Key Components of Human Cells

Task 1:

Question 1:

“Compare and contrast of structure of Eukaryotic and prokaryotic cell”.

Structure of Eukaryotic cell:

In these cells, the "plasma membrane" consists of carbohydrates and proteins. In addition to this, in this kind of cells, there are two prominent layers of “Phospholipids”, and these have been categorized in the cells (Spang et al. 2019). In these cells which are found in the human body, there are many parts of these cells which structured the cell. These are "; cytoplasmic membrane, nucleus, cytoplasm" etc. All of these are the parts of this which formed these cells (Cameron et al. 2017).

Structure of Prokaryotic cells:

These cells do not contain a "true nucleus: wherein genetic material is contained. These kinds of cells have a “nucleoid region" that is considered to be a shaped region which is irregular. In addition, these regions present in these cells also contain the DNA of the cells, and therefore the entire cell is not surrounded by a “nuclear envelope". This can also be stated that there are some of the cells where “flagella" has found, and these have “tail-like structure". The function of having this kind of structure in the cells is to enable the organism so that these organisms can move around (Rensing et al. 2016).

Contrast:

One of the most fundamental and important differences between these two types of cells is that the first of the cells contain “true nuclei" which contain their DNA while "genetic material" in prokaryotes types of cells are not considered to be membrane-bound and they are present in the form of single molecule or circular DNA or chromosome (Tziakas et al. 2019).

In Eukaryotes cells, "chloroplasts" and mitochondria carry out many types of process of metabolic whereas in prokaryotic cells which have been found in the human body the same process is carried out across the "membrane of a cell" and therefore "endosymbionts" are said to be extremely rare. The prokaryotic cells are present in domain bacteria and archea which are unicellular organism lacking membrane-bound organelles whereas eukaryotic cells are present in multi-cellular organism such as plants, animals, fungi and protistis (Bloch et al. 2017). The cell walls in bacteria which are prokaryotes are made-up of peptidoglycan or murein whereas the cell wall in plants which are eukaryotes is made up of cellulose (Rogowska et al. 2019).

Erythrocyte:

The erythrocytes are blood cells which are produced in the bond marrow and it contain the protein haemoglobin that acts as carrier for oxygen. In the lungs, the oxygen from the inhaled air is transmitted to the blood during which the erythrocytes carry the oxygen to different parts of the body (Radunovic et al. 2017). These blood cells are incapable of “aerobic respiration” which aims at preventing all of them from consuming the oxygen in the body.

Macrophage:

Macrophage is the largest white blood cell that aims to locate and engulf foreign particles in the blood. The macrophages originate from the monocytes and perform phagocytosis to destroy unwanted cells in the body (Tsuchimatsu et al. 2018). The structure of this cell is similar to amoeba type cell. It uses a process named “Phagocytosis” for destroying and get rid of unwanted particles. One of the key structural characteristics features of macrophages is that they have prominent electron-dense membrane bound lysosomes which acts as autophagic vacuoles to make them engulf unwanted particles and fuse with phagosomes to form secondary lysosomes (Ren et al. 2017).

Motor Neuron:

Motor neuron is placed on the motor cortex, brain and spinal cord which intervenes each muscle to transmit signals from the brain to perform actions (ZHou et al. 2019). The motor neurons are multipolar in structure which indicates that each cell of the neuron contains single axon and multiple dendrites. The axon fibre of the neurons projects to the spinal cord as well as outside of the spinal cord to directly or indirectly manage the effector organs. The multiple dendrites in the motor neuron collects signal from the cells in the CNS and the extended axon fibers allow the impulses from the CNS to be carried through the spinal cord to the effector organs for them to be managed (Wang et al. 2017).

Male Gamete:

Male gametes are haploid cells that participate in male reproduction by acting to fertilise the egg (Dehkhodaei et al. 2017). The male gamete is known as the sperm and its structure indicates that nucleus in which the sex (X or Y) chromosome is present is located at the head of the sperm. The male gamete contains mitochondria in which the metabolism of fructose occurs in the seminal fluid causing the sperm to swim upward towards the egg for fertilising it and play the role in reproduction (Tsuchimatsu et al. 2020).

Question 2

A. Structure of DNA

B. Structure of DNA

Deoxyribonucleic acid (DNA) is considered to be a molecule which is composed of two "polynucleotide chains" which are seen coil around each other in order to create the "double helix form" (Ohiozebau et al. 2017).

