1. Respiratory system

2. Enduring understanding:
The structure of organs affect their function.

3. Essential Question:
How do we breathe?

4. Functions of respiratory system:
Gas exchange-
oxygen to the blood
carbon dioxide out of the blood

5. organs involved in respiratory system

6. Nose: -external nares = nostrils -nasal cavity
-nasal septum - divides right and left half
-conchae - three lobes - increase surface area
-increase air turbulence
-mucous covered
-trap particles so don't go to
lungs
palate - partition between nasal
and oral cavity
- hard palate - bone
-soft palate - tissue
conchae

7. problem with nose:
-rhinitis - inflammation of nasal mucosa
-cause - cold viruses, allergens
- sinusitis - sinus inflammation
-passageways to sinuses are blocked or infected

8. Pharynx (throat): -passageway for food and air -auditory tubes drain
into nasopharynx
-tonsils located here (immune sys)
-pharyngeal tonsil (adenoid)
-palatine tonsil
-lingual tonsil
problem: tonsillitis - inflammation of tonsils
(remove pharyngeal and palatine tonsils)
pharyngeal tonsil
nasopharynx
oropharynx
laryghgopharynx
palatine tonsil
lingual tonsil

9. Larynx (voice box): glottis -air and food go through
-inferior to pharynx
-thyroid cartilage = Adam's apple
-epiglottis at top
-covers trachea when swallowing
food
-cough reflex
-doesn't work when
unconscious
glottis
vocal folds
looking down from top

10. Trachea (windpipe): -lined with ciliated mucosa -propels mucus
-catches dust particled
-inhibited by smoking
-C rings of hyaline cartilage
-support
-allow food to be swallowed in esophagus
-Heimlich maneuver

11. Tracheostomy - provides alternate route for air if trachea blocked

12. Primary Bronchi: -branches at end of trachea -run obliquely
-right = wider, shorter and straighter, food usually gets lodged here
-air entering this area is warm, cleansed and moist
-goes to smaller
subdivisions

13. Lungs: -paired -in thoracic cavity
-visceral pleura - covering on lungs
-parietal pleura - walls of thoracic cavity
-pleural fluid in between
-Pleurisy = inflammation of pleura
-due to decreased fluid
-painful
- or increased fluid
-creates pressure on lungs
-less painful
ADE-7F5D5E762256%7D/clean_lung_hr.jpg

14. Bronchioles: Alveoli: -smallest branches, farthest from bronchi
-have cartilage in walls
Alveoli:
-air sacs
-site of gas exchange
-millions of these in lungs
-rest of tissue = stroma
-elastic connective
-give "sponginess"

15. SEM of Human lung tissue

16. -surface area of lung tissue of healthy man = 50-70 square meters
-in alveoli - have macrophages that pick up bacteria, carbon particles and debris
-have surfactant = lipid material produced by alveolar cells
-lower surface tension of water lining the cells so that the
alveoli do not collapse between breaths
-premie babies (before weeks) do not make this yet
-called infant respiratory distress syndrome

17. Alveolar membrane

18. Mechanics of breathing:
-"Volume changes lead to pressure changes which lead to flow of gases to equalize pressure"
Inspiration:
-diaphragm and external intercostals contract
-diaphragm moves inferiorly and flattens
-thoracic cavity increases in size
-lungs attached to thoracic cavity stretch
-gases in lungs spread to fill space, decreases gas pressure
-creates a vacuum to suck air in
-when internal pressure = external pressure inspiration stops

19. Expiration:
-depends on elasticity lungs rather than muscles
-inspiratory muscles relax
-ribcage retracts
-lungs recoil
-volume decreases and gas pressure increases above atmospheric
pressure
-gases flow out

21. nonrespiratory movements:
-due to reflexes
1. cough- clears lower passageways
2. sneeze-clears upper respiratory passageways
3. crying-emotion mechanism
4. laughing-emotion mechanism
5. hiccups-spasms of diaphragm, irritation of diaphragm or phrenic nerve
6. yawn-ventilates all alveoli

22. Respiratory volumes:
Normal breathing ~ 500 ml. = tidal volume (TV)
inspiratory reserve volume (IRV) = amount of air taken in forcilby over the tidal volume ~ ml.
expiratory reserve volume (ERV) = amount of air forcibly exhales after tidal volume ~ 1200 ml
residual volume = air left in lungs after ERV blown out
-keeps alveoli inflated
-allows continued gas exchange
vital capacity = total amount of exchangable air = TV + IRV + ERV

23. Dead space volume - air that never reaches alveoli, is in conducting pathways
measure respiratory volumes with respirometer

24. Problems with respiratory system:
1. hypoxia - lack of oxygen to tissues
-bluish tinge to skin
-due to anemia, pulmonary disease or impaired blood
circulation
2. carbon monoxide poisoning
-if present hemoglobin prefers this over oxygen to carry
-due to fires, faulty furnaces
-kills victims quietly, no signs

25. 3. emphysema:
-walls of alveoli break becoming larger and larger chambers
-decreased gas exchange
-fibrosis of tissue
-barrel shaped chest due to overinflation of lungs
4. Bronchitis:
- inflammation of bronchi (mucosa inflamed)
-produce large quantities of mucus
-can lead to pneumonia
5. cystic fibrosis:
-lethal genetic disease (1 in 2400 children)
-faulty CFTR protein - impairs regulation of Cl channels
-oversecretion of thick mucus - clogs passageways
-can lead to infections

26. 7. Asthma:
-chronic inflammation of bronchial passageways
-can be triggered by allegies, stress, exercise
-leads to constriction of airways and increase mucus production
-can cause death if not treated
-symptoms: coughing, wheezing
8. Lung cancer:
-1/3 of all deaths in U.S.
-aggressive, metastasizes quickly
-low survival rate because diagnosed so late
-cause - smoking, exposure to asbestos
-treatment - removal of diseased lung
radiation/chemotherapy

27. nonsmoker smoker