1. Part 1 – The Upper Respiratory Tract
RESPIRATORY SYSTEM
Part 1 – The Upper Respiratory Tract

2. Primary Functions Gas Exchange (oxygen and CO2) Voice Production
Olfaction - Sense of smell
Control blood pH (using CO2)

3. Gas Exchange – Main Steps
Move air into lungs
External respiration – exchange O2 & CO2 with blood and air
Move gases through blood flow
Internal respiration – exchange O2 & CO2 with body cells and blood

4. Main Players Upper Tract: Lower Tract: Nose Nasal Cavity Pharynx
Larynx
Trachea
Bronchial Tubes
Lungs
alveoli

5. The Nose Nasal Cavity – hollow space behind nose
Warms Air
Filters Air
Divided into two nostrils by nasal septum
The inside of your nose is lined with mucosa that produces sticky mucus
Nose Job…

6. ParanasalSinuses Spaces within the facial bones
Makes the skull lighter
Helps with speech
Produces mucus
The bones…
Maxillary
Frontal
Ethmoid
sphenoid

7. Nasal Conchae
The conchae increase surface area so more air is filtered and warmed
The filtered particles (dust, etc.) are swallowed

8. Rhinitis Rhinitis is excessive mucus production caused by…
Cold viruses
allergens
Sinusitis or sinus infection can lead to temporary changes in your voice and headaches called sinus headaches

9. Pharynx The common passage way for food and air
The tonsils are located here

10. Larynx Just below the pharynx The top of the trachea
Contains the vocal cords
Protected by muscles and cartilage. Also called…the Adam’s Apple
See Steve Tyler Video Clip

11. Glottis – triangular slit that opens during breathing/talking, and closes during swallowing 
Epiglottis – flaplike structure that stands upright, allows air to enter larynx, during swallowing it presses downward and prevents food from entering air passages

13. The Respiratory System
Part 2 – Lower Tract

14. The Big Picture

15. The Main Players: Trachea > Primary bronchi--> bronchioles --> alveolar ducts -->  alveoli                                                                        

16. Alveoli & Lungs

17. ALVEOLI

18. The Trachea About 10 cm or 4” in length Is also called the “windpipe”
Is reinforced by C-shaped cartilaginous rings that prevent the trachea from collapsing during each breath
Is lined with pseudostratified ciliated columnar epi

19. Primary Bronchi
The trachea has a “fork in the road” and splits to become the right & left main or primary bronchi
The right primary bronchus is wider, shorter, and bit straighter than the left – food can get caught here if inhaled

20. LUNGS - spongy tissue that sit within the pleural cavity

21. Serous fluid lubricates lungs during breathing
Right Lung          = 3 lobes
Left Lung           = 2 lobes
Serous fluid lubricates lungs during breathing
Apex
Base

22. Bronchi to Alveoli
The main bronchi subdivide into smaller and smaller tubes eventually entering the smallest tubes called bronchioles
Terminal bronchiole lead into respiratory bronchioles that lead into the blind air sacs called alveoli

23. Gas Exchange Respiratory Zone: the only site of exchange of O2 and CO2
The area where you find the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli
All the other passages are called conducting zones

24. The Respiratory Membrane
This membrane is the alveolar and capillary walls
The walls of the alveoli are a single layer of squamous epi cells – so thin that gas exchange is by simple diffusion
Most of your lungs are made up of this membrane
Alveolar macrophages, white blood cells that “sweep” up dust and foreign invaders
You also have cuboidal cells that produce a fat called a surfactant that keeps the membrane moist to facilitate diffusion

25. Breathing Mechanics Breathing is a completely mechanical process
It works by changing the volume and thus the pressure of the thoracic cavity
There are two phases in breathing: inspiration, air flowing in and expiration, air flowing out

27. 1.  Diaphragm moves down, forcing air into airways
2.  Intercostals contract, enlarging cavity even more
3.  Membranes move with the contractions
4.  Surface tension in alveoli and surfactant keep them from collapsing
5.  Other muscles (pectoralis minor and sternocleidomastoid) can force a deeper breath
6.  The first breath in newborns is the hardest due to low surfactant

