The Effects of Obesity on Health

Normal body balance is imperative to maintain the optimal physiological function of body systems. Age as a predisposing factor influences anthropometric interpretation for the elderly; the elderly tend to experience changes in body composition and height compared to a young adult of the same BMI. (WHO, 2014) . According to the WHO, Waist-Hip ratio (Circumference) and Body Mass index are recognized as measures of fat distribution and obesity in the human body. Fats are likely to amass on the abdomen than extremities. This condition is known as adiposity. This results in a higher waist circumference-thigh ratio. Visceral fats, which is the fat coating of internal organs, is best estimated using waist circumference. Brodie’s waist circumference, 100cm, increases risk of disease. BMI is calculated by a person(s) Body mass in Kilogram (Kg) divided by the person’s height in square meters (m2) (Direct, 2018). As per information provided, Brodie’s weight is 95Kg with a height of 1.85m; his BMI can be calculated as;

Brodie has a BMI of 27.75 kg/m2 an approximation of 28.0 this score is interpreted as overweight

        The ideal body shape and size of Brodie should give a waist circumference which is within the normal range and BMI within the normal range as per formula above. According to who, the normal BMI should be between 18.50 and 24.99. The ideal weight of Brodie is obtained using the lower and upper limits of the BMI and height of 185cm. The height is multiplied with the BMI so as to get the weight. Brodie should, therefore, weigh between 63.32 kg and 85.53 using the aforementioned formula. In addition his waist circumference should be less than 100cm.  (WHO, 2014).

        Brodie, being overweight, has a lot of health risks such as stroke, myocardial infarction, diabetes as a result of insulin resistance, hypertension which has already developed, and angina. Brodie should aim at achieving the following in order to reduce his health risks; he needs to lower his low-density lipoproteins and total cholesterol level to the normal range. He should also increase his high density lipoprotein levels. In addition, he should lower his blood pressure to the normal level. He can achieve this by exercising regularly, reducing intake of fats, using lipid lowering drugs to manage hyperlipidemia, and use of antihypertensive medication to control his hypertension. These measures will reduce his BMI and therefore reduce his health risks.  (NHI, 2015)

Different types of cell respiration Aerobic and Anaerobic

         Cellular respiration refers to a set of anabolic and catabolic processes that occurs inside a cell structure that results in the breakdown of nutrients to produce biochemical energy (ATP) for maintaining body function. During normal body functioning, skeletal muscle cells, contracts, and relaxes intermittently. In the process, biochemical energy is consumed in the form of ATP.   The biochemical energy consumed in the process is generated from the skeletal cells in the Mitochondria. Skeletal muscle proves distinct in terms of energy breakdown as they are adapted to allow for aerobic and short-term anaerobic processes with high energy output.

         During a high oxygen supply to the skeletal muscle, aerobic respiration takes place resulting in energy production during manageable exercise. Intense exercises give rise to high energy demand which outweighs the supply of oxygen to muscles leading to anaerobic breakdown process. Intensified exercises can be sustained for short periods since there is the buildup of wastes (lactic acid) which reduces the efficiency of energy production.

         The initial phase of glucose breakdown (energy production) is glycolysis. It takes place in the cytoplasm and is anaerobic in nature. In a series of transitional phases, two molecules of pyruvic acid and two molecules of ATP are produced from one molecule of glucose. The pyruvic acid can enter the citric acid cycle when there is enough oxygen supply. The site of this process is mitochondria. There is a production of a total of 38 ATP molecules. This process involves oxidative phosphorylation to release energy. During a low oxygen supply, the glucose molecule enters glycolysis. It is broken down to produce two pyruvic acid molecules. However, pyruvic acid does not get into the citric acid cycle; instead, it is broken down anaerobically into lactic acid. The buildup of lactic acid result in pain and cramps of muscles which are over-exercised

         The preferred type of energy production in skeletal muscle is aerobic respiration. This is because there is no accumulation of lactic acid which is toxic. In addition, there is production of more energy which is utilized by the muscles. This process provides the long-term energy supply to muscles. On the other hand, anaerobic respiration is limited by insufficient energy production and lactic acidosis.

