Respiratory System Flashcards
4 functions of nasal cavity
- Warms, cleans and humidifies inspired air
- Serve as resonating chambers for speech
- Sense of smell
- Open airway for ventilation
Structure of nasal cavity and paranasal sinuses
- Epithelium?
- Structures which help warm/humidify air? Where?
- Divided in midline by?
- Projections?
- Lined w/ respiratory mucosa
- blood vessels and seromucous glands beneath respiratory mucosa
- nasal septum
- 3 mucosa-covered projections: superior, middle + inferior terminate
What structures does the pharynx connect?
- Nasal cavity to the oral cavity
2. Larynx and the esophagus
3 regions of the pharynx + their position + their function
- Nasopharynx
- posterior to nasal cavity
- air passage - Oropharynx
- posterior to oral cavity
- passage for food and air - Laryngopharynx
- inferior to the epiglottis
- guides where food and air go to
3 functions of the larynx
- Provides open airway (prevents from collapse)
- conducts air
- Sound/voice production
- Diverts air and food in proper directions
Nose:
- Within which structure?
- Composed of which type of cartilage?
- Function?
- Which makes up the midline?
- Nasal cavity
- soft cartilages (lateral, alar and septal)
- hold nose open, prevent from breaking
- septal cartilage
Describe respiratory mucosa
pseudo-stratified, ciliated, columnar epithelium containing goblet cells.
What is the respiratory system and its main function?
A system of connected organs and structures that function to conduct warm, moist, clean air into close proximity with blood for gas exchange.
Which epithelium type lines most of the URT?
Respiratory mucosa: pseudo-stratified, ciliated, columnar epithelium containing goblet cells
What is the main function of the epiglottis?
Prevents food from going into the airway
Structures of the LRT?
Trachea
Bronchi
Bronchioles
Alveoli
3 functions of the trachea
- Maintain open airway for conduction of air
- Clean, warm and humidify inhaled air
- Cilia form the mucociliary escalator remove debris to the pharynx & redirects to the stomach
Structure of trachea
- Position
- Extends b/w
- Epithelium
- Structures w/in submucosa
- Composition
- Anterior to esophagus
- Rigid tubular structure from larynx to primary bronchus
- Lined w/ respiratory mucosa and seromucous glands in the submucosa
- C-shaped rings of cartilage; smooth muscle posteriorly
Describe the bronchial tree and it’s levels.
Include pulmonary + bronchial circulation.
- tubular structures w/ rings of cartilage to prevent collapse
- Levels:
1. Trachea (Lined w/ respiratory mucosa and seromucous glands)
2. Primary bronchi (Lined w/ respiratory mucosa and seromucous glands)
3. Secondary (lobar) bronchi (Lined w/ respiratory mucosa and seromucous glands)
4. Tertiary (segmental) bronchi (Lined w/ respiratory mucosa and seromucous glands)
5. Bronchioles (lack cartilage and submucosal glands; goblet cells start to disappear) - branch to form alveolar ducts and terminate in alveolar sacs
6. Alveoli (flattened pneumocystis)
Pulmonary circulation supplies deoxygenated blood
Bronchial circulation perfuses the lung tissue w/ oxygenated blood from the systemic circulation.
How many lobes and fissures do each of the right and left lung have?
Right:
3 lobes, 2 fissures
Left:
2 lobes, 1 fissure
What are the surface cells of alveoli? What are their structure?
- Type I pneumocytes: squamous
- Type II pneumocytes: cuboidal (surfactant-secreting; reduces surface tension)
What 2 features of alveoli make them efficient at exchanging gases w/ blood?
- Thin membrane
- Close proximity to blood
What are the structures w/in the thoracic cavity?
Sternum
Vertebrae
Ribs
Diaphragm
What are the two types of joints in the thoracic cavity and where are they found?
- Synovial
- (Most) sternocostal joints (b/w hyaline cartilage and sternum)
- Interchondral joint (b/w hyaline cartilage of false ribs)
- Costotransverse and costovertebral joints (b/w thoracic vertebrae and ribs; bi-lateral articulations) - Cartilaginous
- 1 sternocostal joint (first one - attached to clavicle)
- Costochondral (b/w ribs and hyaline cartilage)
What are the muscles of respiration?
- Function?
- Diaphragm
- Increases thoracic cavity length (lowers thoracic floor) which increases vol. –> increases size
- Main muscle involved in inspiration
- Skeletal muscle; contracts during inspiration
- Phrenic nerve innervation - Intercostal muscles
- Increases tc diameter & thus vol. –> size
- Backup/used when necessary
- Two layers of muscle:
a) External intercostals; inspiration; drctn of muscle fibres down and medial
b) Internal intercostals; forced expiration; drctn of muscle fibres down and lateral - Accessory muscles
- Used during forced breathing
- e.g. abdominal muscles
What is pleura?
Where are the two pleurae found?
How does one of them aid in respiration?
What is the function of pleural/serous fluid?
- Serous membranes lining the thoracic cavity which secrete serous/pleural fluid into the pleural cavity
- Visceral pleura covers the lungs
- Parietal pleura lines the thoracic wall & mediastinum; since it is fixed there, thoracic expansion allows the lungs to expand further
- Allows low-friction movement of the lungs, decreases surface tension and adhesion
Is inspiration and/or expiration passive and/or active? Why?
- Inspiration is active; uses muscles to expand thoracic cavity
- Expiration is passive; cartilage and elastin tissue recoil after inspiration
8 functions of the respiratory system?
- Provide O2
- Eliminate CO2
- Filter, warm and humidify inspired air
- Communication
- Sense of smell
- Regulates the pH of the blood
- Microbial defence
- Thermoregulation
What is Dalton’s law (partial pressure)?
What is total pressure for atmospheric air?
Partial pressure (gas) = Fraction of individual gas x total gas pressure ~760mmHg (= barometric pressure)
What is needed for air flow into/out of the lungs?
Pressure gradient (caused by change in vol.); air moves from high to low
What is the intrapleural space?
Function?
- Lung has tendency to recoil inwards, chest wall tends to expand outwards –> gap formed
- Helps lungs stay larger/expanded
What pressure is what prevents the lungs from collapsing?
Transpulmonary pressure
Function of nasal sinuses?
- Sound resonance
- Lighten skull
- Warm air
- Drain mucus