Structure of the DNA:“DNA” is composed of “molecules” which are called “nucleotides". As mentioned, “Phosphate group, nitrogen group and sugar base”. In this part of the DNA, there are four major types of bases of nitrogen found. These are "thymine, guanine, adenine and cytosine". Therefore, this can be stated that the order of these four pairs of the DNA determines its instruction. It is said that the human body has more than 3 billion bases, and it has more than 99 per cent of those bases which are found to be similar in every people. These nitrogenous bases which have been structured in DNA carry out the operation of forming genres (Pedersen and Quinlan, 2017). The molecules of DNA are considered to belong, and these are so long, which cannot be fitted into the cells. In order to make this process, DNA has been collected so highly so as to perform the structure, which is called a chromosome. Each of these "chromosomes" possesses a single molecule of DNA. This can be further stated that the human body has approx. 23 pairs of "chromosomes' ' which have been found within the nucleus of the cells. Replication of DNA is closely associated with chromosomes and its replication which has been seen in turn into the division of cells and also this includes "nuclear division of mitosis" (Hou et al. 2019). This can also be stated that the role of the DNA in the human body holds a greater significance. Researchers have obtained all the accurate structure of the DNA and its process of replication during mitosis. The different stages of mitosis include prophase, metaphase, anaphase and telophase. During the prophase, which is the first phase of mitosis the chromosome present inside the nucleus of the cell is condensed to form tight structures. In the prometaphase, the disintegration of nuclear membrane occurs and the mitotic spindles are able to access the chromosome (Hämälistö et al. 2020). In the metaphase, the microtubules make the chromosome to get arranged in line along the cell equator and the centrosome on the opposite side develop sister chromatids. In the anaphase, the microtubules pulls the sister chromatids apart towards the opposite poles and in the telophase, a new nuclear membrane form around the newly separated developed chromosome through inclusion of sister chromatids (Kabeche et al. 2018).

Question 3

a. Tissues are defined as a "cellular organizational level" which is located between cells and an organ. There are four kinds of tissues which are "muscle", "epithelial", "connective" and "nervous". There are three types of muscle tissues which are smooth (housekeeping function), cardiac (contract to pump blood from heart) and skeletal (moves bones) muscle tissue (Tarasova et al. 2019). The epithelial tissues are divided as simple and stratified and there are further subdivided into squamous, columnar and cuboidal epithelium (Park et al. 2018). The key types of connective tissue include supportive tissue (ensure structure and strength to the body and protect any harm to the soft tissues), fluid tissue (act a transport system) and connective tissue proper (Songstad et al. 2017). The nervous tissues are mainly divided into neurons that transmit electrical signals in the body and the neuroglia which manly protect and support functioning of neurons (Carson et al. 2016).

b. As mentioned, there are four types of tissues which are found in the human body.

“Muscle tissues”:

“Muscle tissues” are the tissues which are made of "excitable cells" which are fibrous and long. This type of tissues is mostly found in our muscles (Kamimoto et al. 2016). It is the location of the tissue. One of the most important functions of this tissue is to make our body movable. There are different types of muscle tissues that are found. These are three forms specifically. These are cardiac, skeletal and smooth muscle tissue. At the outset, this can be relatively stated that Cardiac muscles cells are found in heart’s wall and therefore these are under involuntary control. In addition, the smooth muscles and its fibres are founded in walls in hollow visceral organs and its wall and other than heart. Thus, the role of each of these muscle tissues plays a very significant and important role and also these tissues help in maintaining the smooth function of the body. In addition, there is skeletal muscles and its fibres as well which occur in muscles and therefore are attached to the skeleton. This can also be stated that these are all found and have been under the voluntary control. In addition, all of these are also attached to the bones and its different type of contraction which also makes locomotion and its possibilities.

Epithelial tissue:

Epithelial tissue is composed of "epithelial cells''. The nature of these cells is considered to be vastly different from muscle cells (Marseille et al. 2017). Considering the structure of the cells found in this kind of tissue, this can be stated that the cells which are found in these types of tissues are columnar, flat and cuboids. This type of tissue is found in some of the internal cavities (Freedman, 2019). The function of the epithelium tissues is to allow absorption, secretion, digestion and managing immunity in the digestive system. They are also present in the endometrium and fallopian tubes contributing to manage fertility. The surfactant secretion made by the simple columnar epithelial is essential to support respiration (Kocgozlu et al. 2016).

Connective tissues:

This is one of the “tissues” which makes connective in the “human body”. With the help of these tissues, a human body can easily stretch. Connective tissues carry out different types of function, which includes protection and support. These types of issues are found in the human body (Linder, 2016). This can be stated that these types of tissues provide proper shape to our body.

Nervous tissue:

These types of tissues are found within the nervous system. These types of tissues are composed of unique, specialized cells. The key function of the nervous tissue includes control of the body movements by sending, receiving and carrying electrical impulses and signals to different parts of the body (Conte et al. 2020).

Plasma:

Plasma is one of the main components of blood. This includes water, ions, nutrients, waste which are mixed in (Bansal et al. 2019).Plasma makes up about 55 percent of the blood. This carries out different types of key functions in the body that includes the making transportation of waste materials and products. The fluid component part of the blood is known as plasma where the red and white blood cells along with blood platelets are suspended. The plasma represents half of the blood volume and consists of dissolved salts (electrolytes), nutrients, glucose and albumin as the key protein (Suhre et al. 2017).