How do multiple body systems normally work together for oxygen to enter the body and reach the cells?

         The increasing concentration of carbon dioxide in the body system with decline in concentration of oxygen in the body triggers the ventilation process in the lungs. A response is sent to the medulla oblongata cells notifying a drop in pH as shown below.

                                        [CO 2 + H2O → HCO3 − + H+],

         Medulla oblongata retorts by sending of nerve impulses that regulate the activity of the intercostal muscles and diaphragm. This result in an increased rate of lung ventilation. During lung ventilation downward and upward movement of the diaphragm causes a change in chest cavity length and volume. Further contraction of the diaphragm pulls the lungs downward, while relaxation allows the lungs to compress. Elevation and depression of the ribs, changes chest cavity diameter. As a consequence, the pressure of the intrapulmonary gas is momentarily reduced and thus causing an influx of atmospheric air. (Guyton, 2016, p. 123)

         Atmospheric air which enters the body varies in terms of external environmental conditions such as; the air might be moist or dry, cold or warm, and their quantity of pollutants vary, dirt or dust. During the breathing process, as air moves into the lungs via the nose, it warms to body temperature.

         In the nasal cavity, the air warms, moistens and filters. The three folding conchae lead to increased surface area and spread the air inspired over the whole nasal cavity to enhance the filtering of dust particles, humidification, and warming. Colossal vascularity of mucosa allows fast warming of air as it flows. Large particles are trapped by the hair at the frontal nares whereas small-sized particles attach to mucosa. The mucosa prevents drying and protects the epithelium from irritation. The cilia movement wafts the mucosa towards the throat where it is ingested or coughed up. Warm humidified air is then directed to the larynx via the pharynx eventually through the trachea that which fork into the two main bronchi. The bronchi (b= 1), this divides into the lobar, segmental and 4 to 5 further divisions of cartilaginous bronchi. The next eight generations (b = 8 - 15) constitute progressively smaller, ciliated no cartilaginous bronchioles, the last of which is the terminal bronchiole which is about 0.5 mm in diameter. (Celi, 2016, p. 62)

         This further divides up to and including the terminal bronchioles and eventually into the alveoli. After ventilation, diffusion of oxygen into the pulmonary blood from the alveolar, with carbon dioxide diffusion from blood and into the alveoli take place.  The definite interchange of gases happens between the blood and the alveoli by diffusion of gas molecules. Oxygen moves from their areas of high concentration, alveoli, into the capillaries. On the other hand, carbon dioxide moves from their higher concentration, capillaries, into the alveoli for expulsion.

Sodium, potassium, and calcium, which are present in body fluids, are important for normal neuron function

         Potassium, calcium, and sodium ions are key components of body electrolyte that facilitate proper cell function. These ions assist in the neuronal transmission of electrical impulses.

         Sodium is more in the extracellular compartment than in the intracellular compartment and gains entry into the neuron via the sodium channels. The sodium channels can be ligand-gated or voltage-gated. In a neuron that is in the resting membrane potential, -70mv, sodium channels open leading to movement of sodium into neurons. Depolarization of the neurons occurs as a result. The charge will be about +30mv. The action potential that results is the way of communication between the neuronal cells. Impulses are transmitted from one neuron to another. During repolarization, sodium channels are inactivated and as a result, sodium will not be moving into the neurons. Hypernatremia, higher extracellular sodium levels above the upper limit of the normal range, is manifested in various ways. This result in shifting of fluid from the intracellular compartment into the extracellular compartment. The neurological consequence is that there will be cerebral dehydration whereby the brain tissue will pull away from the meninges as a result, rupturing of meningeal vessels followed by hemorrhage. The neurological symptoms will range from the altered level of consciousness, irritability, altered behavior, seizures, to coma. On the other hand, hyponatremia, which entails lower extracellular sodium level than the normal lower limit, results in the movement of water from the extracellular compartment into the intracellular compartment. This results in cerebral edema with increased intracranial pressure. The clinical manifestations are; nausea, vomiting, papilledema, altered level of consciousness, seizures, and coma. Cerebral edema can also lead to herniation of brain tissue. The Na/K ATPase pump is crucial in the maintaining the normal extracellular and intracellular levels of sodium and potassium ions. For instance, it pumps excess potassium during hyperkalemia into the cells against a concentration gradient.  (Saladin, 2017, p. 239)

