Respiratory System

1
Respiratory System

• Chapter 22

2
Respiratory System

• Anatomy of the Respiratory System
• ______________________
• Gas Exchange and Transport
• Respiratory Disorders

3
General AspectsOrgans and Flow

• Nose, pharynx, larynx, trachea, bronchi, lungs
• Airflow in lungs
• _________________________ ________________________
  _
• ________________ division
• passages for airflow, nostrils to bronchioles
• _______________ division
• distal gas-exchange regions, alveoli
• Upper respiratory tract
• __________________________________________________
  __
• Lower respiratory tract
• __________________________

4
Nose

• Functions
• _____________________ _____________________
• detects odors
• __________________________________________
• Bony and cartilaginous supports

5
Nasal Cavity

• From nostrils to posterior nares
• _____________________ dilated chamber
• vibrissae (guard hairs)
• Nasal septum divides cavity
• Right/left chambers called nasal fossae
• Superior, middle and inferior ________________
  (turbinate bones)
• ____________________
• narrow air passage beneath each conchae

6
Nasal Cavity - Mucosa

• Olfactory mucosa
• ______________________________
• Respiratory mucosa
• rest of nasal cavity
• ciliated pseudostratified epithelium
• sweep debris-laden mucus into pharynx
• Defensive role of mucosa
• mucus (goblet cells) traps particles
• ________________________________
• Spontaneous _______________________
• most common site is inferior concha

7
Pharynx

• ______________________ (pseudostratified
  epithelium)
• Posterior, dorsal to soft palate
• auditory tubes and pharyngeal tonsil
• 90? downward turn traps large particles (gt10?m)
• Oropharynx (stratified squamous epithelium)
• between soft palate and root of tongue
• palatine and lingual tonsils
• Laryngopharynx (stratified squamous)
• hyoid bone to level of cricoid cartilage

8
Larynx

• ______________ vocal cords and opening between
• Epiglottis
• flap that covers glottis, directs food/drink to
  esophagus
• Epiglottic cartilage
• ______ cartilage
• Cricoid cartilage

9
Larynx

• 2 folds on each side of wall
• vestibular folds
• superior pair, close glottis during swallowing
• ____________
• produce sound

10
__________

• 4.5 in. long, 2.5 in. diameter
• anterior to esophagus
• 16 to 20 _____________________ ___________________
  _______
• Ring openings face posterior
• Larynx/ trachea lined with ciliated
  pseudostratified epithelium ? ____________________
  _____

11
Bronchial Tree

• ____________ bronchi
• ________________ enter hilum of lungs
• right bronchus slightly wider and more vertical
  (aspiration)
• Secondary (lobar) bronchi (overlapping plates)
• one 2nd bronchus for each lobe of lung
• ___________________ bronchi (overlapping plates)

12
Bronchial Tree

• ____________ (no cartilage)
• smooth muscle
• ________________________________
• portion ventilated by one bronchiole
• divides into 50 - 80 terminal bronchioles
• ciliated end of conducting division
• _________________________________________
• divide into 2-10 alveolar ducts end in alveolar
  sacs
• ________________________________________________
  ________________________________________________
• Alveoli - from respiratory bronchioles, alveolar
  ducts and alveolar sacs
• _________________________

13
Pleurae and Pleural Fluid

• ________________ (on lungs) and
  ________________(lines cavity) pleurae
• Pleural cavity - space between pleurae,
  lubricated with fluid
• Functions
• _________________________________
• _________________________________
• lower pressure assists lung inflation
• compartmentalization
• prevents spread of infection

14
Respiratory Control Centers

• Respiratory nuclei in ____________________
• inspiratory center
• frequent signals, you inhale deeply
• signals of longer duration, breath is prolonged
• ___________________________
• involved in forced expiration
• __________________
• _________________________
• sends continual inhibitory impulses to
  inspiratory center
• breathe faster and shallower
• apneustic center
• prolongs inspiration, breathe slower and deeper

15
Input to Respiratory Centers

• ____________________________________
• respiratory effects of pain and emotion
• airways and lungs
• irritant receptors
• ________________________________________
• stretch receptors
• excessive inflation triggers reflex
• stops inspiration
• __________________________
• monitor blood pH, CO2 and O2 levels

16
Pulmonary Ventilation

• Breathing (________________) one cycle
  inspiration and expiration
• quiet respiration at rest
• forced respiration during exercise
• Flow of air in and out __________________
  _____________________________________

