Respiratory system anatomy Flashcards
What is the pathway of air from the nose to the alveoli?
nose, nasal passage, pharynx, larynx, trachea, primary bronchi, secondary bronchi, segmental bronchi and alveoli
What are alveoli?
Lined with simple squamous epithelium and involved in gaseous exchange
What is included in the upper airways?
Nasal cavities, nasopharynx, laryngopharynx and larynx
Describe the shape and structure of the nasal cavities
- Triangular, medial and inferior walls are smooth but lateral wall has hair
- Mucosa covers three scroll-like plates of bones called the conchae (middle, inferior and superior)
- Has a complex and important vascular and nerve supply
What happens to air inside the nasal cavities?
It is warmed and humidified so that the lower respiratory tract doesn’t get dried out or cold
During expiration, what happens to the temperature of the expired air?
The air is cooled as the nasal cavity was cooled during inhalation. Water is also retained from the air via condensation.
Why does the nasal cavity have resistance?
The hair and mucus causes resistance and enables the particles to be trapped.
What is the importance of nasal resistance during exercise?
More oxygen is needed whilst exercising and due to resistance, air must be taken in through the mouth
What is the other role of the nasal cavity?
It is important for sense of smell - olfactory tract has epithelium with specialized nerve supply
How many paranasal sinuses are there?
4
Where are the paranasal sinuses and where are they located?
Maxillary sinus - around nose
Frontal sinus - above medial end of eyebrow
Ethmoid sinus - corner of eye
Sphenoid sinus - behind eye (from anterior view appears on bridge of nose)
Why is the maxillary sinus prone to
The drainage area is near where the sinus opening is so not all the fluid is drained hence hard to clear infection
What are the roles of the sinuses?
Reducing weight of facial bones, insulation (from temperature changes and for brain), resonator of sound, and protection during trauma
How are the larynx, trachea and bronchi kept open?
Plates or cartilage
How are the nasal cavities and pharynx opened?
They are attached to bone
How are the alveoli and bronchioles kept open?
Phospholipid causes surface tension
What are the three parts of the pharynx?
Nasopharynx, oropharynx and laryngopharynx
Where is the nasopharynx?
Behind the nasal cavity
Where is the oropharynx?
Behind the tongue and has tonsils
Where is the laryngopharynx?
Behind larynx where water and food coexist
What is the larynx located?
Superior and posterior to thyroid, superior to trachea
What is the role of the larynx?
To allow sound to be varied
What is the arytenoid cartilage?
It is attached to vocal ligaments which control entry into the larynx. They allow the vocal cords to move
What is the structure of the trachea?
C shaped cartilage, around 20. Anterior surface has epithelium and posterior has muscle (for swallowing),
C shape opening on posterior side
At which vertebral level does the trachea bifurcate?
T4 (sternal angle)
What happens to the amount of cartilage as the bronchi branch more?
It decreases and amount of smooth muscle increases
What is the blood-air barrier?
The barrier between the capillary and alveoli - it prevents air bubbles from forming and also stops any blood getting into the lungs.
How does oxygen get from alveoli into blood?
Diffusion down the pressure gradient - pO2 - 100 in alveoli and 40 in blood
What is the diaphragm attached to?
Costal margin
Which two muscles are involved in breathing?
Diaphragm and intercostal muscles
What does expansion of pleural cavities lead to?
Drop in pleural pressure
During inhalation, which part of the pleural cavity is occupied which is normally empty?
The costo-diaphragmatic recess (the diaphragm normally is domed up)
Which motor nerve innervates the diaphragm, and which vertebral levels is it from?
Phrenic nerve
C3,4 and 5
Which part of the larynx allows air into it?
The epiglottis (flap)
What are the nasal conchae?
bone in the nasal cavities- increase SA for air to be warm and moisturized
What is the Adam’s Apple?
Caused by the thryoid cartilage - angle where the two sides meet.
