The Human Body System Overview

Functioning of the Human Body and its Systems

The human body is an amalgamation of cells, tissues, and organs regulated by various systems (Thibodeau & Patton 2009). To appreciate its functioning, it is imperative to examine a number of elements. Information on the various systems and major organs is essential in understanding how the human body works and responds to the environment. Thibodeau and Patton (2009) point out that there are 11 major organs within the human body. In addition, Thibodeau and Patton highlight the existence of 11 systems associated with these organs.

Human Body Systems

Marieb, Mitchell and Smith (2013) cite the nervous system as one of the several structures found in the human body. The system consists of the brain, the spinal cord, and a network of nerves. Collectively, it is referred to as the central nervous system (Thibodeau and Patton 2009). The system is essential in the detection of stimuli within the body. Most of the functions carried out by the human body are controlled by this element.

The second is the musculoskeletal system. Marieb et al. (2013) point out that this particular system comprises of muscles that are attached to the human skeleton. It defines the physical structure of an individual, as well as their mobility. Moreover, the bones are used in the manufacture of white blood cells. They also act as storage points for calcium and phosphate.

Also known as the circulatory system, the cardiovascular structure is responsible for the circulation of blood and other essential fluids within the body. According to Marieb et al. (2013), the system is made up of the heart and the blood vessels. The latter is comprised of veins and arteries. The third is the respiratory system. It plays a vital role in breathing. The system helps to circulate oxygen within the body. At the same time, it expels carbon dioxide from the individual’s internal organs.

The digestive system is another vital element in the human body. Marieb et al. (2013) suggest that an individual requires this system to break down food particles. The same is essential as it helps in the absorption of nutrients into the body. At the same time, unwanted materials are dealt with using this structure. There also exists the integumentary system. It comprises of the skin, nails, and hair. It provides the body with a cover. At the same time, it acts as a sensory organ between the individual and their surroundings.

Another important element is the immune system. Its role is to defend the human body from disease causing elements. The system is made up of red and white blood cells. The lymph is also regarded as another component of this structure. On its part, the lymphatic system is essential in the production and transportation of lymph fluids (Thibodeau & Patton 2009). There is also the urinary system. Its role is to discharge extra water and ions from the body.

Marieb et al. (2013) highlight the existence of the endocrine system. It is essential in the production of hormones. Finally, there is the reproductive system. The generation of human offspring relies on this structure. It is characterised by gonads, which vary depending on the sex of the individual.

The functioning of the systems highlighted above is achieved with the help of the synchronised activities of different organs. The heart, brain, liver, stomach, gonads, and skin constitute the major organs in the human body.

Interaction between Body Systems

As already indicated, the human body comprises of multiple organs and systems. However, their respective roles should be harmonised. The organs and systems should not interfere with the functioning of each other. For this purpose, the human body is structured in such a way that all the systems interact with each other for the growth and functioning of the individual. According to Thibodeau and Patton (2009), the human body attains this form of interaction by means of homeostasis. With the help of this process, the individual is able to regulate their internal environment. The body maintains temperature and pH levels that are needed for the functioning of the systems discussed.

The survival of human beings relies on the interaction between these systems (Thibodeau & Patton 2009). The structure operates when the brain responds to commands. The instructions are received through the neurotransmitters. Consequently, the endocrine system reacts to the information. It responds by releasing enzymes that regulate the quantity and pressure of blood flowing through the body. The pH levels are regulated by means of cell metabolism.

Physical Activity

Response to Physical Activity

Dylan, Karpe, Lafontan and Frayn (2012) argue that all forms of physical activities are treated as stimulus by the body. Consequently, the various systems will respond to such stimuli in a bid to return the body to normalcy. A case in point is the musculoskeletal system of the 25 year old individual. They system is responsible for support. Physical activity causes the muscles to tighten in response to the strenuous activity exhibited by the individual as he is distributing fliers for the marathon.

Physical activity requires energy. Bouchard, Blair and Haskell (2012) point out that power is obtained through respiration. As such, physical exertion increases the rate of respiration. As a result, the respiratory system will have to increase its rate of operation to meet the energy demands of a strenuous physical activity like a marathon. Similarly, the cardiovascular system is forced to ‘work over time’. As previously mentioned, the system plays a very important role in the body. It distributes blood around the body. What this means is that increased demand for energy in the muscles will require the heart to pump more blood.

