The Respiratory System

1. The Respiratory System Chapter 7

2. Overview • Major StructuresWd Part • Nosenas/o • Sinusessinus/o • Pharynxpharyng/o • Larynxlaryng/o • Epiglottisepiglott/o • Tracheatrache/o • Bronchibronch/o, bronchi/o • Alveolialveol/o • Lungspneum/o, pneumon/o, pulmon/o

4. Word Parts • Bronchi/o • Cyan/o • Laryng/o • Ox/i, ox/o, ox/y • Pharyng/o • Phon/o • Pleur/o • -pnea • Pneum/o, pneumon/o, pneu- • Pulm/o, pulmon/o • Somn/o • Tachy- • Thorac/o, -thorax • Trache/o

5. Objectives • ID and describe the major structures and functions of the respiratory system • Recognize, define, spell and pronounce terms related to the pathology and the diagnostic and treatment procedures of the respiratory system

6. Functions of the Respiratory System Bring oxygen (O2) from the inhaled air into the blood for delivery to the body cells Expel waste products (carbon dioxide [CO2] and some water [H2O] waste) returned to the lungs by the blood Produce airflow through the larynx that makes speech possible

7. Structures of the Respiratory System For descriptive purposes, the respiratory system is divided into upper and lower tracts:

8. The Upper Respiratory Tract consists of the nose, mouth, pharynx, epiglottis, larynx, and trachea

9. The Lower Respiratory Tract consists of the bronchial tree and lungs. • These structures are located within, and protected by, the thoracic cavity [aka the rib cage]

12. The Nose • Air enters through the nose and passes through the nasal cavity [the int portion of the nose] • The nasal septum is a wall of cartilage that divides the nose into 2 equal sections • Cilia – thin hairs located just inside the nostrils that filter incoming air • Mucous Membranes – specialized tissues that line the respiratory, digestive, reproductive and urinary systems

13. Mucus – secreted by the mucous membranes, protects and lubricates these tissues • In the nose, they help moisten, warm and filter the air as it enters • Olfactory Receptors – nerve endings that act as the receptors for the sense of smell • Also important to the sense of taste

15. The Tonsils • Form a protective circle of lymphatic tissue • [you were just tested on these ;)]

16. The Paranasal Sinuses • Air filled cavities lined with mucous membrane, located in the bones of the skull and are connected to the nasal cavity via short ducts • Function: • To make the bones of the skull lighter • To help produce sound by giving resonance to the voice • To produce mucus to provide lubrication for the tissues of the nasal cavity • 4 pairs located on either side of the nose and are named for the bones in which they’re located

17. Function, etc • Frontal Sinuses – located in the frontal bone jut above the eyebrows • Sphenoid Sinuses – located in the sphenoid bones close to the optic nerves (an infection here can damage vision) • Maxillary Sinuses – the largest of the paranasal sinuses located in the maxilla • Ethmoid Sinuses – located in the ethmoid bones; their irregularly shaped air cells that are separated from the orbital cavity (eye socket) by a thin layer of bone

19. The Pharynx • Commonly known as the throat; receives air after is passes through the nose • Made up of 3 divisions: • Nasopharynx – posterior to the nasal cavity and continues downward to behind the mouth • Oropharynx – the portion that is visible when looking into the mouth • Laryngopharynx – shared by both respiratory and digestive systems; Air, food and fluids continue down to the openings of the esophagus and trachea where air enters the trachea, while food and fluids flow into the esophagus

21. The Larynx • Also known as the voice box; it’s a triangular chamber located between the pharynx and the trachea • Protected and supported by a series of nine separate cartilages • The thyroid cartilageis the largest; commonly known as the Adam’s Apple • It contains the vocal cords • During breathing the cords are separated to let air pass • During speech they are close together, and sound is produced as air is expeller from the lungs causing the cords to vibrate against each other

