Structure of the airway and lungs Flashcards
Aidan
What are the structures in the respiratory tract?
- Nose, nasal cavity and sinuses.
- Nasopharynx and soft palate.
- Larynx.
- Trachea.
- Bronchi and bronchial tree.
- Lungs and pleura.
- Thoracic wall.
- Diaphragm.
What is respiration?
Providing oxygen to the body and removing carbon dioxide through inhalation and exhalation.
Is the air in the lungs of atmospheric composition or not?
The air in the lungs is not of atmospheric composition and may even change between different areas of the lung
What must air that is brought into the lungs be?
Must be warmed, filtered and humidified.
What structures warm, filter and humidify inhaled air?
Vascular, mucosa, cilia, mucus.
What are the conductive passages of the respiratory system?
Nasal cavity; nasopharynx; larynx; trachea; bronchi.
How is air sucked down the conductive passages and into the lungs?
By creating negative intra-thoracic pressure.
What happens in the body during inhalation?
Contraction (and lowering) of the diaphragm and raising the ribs
Why does inhaling expend energy?
It expends energy as you are contracting muscles.
Why is air in the lungs not of atmospheric composition?
Mainly due to gas exchange.
How is exhalation achieved?
By decreasing the size of the thorax, this is generally a passive process. (Almost no energy expended).
What is the name of the external structure that encloses the nasal cavities?
The nose.
How is the nasal cavity entered?
Via the nares.
What holds the nasal cavities open?
Bone and cartilage.
What is the start of the respiratory tract?
The nasal cavities.
What are the nasal cavities lined with?
A highly vascularised mucosal membrane lined with respiratory epithelium.
How would you describe respiratory epithelium?
Psuedostratified, ciliated, columnar and interspersed with goblet cells.
Are the cells that line the nasal cavity, respiratory tract and mouth one and the same?
No, the cells in the nasal cavity are different from the ones in the rest of the respiratory tract and mouth.
What is the nasal septum?
A midline structure which separates the left and right nasal cavities.
Describe the structure of the septum.
Anteriorly the septum is made of septal cartilage, while posteriorly the septum is made of bone.
What could be a problem that occurs if the septum deviated from the midline?
Sinus drainage may be compromised.
What structure forms the medial boundary of the nasal cavities?
The nasal septum.
What structure forms the floor boundary of the nasal cavities?
The hard and soft palates.
What structure forms the roof boundary of the nasal cavities?
Bone. (ethmoid, frontonasal, sphenoid).
What structure forms the lateral boundary of the nasal cavities?
The nasal conchae.
Which palate is posterior and anterior in the nasal cavity?
The hard palate is anterior and the soft palate is posterior.
What position is the floor of the nasal cavity in?
Horizontal. (Due to placement of the nasogastric tube).
Where is incoming air prepared to enter the lungs? (i.e. filtered, warmed etc.).
It is acclimatised in the nasal cavity.
Where are the nasal conchae located?
They are located on the lateral wall of the nasal cavity.
What are the names of the three conchae?
Superior, middle and inferior.
What do the nasal conchae do?
Provide turbulence and increase the surface areas for airflow and heat exchange.
Which of the meati allow access to the maxillary sinus?
The middle meatus.
What is positioned under each concha in the nasal cavity?
An empty space called a meatus.
Where do air sinuses open into?
They open up into their adjacent meatus
What is the space above the superior concha called?
The Spheno-ethmoidal recess.
What are the structures of the nasal cavity?
- Septum.
- Lateral walls with conchae.
- Meati
- The airway
What are the purpose of the sinuses?
They are empty spaces structurally so they reduce the weight of the skull, they also increase the space in which you can warm air in.
Why is the clearance of mucus in the maxillary sinus dependant on ciliary action?
As the opening is high in its medial wall.
What can happen if ciliary action is compromised by infection?
The mucus in the maxillary sinus cannot be cleared and can possibly lead to sinusitis.
What else may predispose you to sinusitis?
A deviated septum.
What is the problem with the space between the septum and the conchae in the nasal cavity?
It is quite narrow so if inflammation or increased production of mucus occurs it can cause pressure and pain.
Where does the nasolacrimal duct enter and what does it do?
The nasolacrimal duct enters the nasal cavity to drain tears from the conjuctunctiva of the eye.
What are the four main sinuses in the cranium?
- Frontal sinus.
- Ethmoidal (air cells).
- Maxillary Sinus.
- Sphenoidal sinus.
Is the nasal cavity mucosa high vascularised or not highly vascularised?
It is highly vascularised.
What is notable about the vessels in the nasal cavities vascular mucosa?
The vessels anastamose between branches of the external carotids and internal carotids (both left and right).
Why are the nasal cavities vessels so easy to rupture?
They are close to the surface.
Where are the olfactory nerves located?
As the olfactory bulb in the roof (and upper parts of lateral wall) of the nasal cavity.
What is the pharynx?
It is a tube of fibrous and muscular tissue that can be divided into three parts.