Bouchard et al. (2012) suggest that blood pressure will also rise. As indicated earlier, the respiratory system is involved in the circulation of oxygen in the body. The compound is essential in the oxidisation of nutrients. The oxidisation process produces energy and carbon dioxide. As such, the high demand for energy due to physical activity will require the blood to flow, which explains the high pressure. The pumping rate of the heart is increased. The three systems mentioned above ensure the optimal functioning of the human body. They help to meet the energy demands of the body during physical activities.

Cellular and Tissue Response

As a result of physical exertion, the cells become turgid owing to the high blood pressure and volume. As a result, the tissues become tight. Marieb et al. (2013) argue that cellular physiology is determined by the activities carried out by an individual. Strenuous activities like a marathon are bound to result in tight tissues and turgid cells. The response exhibited by the organs is informed by the reaction of the cells and tissues.

Coordination of Internal Activities

According to Frederic, Nath and Edwin (2011), the body is required to maintain certain levels of pH, sugar, temperature, and blood pressure. However, physical activities like the ones highlighted in the case of the 25 year old individual bring about changes to internal operations of the body. His temperature will rise due to the energy produced. In addition, the blood pressure will be high owing to the increased heart rate. The blood sugar levels will also rise.

The changes described above are detected by the nervous system. The brain then sends out a signal to the endocrine system to respond to the changes (Frederic et al. 2011). The system responds to the increased temperature by dilating the superficial blood vessels and activating the sweat glands. The pressure is reduced by decreasing the volume of blood. The same operations can be carried out by the kidneys. Finally, the high demand for blood sugars causes adrenaline to convert glycogen into glucose, which is required in the muscle tissues (Dylan et al. 2012).


Recommended Routine Tests and Measures


Obesity is regarded as a hazardous accumulation of body fat (Mayo Clinic 2013). Under such circumstances, a patient diagnosed with the condition is at risk of suffering from heart related problems and a raft of other issues. In the case of the obese patient who is aged 65 years, a number of tests are recommended. The condition is associated with body mass. As such, it is important to calculate the patient’s body mass index (BMI). Secondly, their waist size needs to be determined.

In addition, such a person should undergo a number of blood tests to determine their cholesterol and blood sugar levels. Blood tests are also essential to determine the performance of the liver. Sherwood (2012) points out that an electrocadiogram would be necessary in certain cases. Considering the symptoms exhibited by this patient, it would be advisable to test them for influenza

Recording the measures

Calculation of the body mass index helps to determine whether an individual is overweight or not. As already mentioned, the patient is obese. Such a test would help to analyse the severity of their condition (Sweeting 2007). The formula used is BMI = m/h2. In this case, (m) stands for weight, while (h) represents height. With regards to the influenza suspicions, the subject should undergo a test to determine the type of the condition. According to the Centres for Disease Control and Prevention (2013), the distinction is made by carrying out analysis of viral cultures. As for the blood tests, the subject should have a given volume extracted from their vessels. The blood is then scrutinised for cholesterol and sugar levels.

Analysis of Information

The most important information obtained from the 65 year old man relates to the BMI and the influenza tests. According to Mayo Clinic (2013), there are three categories of obesity inferred from BMI tests. When an individual’s score falls within the range of 30.00 and 34.99 (kg/m2), they are considered to have class 1 obesity. If the figure is within the range of 35.00 and 39.99 (kg/m2), then they are considered to have class 2 obesity. Any figure higher than 40 (kg/m2) is regarded as class 3 diabetes. It is a very severe condition.

If it is determined that the subject has influenza or any class of diabetes, the practitioner should realise that there might be challenges with regards to their immune system. They are at risk of suffering from organ failure. Influenza is a virus. As such, the body is expected to fight off the disease. It is the responsibility of the immune system to deal with pathogens. Class 3 obesity implies that the individual’s body fat is increasing. As such, it will be safe to assume that the organ responsible for fat conversion has failed (Sweeting 2007).

Care Planning

Patients with obesity have a reduced life expectancy (Sweeting 2007). In certain cases, their level of morbidity is increased. Sweeting (2007) argues that such patients become susceptible to other diseases like type 2 diabetes. The sedentary lifestyle associated with the patient acts as a catalyst as far as the condition is concerned. A caregiver should come up with a regimen that will help improve the performance of the patient’s musculoskeletal system. The cardiovascular and immune systems also need to be included in the caregiver’s recovery plan. The strategy primarily focuses on diet (Kolata 2007).

