Respiratory System Organization pptx

Overview of basic anatomy and functions of respiratory system

1. Respiratory System Organization 2024.09.12

2. Content airways and respiratory muscles descriptive anatomical terms organization in human body

3. Intended Learning Outcomes LLO 4.1.1. Define “external” and “internal” respiration. LLO 4.1.2. State the functions of the respiratory system LLO 4.1.3. Describe the defense mechanisms of the respiratory tract

4. Respiratory Physiology The study of how oxygen is brought to lungs and tissues and how carbon dioxide is removed.

5. External respiration Vs Internal respiration ventilation moves air through a series of passages into and out of the lungs. After this, there is an exchange of gases between the lungs and the blood. This is called  external respiration . The blood transports the gases to and from the  tissue  cells. The exchange of gases between the blood and tissue cells is  internal respiration . Finally, the cells utilize the oxygen for their specific activities: this is called  cellular metabolism , or cellular respiration. Together, these activities constitute respiration.

6. Respiratory system • Gas exchanging organ– lungs • Pump–chest wall, respiratory muscles, neuromuscular junctions, motor nerves, neural tracts in the spinal cord, centers in brain

7. https://youtu.be/snsSQcZtBds?si=2Lby7FSNebIqAc1O

8. Respiratory muscles Primary inspiratory muscles – diaphragm external intercostal muscles – elevate lower ribs, pushes sternal outwards Accessory muscles – sternocleidomastoid, ………………………………… Expiratory muscles – used during forced expiration Internal intercostal muscles Abdominal muscles

9. Functions of respiratory system Main function – gas exchange Other – host defense acid base balance

10. Regions of respiratory tract Upper airway Conducting airway Alveolar airway

11. Upper airway Nasal cavity/mouth ,pharynx, larynx Function – olfaction filtering out large particulates – settle on mucous membranes of nose and pharynx (tonsils and adenoids) warming and humidifying the air

12. Conducting airway Trachea Bronchi Bronchioles Terminal bronchioles Important features Pseudo stratified epithelium Ciliated cells and secretary cells – airway innate immunity Cartilage – more prominent in larger airways Smooth muscle cells – play a more prominent role starting from terminal bronchioles

13. Mucociliary escalator Ciliated epithelium – from ………….. To …………………. Periciliary fluid Beat at rates of 10-15Hz On top – mucus layers Allows trapping of foreign particles and transport out of the airway Defects – smokers, genetic deficiencies……….causing – chronic sinusitis, recurrent lung infections, bronchiectasis

14. https://youtu.be/HMB6flEaZwI?si=vwJ7jgs_Q6FNpmfy

15. Innervation Bronchi and bronchioles – by autonomic nervous system Stimuli – cause contraction of respiratory muscles/ initiate sneeze/ cough Beta 2 adrenergic receptors – bronchodilation

16. Alveolar airway Transitional and respiratory bronchioles Alveolar ducts Alveoli Features Gas exchange takes place Surface area increases Velocity of the airway decreases

17. Alveoli Lined by two types of epithelial cells – type I and type II Type I – primary lining cells of alveoli Type II – produces surfactants Surrounded by pulmonary capillaries Other cells in alveoli – Pulmonary Alveolar Macrophages (PAM), lymphocytes, plasma cells, neuroendocrine cells and mast cells

18. Pulmonary Defense system Inspired air is the source of oxygen for the body, but also introduces numerous particles, toxic gases and microorganisms in the airways. he upper and lower airways together represent the largest epithelial surface exposed to the outside environment; the alveolar surface being the size of a tennis court he upper and lower airways protect the lung with the anatomical barriers. They are associated with the cough reflex and use mucociliary apparatus with enzymes and secretory immunoglobulin A (IgA)

19. The basal layers of the respiratory mucosa in the nose and the conducting airways contain a tight network of dendritic cells (DCs) that sense and catch any invading organisms and bring them to the draining lymph nodes to generate the adaptive immunity. Particles <2 µm reaching the respiratory units beyond the respiratory bronchioles will be caught by alveolar macrophages (AMs) in a milieu that is rich in defence elements, such as IgG, complement, surfactant and fibronectin

20. Depending on the load of pathogens and the innate immune processes locally involved, various amounts of inflammatory cells, in particular neutrophils, will be rapidly recruited. Once adaptive immunity is also involved, memory T-cells will be found in the interstitial around the bronchi and vessels, as well as in the alveoli  https://youtu.be/rgphaHmAC_A?si=4HQXD1GVuhHOfJB8

21. References Ganong Nicod , L. P. (2005). Lung defences : An overview.  European Respiratory Review , 14(95), 45-50.  https://doi.org/10.1183/09059180.05.00009501

22. Thank You