17
Pressure and Flow

• Atmospheric pressure drives respiration
• 1 atmosphere (atm) 760 mmHg
• Intrapulmonary pressure and lung volume
• ________________________________________
• Pressure gradients
• difference between atmospheric and intrapulmonary
  pressure
• ________________________________________

18
Inspiration - Pressure Changes

• ? intrapleural pressure
• volume of thoracic cavity _____,visceral pleura
  clings to parietal pleura
• ? intrapulmonary pressure
• _________________ _________________
• 500 ml of air flows with a quiet breath

19
Expiration

• _______________ breathing
• expiration volume of thoracic cavity ?,
  intrapulmonary pressure ?, air is expelled
• Forced expiration
• _______________ muscles
• depress the ribs
• Contract abdominal muscles
• _____ intra-abdominal pressure forces diaphragm
  upward
• ? pressure on thoracic cavity

20
_____________________

• ______________________________
• loss of negative intrapleural pressure causes
  lungs to collapse
• Collapse of lung (or part of lung) is called
  ____________________

21
Resistance to Airflow

• Pulmonary _________________
• distensibility of lungs
• Bronchiolar diameter
• control over resistance to airflow
• ______________________
• bronchodilation
• sympathetic nerves, epinephrine

22
Alveolar Surface Tension

• film of water needed for gas exchange
• creates ________________ that can collapse
  alveoli
• _______________________ (great alveolar cells)
• decreases surface tension
• Premature infants that lack surfactant suffer
  from _________________________

23
Alveolar Ventilation

• ____________________________
• conducting division of airway
• Physiologic dead space
• sum of anatomic dead space and any pathological
  alveolar dead space
• ____________________________
• air that ventilates alveoli X respiratory rate
• ability to exchange gases

24
Measurements of Ventilation

• Refer to your lab manual

25
Respiratory Volumes and Capacities

• Age - ____________________________________
  _________________________________________
• Exercise - strengthens respiratory muscles
• Body size - ______________________________
• Restrictive disorders
• ? compliance and vital capacity
• Obstructive disorders
• interfere with airflow, expiration requires more
  effort or less complete

26
Composition of Air

• Mixture of gases each contributes its partial
  pressure
• _________________________________________
• nitrogen constitutes 78.6 of the atmosphere so
• PN2 78.6 x 760 mmHg 597 mmHg
• PO2 159
• PH2O 3.7
• PCO2 0.3
• PN2 PO2 PH2O PCO2 760 mmHg

27
Composition of Air

• Partial pressures and gas solubility
• __________________________ _______________________
  ___
• Alveolar air
• humidified, exchanges gases with blood, mixes
  with residual air
• ______________________
• amount of gas that dissolves in water is
  determined by its solubility in water and its
  partial pressure in air

28
Factors Affecting Gas Exchange

• Concentration gradients of gases
• PO2 104 in alveolar air versus 40 in blood
• PCO2 46 in blood arriving versus 40 in alveolar
  air
• Gas solubility
• _________________________
• O2 has ? conc. gradient, CO2 has ? solubility

29
Oxygen Transport

• Concentration in arterial blood
• _______________
• 98.5 bound to hemoglobin
• 1.5 dissolved
• Binding to hemoglobin
• each heme group can bind O2
• _____________________ (HbO2 )
• _____________________ (HHb)

30
Carbon Dioxide Transport

• As carbonic acid - 90
• CO2 H2O ? H2CO3 ? HCO3- H
• As ____________________(HbCO2)- 5 binds to amino
  groups of Hb (and plasma proteins)
• As dissolved gas - ____________

• Alveolar exchange of CO2
• ________________ - 70
• carbaminohemoglobin - 23
• dissolved gas - 7

31
Systemic Gas Exchange

• CO2 loading
• __________________ (RBC)
• CO2 H2O ? H2CO3 ? HCO3- H
• _____________________
• keeps reaction going, exchanges HCO3- for Cl-
• O2 unloading
• H binds to HbO2 releases more O2
• Hb arrives 97 saturated, leaves 75 saturated -
  venous reserve

32
Factors Affecting CO2 Loading

• ______________ effect
• _at_ low HbO2 blood transports more CO2
• HbO2 does not bind CO2 as well as
  deoxyhemoglobin (HHb)
• HHb binds more H than HbO2
• ___________________________________________
• CO2 H2O ? HCO3- H

