Lab Exercise 24 Anatomy of the Respiratory System

Lab Exercise 24 Anatomy of the Respiratory System Portland Community College BI 233 1

Introduction • Provides oxygen to the cells of the body and removes carbon dioxide

Upper & Lower Respiratory System § Upper Respiratory System § § Nose Nasal cavity Paranasal sinuses Pharynx 3

Respiratory system § Lower Respiratory System § § Larynx Trachea Bronchi Lungs 4

Nasal bones • Frontal and nasal bones form the nasal bridge and processes of the maxillae make up the lateral walls. • Nasal septum divides the nasal cavity into right and left halves formed by vomer and perpendicular plate of the ethmoid 5

Uvula • During swallowing, the soft palate elevates and the uvula closes off the internal nares, preventing food or fluids from entering the nasal cavity. 6

Nasal Cavity 7

Nasal Cavity Opening of Auditory Tube Superior Middle & Inferior Turbinates or Chonchae External Nares 8

Nasal Cavity § The nasal epithelium covering the conchae serves to cleanse, warm and humidify the air • Nasal conchae increase the surface areas for the mucus epithelium § The olfactory epithelium in the upper medial part of the nasal cavity is involved in the sense of smell. § The nasal cavity serves as a resonating chamber as well as an avenue for escaping air. 9

Nasal Turbinates or Conchae • Ciliated pseudostratified columnar epithelium with. goblet cells pushes trapped dust toward the back of the throat to be swallowed. 10

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Sinuses All the sinuses are continuous with the nasal cavity are lined by mucous membrane. Mucous secretions drain into the nasal cavities. 12

Pharynx • Connects the nasal and oral cavities to the larynx and esophagus • Anatomically divided into 3 sections: • Nasopharynx • Oropharynx • Laryngopharynx 13

Pharynx 14

Tonsils Pharyngeal Tonsils (Adenoids) Palatine Tonsils Lingual Tonsils 15

Tonsils Pharyngeal tonsils • Tonsils: lymphoid tissue. Palatine tonsils 16

Larynx: aka Voice Box • Made of 9 pieces of cartilage, the most important are: • Thyroid cartilage (Adam’s Apple) • Thyrohyoid membrane • Cricoid Cartilage • Cricothyroid ligament • Epiglottis 17

Larynx Epiglottis Thyroid Cartilage Cricoid Cartilage Hyoid Bone Thyrohyoid Membrane Thyrohyoid ligament Cricothyroid Ligament Tracheal Cartilage 18

Inside the Larynx • Vestibular Folds: • Also called false vocal cords, ventricular band of larynx, ventricular folds, and upper folds • Vocal Cords, or vocal folds • Lower, “true” vocal cords • Attach to the arytenoid cartilages by the vocal ligaments (internal) • Glottis: The vocal cords and the space (rima glottidis) between them. 19

Inside the Larynx 20

Inside the Larynx Rima Glottis Corniculate cartilage True Vocal Cords Cuneiform cartilage Glottis Epiglottis Tongue 21

Glottis: True cords plus opening Rima Glottis: The opening 22

Larynx Airways Trachea The carina is the last cartilage which separates the entrances to the left and right primary bronchi Right Mainstem Bronchi Left Mainstem Bronchi Secondary Bronchi Carina Secondary Bronchi 23

Bronchi • The carina of the last tracheal cartilage marks the end of the trachea and the beginning of the right and left bronchi • Left main stem bronchus • Right main stem bronchus • Bronchi subdivide into secondary bronchi, each supplying a lobe of the lungs 24

Respiratory Tree 25

Branching of Bronchial Tree Trachea Primary Bronchi Secondary Bronchi Tertiary Bronchioles Terminal/Respiratory Bronchioles 26

Lungs • • Apex: the part under the clavicle Base: the part touching the diaphragm Costal Surface: the part touching the ribs Hilus: indentation containing pulmonary and systemic blood vessels • Left Lung has 2 lobes and a cardiac notch • Left upper lobe • Left lower lobe • Right Lung has 3 lobes • Right upper lobe, middle lobe, lower lobe 27

Apex Lungs LUL Ob tal fi s sure liq ue re su fis RML Obl izon Hilus Car d notc iac h Hor ique fissu re RUL LLL RLL Base 28

Lungs: Medial View 29

Lung Lobes 30

Pleura • Pleura is the double-layered sac of serous membrane • Parietal Pleura is the outer layer and is attached to the thoracic walls • Visceral Pleura is the inner layer covering the lung tissue • The layers are only touching, they are not fused together • The potential space is called the pleural cavity • There is serous fluid between the layers which allows them to slide against each other during breathing 31

Pleural cavity is in between the two layers 32

Mediastinum • The area between the lungs. • Posterior to the sternum • Anterior to the vertebrae • Contains the heart, great vessels, esophagus and thymus 33

Trachea Histology • Composed of three layers • Mucosa: made up of goblet cells and ciliated pseudostratified columnar epithelium • Submucosa: connective tissue deep to the mucosa • Adventitia: outermost layer, has C-shaped rings of hyaline cartilage 34

Trachea 35

Trachea Histology 36

Trachea Histology 37

Seromucous Glands (Trachea) 38

Trachea Pseudostratified Columnar Epithelium Submucosa with seromucous glands Hyaline Cartilage 39

Bronchioles • Tissue walls of bronchi mimic that of the trachea • As conducting tubes become smaller, structural changes occur and eventually they become bronchioles • Cartilage support structures change • Bronchioles differ from bronchi in that they lack cartilage • Epithelium types change • Amount of smooth muscle increases 40

Bronchi Histology 41

Bronchiole Histology Notice the lack of cartilage Simple columnar epithelium 42

Bronchioles Respiratory Bronchioles • Respiratory Bronchioles : Continued branching leads to the area where gas exchange occurs by simple diffusion 43

Respiratory Bronchioles Alveolar Ducts Alveolar sacs 44

Alveolar sacs Alveoli • Alveolar sacs look like clusters of grapes • The “individual grapes” are Alveoli 45

Alveoli Histology 46

Type II Pneumocytes are cuboidal and produce surfactant Type 1 Pneumocytes are flattened for gas exchange 47

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Respiratory Membrane • The area where gas exchange between air and blood occurs • It is the fused alveolar and capillary walls (3 layers) 1. Squamous type 1 alveolar epithelium 2. Fused basal laminae 3. Squamous endothelial cells in pulmonary capillaries 49

Respiratory Membrane 50

The End • Make sure that you can identify structures on the models • Identify the structures on microscopes 51