The Respiratory System Helps In Excretion And Manages Hydrostatic Pressure, Causing Oedema. (70 Characters)

1. Explain the role of hydrostatic and osmotic pressure in the formation and reabsorption of tissue fluid.

2. Explain oedema and some possible causes.

3. Explain the structure of the respiratory system.

4. Explain mechanisms of breathing, diffusion in the lungs, and how oxygen combines with haemoglobin to be carried around the body.

5. Explain how diseases such as asthma and emphysema compromise the uptake of oxygen, and the effect of smoking on the respiratory system.

6. Define excretion, explain why excretion is vital for health and include examples of structure and function of related organs and systems.

The role of hydrostatic and osmotic pressure in the formation and reabsorption of tissue fluid

1. Hydrostatic pressure can be defined as pressure of a fluid that is in an enclosed space. This is the pressure that is primarily responsible for the movement of fluids between the capillaries and the tissues (Collins and Varmus, 2015). In other words, it is the pressure that is mainly responsible for movement of fluid from the capillaries to the tissues. It follows that the pressure plays a key role in the formation of tissue fluid. One kind of this pressure is the blood hydrostatic pressure. It refers to the force that is exerted by blood which is enclosed by the capillaries or the chambers of the heart (VanPutte, Regan and Russo 2017). There is also capillary hydrostatic pressure. This refers to the pressure applied by blood to the walls of capillaries. As seen above this pressure is responsible for the formation of tissue fluid through movement of fluids from the capillaries to the tissues.

Osmotic pressure is antagonistic to the hydrostatic pressure. It is responsible for the movement of fluids from the tissue fluid back to the capillaries (Lavie et al. 2015). This process is referred to as reabsorption. It is also known as oncotic pressure. While the hydrostatic pressure leads to movement of fluids from the capillaries, osmotic pressure causes the fluids to move back to the capillaries. Osmotic pressure is dependent on the osmotic concentration gradient. This refers to the difference between the concentration of water and solutes. Water moves from a region where it is in high concentration to a region where it is in low concentration across a semi-permeable membrane. 

2. Oedema refers to a condition where there is accumulation of body fluid in excessive quantities. The fluid accumulation occurs in body tissues. Oedema may occur in almost any part of the body. Although this is the case oedema may occur more in certain parts of the body. These include the legs, hand, feet, arms and ankles. The condition is characterized by swelling which occurs directly beneath the skin and especially in the legs. It may also lead to stretching of the skin to the pressure applied by the swelling. Oedema may also cause the abdomen to be swollen (Foster and Coetzee 2015). One common way of determining oedema is through using the thumb to press the area suspected. In cases of oedema, a pit is usually left. The pit disappears slowly. The condition may be given different names depending on the area of the body that it affects. For instance, there is pulmonary oedema, peripheral oedema etc.

There are several possible causes of oedema. The common mode of causation is through leaking of fluid from the blood vessels in to the neighbouring environment. Mild cases may be caused by such factors as: sitting in a place for a long period, consuming a diet that is high in sodium and pregnancy (Smith 2014). Oedema could also present as a side effect of certain medications. For instance, drugs used to treat hypertension, oestrogens, thiazolidinediones (drugs for diabetes management) and steroid drugs. In some instances, oedema may be a symptom of another serious condition (Waugh and Grant 2014). Such conditions include congestive heart failure and kidney diseases.

Examination of oedema and some possible causes

3. This is the system that  carries out the proves of breathing/ gaseous exchange. The process is fundamental to life and any illness affecting the system poses a significant threat to life. The process of breathing involves two main processes. The fist is inhalation which refers to the absorption of oxygen from the air for respiration purposes. The second process is exhalation. This is discarding of carbon dioxide from the body. Carbon dioxide is a by-product of metabolism. The system is categorized in two: the upper part and the lower part.

The upper part is composed of the organs running from the nose to the trachea. The mouth is also an organ of the upper part. The lower part is composed of the trachea, the bronchi, bronchiole and the lungs. These organs (those of the lower respiratory tract) are contained in the chest cavity. The trachea can be defined as tubular structure which bridges the throat and the bronchi. The bronchi (singular bronchus) refers to two tubes that branch from the trachea. These go to the lungs. The bronchi divide further in to tubular structures called bronchioles. There are also the pulmonary alveoli. This refers to tiny air sacs that have a single layer membrane and connect to blood capillaries. Gaseous exchange occurs at the pulmonary alveoli. The lung refers to the organ including the air tubes from the bronchi each ending to an alveolus. It is the organ at the centre of gaseous exchange.

