1. Chapter 13 Respiratory System
Anatomy and Physiology

2. 13.1 Respiratory functional anatomy
The organs of the respiratory system include the nose, pharynx, larynx, trachea, bronchi and the lungs

4. 13.1 Respiratory functional anatomy
The nose is the only externally visible part of the respiratory system
When breathing air enters through the external nares (nostrils) and enters the nasal cavity (which is divided by the septum)
The nasal cavity is lined with mucosa, and also the olfactory receptors are located there
The palate separates the nasal and oral cavities
The bone supported anterior section is called the hard palate and the unsupported posterior section is called the soft palate

5. 13.1 Respiratory functional anatomy
The nasal cavity is surrounded by paranasal sinuses
They function to lighten the skull, allow for resonance of speech and they produce mucus, which drains into the nasal cavities
Pharynx
A muscular passageway for food and air that is about 5 inches long
Commonly called the throat
It extends from the nasal cavity
There are three regional divisions; nasopharynx, oropharynx and laryngopharynx
There are tonsils found in this region, called the pharyngeal tonsils or adenoids (they are found in other places too)

7. 13.1 Respiratory functional anatomy
Larynx
This is the voice box
Formed by 8 rigid hyaline cartilages (the largest called the thyroid cartilage, also called the Adam’s apple) and a spoon shaped flap of elastic cartilage called the epiglottis
The epiglottis protects the superior opening of the larynx when we are swallowing
The vocal cords are formed by mucus membranes, the passageways between the folds is called the glottis

8. 13.1 Respiratory functional anatomy
Trachea
It is about 4 inches long and is fairly rigid due to the C shaped hyaline cartilage
The C are open in the back, where the esophagus abuts the trachea, allowing the esophagus to expand as we swallow food
It is lined with ciliated mucosa
Main bronchi
The right and left bronchi are branches off the trachea
Air at this point is clean, moist and warm

9. 13.1 Respiratory functional anatomy

10. 13.1 Respiratory functional anatomy
Lungs
They are large organs that occupy most of the thoracic cavity, except the mediastinum, where the heart is located
The apex is the superior, top portion of the lungs
The base of each lung rests on the diaphragm
Each lung is covered by a membrane called the pulmonary or visceral pleura
The thoracic cavity itself is lined with a membrane called the parietal pleura
The two membranes have a slippery fluid between them that cuts down on friction called pleural fluid

12. 13.1 Respiratory functional anatomy
The bronchi continue to branch as they go inside the lung tissue
The smallest airways, called bronchioles do not have reinforcing cartilage, all the other bronchi do
Each bronchiole ends in an alveoli; or cluster of air sacs
The respiratory zone includes the end of the a bronchiole and the alveoli
All the other bronchi are considered conducting zone structures
The respiratory membrane is the air-blood barrier and it consists of the capillary walls fused to the alveolar membrane; carbon dioxide and oxygen are passed between the air and blood by diffusion

14. 13.2 Respiratory Physiology
Four events take place to accomplish the intake of oxygen and the disposal of carbon dioxide; collectively they are called respiration
1. Pulmonary Ventilation: also called breathing; is the movement of air in and out of the lungs
2. External respiration: occurs as gases (CO2 and O2) are exchanged between the pulmonary blood and the alveoli
3. Respiratory gas transport: the movement of the gases through the blood stream
4. Internal respiration: exchange of gases between the blood in capillaries and tissue cells

15. 13.2 Respiratory Physiology
Mechanics of Breathing
Basically volume changes lead to pressure changes which lead to the flow of gases to equalize pressure
There are two phases to breathing; inspiration and expiration

16. 13.2 Respiratory Physiology
Inspiration occurs when the external intercostal muscles between the ribs contract along with the diaphragm to increase the volume of the thoracic cavity
This increase in volume causes a decrease in pressure which means air rushes into the lungs (God’s design is so amazing!!!)

17. 13.2 Respiratory Physiology
Expiration occurs because the ribs and diaphragm relax, decreasing volume which increases pressure, causing air to flow out. It is a passive process in healthy people

20. 13.2 Respiratory Physiology
Nonrespiratory Air Movements
1. Cough
Sneeze
Crying
Laughing
Hiccups
Yawn
All are explained on page 437

23. 13.2 Respiratory Physiology
Control of Respiration
The neural centers that control respiratory rhythm and depth are located in the medulla and pons
The medulla sets the basic rhythm of breathing, while the pons appears to smooth out that rhythm
The normal respiratory rate is referred to as eupnea

25. 13.2 Respiratory Physiology
Factors that influence respiratory rate and depth
1. Physical factors: talking, coughing, exercising, etc
2. Volition: (conscious control)we control our breathing for swimming, singing, etc, but we can only control it so much. If you hold your breath long enough, the involuntary controls take over
3. Emotional factors: watching horror movies, etc
4. chemical factors: mostly the levels of CO2 and O2

26. 13.3 Respiratory Disorders
COPD: Chronic Obstructive Pulmonary Disease
 is a progressive disease that makes it hard to breathe
In COPD, less air flows in and out of the airways because of one or more of the following:
The airways and air sacs lose their elastic quality.
The walls between many of the air sacs are destroyed.
The walls of the airways become thick and inflamed.
The airways make more mucus than usual, which can clog them.

27. 13.3 Respiratory Disorders

28. 13.3 Respiratory Disorders
Chronic bronchitis
is a serious long-term disorder that often requires regular medical treatment.
Chronic bronchitis is one of two main types of a COPD. The other main form of COPD is emphysema. Both forms of COPD make it difficult to breathe.

30. 13.3 Respiratory Disorders
Emphysema
Emphysema is a long-term, progressive disease of the lungs that primarily causes shortness of breath due to over-inflation of the alveoli
 In people with emphysema, the lung tissue is impaired or destroyed