Respiratory System

1. Chapter 7 Respiratory System

2. Related Combining Forms

3. Functions of Respiratory System • Delivers air to the lungs • Conveys oxygen from inhaled air to blood • Expels waste products through exhalation • Produces airflow through larynx making speech possible

4. Structures of Respiratory System

5. Structures of Respiratory System • Upper respiratory tract • Nose, mouth, pharynx, epiglottis, larynx, and trachea • Lower respiratory tract • Bronchial tree and lungs • Located within and protected by thoracic cavity

6. Structures of Respiratory System

7. Nose • Air enters through nose, and passes through nasal cavity • Nostrils • External openings of nose • Nasal septum • Wall of cartilage dividing the nose into two equal sections

8. Nose • Cilia • Thin hair located inside nostrils • Filter incoming air to remove debris • Mucous membranes • Specialized tissues lining parts of the respiratory, digestive, reproductive, and urinary systems

9. Nose • Mucus • Secretion produced by mucous membranes • Helps moisten, warm, and filter air entering the nose • Olfactory receptors • Nerve endings acting as receptors for sense of smell • Also important also for sense of taste

10. Tonsils • Help protect body from infection entering through nose or mouth • Palatine tonsils • Located at back of the mouth • Nasopharyngeal tonsils • Located behind the nose and roof of the mouth • Adenoids

11. Paranasal Sinuses • (para-: near; nas: nose; -al: pertaining to) • Air-filled cavities lined with mucous membrane • Located in bones of the skull • Three functions • Make bones of skull lighter • Give resonance to the voice • Secrete mucus to lubricate nasal cavity

12. Paranasal Sinuses • Four pairs • Frontal sinuses • Located in frontal bone just above eyebrows • Infection causes pain in this area • Sphenoid sinuses • Located in sphenoid bone behind eye and under the pituitary gland • Near the optic nerves • Infection may damage vision

13. Paranasal Sinuses • Maxillary sinuses • Located in maxillary bones under the eyes • Infection causes pain in posterior maxillary teeth • Ethmoid sinuses • Located in ethmoid bone between nose and eyes • Separated from orbital cavity by thin layer of bone

14. Pharynx • Commonly known as throat • Receives air and food • Three divisions • Nasopharynx • (nas/o: nose; -pharynx: throat) • Posterior to nasal cavity; continues downward toward the mouth • Transports air only • Opens into the oropharynx

15. Pharynx • Oropharynx • (or/o: mouth; -pharynx: throat) • Visible when looking into the mouth • Shared by respiratory and digestive systems • Transports air, food, and fluids to the laryngopharynx

16. Pharynx • Laryngopharynx • (laryng/o: larynx; -pharynx: throat) • Shared by respiratory and digestive systems • Air, food, and fluids continue to the opening of esophagus and trachea; air enters trachea; food and fluids enter esophagus

17. Larynx • Also known as voice box • Located between pharynx and trachea • Supported by nine cartilages; largest is thyroid cartilage (Adam's apple) • Contains vocal cords that • Separate to allow passage of air • Close to assist with sound production

18. Protective Swallowing Mechanisms • Two mechanisms prevent entrance of food or water into trachea • Soft palate moves up and backward to close off the nasopharynx • Prevents food from entering the nose • Epiglottis swings downward and closes off the laryngopharynx • Prevents food from entering the trachea and lungs

19. Trachea • Commonly known as windpipe • Transports air to and from lungs • Located in front of the esophagus • Held open by flexible C-shaped cartilage rings • Allow food to pass down the esophagus

20. Trachea

21. Bronchi • Primary bronchi branch from trachea to convey air into the two lungs • Each bronchus divides and subdivides into increasingly smaller bronchioles

22. Alveoli • Also known as air sacs • Located at the end of each bronchiole • Site of gas exchange • Produce surfactant that reduces surface tension of the fluid in the lungs preventing collapse during exhalation

23. Lungs • Right lung has three lobes • Upper (superior), middle, lower (inferior) • Left lung has two lobes • Upper (superior), lower (inferior) • Space is restricted due to location of the heart

24. Lungs

25. Mediastinum • Middle section of chest cavity • Located between the lungs • Contains connective tissue • Contains organs • Heart and its veins/arteries, esophagus, trachea, bronchi, thymus gland, lymph nodes

26. Pleura • Moist membrane covering outer surface of lungs and lining inner surface of thoracic cavity • Parietal pleura • Outer layer • Attached to chest wall • Lines thoracic cavity, covers diaphragm, and forms sac containing each lung

27. Pleura • Visceral pleura • Inner layer • Attached directly to each lung • Pleural cavity (space) • Fluid-filled space between parietal and visceral pleural membranes • Fluid acts as a lubricant