23. Protective Swallowing Mechanism • Because the respiratory and digestive systems share part of the pharynx, during swallowing there is a risk of blocking the airway or pneumonia caused by food or H2O going into the trachea and entering the lungs (to aspirate) • During swallowing, the soft palate (the muscular post portion of the roof of the mouth) moves up and backward to close off the nasopharynx (which is why food and such doesn’t come out our noses!) • At the same time the eppiglottis (the lid-like structure at the base of the tongue) sings downward to close off the laryngopharynx to stop food from entering the trachea and lungs

25. The Trachea • Commonly known as the wind pipe; the tube located in front of the esophagus that extends from the neck to the chest • Transports air to, and from, the lungs • It is held open by a series of C-shaped cartilage rings • The wall between the rings is flexible which makes it possible for the trachea to adjust to different body positions

27. The Bronchi • Formed where the trachea divides into two branches known as the primary bronchi • Because they look like an inverted tree, it’s referred to as the bronchial tree • Within the lung, each primary bronchus divides and subdivides into increasingly smaller bronchioles (the smallest branches of the bronchi)

29. The Alveoli • Also known as air sacs; the very small grape-like clusters found at the end of each bronchiole • Each lung contains millions of alveoli that are filled with air from the bronchioles • A network of microscopic pulmonary capillaries surround the thin, elastic walls of the alveoli • During respiration, the exchange of O2 and CO2 between the alveolar air and the pulmonary capillary blood occurs through the walls of the alveoli

32. The Lungs • The organs of respiration; are divided into lobes (subdivisions of the whole) • Right Lung – 3 lobes; superior, middle and inferior • Left Lung – 2 lobes; the superior and inferior; slightly smaller because of the space taken up by the heart • They produce a detergent-like substance called surfactant that reduces the surface tension of the lungs allowing air to flow over the lungs and be absorbed more easily

34. The Mediastinum • The cavity located between the lungs • Contains connective tissue and organs, including the heart and its veins and arteries, the esophagus, trachea, bronchi, thymus gland, and lymph nodes

36. The Pleura • A thin, moist, and slippery membrane that cover the outer surface of the lungs and lines the inner surface of the rib cage • Parietal Pleura – the outer layer or the pleura that lines the walls of the thoracic cavity • Visceral Pleura – the inner layer of the pleura that surrounds each lung • The Pleural Cavity – the airtight area between the layers of the pleural membranes • Contains a thin layer of fluid that allows the membranes to slide easily during respiration

38. The Diaphragm • The muscle that separates the thoracic cavity from the abdomen. • The contraction and relaxation of the diaphragm is what makes breathing possible • Stimulated by the phrenic nerves causing it to contract

41. Respiration The exchange of O2 and CO2 that is essential to life One respiration consists of one inhalation and one exhalation

42. Inhalation and Exhalation • Inhalation – the act of taking in air as the diaphragm contracts and pulls downward • Causes the thoracic cavity to expand • Produces a vacuum within the thoracic cavity that draws air into the lungs • Exhalation – the act of breathing out • The diaphragm relaxes and moves upward causing the thoracic cavity to become narrower and force air out of the lungs

44. External Respiration– the act of bringing air into and out of the lungs and exchanging gases from this air • Air is inhaled into the alveoli, O2 immediately passes into the surrounding capillaries and is carried by RBCs to all the body cells • At the same time, CO2 (waste) is transported to the air spaces in the lungs to be exhaled • Internal Respiration • O2 passes from the bloodstream into the cells • Cells give off CO2 (waste) • Bloodstream transports CO2 to the lungs to be expelled

46. Internal Respiration External Respiration

47. Medical Specialties Related to the Respiratory Systems

48. Otolaryngologist – ENT; a physician who specializes in the dx and tx of diseases and disorders of the ear, nose, throat and related structures of the head and neck • Pulmonologist – a physician who specializes in the dx and tx of the lungs and associated tissues

49. Pathology of the Respiratory System

50. Chronic Obstructive Pulmonary Diseases • COPD; a lung disease in which it is hard to breath • Damage to the bronchi obstructs them, making it difficult to get air in and out • Often occurs in smokers or former smokers • Chronic Bronchitis– the airways have become inflamed and thickened, and there is an increase in the number and size of mucus-producing cells