8. respiratory system

The process of supplying the body with O2 and removing CO2 is known as respiration

1. THE RESPIRATORY SYSTEM Dr. S P SRINIVAS NAYAK, PharmD , MSc .,PGDND .,(PhD ) Dept. of Pharmacy Practice Assistant Professor, Parul institute of Pharmacy and Research, PU

2. INTRODUCTION Your body’s cells continually use oxygen (O2) for the metabolic reactions that generate ATP from the breakdown of nutrient molecules, these reactions release carbon dioxide (CO2) as a waste product. GLU + OXYGEN ---  CO2 + H2 O + ATP The branch of medicine that deals with the diagnosis and treatment of diseases of the ears, nose, and throat ( E N T ) is called oto rhino laryng ology

3. THE STEPS INVOLVED IN RESPIRATION The process of supplying the body with O2 and removing CO2 is known as respiration , which has three basic steps. 1. Pulmonary ventilation: the exchange of air between the atmosphere and the alveoli of the lungs . 2. External (pulmonary) respiration: It is the exchange of gases between the alveoli of the lungs and the blood in pulmonary capillaries across the respiratory membrane 3. Internal (tissue) respiration: In this step the blood loses O2 and gains CO2. Within cells, the metabolic reactions that consume O2 and give off CO2 during the production of ATP are termed cellular respiration

4. THE STEPS INVOLVED IN RESPIRATION The process of supplying the body with O2 and removing CO2 is known as respiration , which has three basic steps . Pulmonary ventilation: the exchange of air between the atmosphere and the alveoli of the lungs . 2 . External (pulmonary) respiration: It is the exchange of gases between the alveoli of the lungs and the blood in pulmonary capillaries across the respiratory membrane 3. Internal (tissue) respiration: In this step the blood loses O2 and gains CO2. Within cells, the metabolic reactions that consume O2 and give off CO2 during the production of ATP are termed cellular respiration

5. COMPONENTS OF THE RESPIRATORY SYSTEM Structurally, the respiratory system consists of two parts: ( 1) The upper respiratory system includes the nose, nasal cavity , pharynx, and associated structures; ( 2) the lower respiratory system includes the larynx, trachea, bronchi, and lungs.

6. Functions of the respiratory system 1 . Provides for gas exchange: intake of O2 for delivery to body cells and removal of CO2 produced by body cells . 2. Helps regulate blood pH. 3. Contains receptors for sense of smell , filters inspired air, produces vocal sounds (phonation), and excretes small amounts of water and heat . 4. Endocrine functions: releases ACE.

7. THE UPPER RESPIRATORY SYSTEM Nose: The nose is a specialized organ at the entrance of the respiratory system that consists of a visible external nose( consists of a supporting framework of bone and hyaline cartilage , covered with muscle and skin and lined by a mucous membrane ) frontal bone, nasal bones, and maxillae form the bony framework of the external nose. The interior structures of the external nose have three functions : warming , moistening, and filtering incoming air ; detecting olfactory stimuli ; and modifying speech vibrations as they pass through the large, hollow resonating chambers. Rhinoplasty : is a surgical procedure in which the shape of the external nose is altered.

8. Nasal cavity: it is lined with muscle and mucous membrane. A vertical partition, the nasal septum , divides the nasal cavity into right and left sides . The bony and cartilaginous framework of the nose help to keep the vestibule and nasal cavity patent , The olfactory receptor cells, supporting cells, and basal cells lie in the respiratory region, which is near the superior nasal conchae and adjacent septum. These cells make up the olfactory epithelium . It contains cilia but no goblet cells. Tonsillectomy: is surgical removal of the tonsils.

9. PHARYNX The pharynx lies just posterior to the nasal and oral cavities, superior to the larynx , and just anterior to the cervical vertebrae . Its wall is composed of skeletal muscles and is lined with a mucous membrane. Relaxed skeletal muscles help keep the pharynx patent . Contraction of the skeletal muscles assists in deglutition (swallowing). The pharynx functions as a passageway for air and food, provides a resonating chamber for speech sounds, and houses the tonsils, which participate in immunological reactions against foreign invaders. The pharynx can be divided into three anatomical regions: (1) nasopharynx , ( 2) oropharynx, and (3) laryngopharynx.

10. The Lower Respiratory System The lower respiratory system includes the larynx, trachea, bronchi, and lungs. A) LARYNX The larynx, or voice box , is a short passageway that connects the laryngopharynx with the trachea. It lies in the midline of the neck anterior to the esophagus and the fourth through sixth cervical vertebrae (C4–C6)

11. THE STRUCTURES OF VOICE PRODUCTION The mucous membrane of the larynx forms two pairs of folds: a superior pair called the vestibular folds (false vocal cords) and an inferior pair called the vocal folds (true vocal cords). The space between the vestibular folds is known as the rima vestibuli .

