what is human respiratory system? air passage way and disease revealed to air passage way

 RESPIRATION

respiration is a physical process of gaseous exchange between the organism and its environment also known as breathing or ventilation

inhaled air have more amount of oxygen and less amount of carbon dioxide whereas the exhaled air have more amount of carbon dioxide and very less amount of oxygen

                  important point here is that respiration is not to be confused with cellular respiration because of following reasons

•  as simple respiration is defined as exchange of respiratory gaseous between the organism and its environment where as cellular respiration is defined as a process by which cells of a living organism utilizes oxygen and produces carbon dioxide extracts energy from this process and conserve this energy for later use and store it in biological useful forms such as ATP
• the second main difference between respiration and cellular respiration is that respiration is a physical  process whereas cellular respiration is a chemical and biochemical process

HUMAN RESPIRATORY SYSTEM 

         human respiratory system consist of two main things that are as following 

• air passage way 
• lungs
• breathing in humans is controlled by pons and medulla which are the sections of the hind-brain  

AIR PASSAGE WAY

               human respiratory system consist of following components 

• external nostrils
• nasal cavity
• internal nostrils
• pharynx 
• larynx
• bronchi 
• bronchioles
• alveolar ducts
• alveolar sacs 

 NASAL CAVITY

              air from outside gets into the air passage way by the help of external nostrils the external nostrils channelize air into the nasal cavity. Nasal cavity is is divided into two by the help of a cartilage nasal cavities are lines by mucous membrane and have a ciliated epithelium each nasal cavity is subdivided into three passage ways by the projection of bones from the walls of the internal nose air that enters through nostrils comes into nasal cavity in the nasal cavity larger dust particles are trapped by the help of mucous and hairs the incoming air is also warned and its the temperate of incoming air is made equal to the temperate of the body after trapping of dust particles and warming of air it is than channelized into pharynx 

PHARYNX 

                pharynx is a muscular passage that is both common to air and to food that enter here goes to esophagus were as the air goes to trachea of wing pipe pharynx is also covered by mucus membrane from here air is send into larynx 

LARYNX 

             larynx is a cartilaginous structure that is present at the top and covering the top region of trachea larynx is also know as voice box as it is responsible for producing sound and but the help of vocal cords cheeks teeth tongue plate we are able to make a complete speech during the process of swallowing to prevent from entry of food into air passage way way a hinge like epiglottis covers the opening of the larynx during the act of swallowing and thus prevent from entry of food in it 

GLOTTIS 

                  it is the opening of larynx and it is also covered by mucous membrane 

TRACHEA

              trachea also know as wing pipe is present to the ventral side of esophagus also it extends in to the chest cavity where it divides to form left and right bronchi and each bronchi goes into its respective lung it also have mucous membrane and ciliated epithelium in it that traps any of the dust particles that escapes from the nasal cavity and than the dust particles is removed out of the body it have cartilage in it but the special thing about the cartilage in it is that it have c shaped cartilaginous ring that prevents it from collapsing even no air in prevent in it 

BRONCHI AND BRONCHIOLES

                  each of the bronchus that were formed from the trachea after going into respective lung and divides to form bronchi and continue to divide further and when they have a diameter less that 1 mm than they are know as bronchioles bronchi have cartilages rings mucus membrane ciliated epithelium but when it continues to divide further and further than it starts to losses them progressively bronchioles are mainly made up of circular smooth muscles 

ALVEOLAR SACS AND ALVEOLAR DUCTS 

                    inside the lungs the bronchioles continues to divide and sub divide and ultimately form several microscopic single layers structures know as alveoli overlapped alveoli with blood capillaries is the best site for the gaseous exchange 

LUNGS 

lungs are the primary organs present in humans and other animals that are responsible for the exchange of respiratory gaseous between the organism and its environment lungs are the a pair of spongy air filled organs present in the thoracic cavity of the chest all of the inhaled air goes into the the lungs through trachea by passing through tubular branches known as bronchi the bronchi further divides in to bronchioles than into alveolar duct and ultimately into alveolar sac where the exchange of respiratory gases takes place
humans have a pair of lungs present in the thoracic cavity (of the chest) that is a left lung and a right lung the lungs together weight about 1.3 kg in humans right lung is slight heavier as it have 3 lobes (superior lobe middle lobe and inferior lobe ) where as left lung have only two lobes (superior lobe and inferior lobe ) the lungs have a unique blood supply receiving deoxygenated blood from the heart in the form of pulmonary circulation from the purpose of adding oxygen in that blood and removing carbon dioxide from it and than this blood is supplied again to the heart to be circulated in the body lungs also revive oxygenated blood for its own tissues in the form of bronchial circulation
chest cavity is bounded by by ribs and intercostal muscles on the floor of the chest cavity there is a sheet of skeleton muscle known as a diaphragm that is responsible for inhalation and exhalation
lungs are covered by doubled membrane known as pleura ( inner and outer pleural membrane ) and both of the lungs have a pleural fluid between them that protects lungs from any slight trauma and also from friction

