Chapter 23:The Respiratory System - WordPress.com · Diseased/Disorders 1. Chronic obstructive...

Chapter 23:

The Respiratory

System

Copyright 2009, John Wiley & Sons, Inc.

Respiratory System Anatomy

■ Structurally

❑ Nose, pharynx and associated structures

❑ Larynx, trachea, bronchi and lungs

■ Functionally❑ conducts air to lungs

❑ Gas exchange


Respiratory System Anatomy

■3 anatomical regions

❑ Nasopharynx

❑ Oropharynx

❑ Laryngopharynx


Larynx

■Composed of cartilage❑ Thyroid cartilage or Adam’s apple

■Epiglottis - allows air to the trachea during breathing and food to the esophagus during swallowing.


Larynx

■Ventricular folds (false

vocal cords) - Function

in holding breath.

■Vocal folds (true

vocal cords) - Vibrate

and produce sound

with air


Larynx

■Muscle

contraction pulls

vocal folds into

airway

■Androgens

make folds

thicker and

longer – slower

vibration and

lower pitch


Trachea

❑ Extends from larynx■ Divides into right and

left primary bronchi (leads to the lungs).

❑ C-shaped rings of hyaline cartilage■ Keeps trachea open

(unlike the esophagus).


Location of Trachea


Lungs

❑ Right and left primary bronchus goes to lungs

❑ Mediastinum - tissue in between the lungs

❑ Pleural membrane -encloses each lung.

❑ Pleural fluid - aids in gas exchange


Alveoli

❑ Very thin – only 0.5 µm thick to allow rapid diffusion of gases

❑ Pulmonary artery -deoxygenated blood

❑ Bronchial arteries –oxygenated blood to bronchi and bronchioles


Alveoli

❑ 2 types of alveolar cells

❑ Type I alveolar cells –most common, main site of gas exchange

❑ Type II alveolar cells (septal cells) – secrete alveolar fluid (aka surfactant)


Inhalation

❑Pressure inside alveoli lust become lower than atmospheric pressure for air to flow into lungs

❑Achieved by increasing the size of lungs

❑Inhalation – lungs must expand, increasing lung volume, decreasing pressure below atmospheric pressure


Inhalation

❑Inhalation is caused by contracting the diaphragm and the external intercostals. ❑Diaphragm – most

important muscle of inhalation❑Responsible for 75% of

air entering lungs during normal quiet breathing


Inhalation

❑External intercostals❑Contraction elevates

ribs❑25% of air entering

lungs during normal quiet breathing


Exhalation

❑Pressure in lungs greater

than atmospheric pressure

❑Passive – muscle relax

instead of contract

■ Diaphragm relaxes

■ External intercostals

relax and ribs drop

❑Exhalation only active

during forceful breathing


Oxygen Transport

❑1.5% of O2 is

dissolved in plasma

❑98.5% bound to

hemoglobin in red

blood cells❑ Factors that affect

O2 transport■ Acidity■ PCO2■ Temperature

Carbon Dioxide Transport

❑ 7% of CO2 is dissolved

in blood.

❑ About 23% combines with

hemoglobin

❑ 70% transported in

plasma as HCO3-

Carbon Dioxide + Carbonic Acid → Hydrogen Ions + Bicarbonate

CO2 + H2CO3 → H+ + HCO3

-

Diseased/Disorders

1. Chronic obstructive

pulmonary disease

(COPD) (Both bronchitis

and emphysema)

2. Cystic Fibrosis

3. Asthma

4. Lung cancer

5. Sudden Infant Death

Syndrome (SIDS)

6. Strep throat

7. Diphtheria

8. Influenza

9. Pertussis (Whooping

cough)

10. Tuberculosis

11. Pneumonia

Chapter 23:The Respiratory System - WordPress.com · Diseased/Disorders 1. Chronic obstructive...

Documents

Transcript of Chapter 23:The Respiratory System - WordPress.com · Diseased/Disorders 1. Chronic obstructive...