Effects of Age on the Human Body

Body Structure and Functioning

According to Marieb et al. (2013), the human anatomy experiences changes as an individual advances in age. The same is brought about by the fact that cells begin to age and die. Replacement of dead cells is lower at old age compared to the rate of reproduction at a younger age. Cells form tissues that make up the muscles. As such, the muscles will also experience aging. Once cells and muscles age, the performance of individual organs is reduced. For instance, the 85 year old woman will have difficulties with her eyesight.

The integumentary system represents the most visible changes once an individual starts to age. The wrinkling of the skin is an illustration of dying cells that are not replaced. Old people will often experience changes in their hair. According to the Cleveland Clinic (2013), the aged exhibit poor functionality with regards to the organs within this system. The respiratory system also suffers due to old age owing to the reduced activities of the heart. The efficiency of the nervous system is also reduced as a result of the dying cells. However, there are instances where the brain cells of an individual remain functional even in old age (MedicinePlus 2011).


The reduced activities of the respiratory system imply that such a patient will be unable to engage in any productive physical activities. According to Sherwood (2012), the aged are unable to undertake strenuous activities since they require a lot of energy. Their respiratory system is unable to meet the high demand for oxygen. The oxygen is needed to oxidise nutrients to produce energy. Other impacts include the reduced performance of such organs as the eyes and the ears (Cleveland Clinic 2013).

Care and Support

The subject is 85 years and has type 2 diabetes. According to the American Diabetes Association (2004), patients with the medical condition require protection from tissue damage. As such, a care giver is expected to ensure that a patient with type 2 diabetes is provided with protective material. Patients with the condition often have problems with tissue repair. The risk of developing these problems is heightened in the case of the 85 year old patient. Their situation is compounded by the inability of their epidermal cells to reproduce at an advanced age.


American Diabetes Association 2004, ‘Standards of medical care in diabetes’, Diabetes Care, vol. 28 no. 1, pp. 4-36.

Bouchard, C, Blair, M & Haskell, W 2012, Physical activity and health, Human Kinetics, Illinois.

Centres for Disease Control and Prevention 2013, Rapid diagnostic testing for influenza: information for clinical laboratory directors, Web.

Cleveland Clinic 2013, Diseases & conditions, Web.

Dylan, T, Karpe, F, Lafontan, M, & Frayn, K. 2012. ‘Physical activity and exercise in the regulation of human adipose tissue physiology’, Physiological Reviews, vol. 92, pp. 157-191.

Frederic, H, Nath, L & Edwin, F 2011, Fundamentals of anatomy & physiology, Pearson, London.

Kolata, G 2007, Rethinking thin: the new science of weight loss and the myths and realities of dieting, Picador, New Jersey.

Marieb, N, Mitchell, J & Smith, A 2013, Human anatomy & physiology: laboratory manual, Pearson, London.

Mayo Clinic 2013, Obesity: tests and diagnosis, Web.

MedicinePlus 2011, Aging changes in organs- tissue- cells, Web.

Sherwood, L 2012, Human physiology: from cells to systems, Cengage Learning, Michigan.

Sweeting, H 2007, ‘Measurement and definitions of obesity in childhood and adolescence: a field guide for the uninitiated’, Nutrition Journal, vol. 6, p. 32.

Thibodeau, A & Patton, T 2009, Anatomy & physiology, Mosby, New Jersey.

Cite this paper

Select a referencing style


AssignZen. (2022, May 25). The Human Body System Overview.

Work Cited

"The Human Body System Overview." AssignZen, 25 May 2022,

1. AssignZen. "The Human Body System Overview." May 25, 2022.


AssignZen. "The Human Body System Overview." May 25, 2022.


AssignZen. 2022. "The Human Body System Overview." May 25, 2022.


AssignZen. (2022) 'The Human Body System Overview'. 25 May.

Click to copy

This report on The Human Body System Overview was written and submitted by your fellow student. You are free to use it for research and reference purposes in order to write your own paper; however, you must cite it accordingly.

Removal Request

If you are the original creator of this paper and no longer wish to have it published on Asignzen, request the removal.