1. Respiratory System

2. Respiration Ventilation: Movement of air into & out of lungs
External respiration: Gas exchange b/n air in lungs & blood
Transport of O2 and CO2 in the blood
Internal respiration: Gas exchange b/n the blood & tissues

3. Respiratory System Functions
Gas exchange: O2 enters blood & CO2 leaves
Regulation of blood pH: Altered by changing blood CO2 levels
Voice production: Movement of air past vocal folds makes sound & speech
Olfaction: Smell occurs when airborne molecules drawn into nasal cavity
Protection: Against microorganisms by preventing entry & removing them

4. Respiratory System Divisions
Upper tract
Nose, pharynx & associated structures
Lower tract
Larynx, trachea, bronchi, lungs

5. Nose and Pharynx Nose Pharynx External nose Nasal cavity
Functions
Passageway for air
Cilia cleans the air
Mucous humidifies (moistens air inhaled)
Capillaries warm air
Smell
Along with paranasal sinuses are resonating chambers for speech
Pharynx
Common opening for digestive & respiratory systems
Three regions
Nasopharynx
Oropharynx
Laryngopharynx

6. Larynx Functions Maintain an open passageway for air movement
Epiglottis & vestibular folds prevent swallowed material from moving into larynx (can move to cover trachea)
Vocal folds are primary source of sound production

7. Structure of Larynx AKA voice box Thyroid cartilage: AKA Adam’s apple
Protects vocal cords
Moves when you swallow
Epiglottis: closes off larynx so food & liquid travel down the esophagus

8. Voice Production False vocal cords: assist w/ hold breath
True vocal cords:
Space between them called glottis
Vibration produces sound
In combination with tongue, mouth, & nose to produce words

9. Trachea Insert Fig 23.5 all but b Windpipe Divides to form
C-shaped cartilage with smooth muscle which keeps diameter to allow fluent air flow
Lined with cilia and mucus to moisten and clean air
Divides to form
Primary bronchi
Carina: Cough reflex
Insert Fig 23.5 all but b

10. Organs of Respiration Trachea: AKA windpipe
Smooth muscle supported by C-shaped rings of cartilage
food can travel down esophagus easier
Passageway for air from larynx to bronchi
Lined w/ cilia & mucous

11. Tracheobronchial Tree
Conducting zone
Trachea to terminal bronchioles which is ciliated for removal of debris
Passageway for air movement
Cartilage holds tube system open & smooth muscle controls tube diameter
Respiratory zone
Respiratory bronchioles to alveoli
Site for gas exchange

12. Organs of Respiration Bronchi:
Left & right primary bronchi branch off trachea
Lined w/ cilia
Supported by cartilage

13. Bronchial Tree

14. Terminal bronchiole: the last portion of the nonrespiratory conducting airway, which subdivide into respiratory bronchioles.
Respiratory bronchiole: the final branch of a bronchiole, communicating directly with the alveolar ducts; a subdivision of a terminal bronchiole, it has alveolar outcroppings and itself divides into several alveolar ducts.

15. Bronchioles and Alveoli

16. Alveolus and Respiratory Membrane

17. Lungs Two lungs: Principal organs of respiration
Right lung: Three lobes
Left lung: Two lobes

18. Organs of Respiration Alveoli:
Extremely thin-walled sacs covered w/ capillaries
CO2 & O2 move by diffusion across the respiratory membrane
About 300 million alveoli in two lungs
Size of a tennis court

19. Organs of Respiration Alveoli:
Surfactant lines the alveoli to aid diffusion & decrease surface tension
To prevent the alveoli from collapsing & sticking shut

20. Pleura Pleural fluid produced by pleural membranes Acts as lubricant
Helps hold parietal & visceral pleural membranes together

21. Ventilation Movement of air into and out of lungs
Air moves from area of higher pressure to area of lower pressure (AKA Diffusion)
Pressure is inversely related to volume

22. Inspiration Breathing in
When pressure in the lungs is less than the air pressure in the atmosphere
Diaphragm— will contract and lower, increasing the size of the thoracic cage

23. Inspiration
Increased volume will decrease the pressure & the lungs will expand

24. Expiration Breathing out
When the pressure inside the lungs is greater than the pressure in the atmosphere
Diaphragm— relaxes and rises; decreases the size of the thoracic cage

25. Expiration
Decreased volume will increase pressure & lungs will decrease and push air out

26. Internal Respiration
Exchange of O2 and CO2 between tissue capillaries and tissue cells
CO2 moves from high concentration in cells to low concentration in blood

27. External Respiration
Conversion of deoxygenated blood to oxygenated blood
Aided by thin membranes
Large surface area
Narrow capillaries

28. Changing Alveolar Volume
Lung recoil
Causes alveoli to collapse resulting from
Elastic recoil and surface tension
Surfactant: Reduces tendency of lungs to collapse
Pleural pressure
Negative pressure can cause alveoli to expand
Pneumothorax is an opening between pleural cavity & air that causes a loss of pleural pressure

