Wk 4: Respiratory System Flashcards
Cellular respiration
The process by which cells produce energy by metabolism of organic molecules
Mechanical respiration
Process by which O2 (required for cellular respiration) is absorbed from the atmosphere into the vascular system & CO2 is excreted into the atmosphere
Steps of Mechanical Resp
- Air drawn in via inhalation
- Air cleaned w removal of particular matter
- Air warmed so that temp = that of body
- Air moistened
- In lung tissue, O2 extracted from air & transferred to bloodstream where it binds to haemoglobin & transported in systemic arterial circulation
- At the same time, CO2 (byproduct of cellular metabolic activity) is transfered from blood to air
- After gaseous exchange, air returned to atmosphere via exhalation
What happens to the diaphragm during inspiration
- Diaphragm contracts (moves down)
- Increases thoracic cavity volume - draws in air
What happens to the diaphragm during expiration
- Diaphragm relaxes (moves up)
- Elastic tissue within lungs cause lungs to collapse - expels air
Functions of conducting zone (2)
- Gaseous transport
- Filters, humidifies & warms air
Function of respiratory zone (1)
- Site of gaseous exchange between atmosphere & blood
Functions of upper respiratory system
- Flitration
- Humidification
- Temp regulation
- Olfaction - sense of smell
- Gives resonance to speech & lightens the skull
- Equilibriation of air pressure in middle ear
What kind of epithelium is respiratory epithelium made of
Pseudostratified ciliated columnar epithelium containing goblet cells
What layer underlies the respiratory epithelium & whats it made of
- Lamina Propria
- Loose collagenous layer underlying resp epithelium
What makes up the respiratory mucosa
- Respiratory epithelium
- Lamina propria
Function of the respiratory mucosa in the nasal cavity (2)
- Adjusts temperature & humidity of inspired air
- Filtration
What do goblet cells secrete
Mucous
Structure of trachea
- C shaped rings of hyaline cartilage support tracheal mucosa
- Bands of smooth muscle called trachealis muscle join the free ends of the rings of hyaline cartilage
- Longitudinal muscle is found behind the trachealis muscle
5 types of cells in the respiratory epithelium of the trachea
- tall pseudostratified columnar cells w cilia
- goblet cells
- serous cells
- basal cells
- stem cells - differentiate to replace other cell types
Whats beneath the basement membrane of the trachea (2)
- Lamina Propria - loose vascular supporting tissue
- Submucosa - mixed seromucinous glands
Structure of the respiratory epithelium in primary bronchi
- Pseudostratified epithelium
- Goblet cells
What does the underlying lamina propria contain in the primary bronchi (2)
Underlying LP contains elastin & mast cells
Structure of the respiratory epithelium of tertiary bronchi
- Tall & columnar epithelium - little pseudostratification
- Goblet cells low in number
Structure of the LP in tertiary bronchi
- Thin, elastic & encircled by smooth muscle
Function of LP in tertiary bronchi
Permits contraction of bronchi
What is the respiratory epithelium of bronchioles composed of (3)
- Ciliated columnar cells
- Few goblet cells
- Clara cells
What kind of epithelium in respiratory bronchioles
Ciliated cuboidal cells
3 functions of Clara Cells in respiratory bronchioles
- Produce surfactant
- Act as reserve cells (stem cells)
- Contains enzymes to detoxify substances
Description of type 1 pneumocytes
- Large
- Squamous
Function of type 1 pneumocytes
Part of gaseous diffusion barrier
Description of type 2 pneumocytes
- Round cells
- Capable of division
Function of type 2 pneumocytes
Secrete surfactant - prevents alveolat collapse during expiration
What are the supporting tissues of the alveolar wall
- Reticular fibres
- Collagenous fibres
- Elastic fibres
- Some fibroblasts