4. Gaseous exchange refers to the process by which the oxygen is obtained from the surrounding environment to the blood stream and the elimination of carbon dioxide. As observed in the previous discussion, the lung is at the centre of this process. The process of gaseous exchange between the blood and the pulmonary alveoli occurs through the process of simple diffusion (Reed, Bayly and Sellon 2017). For the process of diffusion to occur efficiently, it is necessary that a concentration gradient be maintained (Rizzo 2015). This means that the oxygen concentration in the alveoli should consistently be lower than that in the blood while the level of carbon dioxide  in the blood should be greater than that in the alveoli. This is maintained by the continuous process of breathing which eliminates carbon dioxide from the body while supplying air rich in oxygen and low in carbon dioxide.

The process of breathing is active and involves contraction and relaxation of muscles. The muscles mainly involved in the process are internal and external intercostal muscles; and the diaphragm. Haemoglobin is the protein that is mainly responsible for transport of blood to most tissues of the body. Haemoglobin is contained in the red blood cells. Each contains four groups of haem and each group contains iron. One haemoglobin group can carry four oxygen molecules. Reaction between haem and oxygen leads to formation of oxyhaemoglobin.

5. There are certain disease conditions that may affect the integrity of the respiratory system and pose significant threat to health. One of such conditions is asthma. Asthma is a condition that causes the inflammation of the air passages (Asthma, 2014). The result of the inflammation is a temporary narrowing of the airway. Symptoms of asthma include coughing, chest tightness, wheezing and shortness of breath (Network, 2014). When the airway is narrowed, the normal functioning of the respiratory system is altered (Lambrecht and Hammad 2015). It becomes harder for oxygen to reach the lungs and for carbon dioxide to be excreted. If the condition is severe, it may greatly deteriorate the quality of living.

Structure of the respiratory system

Emphysema is another condition that may negatively alter the integrity of the respiratory system. When one has emphysema, the alveoli get damaged (Bogner, 2018). This causes the airway to collapse and makes the process of gaseous exchange difficult. The result is inadequate exchange of gases which may pose a great threat to life. One cannot survive for long when the process of gaseous exchange is severely altered. The disease may cause a total collapse of the airway which caused death. It can therefore be concluded that emphysema severely affects the operations of the respiratory system in a negative way.

Smoking is another factor that may affect the integrity of the respiratory system in a negative way. Extensive evidence has suggested that smoking increases the chance of developing lung disease including lung cancer chronic bronchitis and emphysema. All these reduce the ability of the respiratory system to carry out its function.

6. Excretion refers to the process by which the body gets rid of the waste products of metabolism. The normal bodily processes such as metabolism lead to formation of by-products which may be toxic to the body. It is therefore undesirable that these wastes accumulate in the body for they could cause harm. The body has a complex system that ensures homeostasis. Homeostasis simply refers to the process by which the body maintains body concentrations at a relatively normal range. The excretory system is involved in getting rid of the waste products. Removal of waste products is done by various organs. Some of these are the sweat glands, liver, kidney and lungs.

The kidney carries the most excretory work (Scanlon and Sanders 2018). It is composed of three parts. These are the renal medulla, renal cortex and renal; pelvis. The kidney is used in eliminating waste products from the blood. The blood enters the organ through the renal artery. The artery branches into many different arterioles. These further divide in to tiny structures known as the nephrons. The nephron is the basic unit of a kidney. When the blood flows to the bowman’s capsule of the kidney, pressure is applied, and this leads to filtration. The wastes are filtrated/taken out by the application of the pressure. There are some capillaries (peritubular) that surround the nephron so that substances can move in and out of the blood. The renal pelvis takes the urine (waste) away using the ureter. The contents of the ureter are emptied in to the urinary bladder.

References

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Collins, F.S. and Varmus, H., 2015. A new initiative on precision medicine. New England Journal of Medicine, 372(9), pp.793-795.

Foster, M.N. and Coetzee, W.A., 2015. KATP channels in the cardiovascular system. Routledge.

Lambrecht, B.N. and Hammad, H., 2015. The immunology of asthma. Routledge.

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Network, G.A., 2014. The global asthma report 2014. Routledge.

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