29. Compliance Measure of the ease with which lungs & thorax expand
The greater the compliance, the easier it is for a change in pressure to cause expansion
A lower-than-normal compliance means the lungs and thorax are harder to expand
Conditions that decrease compliance
Pulmonary fibrosis
Pulmonary edema
Respiratory distress syndrome

30. Pulmonary Volumes Tidal volume Inspiratory reserve volume
Volume of air inspired or expired during a normal inspiration or expiration
Inspiratory reserve volume
Amount of air inspired forcefully after inspiration of normal tidal volume
Expiratory reserve volume
Amount of air forcefully expired after expiration of normal tidal volume
Residual volume
Volume of air remaining in respiratory passages and lungs after the most forceful expiration

31. Pulmonary Capacities Inspiratory capacity Functional residual capacity
Tidal volume plus inspiratory reserve volume
Functional residual capacity
Expiratory reserve volume plus the residual volume
Vital capacity
Sum of inspiratory reserve volume, tidal volume, and expiratory reserve volume
Total lung capacity
Sum of inspiratory and expiratory reserve volumes plus the tidal volume and residual volume

32. Spirometer and Lung Volumes/Capacities

33. Minute and Alveolar Ventilation
Minute ventilation: Total amount of air moved into & out of respiratory system per minute
Respiratory rate or frequency: Number of breaths taken per minute
Anatomic dead space: Part of respiratory system where gas exchange does not take place
Alveolar ventilation: How much air per minute enters the parts of the respiratory system in which gas exchange takes place

34. Physical Principles of Gas Exchange
Partial pressure
The pressure exerted by each type of gas in a mixture
Diffusion of gases through liquids
Concentration of a gas in a liquid is determined by its partial pressure and its solubility coefficient

35. Physical Principles of Gas Exchange
Diffusion of gases through the respiratory membrane
Depends on membrane’s thickness, the diffusion coefficient of gas, surface areas of membrane, partial pressure of gases in alveoli and blood
Relationship between ventilation and pulmonary capillary flow
Increased ventilation or increased pulmonary capillary blood flow increases gas exchange
Physiologic shunt is deoxygenated blood returning from lungs

36. Oxygen & Carbon Dioxide Diffusion Gradients
Moves from alveoli into blood. Blood is almost completely saturated with oxygen when it leaves the capillary
C02 in blood decreases because of mixing with deoxygenated blood
Oxygen moves from tissue capillaries into the tissues
Carbon dioxide
Moves from tissues into tissue capillaries
Moves from pulmonary capillaries into the alveoli

37. Hemoglobin and Oxygen Transport
Oxygen is transported by hemoglobin (98.5%) and is dissolved in plasma (1.5%)

38. Transport of Carbon Dioxide
Carbon dioxide is transported as bicarbonate ions (70%) in combination with blood proteins (23%) and in solution with plasma (7%)

39. Herring-Breuer Reflex
Limits the degree of inspiration and prevents overinflation of the lungs
Infants
Reflex plays a role in regulating basic rhythm of breathing and preventing overinflation of lungs
Adults
Reflex important only when tidal volume large as in exercise

40. Ventilation in Exercise
Ventilation increases abruptly
At onset of exercise
Movement of limbs has strong influence
Learned component
Decreases slightly
Ventilation increases gradually
After immediate increase, gradual increase occurs (4-6 minutes)
Anaerobic threshold is highest level of exercise without causing significant change in blood pH
If exceeded, lactic acid produced by skeletal muscles

41. Disorders Asthma— spasms of smooth muscle in the bronchioles
Lung cancer
Constant irritation produces excess mucous and puts unnecessary stress on the bronchi
Alveoli destroyed by WBC’s acting on the irritation
Structural cells disappear and cancer cells take over

42. Disorders Emphysema— alveolar walls lose their elasticity
Some alveoli merge and reduce volume
Have to work voluntarily to exhale
Bronchitis— inflammation of the bronchi
Creates site for infection and increases mucous

43. Disorders Pneumonia— infection or inflammation of the alveoli
Tuberculosis (TB)— bacterial infection that destroys lung tissue and is replaced by non-elastic connective tissue

44. Disorders Respiratory Distress Syndrome (RDS) Pulmonary Embolism
Lack of surfactant makes breathing difficult
Alveoli are sticking together
Occurs in infants
Pulmonary Embolism
blood clot obstructs circulation to lung tissue & tissue dies

45. Disorders Respiratory Failure Not enough O2 to maintain metabolism
Cannot eliminate enough CO2
Caused by:
Drugs
Stroke
CO poisoning
Shock

46. Disorders Colds and Flu— viral infections
Sudden Infant Death Syndrome (SIDS)
Crib death
Occurs between 1 week and 12 months
Cause is unknown
Baby stops breathing
Lung Caner:

47. Disorders Laryngitis— vocal cords Pharyngitis— sore throat
Rhinitis— lining of the nose

48. Effects of Aging
Vital capacity and maximum minute ventilation decrease
Residual volume and dead space increase
Ability to remove mucus from respiratory passageways decreases
Gas exchange across respiratory membrane is reduced