Tuesday 27 April 2010

Transportation Of Oxygen and Carbon Dioxide











2.3 Explain The Transport Of Oxygen and Carbon Dioxide In The Blood
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The transport of oxygen and carbon dioxide is done via the cardiovascular system, capillaries, veins, arteries and vessels and also with help from red blood cells. To start with the blood is oxygenated in the lungs, the process of this taking place is as follows.
The right ventricle in the heart sends blood that is de - oxygenated to the lungs, in the lungs the carbon dioxide releases out of the blood and into the lungs and the oxygen that we breath in then combines with the haemoglobin in the blood, it then passes through the lung capillaries. From this the oxyhaemoglobin then goes to the heart this is done via way of the pulmonary vein, it then enters the systemic circulation by the aorta.
In our body tissue there is a low amount of oxygen, it also contains products that are waste, this being carbon dioxide. Due to the high amount of oxygen in the blood and the ow amount in the tissue, the high amount of carbon dioxide in the tissues breaks down into the blood plasma. Finally the blood from the tissues go back to the heart by way of the superior vena cava and the inferior vena cava, the process then stars again.
Overall there is several major parts of our system involved in this process and without each linking to each other via veins, capillaries, vessels and arteries the process wouldn't be able to take place.

Structure Of Red Blood Cells and Relation To Function

Picture taken from www.getwellnatural.com


2.2 Describe The Structure Of A Red Blood Cell and Explain How
It Relates To It's Function
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Red blood cells also known as erythrocytes play a large part in the body. There are around 4.5 - 5.8 million (ivy-rose web), of these cells in the body per micro litre of healthy blood and they last around 120 days. The purpose of red cells is to supply and transport oxygen and to also get rid of carbon dioxide. In order for this to happen the structure helps a lot.
The shape of a red blood cell is a biconcave disk, it as a sunken centre on both sides, this allows the cell to have a larger cell membrane surface which can be exposed to diffusing oxygen whilst it is travelling to the lungs. The structure also enables the cells to be more flexible when it comes to them passing through tight passages like the capillaries. This is because they are flexible, bendy and bounce about, the cells are around 7.8 micrometers (cell tissue suite web) in diameter.
The immature red blood cell contains a nucleus but the mature ones don't, they also don't have mitochondria or other organelles. However the red blood cells do contain hemoglobin, these are molecules of protein and iron. These help in the process of picking up oxygen and transporting it through the vessels of the lung sacs that are called alveoli.
Due to the red blood cells being carried around the body easily they are able to help keep their small energy needs by a form of anaerobic respiration and are also able to distribute oxygen effectively to areas that need it the most.
Red blood cells also have something called carbonic anhydrase, this is an enzyme, it makes carbon dioxide and water, it then catalyzes to make a molecule called bicarbonnate. This is able to dissolve a lot better than carbon dioxide in the fluid, meaning that a greater amount can be carried around without the need to be in the small red blood cells.
Overall without red blood cells the oxygen in our body wouldn't be able to circulate and we wouldn't be able to get rid of the carbon dioxide. There for they are a very important part of our blood and their structure helps a lot in the process they carry out.

