Chap 21 – Respiratory

System

Learning Objectives (Part 1):

1. Know the entire structures (and their associated functions) in the respiratory system.

2. Be able to explain common diseases of the respiratory system including causes, symptoms, etc. (such as rhinitis, sinusitis, laryngitis, pneumonia, tuberculosis, lung cancer, etc.)

Brainstorming

What are some of the deadliest lung diseases?

Lung Cancer Kills Dana Reeves… Dead at 44

March 8, 2006 - 2:19PM

Did years of singing in smoky nightclubs kill Dana Reeve, the widow of paralysed Superman actor Christopher Reeve? She died yesterday of lung cancer even though she was not a smoker.

"Ten to 15 per cent of people who develop lung cancer are thought to be non-smokers. It was said that she had, in the course of being an entertainer, spent a lot of time in pubs, in nightclubs, in which there is a lot of cigarette smoke," said Dr James Mulshine from Rush University Medical Centre in Chicago.

In the US more women die of lung cancer than breast cancer, and one in five American women diagnosed with the disease have never lit a cigarette. "We know that 90 per cent of lung cancer is linked to direct smoking, the other 10 per cent is tied to occupational exposures, radon and secondhand smoke," said Pat McKone, a senior director of tobacco control with the American Lung Association.

"Dana Reeve was not a smoker, but she did spend many years of her singing career in smoke filled nightclubs.

Her death comes amid a worldwide debate on the danger of passive smoking and attempts to ban smoking from bars, clubs and eateries.

Lung Cancer

• Accounts for 1/3 of all cancer deaths in the U.S.• 90% of all patients with lung cancer were

smokers• The three most common types are:

– Squamous cell carcinoma (20-40% of cases) arises in bronchial epithelium

– Adenocarcinoma (25-35% of cases) originates in peripheral lung area

– Small cell carcinoma (20-25% of cases) contains lymphocyte-like cells that originate in the primary bronchi and subsequently metastasize

Tuberculosis• Infectious disease caused by the bacterium

Mycobacterium tuberculosis • Symptoms include fever, night sweats, weight

loss, a racking cough, and splitting headache• Treatment entails a 12-month course of

antibiotics• For more on drug resistant TB:

http://www.cdc.gov/tb/pubs/tbfactsheets/mdrtb.htm

Pneumonia

Lungs fill with watery mucous secretions from invasion of bacteria (or virus)

Some strains of pneumonia are very serious and do not respond well to antibiotics

Chronic Obstructive Pulmonary Disease (COPD)

• Exemplified by chronic bronchitis and obstructive emphysema

• Patients have a history of:– Smoking– Dyspnea, where labored

breathing occurs and gets progressively worse

– Coughing and frequent pulmonary infections

• COPD victims develop respiratory failure accompanied by hypoxemia & carbon dioxide retention

Introduction: Functions of the Respiratory System

• Transport of O2 and CO2 between lungs & tissuesTo supply the body with oxygen and dispose of carbon dioxide

Respiration – four distinct processes must happen:

Pulmonary ventilation – moving air into and out of the lungsExternal respiration – gas exchange between the lungs and the bloodTransport – transport of oxygen and carbon dioxide between the lungs and tissuesInternal respiration – gas exchange between systemic blood vessels and tissues

A Closer Look at the General Anatomy – Major Respiratory Organs

Label your practice diagram.

http://www.airwaycam.com/flash/fpsinterview.aspx

What Are The Structures of the Respiratory System & What Do They Do?

Instructions: Working individually, match the structure with the function. Write the letter of the answer. Refer to page 736.

1. Alveoli a. connects trachea to alveoli

2. Trachea b. vital organs that house smallest passageways

3. Larynx c. site of gas exchange

4. Pleurae d. cleans, warms, and moistens incoming air

5. Nose e. passageway for air & food

6. Lungs f. area of voice production

7. Pharynx g. houses smell receptors

8. Bronchial h. produce lubricating fluid & compartmentalize lungs

tree

Functions of the Nose

• The only externally visible part of the respiratory system that functions by:– Providing an airway for respiration– Moistening and warming the entering air– Filtering inspired air and cleaning it of foreign

matter– Serving as a resonating chamber for speech– Housing the olfactory receptors

Nose continued

• The nose is divided into two regions– The external nose, including the root, bridge,

dorsum nasi, and apex – The internal nasal cavity

• Philtrum – a shallow vertical groove inferior to the apex

• The external nares (nostrils) are bounded laterally by the alae

External NoseStudents: You don’t have to know this anatomy. Just reference.

Nasal Cavity

• Lies in and posterior to the external nose

• Is divided by a midline nasal septum

• Opens posteriorly into the nasal pharynx via internal nares

• The ethmoid and sphenoid bones form the roof

• The floor is formed by the hard and soft palates

Nasal Cavity continued

Respiratory mucosa – Lines the balance of the nasal cavity – Glands secrete mucus containing lysozyme and defensins to

help destroy bacteria

Vestibule – nasal cavity superior to the nares – Vibrissae – hairs that filter coarse particles from inspired air

Olfactory mucosa– Lines the superior nasal cavity – Contains smell receptors

Nasal Cavity continuedLabel your practice diagram.

Nasal Cavity continuedLabel your practice diagram.

Part II – Respiratory System

Learning Objectives (part II):3. Discuss the 3 regions of the pharynx.4. Explain the 3 layers of the trachea as well

as the other major anatomical features.5. Explain the special anatomy (types of

hyaline cartilage) as well as other featured of the larynx.

6. Be able to identify & describe vocal cord anatomy & function.

Pharynx

• Funnel-shaped tube of skeletal muscle that connects to the:– Nasal cavity and mouth superiorly– Larynx and esophagus inferiorly

• Extends from the base of the skull to the level of the sixth cervical vertebra

• It is divided into three regions– Nasopharynx – strictly an air

passageway; closes during swallowing to prevent food from entering the nasal cavity

– Oropharynx - Extends inferiorly from the level of the soft palate to the epiglottis; common passageway for food and air

– Laryngopharynx - Serves as a common passageway for food and air; lies posterior to the upright epiglottis; extends to the larynx, where the respiratory and digestive pathways diverge

Trachea

• Flexible and mobile tube extending from the larynx into the mediastinum

• Composed of three layers– Mucosa – made up of goblet cells and ciliated

epithelium – Submucosa – connective tissue deep to the

mucosa– Adventitia – outermost layer made of C-

shaped rings of hyaline cartilage

Trachea continued Label your practice diagram.

Larynx (Voice Box)

• Attaches to the hyoid bone and opens into the laryngopharynx superiorly

• Continuous with the trachea posteriorly

• The three functions of the larynx are:– To provide a patent airway– To act as a switching mechanism to route air

and food into the proper channels– To function in voice production

Larynx continued

• Cartilages (hyaline) of the larynx– Shield-shaped anterosuperior thyroid cartilage

with a midline laryngeal prominence (Adam’s apple)

– Signet ring–shaped anteroinferior cricoid cartilage

– Three pairs of small arytenoid, cuneiform, and corniculate cartilages

• Epiglottis – elastic cartilage that covers the laryngeal inlet during swallowing

Framework of the LarynxLabel your practice diagram.

Vocal Cords

• http://www.voicedoctor.net/media/video/index.html

Diagnosis LaryngitisWe know the familiar symptoms…

hoarseness, loss of vocal abilities, etc.

Maybe you talked too much or screamed for your favorite team…

What is really going on?