Red blood cells (RBCs): “Red blood cells” in our blood carry CO2 and carbon dioxide. The shape of the red blood cell is of a bioconcave discs that are packed with haemoglobin molecules containing heme as the pigment. The RBCs lack nucleus to have large surface area to absorb oxygen. The protein present in the RBCs is haemoglobin which contains four heme groups surrounded by a globin group leading to for a tetrahedral structure. In each molecule of haemoglobin, there are four iron atoms which binds with the oxygen atoms and the globin is made-up of two polypeptide chains that are linked together (Tsvirkun et al. 2017).

“Platelets”: “Platelets” are responsible for “Blood clotting” and they are mainly considered as cell fragments which when activated become round and elongated fragments. The structure of blood platelets indicates that they nucleus and contains fragments of cytoplasm which are derived from the mehakaryocytes present in the bone marrow that enters the circulation. The inactive platelets circulating in the blood are lens-shaped and are 2-3µm in diameter at the maximum (Yadav and Storrie, 2017).

“White blood cells” (WBCs): These are the parts of “human immune system” and it functions in the immune response. This has a cellular component in terms of blood which lacks haemoglobin and contains nucleus. The size of the WBCS range from 6-9µm to 10-14µm and based on their appearance they are differentiated as granulocytes and agranulocytes. The neutrophils, basophils and eosinophils contain granules in addition to the general structure of WBCS where as the lymphocytes and monocytes lack presence f any granules (Bain, 2017).

Task 2

Question 1

“Tissue fluid” is composed owing to the high “hydrostatic pressure” of the blood at the arteriole end of the capillary. This fluid occupies the intracellular space, thereby connecting the link in nutrition transport, metabolic and “gases” among “blood capillaries”, cells of “tissues” and the “lymph”. One of the main functions of the 'tissue fluid" is also to constitute the “internal environment” of the body. Formation of tissue fluid depends on “Capillary permeability, and the different types of pressures between the tissue fluid and the capillary. It is quite complicated to get a pure sample of “tissue fluid"; hence, the accurate composition thereof is not known. Tissues fluid, along with its volume and composition, is often regulated by always interchange with lymph and blood (Baliu-Piqué et al. 2018). There are many factors which affect tissue fluid and its formation. These are “permeability of capillaries, diffusion, filtration and reabsorption and filtration and metabolic activity of tissues”. This can be stated that tissue fluid and its filtration happen at capillaries and its ultimate end. The pressure of blood at the venous end seems to be a very low approximate 10 mm of Hg and therefore “colloidal osmotic pressure” is much higher (Mitchison, 2019.). In addition, the amount of water also plays a very significant role in the formation of tissue which is claimed to have gone out of the blood and ultimately it is drawn at the “venous side” of the capillaries. This can be further stated that “vascular capillaries” are not able to drive away the amount of metabolic water which is formed by tissue cells. It can also be further stated that the lymphatic system is developed due to the process of drainage of this excess water (Szili et al. 2018). The tissue fluid has a gravity of 1.015 to 1.023. This is also to be noted that this possesses few erythrocytes. In terms of “White cells, the tissue fluid”, therefore, contains a suitable number of "granulocytes and lymphocytes”. The quantities of nutrient contents and blood proteins are extremely low. This does not have platelets. [Referred to Appendix 2] The process of osmotic pressures and hydrostatics in a capillary bed also assumes greater significance. The fluid transport which is being derived by the primary force between tissues and capillaries is stated to be “hydrostatic pressure” which can also be termed as fluid pressure which is enclosed in a space. “Blood hydrostatic pressure” is defined as a force which is exerted by the blood which is confined within heart chambers and “blood vessels” whereas “osmotic pressure” which is being done is also called one of the processes which have to be completed (Oh et al. 2016).

Question 2

Oedema:

“Oedema”, also known as “dropsy” is considered to be a “medical term” for “fluid retention” in the human body. This is considered to be a swelling which is caused by excessive fluid which was trapped in tissues of our body. It can be seen in the ankles. This can be stated that mild Oedema is one of the common things which cause harm (Moffatt et al. 2017). Experts believe that this is happening due to allergies, medication or more grave and complicated disease. There are two types of Oedema which can be seen. Peripheral Oedema affects ankles and feet, and in some of the cases, this can also be seen in the arms whereas pedal Oedema is seen in the lower legs mostly. This complication is much more common for those who are pregnant or older (Svensson, 2019). Although some of the Oedema is considered to be harmless, however, it can also cause serious complication of health. In this case, Both Javinda and John have pedal oedema. There would be a specific reason by which this kind of complication often arises. Specifically, pedal oedema is considered to be fluid accumulation which is mostly seen in lower legs and feet. In this particular case, both Javinda and John have the complication where they need treatment for this. The causes by which both of them have developed this complication can be associated with some of the crucial factors which are "low albumin, allergic reactions, obstruction of flow, critical illness” (Busch et al. 2020). These are some of the causes which might trigger this complication.

