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Lab Exercise 24

Anatomy of the Respiratory System

Portland Community CollegeBI 233

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

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Respiratory system

Lower Respiratory System Larynx Trachea Bronchi Lungs

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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

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Uvula

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

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Nasal Cavity

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Nasal CavitySuperior Middle & Inferior Turbinates or Chonchae

External Nares

Opening of Auditory Tube

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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.

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Nasal Turbinates or Conchae

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

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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.

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Pharynx

• Connects the nasal and oral cavities to the larynx and esophagus

• Anatomically divided into 3 sections:

• Nasopharynx

• Oropharynx

• Laryngopharynx

Pharynx

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Tonsils

Pharyngeal Tonsils(Adenoids)

PalatineTonsils

LingualTonsils

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Tonsils

• Tonsils: lymphoid tissue. Palatine tonsils

Pharyngeal tonsils

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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

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Thyroid Cartilage

Cricoid Cartilage

Tracheal Cartilage

Epiglottis

LarynxThyrohyoid Membrane

Cricothyroid Ligament

Hyoid Bone

Thyrohyoid ligament

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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.

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Inside the Larynx

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Inside the LarynxCorniculate cartilage

Tongue

Epiglottis

True Vocal Cords

Rima Glottis

Glottis

Cuneiform cartilage

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Glottis: True cords plus openingRima Glottis: The opening

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AirwaysTrachea

Larynx

Carina

Left Mainstem Bronchi

Right Mainstem Bronchi

Secondary Bronchi

Secondary Bronchi

The carina is the last cartilage which separates the entrances to the left and right primary bronchi

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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

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Respiratory Tree

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Branching of Bronchial Tree

Trachea

Primary Bronchi

Secondary Bronchi

Tertiary Bronchi

Bronchioles

Terminal/Respiratory Bronchioles

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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

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LungsRUL

RLL

RML

LUL

LLL

Oblique fissure

Horizontal fissure

Obl

ique

fiss

ure

Car

diac

no

tch

Apex

Base

Hilus

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Lungs: Medial View

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Lung Lobes

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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

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Pleural cavity is in between the two layers

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Mediastinum

• The area between the lungs.

• Posterior to the sternum

• Anterior to the vertebrae

• Contains the heart, great vessels, esophagus and thymus

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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

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Trachea

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Trachea Histology

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Trachea Histology

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Seromucous Glands (Trachea)

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Pseudostratified Columnar Epithelium

Submucosa with seromucous glands

Hyaline Cartilage

Trachea

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Bronchi 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

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Bronchi Histology

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Simple columnar epithelium

Notice the lack of cartilage

Bronchiole Histology

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Bronchioles Respiratory Bronchioles

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

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Respiratory BronchiolesAlveolar Ducts Alveolar sacs

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Alveolar sacs Alveoli

• Alveolar sacs look like clusters of grapes

• The “individual grapes” are Alveoli

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Alveoli Histology

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Type 1 Pneumocytes are flattened for gas exchange

Type II Pneumocytes are cuboidal and produce surfactant

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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

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Respiratory Membrane

The End

• Make sure that you can identify structures on the models

• Identify the structures on microscopes

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