1. Respiratory System

3. Nose 2 chambers lined with mucosa Divided by a septum
Separated from the oral cavity by the palate
Function:
Contains smell receptors, warms, filters and moistens the incoming air. It receives drainage from the paranasal sinuses and nasolacrimal ducts

4. Pharynx (throat)
Mucosa lined muscular tube, containing tonsils for defense
3 sections:
Nasopharynx- respiration only
Oropharynx- respiration and digestion
Laryngopharynx- respiration and digestion

6. Larynx (voicebox)
A cartilage structure that connects the pharynx with the trachea
The opening is called the glottis and it is covered by a hood called the epiglottis which prevents aspiration of food or drink into the respiratory passages when swallowing
It contains the vocal cords and the prominent thyroid cartilage – the Adam’s Apple

8. Trachea (windpipe)
A smooth tube lined with ciliated mucosa and reinforced with C shaped cartilage rings
Extends from the larynx to the primary bronchi

9. Trachea

10. Primary Bronchi (right & left)
Subdivision of the trachea, plunges into the hilum of the lung

11. Change picture

13. Visceral Pleura- covers the surface of the lungs
Parietal Pleura- lines the thoracic wall
Pleural secretions are between them and decreases friction during breathing

14. Physiology
Gas travels from an area of high pressure to an area of low pressure (diffusion)
Atmospheric pressure is always higher than intrapleural pressure

15. Ventilation is the movement of air into and out of the lungs

16. Alveoli
This is the smallest structures in the lungs where actual gas exchange occurs.
They have very thin walls to allow for diffusion so O2 can get into the blood and CO2 to get out of the blood

17. Inspiration The diaphragm and external intercostals contract 
The superior- inferior volume of the intercostals increases
The lungs increase in volume as they cling to the thorax wall
Results in a partial vacuum
Sucks in air

18. Expiration The diaphragm relaxes and returns to it’s dome shape
The elastic lungs recoil and their volume decreases
Air flows out (passively)

19. Diaphragm

20. Boyle’s Law Pressure varies inversely with volume P1V1 = P2V2
(when temperature is constant)

21. Non respiratory air movements
Voluntary or reflex activities that move air into or out of the lungs:
Coughing, Sneezing- involuntary clearing
Talking, Singing - voluntary
Laughing, Crying
Hiccupping- irritation of the diaphragm or the phrenic nerve
Yawning

22. Normal quiet breathing = about 500 ml of air/ breath
This is referred to as
Tidal Volume (TV)

24. The amount of air that can be taken in forcibly over the tidal inspiration is the Inspiratory Reserve Volume (IRV)

25. The amount of air that can be forcibly exhaled after a tidal expiration is the Expiratory Reserve Volume (ERV)

26. The air that remains in the lungs and cannot be expelled even during strenuous expiration is the Residual Volume (RV)
It keeps the lungs inflated

27. The air that remains in the passages (trachea, bronchi) never reaches the alveoli so there is no exchange. It is called dead space volume and is not part of the total lung capacity

28. VC=TV + IRV + ERV Vital Capacity
The total amount of exchangeable air is the vital capacity=
VC=TV + IRV + ERV

29. External Respiration According to the laws of diffusion Gas transport
Exchange= air to blood or blood to air
Oxygen moves from the alveolar air to the pulmonary blood
Carbon dioxide moves from the pulmonary blood to the alveolar air

31. Internal Respiration Gas exchange at the systemic capillaries
Oxygen unloads from the blood
Carbon dioxide unloads from the tissue

32. Cellular Respiration
Oxygen is used at the cellular level to breakdown sugars to produce energy
Carbon dioxide is produced (waste) from the cellular reaction that breaks down sugar to release energy

33. Control
Nervous system- stretch reflexes in the lungs send a message to the centers in the medulla and pons
Physical factors- body temperature, exercise, speech, yawning, singing
Voluntary control- as long as it does NOT interfere with homeostasis
Emotional- fear, anger, excitement

34. Chemical Factors
Carbon Dioxide levels are the most important stimuli affecting respiration in healthy people
Increase or decrease in the levels of CO2 will affect respiratory timing and depth
It is controlled in the medulla

35. pH
Hyperventilation causes alkalosis (raises blood pH), apnea, and dizziness
Breathing into a paper bag will make you breathe CO2 which adds carbonic acid to the plasma which will bring the blood pH down towards neutral

36. Pathology COPD- Chronic Obstructive Pulmonary Disease Symptoms:
Includes : Emphysema & Chronic Bronchitis
80% associated with smoking or pollution
Symptoms:
Dyspnea- labored or difficult breathing
Hypoventilation- CO2 retention, hypoxia, acidosis
Ultimately respiratory failure

37. Emphysema
Permanent enlargement of the alveoli, with destruction of the alveoli walls. Alveoli lose elasticity.
Hyperinflation of alveoli makes expiration difficult & requires energy for expiration

38. Chronic Bronchitis
Inhaled irritants leads to chronic mucus production  inflammatory response and fibrosis of tissue  impaired ventilation and gas exchange, and increased bacterial infections

39. Asthma Characterized by coughing, wheezing, and chest tightness
Is a reversible obstructive condition- as long as patients use medication and avoid things that bring on an attack
Caused by an immune response (IgE) inflammatory response in the passageways that makes the tissues hypersensitive to any irritants

40. Tuberculosis Infectious, caused by a bacteria spread by coughing
Usually causes fibrous nodules in the lungs
Until the 1930s TB caused 1/3 of all deaths of year olds
1940s antibiotics caused a major decline
1990s antibiotic resistance causes a sharp increase