Task 3

Question 1

“Circulatory System”

The systemic and pulmonary circulatory systems:

Pulmonary Circulation:

The pulmonary circulation is the process in which deoxygenated blood is carried from the heart through the pulmonary artery to the lungs for being oxygenated and returned to the heart for delivering it to the rest of the body (Noordegraaf et al. 2019). The arteries are blood vessels that mainly contain oxygenated blood in exception for pulmonary artery that carries deoxygenated blood. The pulmonary circulation mainly initiates with deoxygenated blood being poured by the inferior and superior venacava into the right atrium. The blood then travels to right ventricle and the deoxygenated blood is carried by the pulmonary artery to the lung. The pulmonary vein then receives oxygenated blood from the lungs and transmits them to the left atrium which then flows into the left ventricle (Pinsky, 2016). The six key blood vessels which carries oxygenated blood are aorta (present near the chest), carotid arteries (extends to the neck by branching from the aorta), subclavian arteries (vertebrae), axillary arteries (thorax, axilla and upper limb), ulnar artery (elbow and forearm) and femoral artery (legs and lower part of the body) (Guazzi et al. 2016).

“Systemic circulation”:

The systemic circulation is the process in which oxygenated blood from the left ventricle of the heart is carried to different parts of the body through the aorta that later branch into different arteries in the body (Vellonen et al. 2017). The oxygenated blood while travelling through the arteries in systemic circulation picks up carbon dioxide and waste while delivering oxygen to the cells for their effective functioning. The two key blood vessels that contribute to deliver deoxygenated blood to the heart from the body after systemic circulation are superior vencava and inferior venaca which are veins (Kiranmayi et al. 2016). The superior and inferior venacava are considered to be part of the systemic circulation. The other blood vessels which carry deoxygenated blood in the body are subclavian vein, cephalic vein, femoral vein and cephalic veins (Vellonen et al. 2017).

Question 2

Differences between “arteries, veins and capillaries”

Question 3

a. Pericardium:

Human heart is relatively enclosed within a "fluid-filled cavity” which is illustrated as “pericardial activity”. The heart is located in the middle and front of the lungs and is slightly bend to the breastbone and the diaphragm below it. The lining and the walls of this cavity are composed of “membrane” that is also known as “pericardium" (Subudhi et al. 2016). It is considered as an "external covering" of the human heart. Further, this pericardium has considerably two layers which are parietal layer and visceral layer. The wall structure of the heart also comprised three prominent layers. "Epicardium, endocardium, and myocardium”. There are three layers of tissues from the wall of the heart. The “epicardium” is considered to be the outer layer of the wall of the heart. “Myocardium” is considered to be the middle layer thereof. Further, this can be added that there are total of four chambers of internal cavity of the heart. The heart is mainly made up of cardiac muscles which is a nature of vertebrate muscle. The cardiac muscle is striated muscle which has a single nucleus and the intercalated discs joins the branched tissues to resolve the gaps for depolarisation present between cells and desmosome for holding together the fibres while the heart contracts (Kaneko et al. 2017). The “cardiac muscles” are akin to skeletal muscles and this possesses contractile units that are known as sarcomeres. In addition, cardiac muscles and its contraction is therefore regulated by the “sinoatrial node” of the heart.

B).“Internal structure of the heart”:

The internal structure of the heart informs that it is divided into four chambers which are right and left auricle and right and left ventricle. In between right atrium and right ventricle, tricuspid valve is present whereas between the opening of the left atrium and left ventricle. In between right ventricle and pulmonary artery, the pulmonary valve is present and aortic valve is present between the left ventricle and aorta (Narayanan et al. 2019). The functions of the valves within the heart are to prevent back flow of blood and ensure effective circulation of blood from heart to lungs and the body (Narayanan et al. 2019).

C). Process of a cardiac cycle:

