups have many differences. Protein hormones can travel easily through aqueous solutions such as blood. They also bring about rapid and instant changes within target cells. They have a short half-life which means they decompose rapidly. Protein hormones make use of their biological effect on target cells through a second messenger system.
Steroidal hormones must be transported through aqueous solutions with the help of a transport protein. Steroidal hormones like protein hormones also induce changes in target cell nuclei while doing this it alters mRNA transcription. They are hydrophobic which makes then non-polar. Unlike protein hormones, steroidal hormones have a reasonably long half-life.
As humans we need hormones. They help our bodies function and keep us healthy.
The concentration of hormones depends on three factors. The rate of production, the rate of delivery and the rate of degradation and elimination. Rate of production :: Synthesis and secretion of hormones are the most highly regulated feature of endocrine control. The management of the rate of production is controlled by both positive and negative feed back circuits. The rate of delivery :: An example of delivery would be the blood flow to an organ or a group of target cells. When there is a high blood flow more hormone is delivered and when there is a low blood flow it is the opposite. Meaning there is less amount of hormone delivered. Rate of degradation or elimination :: All hormones have featured rates of decay and are eliminate through one of several different routes. When the secretion of a hormone that has a short half-life gets shut off, the hormone concentration drops. However, when the half-life is long effective concentrations continue for more time after the secretion ceases.
We talked about the two major hormone categories. Those two groups are protein and steroidal hormones. These two groups have many differences. Protein hormones can travel easily through aqueous solutions such as blood. They also bring about rapid and instant changes within target cells. They have a short half-life which means they decompose rapidly. Protein hormones make use of their biological effect on target cells through a second messenger system.
Steroidal hormones must be transported through aqueous solutions with the help of a transport protein. Steroidal hormones like protein hormones also induce changes in target cell nuclei while doing this it alters mRNA transcription. They are hydrophobic which makes then non-polar. Unlike protein hormones, steroidal hormones have a reasonably long half-life.
As humans we need hormones. They help our bodies function and keep us healthy.
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