The Components Of Plasma and Their Function

Picture from www.goalfinder.com


2.1 Describe The Components Of Plasma and Explain Their Functions
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In this post I am going to talk about what is in blood and say what plasma is and it's function.
Blood is made up of components 55% of it is plasma and 45% is blood cells. Of the cells 99% are erythrocytes, these are red blood cells and 1% are leucocytes which are white blood cells and thrombocytes, these are platelets (ivy-rose web).
The normal structure of plasma is 90 - 92% of water and the rest is a straw coloured fluid. The fluid is where the blood cells are suspended and they contain substances that dissolve, these include electrolytes, things like sodium, chlorine, potassium, maganese and calcium ions. Also in the fluid is blood plasma proteins, these are albumin, globulin and fibrinogen, hormones are also in the fluid.
There are several functions of plasma. One of the functions is to allow the blood cells to move around the body effectively, this is done via blood vessels, it also helps us to keep a optimum body temperature, helps us to control our pH in the blood and body tissues, keeping it at a range that the cells can thrive. The last function is to help maintain an ideal balance of electrolytes in the blood and tissue.
Erythrocytes, being red blood cells when they are immature contain a nucleus, but a mature one doesn't have one. Erythrocytes contain a 'prosthetic group', in this there is an active component and this is called haem (ivy-rose web). The haem works with the help from iron, haem connects with oxygen and this then makes oxyhaemoglobin.
The erythrocytes last about 120 days before they break down, this is done by the spleen. The broken down pieces are then transported to the liver by the blood, here the iron is re-cycled to be used by new erythrocytes, the blood pigments form bile salts. The body contains around 4.5 - 5.8 million erythrocytes per micro litre of healthy blood (ivy-rose web). The red blood cells help carry oxygen around the body and eliminate carbon dioxide.
Leucocytes also called white blood cells last only for a few hours to a few days and there are around 5000 - 10,000 per micro litre of blood in the body.There are different types of leucocytes they are granular and agranular. The granular are neutrophils, eosnophils and basophils, and the agranulor do not contain granules are monocytes and lymphocytes. The white blood cells help play a very big part in the immune system.
Lastly there are the trombocytes also known as platelets. These are fragments of a cell, they are a disk shape with a size of 2 - 4um, (1micro metre=1um), (ivy-rose web). The trombocytes contain a lot of granuels but they do not have a nucleus and they last for around 5 - 9 days.In the body there are around 150,000 - 4000,000 platelets per micro litre of blood.
The purpose of the platelets is to help with the process of blood clotting, it also helps to stop the loss of body fluids.
Overall there is a lot contained in the blood and it pays a very important part in the function of our body.

Tuesday 20 April 2010

The Nervous System and Role In Breathing

1.3 The Role Of The Nervous System In
Generating Breathing Rhythm
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Our nervous system is what is responsible for receiving information that we get from outside the body, for example it lets us know if we are too cold or toowarm. The nervous system consist in the brain, the spinal cord and our nerves. The spinal cord is a long, round shape organ, it is in the spinal canal that sits inside the vertebrae, inside the spinal canal there is a central cavity that consist off cerebrospinal fluid. The nerves are made of either nerve cells or neurones, their structure varies as to where they are in the body and what they do. All of the cells have a cell body that contains a nucleus, these are normally in the brain or spinal cord. The brain as four parts one is the brain stem also known as the medulla, this is responsible for our involuntary reflex actions, the cerebellum is responsible for our posture and helps coordinate our movement, messages are received from the cerebrum, muscles and joints, the third is the diencephalon this controls the homeostatic mechanisms and our automatic nerve system. This contains the thalamus and the hypothalamus. The last part is the cerebrum, this is the largest part of the brain and it is a big part of the forebrain. This is divided into three sections and they control movement, figure out our sensory impulses and help us figure out our thoughts, memory's, emotions and also help us deter our own personalities.
The nerves that come from the diaphragm go up to the spinal cord and lead to the medulla oblongata, this is what is responsible for controlling our breathing, it is known as our respiratory centre. The neurones that are in the medulla oblongata are also connected to a second respiratory centre in the pons. It is the interaction between these two centres that enable us to breath with out thinking about it, the neurons are both stimulatory and inhibitory. If we try to control our breathing then the centres are taken over by the cerebella cortex, this is because there is a direct connection to the muscles that control respiration through the relevant motor neurones that come straight from the motor cortex of the cerebella cortex. The pons consist of a standard breathing rate, however this differs and that is so a connection can be made between the pons and medulla, the sensors that detect oxygen and carbon dioxide concentration in the blood are found in the aortic arch.
In conclusion our nervous system help control everything in our body and if they fail then our body wouldn't be able to function. Our breathing is fully controlled by messages being sent through us inhaling and the medulla picking this up.