The “cardiac cycle” is defined as a “performance of heart” forms its process of a heartbeat. This has prominently two periods that are systole and diastole. The systole is followed by diastole leading to create lub-dub sound of heartbeat. [Referred to Appendix 4]. The systole is referred to the period of contraction of ventricles in which the actions leads to eject blood into the aorta and pulmonary trunk to be carried all over the body. After filling of right atrium with blood from the venacava, the atria systole occurs during which the right atria contracts and tricuspid valves are expanded whereas pulmonary valve are constricted in the right part of the heart allowing the blood to be pumped into the right ventricles. During this phase, in the left part of the heart, the mitral or bicuspid valves is expanded allowing oxygenated blood from the left atrium to be pumped into the left ventricle (Kunzendorf et al. 2019). In ventricular systole, in the right side of the heart, the tricuspid valves remain closed to avoid backflow of deoxygenated blood from the right ventricle to the right atrium. However, the pulmonary valve is relaxed allowing emptying the blood from the left ventricle into the pulmonary artery. In the left side of the heart, during this phase, the ventricle pumps blood into the aorta to allow it to be transferred all over the body. In diastole, the heart muscles mainly relax to allow the chambers to be filled with blood. In ventricular diastole, the left and right ventricles are found to be relaxing from contraction and then dilating to be filled with blood. In atria diastole, the left and right atriums are relaxed from the suction and dilate (Tornow et al. 2018). The sympathetic and parasympathetic nervous systems which are two branches of the autonomic nervous system are involved in managing the heart beat. The sympathetic nervous system (SNS) release catecholamines such as epinephrine and norepinehrine to increase the heart beat. The parasympathetic nervous system (PNS) releases acetylcholine hormone that acts to lower the heart rate (Floras, 2019). During exercise and stress on the body, the heart rate is increased through SNS leading increased amount of oxygen and nutrients to be supplied to the cells of the body to support effective functioning and meet needs of energy. However, during aggregated situation of the body such as anxiety and others, the PNS is triggered to create a calm and relaxed feeling along with lower the raised heart beat to avoid heart attack (Floras, 2019).

Question 4

A). Major organs of the Respiratory system:

The human respiratory system mainly support breathing process in human in which they take in oxygen and breathe out carbon dioxide (Casero et al, 2019). The system consists of “nose, Mouth, larynx, pharynx, lungs, and diaphragm”. Each of these organs found in this system has a specific function. The following are essential parts of the respiratory system:

The structure of the tissues in this system of respiratory has been adapted for the overall functioning of the organs of the system. Considering the histological layers within this system, there are relatively four types of histological layers found in this. The various types of tissues which have been found out in this system help the organism found in this system to carry out the function (Nakahashi-Ouchida et al. 2018).Respiratory system plays a very important role in terms of this and this has been one of the most crucial and important parts of the human body system that helps in sustaining the process of breathing. There have been multiple approaches that have been taken into this regard. The respiratory system of the body helps in sustaining the smooth function of breathing. The major organs which are the parts of this system functions primarily in terms of provide oxygen. Also, this provides for the tissues of the body for cellular based respiration. It helps in removing the waste product; carbon di-oxide and also helps in maintain the balance of “acid base”. Furthermore, this can also be stated that portion of this system are also used for making the function of non vita with the help of using sensing odors straining and speech production. Each and every component of this play a very important role including the role of mouth that helps in sustains the process of breathing effectively (Nakahashi-Ouchida et al. 2018).

B). The mechanical process of breathing:

The mechanical process of breathing is divided into phases that are inspiration and expiration. During inspiration, air enters inside the lungs which are initiated by flattening of the diaphragm and extension of the dimensions of the thoracic cavity. Moreover, the external intercostals muscles elevate the sternum and ribs which allows extension of the thoracic cavity to allow increase in volume of the lungs. The increase in volume of the lungs creates lower p0reesure inside compared to the external environment leading the air to get inside due to low pressure gradient (Pal et al. 2018). However, during expiration the intra-abdominal pressure is increased leading the diaphragm to move upwards to the thoracic cavity. In addition, the internal intercostals muscles get contracted causing the thoracic cavity to be decreased. This creates high pressure inside the lungs compared to the external environment leading to let the air out through the airway to be exhaled (Roth et al. 2017). The gaseous exchange in the lungs takes place through million alveoli that are enveloped by capillaries. At the cellular level, the oxygen present in the alveoli crosses the alveolar walls and enters the blood stream through the capillary wall with the help of diffusion. At the same time, the carbon dioxide molecules cross the capillary wall and enter the lungs through the alveolus wall that the present in the form of fussed basal membrane with the capillaries (Cedar, 2018).

C. In asthma, the airways are swollen and produce more mucus which narrows the air space leading to hinder air present with oxygen to be moved in and carbon dioxide out of the lungs. The inflamed airways are sensitive and can be tightened with present of smoke and dust. Thus, during smoking among asthma patients, the muscles which are wrapped around the airway are also seen to be tightened making the individual face hardship in breathing air in and out of the lungs in turn causing hindrance on oxygen uptake (Jacinto et al. 2017). During smoking, the chemical deposits on the vulnerable and delicate cell walls of the alveoli leading to cause its destruction and developing emphysema among individuals. The destruction of the alveoli creates air pockets known as bullae which prevent the oxygen to enter the blood capillaries through the lung tissues in turn creating breathlessness (Gramegna et al. 2018).

Question 5:

Essay

Excretory system:

“Excretory system” in the “human body” is one of the systems which aim at performing excretion (Sundaram and Buechner, 2016). This is one of the systems which are responsible for eliminating all kinds of waste which is generated by homeostasis.

