1. Functions of Respiratory System
Ventilation - moves air to and from alveoli
Gas exchange between air and circulating blood
Defend respiratory system from pathogens
Help homeostasis of:
blood volume, pH, and pressure
Permit vocal communication

2. Respiration Ventilation- environment and lungs
External Respiration – alveoli and blood
Internal respiration – Blood and cells
Cellular Respiration – Biochemical inside cell

3. Respiratory organs Respiratory organs Divided into:
Nose, nasal cavity, and paranasal sinuses
Pharynx, larynx, and trachea
Bronchi and smaller branches
Lungs and alveoli
Divided into:
upper
lower

4. External nares

5. Upper respiratory system
Nose
Nasal cavity
Pharynx
Functions
Warm, Filter and Humidify
incoming air
Lower Respiratory System
Larynx
Trachea
Bronchi
Bronchioles
Alveoli

6. The Nose Provides an airway for respiration Moistens and warms air
Filters inhaled air
Houses olfactory receptors

8. PARANASAL SINUSES

9. Respiratory Epithelium.
Lines conducting portions
Pseudostratified ciliated columnar epithelium with goblet cells PSCC
Produces mucus to trap foreign particles

10. Respiratory Epithelium.

11. cilia rhythmically ‘sweeps’ debris up to be swallowed or expelled at pharynx
Mucus escalator
Alveolar macrophage
Hairs in nose
Cilia - lining respiratory tract

12. External nares
Open into nasal cavity
Vestibule guarded by hairs
Nasal cavity
Superior, middle and inferior meatuses
Narrow grooves and concha surfaces
Hard palate
Nasal and oral cavities
Soft palate
Superior nasopharynx and pharynx
Internal nares
Between nasal cavity and nasopharynx

13. The Pharynx Shared by digestive and respiratory systems Nasopharynx
Superior portion: from internal nares to uvula.
Oropharynx
Continuous with oral cavity
Laryngopharynx
Between hyoid and entrance to esophagus

14. Nasopharynx Superior to the point where food enters
Only an air passageway
Closed off during swallowing
Pharyngeal tonsil (adenoids)
Located on posterior wall
Destroys entering pathogens
Contains the opening to the auditory tube

15. Oropharynx Extends from soft palate to the epiglottis
Epithelium is stratified squamous epithelium
Two tonsils in the oropharynx
Palatine tonsils – in the lateral walls
Lingual tonsils – covers the posterior surface of the tongue

16. Laryngopharynx Passageway for both food and air
Lined with stratified squamous epithelium
Continuous with the esophagus and larynx

17. The Lower Respiratory System
Surrounds glottis - air passes through glottis to reach lungs
Epiglottis - prevents solids from entering respiratory system
Larynx

18. During swallowing, elevation of the larynx folds epiglottis over the glottis, steering materials into the esophagus.

19. Trachea Submucosa includes “C” rings of cartilage Tracheal cartilages
Stiffen tracheal walls and protect airway
Posterior wall distorts allowing food passage through esophagus

22. Left and Right 1o Bronchi
Right and left primary bronchi
Trachea branches within mediastinum
Bronchial tree
Enters lungs at hilus
Root of lung
Bronchus, primary vessels, nerves
Bronchial tree – extensively branching respiratory passageways
Primary bronchi (main bronchi) – largest bronchi
Right main bronchi – wider and shorter than the left

23. Lungs Right lung has three lobes Left lung has two lobes
Superior lobar, middle lobar and inferior lobar bronchi
Left lung has two lobes
Superior lobar and inferior lobar bronchi
Cardiac notch

26. Secondary (lobar) bronchi
Three on the right
Two on the left
Tertiary (segmental) bronchi
Branch into each lung segment
Bronchioles – little bronchi, less than 1 mm in diameter
Terminal bronchioles – less than 0.5 mm in diameter

28. Bronchi and Bronchioles

29. For clarity, the degree of branching has been reduced: an airway branches approximately 23 times before reaching the level of a lobule.

30. Fig
24.11

34. Alveolus – cells and composition
Simple squamous epithelium (type I)
Septal cells (type II)
Produce surfactant
Alveolar macrophages (dust cells)
Patrol epithelium
Engulf foreign particles

35. Basic structure of a lobule,
cut to reveal the arrangement
between the alveolar ducts
and alveoli.

36. Respiratory Membrane Respiratory Membrane (blood-air Barrier)
“point of gas exchange”
 Alveolar Epithelium simple squamous epithelia
Fused basement membrane
Capillary endothelium simple squamous epithelia

37. Respiratory Epithelium
Air epithelia tissue
Nasal cavity stratified squamous
Nasopharynx PSCC
Oropharynx stratified squamous
Laryngopharynx stratified squamous
Larynx PSCC
Trachea PSCC
Rt./Lt. primary bronchi PSCC
Secondary (lobar) bronchi PSCC
Tertiary (segmental) bronchi PSCC
Terminal bronchioles simple cuboidal
Respiratory bronchioles simple cuboidal
Alveolar duct simple squamous
Alveolar sac simple squamous
Alveolus simple squamous

38. Ep=pscc
Subm=tunica submucosa
Cart=tracheal ring
Adv=tunica adventitia (externa)

39. Respiratory Muscles
Ventilation - movement of air into and out of lungs.

40. Eupnea - normal quite
breathing at rest.
Inspiration:
 volume of
thoracic cavity.
Muscle activity required:
Diaphragm
External Intercostals
Sternocleidomastoid

41. When Forcefully
exhaling (hypereupnea):
Muscles used:
Internal Intercostals
Rectus abdominis
Transverse abdominis,
Internal and External
obliques.

42. Bronchial asthma – a type of allergic inflammation
A hypersensitivity to irritants in the air or to stress
Asthma attacks characterized by:
Contraction of bronchiole smooth muscle
Secretion of mucus in airways
Chronic obstructive pulmonary disease (COPD)
Airflow into and out of the lungs is difficult
Obstructive emphysema
Chronic bronchitis
History of smoking

43. Cystic fibrosis (CF) – inherited disease
Exocrine gland function is disrupted
Respiratory system affected by:
Over secretion of viscous mucus
Epistaxis – nosebleed
Epiglottitis – inflammation and swelling of the epiglottis
Dyspnea – difficulty in breathing
Apnea – cessation of breathing