28. ATMOSPHERIC PRESSURE = 760 Hg
Pressure is necessary for breathing, which is why it is difficult to breathe in high altitudes and also why a punctured lung can be dangerous.
A hole in the pleural cavity can cause the lung to collapse or deflate

29. EXHALATION
As the diaphragm and other muscles relax, ELASTIC RECOIL from surface tension forces air out.  
Muscles can force extra air out or in

30. NON-RESPIRATORY MOVEMENTS
Coughing, sneezing, laughing, crying
Hiccup - spasm of the diaphragm
Yawn - possibly causes by low oxygen levels

32. Also check out this procedure where  fluid is drained from the lungs - not for those with a weak stomach!

33. The Respiratory System
Part 3: Respiratory Volumes to Control of Respiration

34. Respiratory Air Volumes
Spirometry - measures the amount (volume) of air moving in and out of the lungs
Respiratory Cycle - 1 inspiration and 1 expiration

35. Measured by Spirometry:
Tidal Volume (TV)  -  amount of air that enters the lungs during one cycle during a normal breath
Expiratory Reserve Volume (ERV) – air that can be exhaled after a normal exhalation
Inspiratory Reserve Volume (IRV) – the amount of air that can be inhaled after a normal inhalation
Using a spirometer

36. Human lung size is determined by genetics, gender, and height
Maximum capacity of an average lung is around 6 liters of air – though your lungs rarely operate at maximum capacity
Air in the lungs is measured in terms of lung volumes and lung capacities
Volume measures the amount of air for function (like TV) and capacity is any two or more volumes
Ex., Vital Capacity (ERV + TV + IRV), Inspiratory capacity (TV + IRV), Functional Residual Capacity (ERV + RV), and total lung capacity (RV + ERV + TV + IRV)
Residual Volume (RV) is a lung volume of the amount of air left in the lungs after a forced exhalation – it can’t be measured, only calculated

37. Capacities

38. Normal Lung Capacities

39. Image adapted from http://www.arthursclipart.org/

41. (based in the medulla and the pons)
Breathing is involuntary, but muscles are under voluntary control
Respiratory Center – groups of neurons in the brain that control inspiration and expiration
(based in the medulla and the pons)

42. Medulla Rhythmicity Area
  Dorsal Respiratory Group       (rhythm)
   Ventral Respiratory Group       (forced)
Pneumotaxic Area (pons) - inhibit 

43. Factors Affecting Breathing
*Chemosensitive areas – detect concentrations of chemicals like carbon dioxide and hydrogen
1. Rise in CO2 2. Low blood oxygen (peripheral chemoreceptors, carotid and aortic bodies, sense changes) 3. Inflation reflex – regulates the depth of breathing, prevents overinflation of the lungs 4. Emotional upset, fear and pain

44. Hyperventilation - increase breathing, lower CO2 concentration
Breathing into a bag can restore CO2 concentrations

45. Hypoxia is a disease in which there is an overall lack of oxygen content within the body's tissue and vital human organs (specifically the brain).
Hypoxia has several potential causes, including: cardiac arrest, severe head trauma, carbon monoxide poisoning, suffocation, strangulation, and choking, as well as any instance in which oxygen supply is deprived from the body.
Asphyxia is a condition of severely deficient supply of oxygen to the body that arises from being unable to breathe normally.
An example of asphyxia is choking. Asphyxia causes generalized hypoxia, which primarily affects the tissues and organs.

46. ILLNESSES RELATED TO THE RESPIRATORY SYSTEM
1. Cystic Fibrosis (genetic) 2. Asthma 3. Bronchitis 4. Apnea 5. Emphysema 6. Lung Cancer 7. Altitude Sickness 8. Chronic Obstructive Pulmonary Disease (COPD) 9. Sinusitis 10. Bacterial or Viral Infections (cold, flu, pneumonia)