Structure of excretory system: The structure of excretory system includes organs such as kidneys, ureters, urinary “bladder and urethra” [Referred to Appendix 5].

Kidneys: Kidneys are part of the excretory system. This is one of the most important organs in this system. The shape of the kidney is bean-shaped, and the location of this organ is the backbone and it’s either side which is protected by the muscles and ribs (Cohen et al. 2020). The length of the kidneys found in the human body is considered as is 10-12 cm, a width of 5-7 cm and its weights approx. 170g. The inner concave structure is found in the kidney in addition to this, considering the structure of the kidney both internally and externally, this can be stated at the centre of this organ, a "notch" is found which is called "Hilum” and this is the part where the nerves and blood vessels are entered within the organ. “Renal pelvis" is found towards the inner surface of this (Kusel, 2017). It plays a very key role in the excretory system of the body. The kidney in the human body is well structured, and there are various parts in its structure.

Kidney has its own structured, which can be illustrated the following:

Capsule: Capsule is found in the outer layer of the kidney. Considering the inner zone of the kidney, there are specifically two zones found. The outer zone is called the cortex, and the inner zone inside the kidney is called the medulla (Konstanzova et al. 2016).

Nephrons: Nephrons are considered to be the “functional unit”. Each of the nephrons which have been found in the kidney has two parts which are renal tube and glomerulus.

Ureter: It is a kind of muscular tube which is very thin, and it has been seen that each of these parts of the kidney (Cohen et al. 2020). The main function of Ureter is to carry urine to the bladder.The function of this organ in this system plays a very important role. This has been seen that it comes out of each part of the kidney as a form an extension that is related to renal pelvis. This is already mentioned that the role of this system is to generate the waste materials in the body and this helps in extracting the waste materials from the body. At the time of this process, the ureter in this system helps in flushing out all kind of waste materials.

Urinary bladder: Urinary bladder is like ac" sac-like structure" which stores urine. In addition, there are some of the smooth layer of muscles as well that are found in this. Significantly, it stores the urine at the time of until micturition. In addition, this micturition is one of the acts that helps in expelling the components of urine from the body. This can be stated that the bladder in this receives all stored urine from the organ of ureter.

Urethra: This is a kind of tube which arises and comes through the urinary bladder. This helps in flushing out the urine, which contains waste materials. This organ of the excretory system is surrounded by a "sphincter" (Fuchs et al. 2016).There are two different shapes of this as per the gender group of an individual. For instances, it is quite shorter in women and whereas this is found quite longer in men. The function of this in men is common path for urine and sperms. The role of this part of this system plays a very important role and acts as a common path for removing waste materials of the body.

Homeostasis: Homeostasis is considered to be a condition that aims at self-regulating the process in which biological system often aims at maintaining stability. At the time of doing this, the adjustments of all of these conditions which are optimal for survival are also taken into consideration. Therefore, this can also be the condition of steady, chemical condition that is usually maintained by human living system. This condition includes many types of variable such as fluid balance and body temperature. This process of homeostasis can be brought about by a kind of natural resistance in terms of changing while considering these aspects of optimal condition.

The function of the excretory system

There are the following functions of the “excretory system” in the “human body”. This has the function of eliminating all the “waste materials” from the body. All the “waste materials” which were produced in the human body were removed and eliminated by this system (Konstanzovaet al. 2016). This is one of the most important roles of this system. With this excretory system, all the waste products within the body get removed and eliminated. This is very important for our body to eliminate all sorts of waste materials (Maeda, 2018). Excretory system in the body also helps in removing the “Nitrogenous wastes” from our body. This is a significant function of this system. Another main role of this system is to maintain the “osmotic level of plasma and blood”. This system in the “body” also helps in maintaining the “electrolyte balance” in the body (Angelova, 2019). Excretory system in the “body” always helps in the process of metabolism. One of the most important parts of this system is to maintain the balance of all sorts of chemical concentration in the human body (Fuchs et al. 2016). This is one of the most important functions of this system as there are many types of chemical reaction which always occur in the human body and therefore in order to curb this kind of chemical reaction in the body, this part of the system holds an important (Wijaya et al. 2018). Excretory system of the human body helps in filtering the blood as well. The excretory system in the “human body” also helps in regulating the “osmotic pressure” of a mammal’s blood by the process of excessive filtration and purification. This process is also called osmoregulation (Rosadi et al. 2018). The liver is an essential organ of the excretory system in which they plays the key role in breaking down substances in the blood like toxins and others. The liver releases bilirubin which is a waste product of haemoglobin in the bile. The bile secreted by the liver contains bile acids that assist to digest and absorb fat and vitamins in the small intestine and it allow waste products from the body to be collected and eliminated through faeces (Nilsson et al. 2020). The lungs excrete carbon dioxide, water and other harmful substances from the body by collecting it from the blood through the alveoli and releasing it through expiration (Janssens et al. 2020). The skin executes their role in excretion by producing sweats by the sweat glands where excess water and salts are released along with urea that is a catabolism byproduct. The skin has minute pores on the surface of the body that are connected with the sweat glands (Choi et al. 2018).

