Respiratory system Flashcards
What are the main functions of the respiratory system?
- allow continuous supply of oxygen to cells so they can carry out normal function
- produce sound
- remove waste gas
- sense of smell
- protect airway from harmful substances and pathogens
What are the two ways the respiratory tract can be divided into components?
- the conducting portion (moving air from outside into the lungs) and the respiratory portion (where gas exchange happens)
- upper respiratory tract and lower respiratory tract
What are the main parts of the nasal cavity?
- nasal septum
- vestibule area
- rich blood supply
- turbinates
- paranasal sinuses
What are the parts of the upper respiratory tract?
- nasal cavity
- pharynx
- larynx
What are the features and functions of the vestibule area of the nasal cavity?
Made of skin-like squamous epithelium with coarse hairs to trap larger particles from entering
What cells are above the vestibule in the nasal cavity?
ciliated psuedostratified columnar epithelial cells and goblet cells (mucous)
What is the role of the rich blood supply in the nasal cavity?
Warms the air entering
What is the function of turbinates?
They increase surface area of cavity and cause turbulence. This makes the air twist as it passes through which traps more particles
What are the features and functions of the paranasal sinuses?
- They are air filled cavities in she skull and the bones around the nose which are lined with columnar ciliated epthelium and goblet cells
- They are a source of moisture if nasal cavity becomes dry and are imp for making speech sounds
What is the pharynx lined with?
Ciliated pseudostratified columnar epithelium with goblet cells and mucous glands
What are the three parts of the pharynx?
Nasopharynx, oropharynx, and laryngopharynx
What are the main parts of the larynx?
- lined by ciliated psuedostratified columnar epthelium
- cartilage reinforcement
- epiglottis
- vocal folds
What are the roles of the larynx?
- protect airway by preventing food and liquid from entering pharynx
- generate sounds for speech
What are the parts of the lower respiratory tract?
- trachea
- bronchi
- bronchioles
- terminal bronchioles
- respiratory bronchioles
- lungs
- alveoli
What are the features of the trachea?
- lined by ciliated psuedostratified columnar epithelium with some goblet cells
- stack of 16-20 c-shaped hyaline cartilages around its anterior
- cartilage connected by trachealis muscle which can constrict and dilate
Where does the trachea end?
At the carina bifurcation where it divides into right and left bronchi
What is the order of bronchi branching?
- right and left primary bronchi
- secondary (lobar) bronchi (3 right lung, 2 in left lung)
- bronchioles
What are the features of the primary bronchi?
- cartilage
- layer of smooth muscle
- ciliated psuedostratified epithelial cells and goblet cells in lining
What are the features of the bronchioles?
- smooth muscle
- less cartilage so rely on elastic tissue for support
- simple ciliated columnar epithelium
- clara cells instead of goblet cells
What are the lobes of the right lung?
Superior, middle and inferior
What are the lobes of the left lung?
Superior and inferior
What is the cardiac notch?
The space for the heart in the mediastinal cavity of the left lung
What is the hilum?
Where the pulmonary artery and the pulmonary vein enter and exit the lungs
What are the three pleural membranes in the lower respiratory tract?
- visceral pleura - encases lungs
- parietal pleura - lines the thoracic cavity
- diaphragmic pleura - contacts the diaphragm
Where is pleural fluid found?
In the pleural cavity between the pleural membranes
What are the functions of pleural fluid?
- allows frictionless movement of the lungs inside the thoracic wall
- creates a bond between the layers so that is the thorax expands and moves up, the lungs do the same
What do terminal bronchioles divide into?
respiratory bronchioles
What are the features of respiratory bronchioles?
- smooth muscle
- elastic fibres
- end in alveolar sacs which contain alveoli
What are the features of alveoli?
- thin walls - one squamous epithelial cell on a basement membrane
- extensive blood capillaries
How many alveoli are in each lung?
Approx. 150 million
Define external respiration
The exchange of oxygen and carbon dioxide between the alveoli of the lungs and the pulmonary capillary