L5 Flashcards
Five activities of respiratory system
- Pulmonary ventilation: movement of air in and out the lungs
- External gas exchange: absorb oxygen from alveolar air & remove co2 from blood into alveolar air
- Gas transport
- Internal gas exchange: transfer oxygen from blood to cell
- Cellular respiration
Airway characteristics
Lined by pseudostratified, ciliated epithelium.
Epithelial membrane warmth and moisturise the inhaled air
Mucus can trap particular object
Ciliate can move particulate-laden mucus move to pharynx 痰
Upper respiratory system
Lower respiratory system
Upper respiratory system
Nose, nasal cavity, paranasal sinus, pharynx
Lower respiratory system
Larynx, trachea, bronchi, lungs
Nose external / internal
Open divided by a midline
Composed of cartilage, bone and fibrous tissue
Hair inside can trap small particles
Internal: anterior is bony, posterior is soft palate
Mucosal area create turbulence to warmth the inhaled air
Paranasal sinus
Hollow, warmth air, sound resonance
Pharynx+ larynx
Larynx is 5 cm tube consist of cartilage & skeletal muscle
Function. Air conduction
Diverse food into oesophagus, air into trachea
Phonation
Cough reflex
Trachea
Flexible tube 12*2cm
Anterior to neck
Divided into left and right bronchi
3 layers
1. Respiratory mucous membrane
2. 16-20 c shape rings of tracheal cartilage
3. Outer fibrous tissue
Bronchi tree
Primary-) secondary -) tertiary bronchi-) bronchioles -) alveolar duct in respiratory zone
Bronchioles no c shape cartilage
Alveoli
Tiny air sacs in the respiratory zone
Type 1: flat squamous cell
Type 2: secretee surfactant to keep alveoli open
Secrete antimicrobial protein to avoid infection
Gas exchange of alveoli
20% free exchange, 80% bind with rbc
Lung
Cone shaped, round apex
Right side larger
Right 3 lobes left 2
Cover by
Visceral pleura (inside)
Parietal pleura (outside)
Pleural cavity -) interstitial space filled with liquid
Lung’s blood supply & nervous control
Pulmonary artery
Bronchial arteries
Pulmonary vein
Bronchial vein
Nerve
Sympathetic (relax bronchial smooth muscle)
Parasympathetic (maintain in a slightly constricted state)
Muscles used in ventilation ( inhalation / exhalation)
Diaphragm
External intercostal muscle
Scalene of neck
Exhale: anterior muscle of abdominal wall
Internal intercostal muscle
Inspiration steps
- Inhalation
- Rib intercostal muscle expand
- Diaphram pulled downward
- Air flow into lung cpacity due to reduced pressure
Exhalation
- Interior intercostal muscle contract
- Diaphragm relax and return to place
- Lung capacity reduced and pressure increased
- Air flow of lung through nasal cavity
Factors affecting ventilation
Strength of diaphragm and related muscle
Strength of airway
Strength of lung to expand and return
Compliance of lung
Ventilation amount terms
Tidal volume: amount of oxygen in and out
Anatomical deadspace: amount of air trapped in conducting zone when no gaseous exchange happening
Inspiratory reserve volume: extra air that can be inhaled
Expiratory reserve volume: extra volume of air that can be forcefully exhaled.
Residual volume: amount that cannot be exhaled
Inspiratory capacity: amount of air could breathe in after entire inhale process
Function residual capacity
Expiratory reserve volume + residual volume
Vital capacity: total amount of air can forcefully breathe in & out
Tidal volume+ IRV + ERV
Total volume:
Vital capacity + residual volume
Forced exhale volume
Max 1 sec exhale volume
Haemoglobin saturation factors
Partial pressure of oxygen-) up then up
Partial pressure of co2 -) up then down
Acidity -) up then down
Temperature-) up then down
80-90% carbon dioxide bind to oxygen as bicarbonate
Roles of lungs in acid-base balance
Lung remove co2 when exhalation to maintain homeostasis of pH
Acidosis vs alkalosis
Acidosis: lung cannot remove enough co2
Acidic cause ventilation failure
Alkalosis
Cause hyperventilation: heart attack, pain
Control of respiration
Usually 12rr/min
Consciously: required cereBral cortex to commanding voluntary muscle
Unconsciously:
Disease related to respiratory system
Nasopharyngeal cancer
Nosebleed, trouble hearing
Oropharyngeal cancer
Affect swallowing, mouth & tongue movement
Asthma
Difficult breathing
Pneumonia
Cause by bacteria
High fever
