1. Respiratory System

2. Respiratory Tract
Conducting passageways carrying air to and from the alveoli
Upper respiratory
Nasal Cavity
Larynx
Pharynx
Lower passageways
Trachea
Lungs
Bronchi
Bronchioles
Alveoli
Diaphragm
Pathway
nasal cavities (or oral cavity) → pharynx → trachea → primary bronchi (right & left) → secondary bronchi → tertiary bronchi → bronchioles → alveoli

3. Nasal Cavity/Nose Functions Selected anatomical features
Provides an airway for respiration
Moistens and warms entering air
Filters and cleans inspired air
Resonating chamber for speech
Detects odors in the airstream
Selected anatomical features
Vibrissae (guard hairs) – stiff hairs that filter large particles from the air
Nasal cilia – hair-like projections that propel trapped particles towards the throat for digestion by digestive enzymes
Rich supply of capillaries warm the inspired air
Nasal conchae – folds in the mucous membrane that increase air turbulence and ensures that most air contacts the mucous membranes
Olfactory mucosa – mucous membranes that contain smell receptors
Respiratory mucosa – pseudostratified ciliated columnar epithelium containing goblet cells that secrete mucus
Mucus
Stickiness traps inhaled particles
Lysozyme kills bacteria
Lymphocytes and IgA antibodies protect against bacteria

4. Respiratory Mucosa

5. Upper Respiratory

6. Paranasal Sinuses

7. Pharynx Three regions of the pharynx
Nasopharynx – air passage (pseudostratified columnar epithelium)
Oropharynx – passageway for air, food, and drink (stratified squamous epithelium)
Laryngopharynx – passageway for air, food, and drink (stratified squamous epithelium)

8. Larynx Functions 1. Keeps food and drink out of the airway
2. Sound production
3. Acts as a sphincter during abdominal straining (ex. during defecation and heavy lifting)

9. Larynx Selected anatomical features
Nine c-rings of hyaline cartilage form the framework of the larynx
Muscular walls aid in voice production and the swallowing reflex
Glottis – the superior opening of the larynx
Epiglottis – prevents food and drink from entering airway when swallowing
False vocal cords – aid in closing the glottis when swallowing
True vocal cords – produce sound when air passes between them
The shorter and thinner these membranes are, the faster air moves over them – produces high pitched sounds
The longer and thicker these membranes are, the slower air moves over them – produces low pitched sounds

10. Glottis

11. Trachea Functions Air passageway
2. Cleans, warms, and moistens incoming air
3. Selected anatomical features
Rings of hyaline cartilage – reinforce the trachea and keep it from collapsing when you inhale
Ciliated pseudostratified epithelium – traps inhaled debris and propels mucus up to the pharynx where it is swallowed

14. Lung Anatomy

16. Function - Solely an air passageway
Selected anatomical features
1. Left and right primary bronchi branch off from trachea
2. Once the left and right primary bronchi enter the lungs they are subdivided into smaller tubes:
Secondary bronchi (one for each lobe) → tertiary bronchi → bronchioles → terminal bronchioles → respiratory bronchioles → alveolar ducts → alveolar sacs
3. Alveolar sacs are clusters of alveoli
4. Alveoli are the site of gas exchange
5. Other tissue types present in the alveoli
a. Smooth muscle rings aid in resistance to air flow
b. Elastic connective tissue fibers aid in expelling air from the lungs

17. Anatomy of Bronchi

21. Pulmonary arteriogram
Lung bronchiogram

22. Respiratory Physiology
Diaphragm contracts - increase thoracic cavity vl -
Pressure decreases - causes air to rush into lungs
Diaphragm relaxes - decrease thoracic cavity vl -
Pressure increases – forces air out of lungs

23. Inspiration

24. Expiration

25. Patterns of Breathing
Apnea – temporary cessation of breathing (one or more skipped breaths)
Dyspnea – labored, gasping breathing; shortness of breath
Eupnea – Normal, relaxed, quiet breathing
Hyperpnea – increased rate and depth of breathing in response to exercise, pain, or other conditions
Hyperventilation – increased pulmonary ventilation in excess of metabolic demand
Hypoventilation – reduced pulmonary ventilation
Orthopnea – Dyspnea that occurs when a person is lying down
Respiratory arrest – permanent cessation of breathing
Tachypnea – accelerated respiration

26. Clinical Disorders and Diseases of the Respiratory System
Hypoxia – deficiency of oxygen in a tissue or the inability to use oxygen
Oxygen toxicity – excess oxygen, causing the build up of peroxides and free radicals
Chronic obstructive pulmonary diseases (COPD) – long-term obstruction of airflow and a substantial reduction in pulmonary ventilation
Chronic bronchitis – cilia are immobilized and reduced in number; goblet cells increase their production of mucus → mucus clogs the airways and breeds infection
Emphysema – alveolar walls break down and the surface area of the lungs is reduced
Asthma – allergens trigger the release of histamine and other inflammatory chemicals that cause intense bronchoconstriction. In asthma, periodic constriction of the bronchi and bronchioles makes it more difficult to breathe in and, especially, out. Attacks of asthma can be triggered by airborne irritants such as chemical fumes and cigarette smoke airborne particles to which the patient is allergic.
Lung cancer –most common cancer and most common cause of cancer deaths in U.S. males. There are several forms of lung cancer, but the most common (and most rapidly increasing) types are those involving the epithelial cells lining the bronchi and bronchioles. Ordinarily, the lining of these airways consists of two layers of cells. Chronic exposure to irritants causes the number of layers to increase. The ciliated and mucus-secreting cells disappear and are replaced by a disorganized mass of cells with abnormal nuclei. If the process continues, the growing mass penetrates the underlying basement membrane. Malignant cells can break away and be carried in lymph and blood to other parts of the body where they may lodge and continue to proliferate. It is this metastasis of the primary tumor that eventually kills the patient.

27. Clinical Disorders and Diseases of the Respiratory System
Acute rhinitis – the common cold
Laryngitis – inflammation of the vocal folds
Pneumonia – lower respiratory infection of the alveoli that causes fluid build up in the lungs. It can be caused by many kinds of both bacteria (Streptococcus pneumoniae) and viruses. Tissue fluids accumulate in the alveoli reducing the surface area exposed to air. If enough alveoli are affected, the patient may need supplemental oxygen.
Sleep apnea – Cessation of breathing for 10 seconds or longer during sleep
Tuberculosis – pulmonary infection with Mycobacterium tuberculosis; reduces lung compliance
Pleuritis - Inflammation of the pleura, producing more than the normal amount of fluid, causing a pleural effusion. The pain fibers of the lung are located in the pleura. When this tissue becomes inflamed, it results in a sharp pain in the chest that is worse with breathing in. Other symptoms of pleurisy can include cough, chest tenderness, and shortness of breath.
Cystic fibrosis - caused by inheriting two defective CFTR genes, a transmembrane protein needed for the transport of Cl− ions out of the epithelial cells of the lung thus enabling water to follow by osmosis. Diminished CFTR function reduces the water content of the fluid in the lungs making it more viscous and difficult for the ciliated cells to move it up out of the lungs. The accumulation of mucus plugs the airways interfering with breathing and causing a persistent cough. Cystic fibrosis is the most common inherited disease in the U.S. white population.