28. Diaphragm • Muscle separating thoracic cavity from the abdomen • Breathing occurs as diaphragm contracts and relaxes • Contraction stimulated by phrenic nerves

29. Diaphragm

30. Respiration • Exchange of oxygen for carbon dioxide • 1 inhalation + 1 exhalation = 1 respiration

31. Inhalation and Exhalation • Inhalation • Breathing in • Diaphragm contracts, and pulls downward; thoracic cavity expands causing vacuum drawing air into lungs • Exhalation • Breathing out • Diaphragm relaxes, and moves upward; thoracic cavity narrows forcing air out of lungs

32. Inhalation and Exhalation

33. External Respiration • With inhalation of air into alveoli, oxygen is passed into capillaries and carried by erythrocytes to body cells • Carbon dioxide, as a waste product, is passed into bloodstream and transported into air spaces for exhalation

34. Internal Respiration • Exchange of gases within cells of blood and tissues • Oxygen passes into cells; carbon dioxide passes into bloodstream where it is transported to the lungs, and expelled during exhalation

35. Medical Specialties Related to Respiratory System • Otolaryngologist • Specializes in diagnosing/treating diseases/disorders of head and neck • (ot/o: ear; laryng/o: larynx; -ologist: specialist) • Pulmonologist • Specializes in diagnosing/treating diseases/disorders of respiratory system • (pulmon: lung)

36. Medical Specialties Related to Respiratory System • Thoracic surgeon • Performs surgery on organs inside thorax, or chest including heart, lungs, and esophagus

37. Pathology of Respiratory System • Chronic obstructive pulmonary disease (COPD) • Group of lung diseases • Obstructed bronchial airflow causes difficult exhalation • Common cause: smoking

38. Chronic Bronchitis • (bronch: bronchus; -itis: inflammation) • Inflammation of airways due to recurrent exposure to inhaled irritant (such as cigarette smoke) • Mucus-producing cells increase in size and number resulting in excessive mucus production and thickening of walls of air passages

39. Emphysema • Progressive loss of lung function • Characterized by decrease in number of alveoli, enlargement of remaining alveoli, and destruction of their walls • Lungs overinflate, remain partially expanded resulting in a barrel chest appearance • Common cause: smoking

40. Asthma • Chronic inflammatory disease of bronchial tubes • May be triggered by allergic reaction • Partial obstruction of airway results in wheezing • May be induced by exercise

41. Upper Respiratory Diseases • Upper respiratory infection and acute nasopharyngitis • Describe the common cold • Usually due to human rhinovirus • Allergic rhinitis • Allergic reaction to airborne allergens resulting in increased mucus flow • (rhin: nose; -itis: inflammation)

42. Upper Respiratory Diseases • Croup • Acute respiratory infection in children and infants • Barking cough and stridor result from obstruction of larynx and swelling around vocal cords

43. Upper Respiratory Diseases • Diphtheria • Bacterial infection of throat and upper respiratory tract • Toxins may damage heart muscle and peripheral nerves • Immunization available

44. Upper Respiratory Diseases • Epistaxis • Nosebleed • May be caused by dry air, injury, medication, or hypertension • Influenza • Acute, highly contagious viral infection • Spread by respiratory droplets • Many strains; some may be prevented by annual immunization

45. Upper Respiratory Diseases • Pertussis • Whooping cough • Contagious bacterial infection • Paroxysmal cough followed by breathlessness and noisy inspiration • Immunization available

46. Upper Respiratory Diseases • Rhinorrhea • Watery flow of mucus from nose • (rhin/o: nose; -rrhea: abnormal discharge) • Sinusitis • Inflammation of sinuses • (sinus: sinus; -itis: inflammation)

47. Pharynx and Larynx • Pharyngitis (pharyng: pharynx) • Sore throat • Inflammation of pharynx • Laryngospasm • (laryng/o: larynx; -spasm: a sudden involuntary contraction) • Sudden spasmotic closure of larynx

48. Voice Disorders • Aphonia • Loss of ability of larynx to produce normal speech sounds • (a-: without; phon: sound or voice: -ia: abnormal condition) • Dysphonia • Difficulty in speaking • (dys-: bad)

49. Voice Disorders • Laryngitis • Inflammation of larynx • Often results in loss of voice • (laryng: larynx; -itis: inflammation)

50. Trachea and Bronchi • Tracheorrhagia • (trache/o: trachea; -rrhagia: bleeding) • Bleeding from mucous membranes of trachea • Bronchiectasis • (bronch/i: bronchus; -ectasis: stretching or enlargement) • Permanent dilation of bronchi due to chronic infection/inflammation