Respiratory System Anatomy and Functions

1. 2013 Respiratory System.

2. The nose, nasal cavity, sinuses, pharynx, larynx, trachea, bronchi and structures within and associated with the lungs constitute the? ________________ • The passages conducting air and from respiratory surfaces plus the respiratory surfaces themselves make up the? _______________ The cup-shaped air sacs in which processes of gas exchange take place are? ________________

3. Upper respiratory system Lower respiratory system

4. Respiratory System: Functional Aspects/Anatomy • Surfaces for gas exchange • Passages and means of movement of air to exchange surfaces • Mechanisms for protection of respiratory surfaces from: dehydration/infection/temperature • vocalizations • Physiological regulation: blood chemistry, pressure, volume

5. Nasal bones • Lateral nasal cartilage • Alar cartilages • external nares

6. Nose -- Internal Structures • Large chamber within the skull • Roof is made up of ethmoid and floor is hard palate • Internal nares (choanae) are openings to pharynx • Nasal septum is composed of bone & cartilage • Which bones? • Bony swelling or conchae on lateral walls • Each encloses a nasal meatus

7. Nasal Cavity: • Nasal vestibule • External/internal nares (choanae) • Nasal conchae • Hard/soft palate • Paranasal sinuses • Olfactory region/cribiform plate

8. Nasal Structures – Functional Aspects • Olfactory epithelium for sense of smell • Pseudostratified ciliated columnar with goblet cells lines nasal cavity • warms air – highly vascular • mucous moistens air & traps dust • cilia move mucous towards pharynx • Paranasal sinuses open into nasal cavity • found in ethmoid, sphenoid, frontal & maxillary • lighten skull & resonate voice

9. Rhinoplasty Rhino - Nose

10. Rhinoplasty • Commonly called a “nose job” • Surgical procedure done for cosmetic reasons / fracture or septal repair • Procedure • local and general anesthetic • nasal cartilage is reshaped through nostrils • bones fractured and repositioned • internal packing & splint while healing

11. Paranasal Sinuses: Frontal Ethmoid Sphenoid Maxillary Decrease mass Add resonance to voice

12. Pharynx • 3 regions –connects oral and nasal passages with esophagus/trachea • Nasopharynx – superior portion, behind internasal nares, above soft palate • Oropharynx- soft palate to base of tongue • Laryngopharynx – hyoid bone to entrance of esophagus – common passage for food and air

13. Nasopharynx Pharyngeal oriface – auditory tube Pharyngeal tonsil uvula Oropharynx Palatoglossal Arch Palatine Tonsil Palatopharyngeal arch Laryngopharynx

14. Lower Respiratory - Larynx down • Larynx – 9 cartilages (details) - • Trachea • Mucus membrane, C-shaped cartilages • Primary bronchi – enter lungs • Right/left • Lungs – left 2 lobes, right 3 lobes

15. Larynx Details • Thyroid (Adam’s apple) • Thyrohyoid membrane connects to hyoid • Cricoid (inferior to thyroid) – sits on top of trachea • Cricothyroid ligament connects to thyroid cartil. • Epiglottis – covers thyroid • 3 smaller paired cartilages • Arytenoid • Corniculate • Cuneiform: located in aryepiglottic fold

18. Laryngeal Ligaments and Vocal Cords • Vocal ligaments and vestibular ligaments • Extend between arytenoid and thyroid cartilage • True vocal folds = vocal cords: vocal ligaments + mucous membrane • Cover rimaglottidis (opening) • Rimaglottidis + vocal folds = glottis • False vocal folds – lateral to true vocal folds • Mucous membrane + vestibular ligaments • Extend between

20. Trachea • 5 in. long & 1in. diameter • Extends from larynx to T5 anterior to the esophagus and then splits into bronchi • Layers • mucosa = pseudostratified columnar with cilia & goblet • submucosa = loose connective tissue & seromucous glands • hyaline cartilage = 16 to 20 incomplete rings • open side facing esophagus contains trachealis m. (smooth) • internal ridge on last ring called carina • adventitia binds it to other organs

21. Histology of Trachea • Mucosa: mucous membrane • Respiratory epithelium • continuous with lower larynx • Pseudostratified, ciliated columnar • Goblet cells • Mucus catches debris • Cilia sweep outwards • Lamina propria • Submucosa • Cartilages - C shaped • Elastic ligament + trachialis closes • Subject to autonomic nervous control • Joined by annular ligaments