Reference List

Angelova, S., 2019. Variations of Carbohydrate Nutrition and Impact Upon Oral Health in Children with Excretory System Disorders. In Varna Medical Forum, 8, pp. 25-30.

Bain, B.J., 2017. Structure and function of red and white blood cells. Medicine, 45(4), pp.187-193.

Baliu-Piqué, M., Verheij, M.W., Drylewicz, J., Ravesloot, L., De Boer, R.J., Koets, A., Tesselaar, K. and Borghans, J.A., 2018. Short lifespans of memory T-cells in bone marrow, blood, and lymph nodes suggest that T-cell memory is maintained by continuous self-renewal of recirculating cells. Frontiers in immunology, 9, p.2054.

Bansal, N., McCulloch, C.E., Lin, F., Robinson-Cohen, C., Rahman, M., Kusek, J.W., Anderson, A.H., Xie, D., Townsend, R.R., Lora, C.M. and Wright, J., 2016. Different components of blood pressure are associated with increased risk of atherosclerotic cardiovascular disease versus heart failure in advanced chronic kidney disease. Kidney international, 90(6), pp.1348-1356.

Bloch, S., Węgrzyn, A., Węgrzyn, G. and Nejman-Faleńczyk, B., 2017. Small and smaller—sRNAs and microRNAs in the regulation of toxin gene expression in prokaryotic cells: a mini-review. Toxins, 9(6), p.181.

Busch, C., Okada, M., Zur, D., Fraser‐Bell, S., Rodríguez‐Valdés, P.J., Cebeci, Z., Lupidi, M., Fung, A.T., Gabrielle, P.H., Giancipoli, E. and Chaikitmongkol, V., 2020. Baseline predictors for visual acuity loss during observation in diabetic macular oedema with good baseline visual acuity. Acta Ophthalmologica. 11(2), pp.77-81.

Cameron, K.A., Stibal, M., Hawkings, J.R., Mikkelsen, A.B., Telling, J., Kohler, T.J., Gözdereliler, E., Zarsky, J.D., Wadham, J.L. and Jacobsen, C.S., 2017. Meltwater export of prokaryotic cells from the Greenland ice sheet. Environmental microbiology, 19(2), pp.524-534.

Carson, J.L., Stanworth, S.J., Roubinian, N., Fergusson, D.A., Triulzi, D., Doree, C. and Hebert, P.C., 2016. Transfusion thresholds and other strategies for guiding allogeneic red blood cell transfusion. Cochrane database of systematic reviews, (10). pp.29-30

Conte, M., Gerardo-Giorda, L. and Groppi, M., 2020. Glioma invasion and its interplay with nervous tissue and therapy: A multiscale model. Journal of Theoretical Biology, 486, p.110088.

Floras, J.S., 2019. Alterations in the Sympathetic and Parasympathetic Nervous Systems. Heart Failure: A Companion to Braunwald's Heart Disease E-Book, p.181.

Fuchs, D., Wilby, P.R., von Boletzky, S., Abi-Saad, P., Keupp, H. and Iba, Y., 2016. A nearly complete respiratory, circulatory, and excretory system preserved in small Late Cretaceous octopods (Cephalopoda) from Lebanon. PalZ, 90(2), pp.299-305.

Guazzi, M., Villani, S., Generati, G., Ferraro, O.E., Pellegrino, M., Alfonzetti, E., Labate, V., Gaeta, M., Sugimoto, T. and Bandera, F., 2016. Right ventricular contractile reserve and pulmonary circulation uncoupling during exercise challenge in heart failure: pathophysiology and clinical phenotypes. JACC: Heart Failure, 4(8), pp.625-635.

Jacinto, T., Malinovschi, A., Janson, C., Fonseca, J. and Alving, K., 2017. Differential effect of cigarette smoke exposure on exhaled nitric oxide and blood eosinophils in healthy and asthmatic individuals. Journal of breath research, 11(3), p.036006.

Kaneko, Y., Shinohara, G., Hoshino, M., Morishita, H., Morita, K., Oshima, Y., Takahashi, M., Yagi, N., Okita, Y. and Tsukube, T., 2017. Intact imaging of human heart structure using x-ray phase-contrast tomography. Pediatric cardiology, 38(2), pp.390-393.