12. B) TRACHEA The trachea or windpipe, is a tubular passageway for air that is about 12 cm (5 in.) long and 2.5 cm (1 in.) in diameter. It is located anterior to the esophagus It extends from the larynx to the superior border of the fifth thoracic vertebra (T5), where it divides into right and left primary bronchi The layers of the tracheal wall, from deep to superficial, are the (1) mucosa, (2) submucosa , (3) hyaline cartilage, and (4) adventitia (composed of areolar connective tissue).

13. C) BRONCHI At the superior border of the fifth thoracic vertebra, the trachea divides into a right main (primary) bronchus which goes into the right lung, and a left main (primary) bronchus, which goes into the left lung The right main bronchus is more vertical, shorter, and wider than the left . As a result, an aspirated object is more likely to enter and lodge in the right main bronchus than the left . Like the trachea, the main bronchi contain incomplete rings of cartilage and are lined by ciliated pseudostratified columnar epithelium.

14. On entering the lungs, the main bronchi divide to form smaller bronchi—the lobar (secondary) bronchi , one for each lobe of the lung. (The right lung has three lobes; the left lung has two.) The lobar bronchi continue to branch, forming still smaller bronchi, called segmental (tertiary ) bronchi that supply the specific bronchopulmonary segments within the lobes. The segmental bronchi then divide into bronchioles. Bronchioles in turn branch repeatedly, and the smallest ones branch into even smaller tubes called terminal bronchioles . These bronchioles contain club (Clara) cells, columnar, nonciliated cells interspersed among the epithelial cells. Club cells may protect against harmful effects of inhaled toxins and carcinogens, produce surfactant and function as stem cells (reserve cells), which give rise to various cells of the epithelium . The terminal bronchioles represent the end of the conducting zone of the respiratory system. This extensive branching from the trachea through the terminal bronchioles resembles an inverted tree and is commonly referred to as the bronchial tree

15. THE LUNGS A pulmonologist is a specialist in the diagnosis and treatment of lung diseases. The lungs are paired cone-shaped organs in the thoracic cavity, They are separated from each other by the heart and other structures of the mediastinum, which divides the thoracic cavity into two anatomically distinct chambers. As a result, if trauma causes one lung to collapse, the other may remain expanded.

16. Each lung is enclosed and protected by a double-layered serous membrane called the pleural membrane or pleura. The superficial layer, called the parietal pleura thoracic cavity the deep layer, the visceral pleura , covers the lungs themselves

17. The lungs extend from the diaphragm to just slightly superior to the clavicles and lie against the ribs anteriorly and posteriorly. The broad inferior portion of the lung, the base, is concave and fits over the convex area of diaphram

18. Lobes, Fissures, and Lobules One or two fissures divide each lung into sections called lobes . Both lungs have an oblique fissure, which extends inferiorly and anteriorly; the right lung also has a horizontal fissure. The oblique fissure in the left lung separates the superior lobe from the inferior lobe. In the right lung, the superior part of the oblique fissure separates the superior lobe from the inferior lobe; the inferior part of the oblique fissure separates the inferior lobe from the middle lobe, which is bordered superiorly by the horizontal fissure.

19. Each lobe receives its own lobar bronchus . Thus, the right main bronchus gives rise to three lobar bronchi called the superior, middle, and inferior lobar bronchi . and the left main bronchus gives rise to superio r and inferior lobar bronchi

20. Each lobe of the lungs has many small compartments called lobules ; each lobule is wrapped in elastic connective tissue and contains a lymphatic vessel , an arteriole , a venule , and a branch from a terminal bronchiole Terminal bronchioles and lobule subdivide into microscopic branches called respiratory bronchioles

21. Alveolar Sacs and Alveoli Each alveolar sac is composed of outpouchings called alveoli

22. The wall of each alveolus (singular) consists of two types of alveolar epithelial cells . The more numerous type I alveolar (squamous pulmonary epithelial) cells are simple squamous epithelial cells that form a nearly continuous lining of the alveolar wall. Type II alveolar cells , also called septal cells, are fewer in number and are found between type I alveolar cells .

