Lp 52 Flashcards
-supplies O2 to body cells via CV system
-removes CO2 (prevent acidosis)
Respiratory system
Respiration involves 4 processes
- pulmonary ventilation: breathing
- external respiration: O2-lungs to blood & CO2-blood to lungs
- Transport of respiratory gases: O2 & CO2
- Internal respiration:
-O2-blood to tissues
-CO2-from tissues to blood
-O2 diffusion- lung membranes into pulmonary capillaries
-in tissues: O2 released from Hb & RBCs- diffuses into cells
-6 min w/out O2= irreversible brain damage
-bv’s carry deoxygenated blood to lungs
-oxygenated blood to heart
Pulmonary circulation
-blood supply via bronchial aa
-drained by bronchial vv
Lung tissue
Innervation to lungs
-parasympathetic fibs (bronchoconstriction)
-sympathetic (bronchodilation)
-visceral sense fibers
Respiratory system divided into
-URT= head and throat
-LRT= thorax
Major function of URT
-clear passageway for inhaled air
-filter & condition inhaled air
URT include
-nose
-pharynx
-larynx
-trachea
Flexible cartilaginous structure covering glottis during eating
Epiglottis
Double layered serous membrane
Pleura
-heavily branched
-end in thin sacs
-1* divisions:
~bronchi (1,2 & 3*)
~bronchioles
Bronchial tree
Bronchial tree has 2 zones
-conducting
-respiratory: respiratory bronchioles & alveoli
Breathing (pulmonary ventilation)- 2 stages
-inhalation (inspiration): active
-exhalation (expiration): passive unless forced
Mm of inspiration
-diaphragm
-external intercostal mm
Accessory mm facilitate forced inspiration (help elevate ribs further)
-scalenes
-SCM
-pec minor
Is expiration mainly passive or non passive
Passive
Is forced expiration passive or active
Active; requires contraction of oblique & transverse abdominal mm
Other mm that may aid forced expiration
-internal intercostals
-OL (depress rib cage)
Described relative to local atmospheric pressure
-neg, respiratory P indicates that it is < P atm
Respiratory P
Visual pleura
On lung surface
Parietal pleura
On thoracic wall & diaphragm
-recoil of lung tissue: elasticity leads to tendency for lungs to stay as mall as possible
-surface tension of alveolar fluid: alveolar walls drawn down toward one another d/t fluid lining them
Deflation
Elasticity of the chest wall pulls thorax outward, enlarging lungs
Inflation
Factors influencing breathing
Airway resistance
Alveolar surface tension
Lung compliance
2 Ps keep lungs inflated
- Intrapulmonary (P pull): P exerted by air in alveoli
- Intrapleural (P ip): P exerted w/in pleural cavity & fluctuates w/breathing, but always ~4mm Hg less than P pull
