Respiratory System Flashcards
Function of respiratory system
Gas exchange Regulates blood pH Contains receptors for sense of smell Filters inspired air Produces sounds Rids body of some water & heat in exhaled air
Cooperates with the cardiovascular system to supply O2 & eliminate CO2
Respiration
- Brings in oxygen and ridding body of carbon dioxide
- Nose filters the dust and microbes, from entering the system
- Voice production (voice box houses vibrations on strings, as air moves up and down. Mouth & tongue allows speech).
- pH regulation: by eliminating carbon dioxide. CO2 changes the hydrogen-ion concentration of your blood. CO2 can combine with H2O to become H2CO3 (carbonic acid, unstable so immediately decomposes into ions. Extra H+ will lower your pH. The lower the pH the greater acidity it has)
- Smell , receptors in the upper nose, ‘olfaction’ is a sense of smell.
- thermo regulation through lungs expelling air
Upper Respiratory System
Nose
Pharynx = throat
Lower Respiratory System
Larynx = voicebox / vocal chords (continues as a pipe, carrying air to the trachea).
Trachea = windpipe (one single pipe)
Bronchi = airways
Lungs (Two lungs so tranchea splits into two tubes - called Bronchi (singular is brochus)
Conducting zone – series of interconnecting cavities & tubes
Nose, pharynx, larynx, trachea, bronchi, bronchioles & terminal bronchioles
Respiratory zone – tissues where gas exchange occurs between air & blood
Respiratory bronchioles, alveolar ducts, alveolar sacs & alveoli
pharynx
throat
larynx
voicebox / vocal chords
trachea (windpipe)
- Tubular passageway for air
- 12cm long & 2.5cm in diameter
- Extends from larynx to T5
- Located anterior to oesophagus
- At T5 level splits into left & right primary bronchi
- Composed of 4 layers
bronchi
airways
alveoli
lungs
Trachea (windpipe) layers
Four layers:
- Mucosa: pseudostratified columnar with cilia & goblet
- Submucosa: loose connective tissue & mucous glands
- Hyaline cartilage: 16 to 20 incomplete rings (C-shaped). Open side facing esophagus contains trachealis muscle (smooth). Internal ridge on last ring called carina
- Adventitia - binds it to other organs
The Bronchial Tree
- Primary bronchi supply each lung
- Secondary (lobar) bronchi supply each lobe of the lungs (3 right + 2 left)
- Tertiary (segmental) bronchi supply each bronchopulmonary segment
- The smallest bronchioles branch into even smaller branches called terminal bronchioles
- Repeated branchings called bronchioles form a bronchial tree
What cells are the bronchi made of?
Bronchi is made of pseudostratified ciliated columnar
What are the epithelial tissue changes in the bronchial tree?
Epithelial tissue changes in the bronchial tree:
- Larger bronchioles = ciliated simple columnar with goblet cells
- Smaller bronchioles = ciliated simple cuboidal with no goblet cells
- Terminal bronchioles = nonciliated simple cuboidal - in these regions inhaled particles are removed by macrophages
Visceral pleura
The visceral pleura covers lungs
Parietal pleura
The parietal pleura lines ribcage & covers upper surface of diaphragm
Where is the pleural cavity?
Pleural cavity in between parietal pleura and the visceral pleura. The pleura cavity reduces friction between the two as there is a fluid present (which can increase / decrease in amount, which can affect breathing (asthma). Pleural effusion
Alveoli of the Lung
Alveoli of the lung
- Cup-shaped outpouchings surrounding alveolar ducts
- Lined by simple squamous epithelium & supported by thin elastic basement membrane
- Two or more alveoli make up alveolar sacs
Cells Types of the Alveoli
- Type I alveolar cells: simple squamous cells where gas exchange occurs.
- Type II alveolar cells (septal cells): free surface has microvilli, secretes alveolar fluid containing surfactant.
- Alveolar dust cells: wandering macrophages remove debris