DISORDERS OF RESPIRATORY SYSTEM

like any other organ of the body lungs also show disorders or aliments some of the common disorders related to lungs are as following 

• pneumonia
• pulmonary edema 
• pneumoconiosis
• interstitial lung disease (ILD)
• pulmonary embolism (PE)
• pulmonary hypertension
• asthma 
• lung cancer
• emphysema 
• tuberculosis
• cystic fibrosis
• acute respiratory distress syndrome ( ARDS )
• chronic obstructive pulmonary disease 
• pleural effusion
• pneumothorax 

PNEUMOTHORAX

                                                     in this condition that occurs when air leaks into the space between the lungs and the chest wall that air than puts a pressure on the lungs that results in the collapsing of the lungs it is treated by removing the air by inserting a tube through the chest wall it usually shows symptoms such as shortness of breath and chest pain
PLEURAL EFFUSION 
                        in this condition there is accumulation/collection of fluid in the very thin pleural space between the lungs and the chest wall the main causes of pleural effusion are congestive heart failure pneumonia malignancies and pulmonary embolism its common symptoms are chest pain dry cough difficulty while lying down difficulty during deep breaths persistent hiccups difficulty with physical activity
PULMONARY HYPERTENSION
                              various conditions can lead to high blood pressure in the pulmonary arteries this can cause shortness of breath and chest pain when no symptoms is identified than such a condition is known as idiopathic pulmonary arterial hypertension
PULMONARY EMBOLISM 
                          a blood clot usually present in a deep leg vein breaks off and travels to the heart and from the heart it is pumped into the lungs the clot than clogs/lodges in the pulmonary artery and hence causes closing or narrowing of that artery it t may usually show symptoms such as shortness of breath and low blood oxygen levels
ASTHMA
                  asthma is a serious respiratory disease associated with severe paroxysm of difficult breathing usually followed by a period of complete relief and with recurrence of attack at more or less frequent intervals it is an allergic reaction that causes  as a reaction to pollen spores cold humidity pollution or any other cause asthma result in the release of inflammatory chemicals such as histamine into the circulatory system that causes severe constrictions of bronchioles it is treated with anti inflammatory drugs mainly in the form of inhalers
PNEUMOCONIOSIS 
                                     it is a category of condition caused by the inhalation of a substance that injures the lungs examples includes black lung disease from inhaling coal dust and asbestos  inhaled from asbestos dust
ACUTE RESPIRATORY DISTRESS SYNDROME 
                                                                     it is a server sudden injury to the lungs caused by a illness life support with mechanical ventilation is usually needed to survive until the lungs recover
EMPHYSEMA 
                                  it is a condition caused due to the breakdown of alveolar walls as a result alveoli combines to form larger alveoli this thing result in the formation of fewer and larger alveoli that have increased volume but decreased surface ares and hence there is inadequate surface area for complete gaseous exchange hence the rate of gaseous exchange decrease this condition is more common among smokes as the substances present in the smoke of the tobacco weakens the walls of the alveoli and the irritant substances of smoke generally cause smokers cough and that coughing end up with breaking up of thin and weakened alveoli
PULMONARY EDEMA 
                                    in this condition fluid leaks out of small blood vessels of the lungs into the air sacs and surrounding areas one form is caused by heart failure in another form it is caused by direct injury to lungs that caused the leak of fluid
TUBERCULOSIS
                                 tuberculosis or T.B is a respiratory disorder it is a general name of a group of diseases caused by mycobacterium tuberculosis pulmonary tuberculosis is a disease of lungs in which inside of the lung is damage resulting in fever and cough this condition is more common in poor people living in poor conditions it is a contagious disease malnutrition and poor living conditions facilitates mycobacterium to grow