Respiratory System

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Thecells and organs of a human being depend on the constant supply ofoxygen for them to remain functional. The respiratory system providesoxygen to the body cells while at the same time it eliminates carbondioxide which is a waste product (Regan, 2015). The lungs actas the primary organs of this system as they facilitate the exchangeof gasses when humans breathe (Regan, 2015). The rate ofbreathing depends on the age of a person. Newborns can breathe aboutforty times in a minute while for adults is seventy-two times inevery minute. Our study will emphasize on the respiratory system bydescribing the gross anatomy, general structure, physiology and itscontribution to homeostasis control in the body.

GrossAnatomy and General Structure

Themain external openings of the respiratory system comprise of the noseand the nasal cavity. They act as the first parts of the respiratorytrack where air moves. The nose is made of a bone and cartilagestructure that safeguards the frontal section of the nasal cavitythat enhances filtering, warming and moisturizing of the air that isbreathed inside the body (Rizzo, 2015). Mucus and hair along thenasal cavity trap dust and foreign material before they enter thelungs.

Fig.1:The respiratory system.

Themouth acts as the secondary external opening within the respiratorytrack. The oral cavity is sometimes used as a supplement to regularbreathing in exceptional cases. The pharynx is also referred to asthe throat which comprises of a muscular funnel that runs from theend of the nasal cavity to far end of the larynx and esophagus(Rizzo, 2015). The pharynx has three sections, the nasopharynx thatis located next to the nasal cavity, the oropharynx which receivesthe breathed air from the nasal cavity and the last section islaryngopharynx that transports the air to the larynx. The windpipe ofthe trachea is a log tube that is made of rings of hyaline cartilageand it connects the larynx to the bronchi and facilitates the flow ofair through the neck into the thorax (Regan, 2015). Thehyaline rings will enable the trachea to be open and enhance the flowof air at every time. The windpipe serves as a pathway that allowsthe flow of air into and out of the lungs.

Fig.2:The Pharynx

Thebronchi and bronchioles are located at the lower end of the tracheawhereby the windpipe is divided into the right and left brancheswhich are referred to as the primary bronchi (Regan, 2015).The two divisions of the trachea will run into each lung and thensplit into secondary bronchi which have the role of transporting airinto the lobes of the lungs. Within each lobe, the secondary bronchiwill be sub-divided into smaller tertiary bronchi. The subdivisioncontinues until there are very tiny terminal bronchioles whichfacilitate the flow of air into the alveoli of the lungs (Ionesco,2013). The bronchi are made of cartilage rings that will support theairway and make it open. The primary function of the bronchi andbronchioles is to enhance the movement of air to the lungs (Rizzo,2015). Their walls are made of smooth muscle tissues to improve theregulation of air into the lungs.

Fig.3:The Bronchi, bronchial tree and lungs.

Thelungs are organs that are vast and spongy and located in the thoraxadjacent to the heart and higher to the diaphragm. The lungs areencased by a pleural membrane that offers the room for the lungs toexpand. There is also the provision of negative pressure space thatis determined by the outer section of the body and allows the lungsto be filled passively with air when they relax (Rizzo, 2015). Thetwo lungs have a different shape and size as the heart is situated onthe left side of the body. The inner section of the lungs has spongytissues that house the capillaries and the alveoli which are millionsof air sacs. The alveoli have a special lining, squamous epitheliumthat facilitates the exchange of air with blood as it flows throughthe capillaries (Regan, 2015).

ThePhysiology of the

Thepulmonary ventilation entails the movement of air inside and outsidethe lungs to enhance gaseous exchange. The respiratory system willutilize the muscle contractions and the negative pressure system toachieve this process. The alveoli and the outside atmosphere willestablish a negative pressure gradient in the respiratory system thatwill later give the negative pressure system (Rizzo, 2015). Thepleural membrane seals the lungs and ensures the lungs are at a lowpressure when the lungs rest. The result is that air will flow andfill the lungs. During this process, the lungs pressure will increaseuntil it equals the atmospheric pressure and more air will be inhaledthrough the movement of the diaphragm and the intercostal muscles.During breathing out, the external intercostal muscles and thediaphragm relax and there is a contraction of the internal muscles toallow the reduction of volume in the thorax and enhance pressureincrease in the thoracic cavity (Regan, 2015). This willimprove the reversal of the pressure gradient and air will be exhaledto the point whereby there is equal pressure on the outside body andinside of the lungs. At this moment, the lungs will recoil back toresting position and negative pressure gradient will be restoredduring inhalation.