33
Blood Chemistry and Respiratory Rhythm

• Rate and depth of breathing adjusted to maintain
  levels of
• pH
• PCO2
• PO2

34
Effects of Hydrogen Ions

• _____________ (powerful respiratory stimulus)
• Respiratory ___________ (pH lt 7.35) failure of
  pulmonary ventilation
• hypercapnia PCO2 gt 43 mmHg
• CO2 easily crosses blood-brain barrier
• central chemoreceptors stimulate inspiratory
  center
• blowing off CO2 pushes reaction to the left
  CO2 (expired) H2O ? H2CO3 ? HCO3- H
• so hyperventilation reduces H (reduces acid)

35
Effects of Hydrogen Ions

• Respiratory alkalosis (pH gt 7.45)
• ____________________ PCO2 lt 37 mmHg
• __________________ (? CO2), pushes rxn to the
  right ? CO2 H2O ? H2CO3 ? HCO3- H
• ? H (increases acid), lowers pH to normal
• metabolic causes of pH imbalances
• ______________________________________
• fat oxidation causes ketoacidosis, may be
  compensated for by Kussmaul respiration
• (deep rapid breathing)

36
Hypoxia

• _______________________, PO2 lt 60 mmHg,
  stimulates ventilation
• ___________________________________
• high altitudes after several days
• Causes
• ___________________ - poor pulmonary gas exchange
• high altitudes, drowning, aspiration, respiratory
  arrest, degenerative lung diseases, CO poisoning
• ischemic hypoxia - inadequate circulation
• ___________hypoxia - anemia
• _____________ hypoxia - metabolic poison
  (cyanide)
• Signs cyanosis - blueness of skin
• Primary effect tissue necrosis,
• organs with high metabolic demands
• affected first

37
Oxygen Excess

• _________________ pure O2 breathed at 2.5 atm or
  greater
• generates free radicals and H2O2
• _____________________
• damages nervous tissue
• __________________________
• ________________________
• formerly used to treat premature infants, caused
  retinal damage, discontinued

38
The United States Food and Drug
Administration-approved diagnoses for application
of HBOT are Certain non-healing wounds
(post-surgical or diabetic) Radiation soft
tissue necrosis and radiation osteonecrosis
Necrotizing fasciitis (flesh eating bacteria)
Carbon monoxide poisoning Decompression
sickness Severe infection by anaerobic bacteria
(such as gas gangrene) Air or gas embolism
Severe uncorrected anemia Chronic refractory
Osteomyelitis Enhancement of healing in problem
wounds Sports injuries Used in the 24 Hour Le
Mans race for drivers to attain further sleep in
less time
39
__________________________________(COPD)

• ______________________
• allergen triggers histamine release
• intense bronchoconstriction (blocks air flow)
• Other COPDs usually associated with smoking
• chronic bronchitis
• ______________________________
• Chronic bronchitis
• ________________________________
• goblet cells enlarge, produce excess mucus
• sputum formed (mucus and cellular debris)
• ideal growth media for bacteria
• leads to chronic infection and bronchial
  inflammation

40
Chronic Obstructive Pulmonary Disease

• Emphysema
• ______________________________
• much less respiratory membrane for gas exchange
• ____________________________
• air passages collapse
• obstruct outflow of air
• air trapped in lungs

41
Effects of COPD

• _____________________________________
• Hypoxemia, hypercapnia, respiratory acidosis
• hypoxemia stimulates erythropoietin release and
  leads to polycythemia
• _______________________________
• hypertrophy and potential failure of right heart
  due to obstruction of pulmonary circulation

42
Smoking and Lung Cancer

• Lung cancer accounts for more deaths than any
  other cancer
• most important cause is smoking (15 carcinogens)
• ____________________________ (most common)
• transformation of bronchial epithelium into
  stratified squamous
• cells invade bronchial wall, ?bleeding lesions
• swirls of keratin replace respiratory tissue

43
Lung Cancer

• ________________________
• originates in mucous glands of lamina propria
• __________________________
• _____________, most dangerous
• originates in primary bronchi, invades
  mediastinum, metastasizes quickly

44
Progression of Lung Cancer

• __________________________________
• Tumor invades bronchial wall, compresses airway
  may cause atelectasis
• __________________________________
• Metastasis rapid usually occurs by time of
  diagnosis
• common sites __________________________
  _______________________________________
• Prognosis poor after diagnosis
• _________________________________