         Potassium is essential for neuronal signaling. The normal range of potassium level in the body, in the extracellular compartment, is between 3.5 to 5mEq/L.  In a neuron which is in a depolarized state, activation and opening of potassium channels open cause movement of potassium ions from the intracellular compartment to the extracellular compartment. Potassium is normally more inside cells. This result in a change in membrane potential, repolarization of neurons. Therefore, the neurons will return to the resting membrane potential. Hyperkalemia, high extracellular potassium levels, opposes the efflux of potassium during repolarization and therefore leads to a reduction in membrane potential while facilitating the process of neuronal depolarization. This may present as cardiac arrest, an exhibition of mental confusion and respiratory distress On the other hand, hypokalemia, the low extracellular potassium level, results in hyperpolarization of neurons because of an increased gradient for efflux of potassium.        

         Calcium plays an important role in the neuronal signaling. It functions as a second messenger. Here, calcium cause the release of protein kinases which produce the desired functions. Some other second messenger pathways stimulate the release of calcium which in turn activate protein kinases. An example is the inositol triphosphate which binds to calcium ion channel in the endoplasmic reticulum leading to increased cytosolic calcium followed by binding of calcium to calmodulin and cause a conformational change followed by the activation of protein kinases with the outcome being the desired action. The neurons maintain a low level of cytoplasmic calcium level by active transport of calcium out of the cytoplasm. Calcium result in the release of neurotransmitters which functions in neuronal communication. Hypercalcemia, higher than normal extracellular free calcium, results in the following neurological manifestations; mental changes such as impaired concentration, depression, psychosis, and even coma. Hypocalcemia, on the other hand, is the low free extracellular calcium level. The manifestations are generally a result of an increase in nervous excitability. There is also increased muscle excitability. The clinical presentation includes; cramps, spasms, convulsions, laryngeal stridor, and numbness.  (Justin, 2017, p. 45)

Venous return

         Venous return is the main element of cardiac output.  If the force of left ventricular contraction pumping blood is not adequate to pump the blood into the arterial and venous circulation and back to the heart, it calls for consideration of other factors. Exercise helps in increasing the venous return. This is because of the muscle pump of the calf muscles during exercise and the presence of valves to prevent backflow of blood while maintaining the venous return towards the right atrium. The skeletal muscles contracts, and compress the veins during exercise. The increased requirement and consumption of nutrients and oxygen by muscles during an exercise result in an increased cardiac output which in turn increase the venous return. In addition, exercises will help Brodie to reduce fats that may have been deposited inside his blood vessels leading to reduced resistance to blood flow. Lack of exercise results in impaired venous return. Valvular incompetence within the veins will result in impaired venous return.

      The mean arterial pressure of Brodie being 150/95 mmHg will affect his venous return. Mean arterial pressure is obtained by multiplication of total peripheral resistance with cardiac output. Therefore, increase in mean arterial pressure will result in a rise of the cardiac output when the peripheral resistance is not raised as per formula above. An increase in cardiac output will, in turn, result in high venous return. Hypertensive patients, like Brodie, experiences higher systolic blood pressure in a given instance, and they can also experience rise in their diastolic blood pressure. The reductions of blood pressure after an episodic exercise is the role and necessity of physical exercises in patients with hypertension. (CDC, 2016, pp. 62-80)