Kiranmayi, M., Chirasani, V.R., Allu, P.K., Subramanian, L., Martelli, E.E., Sahu, B.S., Vishnuprabu, D., Kumaragurubaran, R., Sharma, S., Bodhini, D. and Dixit, M., 2016. Catestatin Gly364Ser variant alters systemic blood pressure and the risk for hypertension in human populations via endothelial nitric oxide pathway. Hypertension, 68(2), pp.334-347.

Kunzendorf, S., Klotzsche, F., Akbal, M., Villringer, A., Ohl, S. and Gaebler, M., 2019. Active information sampling varies across the cardiac cycle. Psychophysiology, 56(5), p.e13322.

Mitchison, T.J., 2019. Colloid osmotic parameterization and measurement of subcellular crowding. Molecular Biology of the Cell, 30(2), pp.173-180.

Musah, S., Mammoto, A., Ferrante, T.C., Jeanty, S.S., Hirano-Kobayashi, M., Mammoto, T., Roberts, K., Chung, S., Novak, R., Ingram, M. and Fatanat-Didar, T., 2017. Mature induced-pluripotent-stem-cell-derived human podocytes reconstitute kidney glomerular-capillary-wall function on a chip. Nature biomedical engineering, 1(5), pp.1-12.

Narayanan, S., Firlar, E., Rasul, M.G., Foroozan, T., Farajpour, N., Covnot, L., Shahbazian-Yassar, R. and Shokuhfar, T., 2019. On the structure and chemistry of iron oxide cores in human heart and human spleen ferritins using graphene liquid cell electron microscopy. Nanoscale, 11(36), pp.16868-16878.

Noordegraaf, A.V., Chin, K.M., Haddad, F., Hassoun, P.M., Hemnes, A.R., Hopkins, S.R., Kawut, S.M., Langleben, D., Lumens, J. and Naeije, R., 2019. Pathophysiology of the right ventricle and of the pulmonary circulation in pulmonary hypertension: an update. European Respiratory Journal, 53(1).pp.30-56.

Pal, T., Dutta, P.K. and Maka, S., 2018. Modulation–demodulation hypothesis of periodic breathing in human respiration. Respiratory physiology & neurobiology, 252, pp.28-37.

Pinsky, M.R., 2016. The right ventricle: interaction with the pulmonary circulation. Critical Care, 20(1), p.266.

Rensing, C., Alwathnani, H.A. and McDevitt, S.F., 2016. The copper metallome in prokaryotic cells. Stress and Environmental Regulation of Gene Expression and Adaptation in Bacteria, 2 (2), pp.23-34.

Roth, C.J., Ismail, M., Yoshihara, L. and Wall, W.A., 2017. A comprehensive computational human lung model incorporating inter‐acinar dependencies: Application to spontaneous breathing and mechanical ventilation. International jJournal for Numerical Methods in Biomedical Engineering, 33(1), p.e02787.

Spang, A., Stairs, C.W., Dombrowski, N., Eme, L., Lombard, J., Caceres, E.F., Greening, C., Baker, B.J. and Ettema, T.J., 2019. Proposal of the reverse flow model for the origin of the eukaryotic cell based on comparative analyses of Asgard archaeal metabolism. Nature microbiology, 4(7), pp.1138-1148.

Suhre, K., Arnold, M., Bhagwat, A.M., Cotton, R.J., Engelke, R., Raffler, J., Sarwath, H., Thareja, G., Wahl, A., DeLisle, R.K. and Gold, L., 2017. Connecting genetic risk to disease end points through the human blood plasma proteome. Nature communications, 8(1), pp.1-14.

Tarnoki, A.D., Molnar, A.A., Tarnoki, D.L., Littvay, L., Medda, E., Fagnani, C., Arnolfi, A., Farina, F., Baracchini, C., Meneghetti, G. and Pucci, G., 2018. Heritability of the dimensions, compliance and distensibility of the human internal jugular vein wall. PloS one, 13(3), p.e0192948.

Tsuchimatsu, T., Kakui, H., Yamazaki, M., Marona, C., Tsutsui, H., Hedhly, A., Meng, D., Sato, Y., Städler, T., Grossniklaus, U. and Kanaoka, M.M., 2020. Adaptive reduction of male gamete number in the selfing plant Arabidopsis thaliana. Nature Communications, 11(1), pp.1-9.

Tziakas, D.N., Chalikias, G., Pavlaki, M., Kareli, D., Gogiraju, R., Hubert, A., Böhm, E., Stamoulis, P., Drosos, I., Kikas, P. and Mikroulis, D., 2019. Lysed erythrocyte membranes promote vascular calcification: possible role of erythrocyte-derived nitric oxide. Circulation, 139(17), pp.2032-2048.

Wijaya, A.C., Kardi, S. and Supardi, Z.I., 2018. Developing Biology Learning Tool Of Guided Discovery Model To Increase Junior High School Students’learning Result Excretory System Material. Jpps (Journal Penelitian Pendidikan Sains), 7(2), pp.1472-1478.