Theexternal respiration is another physiological process of therespiratory system. It entails the exchange of air between thealveoli and the blood (Regan, 2015). The air from theatmosphere has higher oxygen as it enters the lungs and littlepartial carbon dioxide pressure that that in the capillaries. Thepressure difference will enhance diffusion of gasses from the high tolow pressure through the lining of the alveoli. The result is thatoxygen will move from the air into the blood and carbon dioxide movesin the reverse direction. The oxygen is then transported to bodyorgans and tissues. For internal respiration, gasses will beexchanged between the blood and body tissues. The blood in thecapillary has higher oxygen pressure and lower carbon dioxide partialpressure than within the tissues (Rizzo, 2015). The pressuredifference results to diffusion of gasses from high to low pressurethrough the walls of the capillaries. The result of internalrespiration is the flow of oxygen to body cells and tissues and theabsorption of carbon dioxide into the blood.

How Maintains Homeostasis in the Body and its Impactson other Functions

Therespiratory system maintains homeostasis in two ways that are throughgaseous exchange and control of blood PH.The lungs enhance the process of gaseous exchange through the removalof carbon dioxide which is a waste product during cellularrespiration. The human body will have a normal breathing rate duringthe regular resting condition, a process known as eupnea (Ionesco,2013). The process is maintained to the point where there is a needof oxygen in the body and this results in a rise in carbon dioxidedue to greater energy. The partial pressure of gasses in the blood ismonitored by the automatic chemoreceptors which will send the signalsto the brain cells which house the respiratory center (Rizzo, 2015).At this moment, the rate and depth of breathing are adjusted toensure blood is returned to average heights of the partial pressuresof the gasses.

Themaintenance of blood pHis critical for the survival of humans. The normal blood pH isslightly basic or alkaline and usually at 7.4. The rising or loweringof the blood pH will result in failures of the brain to functionnormally and this will lead to complications. Blood levels which areabove 7.9 or below 6.9 and experienced for a short time can be veryfatal (Rizzo, 2015). The lungs, kidneys and buffers are the primaryfactors that regulate the change of pH in the body. The buffers areresponsible for releasing or taking in ions to ensure there is themaintenance of H+ concentration at a given level. The respiratoryacidosis is a condition whereby the blood becomes more acidic makingcarbon dioxide and H+ to increase and the pH to decrease as opposedto respiratory alkalosis. The respiratory system will provideresponses by inhaling more oxygen and release the hydrogen ions torespond to this process. In contrast, if the body experiencesrespiratory alkalosis, then the carbon dioxide and hydrogen ions willdecrease and the pH will increase. The effect is that the respiratorysystem will breathe less to release bicarbonate. By this, the bloodpH will be regulated.

CO2+ H2O &lt—&gt H2CO3 &lt—&gt (H+) + HCO3 (Regan, 2015).

H2CO3is carbonic acid

HCO3is bicarbonate.

Fromthe equation above, during the process of respiratory acidosis, theequation will shift to the right and in the case of respiratoryalkalosis, the equation shifts to the left.

Modificationsof the to Improve its Functions

Duringrest, the respiratory system will be regulated by the respiratorycells of the brain and the system will work efficiently at a constantpace (Ionesco, 2013). During the process, ventilation will allowoxygen to be supplied to the tissues of the human body. Nevertheless,the respiratory systems require changing the pace of its functions toenable it to meet the oxygen demand of the body. Due to this, it isrelevant to have modifications to the respiratory system to improveits functions.

Therespiratory system should be modified through hyperpnoea, which is aprocess that increases the rate and depth of ventilation to enhance arise in oxygen demand (Regan, 2015). The procedure will bebeneficial in scenarios whereby one suffers from respiratory diseasesas it will increase the flow of oxygen into the body to meet thedemand by the body cells. The process will impact homeostasis as theupsurge in ventilation rate will result in low carbon dioxide levelswhich in turn will yield high alkaline in the blood. The functioningof the hyperpnoea impacts another neural mechanism such asproprioceptors activation in the joints, tendons and muscles, thepsychological stimulus and activation of the motor neuron of theskeletal muscles. The process of hyperpnoea has a connection tophysical exercise and this is the time it performs efficiently asopposed to the increase in oxygen demand in the tissues.


Ionesco,C. M. (2013). The human respiratory system. In TheHuman (pp. 13-22). Springer London.

Regan,J., Russo, A., &amp Putte, C. V. (2015). Seeley’sEssentials of Anatomy &amp Physiology.McGraw-Hill.

Rizzo,D. C. (2015). Fundamentalsof anatomy and physiology.Cengage Learning.