23. Ciliated pseudostratified columnar epithelium with goblet cells produce a moving mass of mucus.

24. Larynx to Lungs: • Trachea  2 primary bronchi (enter lungs) • Carina: internal ridge – associated with cough reflex • Extrapulmonary bronchi = primary bronchi outside lungs • Histology same as trachea • Entering lungs at hilus: depression on medial surface • Complex of structures entering lung = root: • primary bronchi • Nerves • blood vessels • Lymphatic vessels • anchoring connective

25. Lungs • Lobes • Right: 3 Left: 2 • Right: Superior/middle/inferior • Left: superior/middle • Fissures: • Right: horizontal and oblique • Left: oblique

26. Surfaces • Costal – anterior – against ribs • Mediastinal – medial • root of lung and hilus • Base • apex

28. Divisions of Lung Tissue • Trabeculae divide parenchyma • Elastic connective tissue/smooth muscle • Form partitions • Lobule = smallest self contained bronchio- pulmonary segment of lung • Contains own: • Arteriole • Venule • lymphatic vessel • Division of tertiary bronchiole • 10 right • 8-10 left

30. Bronchial Tree – Branching of: • Intrapulmonary bronchi – within the lungs • Primary bronchi divide  Secondary bronchi (= lobular bronchi) – to each lobe How many in the right lung? In the left? Tertiary bronchi (= segmental bronchi) – to each bronchiopulmonary segment: ~10/lung Bronchioles terminal bronchioles respiratory bronchioles (microscopic)  alveolar ducts alveolar sacs (contain several alveoli)

32. Changes in Histology of Bronchial Tree Deeper in Lungs • Pseudostratified ciliated columnar to nonciliated simple cuboidal to simple squamous • Incomplete rings of cartilage replaced by rings of smooth muscle & then connective tissue • sympathetic NS & adrenal gland release epinephrine that relaxes smooth muscle & dilates airways • asthma attack or allergic reactions constrict distal bronchiole smooth muscle • nebulization therapy = inhale mist with chemicals that relax muscle & reduce thickness of mucus

36. Alveoli – site of gas exchange • Blind ended (‘cup shaped outpouching) contained in alveolar sac • Membrane: simple squamous + elastic basement membrane • Cells: • Type I form continuous lining • Type II (Spetal cells) • Produce alveolar fluid, contains surfactant – prevents collapse of alveoli • Alveolar macrophages (dust cells) • Capillaries surround

37. Details of the respiratory membrane

38. Two Blood Circulation Patterns in Lungs • Pulmonary Circuit • Oxygen poor/Carbon dioxide rich blood from heart via pulmonary artery to lungs • Gas exchange takes place in lungs to supply oxygen to body • Blood returns to heart via pulmonary veins • Bronchial arteries • Branch from aorta • Supply nutrient and oxygen rich blood to tissues of lungs • Drainage via bronchial veins and pulmonary veins

39. Pulmonary Circulation Systemic Circulation

40. Mechanism of breathing (ventilation) • Process of moving air in and out of lungs Respiratory volume • Involves: • Diaphragm and other muscles • Pleural membranes • Neural and sensory control

41. Visceral pleura covers lungs • parietal pleura lines ribcage & covers upper surface of diaphragm • Pleural cavity is potential space between ribs & lungs

42. Pneumothorax = air fills pleural cavity • Hemothorax = blood fills pleural cavity •  collapse of lung (all or part)  atelectasis • Treatment: drain/evacuate, lung normally reinflates

43. Lung Volumes and Capacities • Tidal volume = amount air moved during quiet breathing • Reserve volumes ---- amount you can breathe either in or out above that amount of tidal volume • Residual volume = 1200 mL permanently trapped air in system • Vital capacity & total lung capacity are sums of the other volumes

44. Pulmonary Ventilation • Process of moving air in and out of bronchial tree • increase + decrease in volume of thoracic cavity • Muscles Involved: • Diaphragm • External and Internal intercostals

45. Primary Muscles Involved • Inspiration: (thorax increases in volume and air enters lungs) • Diaphragm flattens • External intercostals elevate ribs • Expiration • Diaphragm relaxes • Internal intercostals depress ribs, reduce width of thoracic cavity

46. Shallow Breathing: only intercostals involved • At rest • During pregnancy (abdominal volume decreases) • Deep Breathing: (Diaphragmatic) – contraction of diaphragm

49. Accessory Muscles: • Assist in elevating ribs during inspiration • Sternocleidomastoid • Serratus anterior • Pectoralis minor • Scalenes • Assist in decreasing thoracic volume during expiration by compressing abdomen: • Transversus thoracis • Obliques and Rectus abdominis