Anatomy of Respiratory System Flashcards
What is the function of the respiratory system?
- Gas exchange 2. Speech 3. Smell
What are the 2 functional divisions of the respiratory system?
- Conducting portion 2. Respiratory portion
What is function of conducting portion?
- Transports air from external environment to structures where gas exchange occurs - Conditions air (warms, moistens, filters)
What does the nasal cavity open out into?
Paranasal sinuses
Where does the conducting portion start and finish?
Nasal cavity to terminal bronchi
What are the paranasal sinuses? How many of the are there?
Group of 4 paired air-filled spaces that surround the nasal cavity. Help to warm, moisten and filter the air.
What are the 4 paranasal sinuses?
- Maxillary sinuses
- Frontal sinuses
- Ethmoidal sinuses
- Sphenoidal sinuses
Where are the maxillary sinuses located?
Under the eyes (inferior)
Where are the frontal sinuses located?
Above the eyes (superior)
Where are the ethmoidal sinuses located?
Between the eyes (middle)
Where are the sphenoidal sinues located?
Behind the eyes (midline)
What is the pharnyx?
The body cavity that connects the nasal cavity and oral cavities with the larynx and oesphagus (route of inspired air)
What is the pharynx divided into?
- Nasopharynx –> superior
- Oropharynx –> middle
- Laryngopharnyx –> inferior
Projecting out of the lateral walls of the nasal cavity are curved shelves of bone. What are these called and how many are there?
Conchae. 3 - inferior, middle and superior
What is the function of the conchae?
- Project into the nasal cavity, creating 4 pathways for the air to flow –> produces turbulent flow of air allowing it to enter the sinuses for conditioning
- Increases surface area of nasal cavity which increases the amount of inspired air that comes into contact with the cavity walls
- Disrupt the fast, laminar flow of air, making it slow and turbulent –> air spends longer in nasal cavity so can be humidified
What are the pathways created by the conchae?
- Inferior meatus –> between the inferior concha and floor of the nasal cavity
- Middle meatus –> between the inferior and middle concha
- Superior meatus –> between the middle and superior concha
- Spheno-ethmoidal recess –> superiorly and posteriorly to the superior concha
Where do the paranasal sinuses drain into?
The nasal cavity
What is the nasolacrimal duct?
Drains excess tears from the eyes to the nose (why your nose runs when you cry). Opens into the inferior meatus.
Where do the intercostal muscles lie? What are the 3 types of intercostal muscles?
In the space between the ribs.
- External
- Internal
- Innermost
What is function of the external intercostals?
Move ribs up and out during inhalation and increase lateral and anterior-posterior diamteter of the thorax (expands chest cavity)
They run inferoanteriorly from rib above to rib below
What is function of internal intercostals?
Responsible for forced exhalation. Depress the ribs and decrease space in the chest cavity.
Run inferoposteriorly from rib above to rib below (opposite direction to external)
What is function of innermost intercostals?
Reduces thoracic volume by depressing ribcage.
Deepest of the intercostal muscles.
How many pairs of ribs are there? What are they divided into?
12 pairs of ribs
- Upper 7 pairs are ‘true’ ribs as attached to sternum
- Lower 5 pairs are ‘false’ ribs as don’t directly attach to sternum
The upper 3 false ribs connect to the costal cartilage of the ribs just above them.
The last 2 ribs have no ventral attachment –> ‘floating’ ribs
What is costal cartilage?
Segements of cartilage that connect the sternum to the ribs and help extend the ribs into a forward motion.
What is the costal margin?
The lower edge of the rib cage running from 7th to 10th rib
Formed by the joined costal cartilages of ribs 7-10. This forms the anterolateral boundary of the inferior throracic aperture.
How does the left and right lung differ?
Right:
- Short, broad, larger
- Has 3 lobes
- Oblique and horizonal fissure
Left:
- Tall, narrow
- Has 2 lobes (due to presence of heart)
- Oblique fissure
N.B. lobes are separated by oblique fissure
What does the trachea branch into? What does this then continue to branch into?
- Trachea branches into 2 primary bronchi (left and right)
- Primary bronchi enter the lung and divide to form lobar (secondary) bronchi (one supplying each lobe)
- Each lobar bronchus then further divides into several segmental (tertiary) bronchi (functional units of the lungs)
- These eventually lead into terminal bronchioles
What is job of pulmonary arteries/veins?
Carry deoxygenated blood from the right ventricle to the lungs for reoxygenation.
Carry oxygenated blood from the lungs to the left atrium of the heart.