Infection would be likely to influence his oxygenation

         The most common viral infection of the upper respiratory tract is a common cold.  This presents with a sore throat, running nose, cough, congestion, and sneezing. Following the upper respiratory tract infection, there is increased mucus production and expulsion with an aim of destroying and removing the pathogens. There is generally increased nasal secretions which cause airway obstruction. This obstruction of nasal passages can force Brodie to breathe using the mouth in compensation. In addition, there is inflammation of the airway following the common cold. This leads to narrowing of airway passages and in turn reduced flow of air into the lungs resulting in insufficient exchange of oxygen and carbon dioxide within the lungs with reduced absorption of oxygen. Coughing also impairs flow of air into the lungs. It is beneficial in that it results in expulsion of foreign particles and mucus with an aim of maintain the patency of the airway. Hypoventilation gives rise to hypoxia in tissues due to insufficient supply of oxygen to various tissues of the body. Deprivation of oxygen supply to the tissues as a result of variations in arterial oxygen concentration enables a switch from aerobic to anaerobic metabolism at the cellular. This is temporary with production of low amounts of energy. The rapid metabolism of carbohydrates and fats, result in the formation of carbon dioxide which combines with water to form carbonic acid. This triggers fast breathing to offset the excess carbon dioxide through ventilation reducing its accumulation to toxic levels hence rapid short breathing. Other body responses to these situations include elevation of bicarbonate levels through cellular buffering as well the renal compensatory occurs with increasing bicarbonate reabsorption in the renal and elimination of carbonic acid. (Shephard RJ, 2016, pp. 35-38)

Blood pressure and cholesterol

Atheroma formation within the coronary arteries occurs as a result of fat deposition within the intima of the vessels. This accumulation can become unstable leading to rupture and the formation of a thrombus. If the plaque lead to stenosis greater than fifty-percent diameter of coronary vessels (or greater than seventy-five percent decrease in cross-sectional area), this shows decreased blood flowing in the coronary artery. Thrombus formation following the disruption of blood flow causes the acute coronary condition. The disruption of blood flow results in limited oxygenation of tissues and cells of the heart leading to termination of aerobic respiration.   The maintenance of the continuous mechanical activity of the heart tissues require high ATP production. As a result of the obstruction and resultant reduction in oxygen supply, anaerobic respiration occurs with the production of toxic lactic acids which accumulate in the cardiac myocyte.  Disturbances in ATP production affect contractile functionality. Cardiac metabolism plays a vital role in furnishing the heart with necessary biochemical energy. Any metabolic alterations also termed as metabolic remodeling, ranging from inadequate supply of oxygen, reduction of nutrients supply to mitochondrial failure. There is impaired contractility as a result of deficient ATP production.  The depletion of ATP is a relevant consequence of metabolic remodeling during heart failure result when cellular building blocks, metabolic pathways, and signaling molecules regulate essential processes such as regeneration and growth of cells. The result of the ischemia depends on the duration whereby reversibility of the injury can be achieved when blood flow is reestablished before a permanent injury ensues. Long-standing coronary ischemia leads to irreversible injury and death to the myocyte. (Brawnwald, 2013, pp. 663-645)

References

Braunwald, E., (2013). Research Advances in Heart Failure. Circulation Research, III(6), pp.       633-645.

CDC, (2016). PHYSIOLOGIC RESPONSES AND LONG-TERM ADAPTATION             EXERCISE.    In: CDC, ed. Respiratory Response to Exercise. Nairobi: CDC, pp. 62-       80.

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            Available at: https://www.healthdirect.gov.au/body-mass-index-bmi-and-waist-            circumference

            [Accessed 7 September. 2018].

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Guyton, (2016). Medical Physiology. 12 ed. Oxford: Elsevier.

Justin, H., (2017). Fluid, Electrolyte, and Acid-Base Balance. 2 ed. Guatemala: Mexico Press.

NHI, (2015). National Institute of Diabetes and Digestive and Kidney Diseases. [Online]

Available at: https://www.niddk.nih.gov/health-information/weight-management/health-risks-   overweight[Accessed 8 9 2018].

Saladin, K., (2017). Human Anatomy. 5th ed. New York: Mc Graw Hill Education.

Shephard RJ, S. P., (2016). Cancer, Immune Function and Physical Activity. Canadian Journal           of Applied Physiology, 2(56), pp. 37-38.

WHO, (2014). Waist Circumference and Hip Ratio. Geneva: WHO.