23. Type II alveolar cells , rounded or cuboidal epithelial cells with free surfaces containing microvilli , secrete alveolar fluid, which keeps the surface between the cells and the air moist. Included in the alveolar fluid is surfactant

24. Inhalation Breathing in is called inhalation (inspiration). Just before each inhalation, the air pressure inside the lungs is equal to the air pressure of the atmosphere, which at sea level is about 760 millimeters of mercury (mmHg), or 1 atmosphere ( atm ). For air to flow into the lungs, the pressure inside the alveoli must become lower than the atmospheric pressure. This condition is achieved by increasing the size of the lungs.

25. Pulmonary Ventilation ( inhalation and exhalation) INTRODUCTION: Pulmonary ventilation, or breathing, is the flow of air into and out of the lungs . In pulmonary ventilation, air flows between the atmosphere and the alveoli of the lungs because of alternating pressure differences created by contraction and relaxation of respiratory muscles. The rate of airflow and the amount of effort needed for breathing are also influenced by alveolar surface tension, compliance of the lungs, and airway resistance.

26. Exhalation Exhalation is Breathing out, called expiration, is also due to a pressure gradient, but in this case the gradient is in the opposite direction: The pressure in the lungs is greater than the pressure of the atmosphere. Normal exhalation during quiet breathing, unlike inhalation, is a passive process because no muscular contractions are involved. Instead, exhalation results from elastic recoil of the chest wall and lungs, both of which have a natural tendency to spring back after they have been stretched.

27. Exchange of Oxygen and Carbon Dioxide EXTERNAL RESPIRATION: External respiration or pulmonary gas exchange is the diffusion of O2 from air in the alveoli of the lungs to blood in pulmonary capillaries and the dif f usion of CO2 in the opposite direction

28. Internal Respiration The left ventricle pumps oxygenated blood into the aorta and through the systemic arteries to systemic capillaries . The exchange of O2 and CO2 between systemic capillaries and tissue cells is called internalrespiration or systemic gas exchange

29. Transport of Oxygen and Carbon Dioxide Oxygen Transport: Oxygen does not dissolve easily in water, so only about 1.5% of inhaled O2 is dissolved in blood plasma, which is mostly water. About 98.5% of blood O2 is bound to hemoglobin in red blood cells Each 100 mL of oxygenated blood contains the equivalent of 20 mL of gaseous O2

30. The heme portion of hemoglobin contains four atoms of iron, each capable of binding to a molecule of O2. Oxygen and hemoglobin bind in an easily reversible reaction to form oxyhemoglobin :

31. Regulation of respiratory system

32. HYPOXIA Hypoxia : is a deficiency of O2 at the tissue level. Based on the cause, we can classify hypoxia into four types 1 . Hypoxic hypoxia is caused by a low PO2 in arterial blood as a result of high altitude, airway obstruction, or fluid in the lungs. 2 . In anemic hypoxia , too little functioning hemoglobin is present in the blood, which reduces O2 transport to tissue cells. Among the causes are hemorrhage, anemia, and failure of hemoglobin to carry its normal complement of O2, as in carbon monoxide poisoning. 3 . In ischemic hypoxia , blood flow to a tissue is so reduced that too little O2 is delivered to it, even though PO2 and oxyhemoglobin levels are normal. 4 . In histotoxic hypoxia , the blood delivers adequate O2 to tissues, but the tissues are unable to use it properly because of the action of some toxic agent. One cause is cyanide poisoning, in which cyanide blocks an enzyme required for the use of O2 during ATP synthesis.

33. Asphyxia Asphyxia  or  asphyxiation  is a condition of deficient supply of oxygen to the body that arises from abnormal breathing. Asphyxia causes generalized hypoxia , which affects primarily the tissues and organs. There are many circumstances that can induce asphyxia, all of which are characterized by the inability of a person to acquire sufficient oxygen through breathing for an extended period of time. Asphyxia can cause coma or death.

34. Dysbarism  refers to medical conditions resulting from changes in ambient  pressure. Various activities are associated with pressure changes.  Underwater diving  is the most frequently cited example, but pressure changes also affect people who work in other pressurized environments and people who move between different altitudes

35. Oxygen therapy and resuscitation

36. Disorders: Homeostatic Imbalances Asthma Chronic Obstructive Pulmonary Disease A. Emphysema: is a disorder characterized by destruction of the walls of the alveoli, producing abnormally large air spaces that remain filled with air during exhalation B . Chronic bronchitis: is a disorder characterized by excessive secretion of bronchial mucus accompanied by a productive cough 3. Lung Cancer 4. Pneumonia 5. Tuberculosis 6. Pulmonary Edema 7. Sudden Infant Death Syndrome 8. Sudden Infant Death Syndrome