Monday 19 April 2010

Effective Gas Exchange

1.2 Conditions Needed For Effective Gas Exchange
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This essay is going to look at the conditions needed for gas exchange to happen effectively. Gas exchange is to do with the alveoli that are in the lungs, they have a large surface area and the average adult has around 600 million of them. The alveoli have one layer of flattened epithelial cells for its walls and this is the same with the walls of the capillaries. This then means that the gases only need to break through two thin cells. Water comes from the alveoli cells and then go into the alveoli itself this keeps it moist. The water causes the oxygen to dissolve, this happens before it diffuses through the cells into the blood, once the oxygen goes into the blood it then goes into the red blood cells, this is done by haemoglobin. The water consist of a substance called surfactant, the purpose of this is to reduce tension and to stop the alveoli collapsing, it is a soapy like substance. There is also something called phagocyte cells in the alveoli this is something that kills any bacteria that manages to get through the mucus. As the oxygen moves out of the alveoli up into the capillaries, the carbon dioxide moves from the capillaries into the alveoli ready to be exhaled

Human Respiratory and how it relates to ventilation

1.1 The Respiratory System and How It Relates To
The Process Of Ventilation
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The respiratory's systems primary function is to supply oxygen around the body and to get rid of the carbon dioxide in our body. The respiratory system is made up of several parts and during this essay I am going to describe them and say what there process is during ventilation.
The first thing air goes through when we breath is the mouth or nose, the nose helps warm the air coming in and to also stop any unwanted particles such as dust and dirt getting into our body, this is done by the little hairs in the nose and also by the mucus. The upper part of the nose is lined with olfactory epithelium and the lower part are lined with pseudostratified ciliated colummnar epithelium (ambulance tech web). After the nose the air travels down to the pharynx, this is divided into three parts nasopharnx, oropharynx and the laryngopharynx. The oropharynx and the laryngopharynx are what help with the respiratory system and are part of the alimentary tract and it is lined with non-keratinized stratified squamous. From the pharynx air goes to the larynx, this helps in warming the air and helps stop unwanted objects getting through. It is lined with the same thing as the pharynx but also contains pseudostratified ciliated columnar epithelium, it as epiglottis, thyroid, arytenoid and cricoid cartilage. Our vocal cords are in this area as well, and when air comes through it causes them to vibrate which makes the sounds we make. Next comes the trachea it is around 10cm long and 2.5cm in diameter (ambulance tech), it as a C shaped hyaline cartilage which is not complete and there are rings around it that are completed by the trachealis muscle. Air passes down the trachea and into the two tubes known as the bronchi these branch off to the left and right and are contected to the lungs. The bronchi are similar structure to the trachea but they have a lining of ciliated columnar epithelium, as the tubes get smaller the cartilage get irregular and smaller until it is gone all together, the smooth muscle then gets thicker, the smaller tubes are called bronchioles. These tubes go into the lungs, the right lung as 3 lobes and the left as 2 lobes and the lungs are between 10 and 12 inches long (ambulance tech web). We breath in 13 pints a minute and we breath in more than 5000 times a day. The function of the lungs is to transport oxygen from the air into the bloodstream and to get rid of carbon dioxide. Attached to the end of the bronchioles that are in the lungs is something called alveoli sacs, these are like a bunch of grapes and it is these that allow new oxygen from the air to be distributed into the bloodstream. The surface area of the alveoli if it was to be laid flat would be a third of the size of a tennis court and it is pure tissue (dr standley web).The alveoli helps the process of gas exchange which is seperating the good air from the carbon dioxide. The lungs also help toowards the diaphragm working because as we breath in the lungs expand causing our ribs to move up and out which causes the diaphragm to lower, as the lungs empty when we breath out the ribs lower and move in which causes the diaphragm to raise.
Overall our respiratory system is a very clever thing, even though it's structure is fairly simple the way in which it works is very complex and it is good how the mucus in the nose helps stop unwanted stuff getting into our body and also how something that looks like a bunch of grapes can help get rid of carbon dioxide and also have such a large surface area.