Lecture 3 DA Flashcards
What significant consequence of being out of breath concerns the shoulders?
Typically, one would inadverdantly fix their humerus by very common actions such as crouching slightly an holding your knees, leaning onto a table or getting on your knees with your hands on the floor.
Why is locking ones shoulders so important, especially when one is out of breath?
Locking the humerus reverses the action of several muscles allowing them to raise the thoracic cage to both facilitate breathing and to expand the cavity within.These muscles are the serratus anterior, pectoralis minor and major.
The cartilage of the trachea are C-shaped. What is the muscle that connects two ends of this C, oesophagus-side, and what is its function?
It is known as the trachealis muscle, and its function is to allow the trachea to expand. It also prevents the airway from collapsing with the help of the cartilage.
What covers the trachealis muscle?
Annular ligament of the lung.
What is the cricoid cartilage, and how does it differ from the other tracheal rings?
The cricoid cartilage is also known as the larynx and is the first tracheal ring. Unlinke the other tracheal rings, it is the only one to form a complete ring, whilst all others are incomplete (C-shaped).
At what dermatome does the first bifurcation fo the trachea occur, what does it give rise to, and what bony structure is present in this area?
The first birfurcation occurs at around T4/5, into two main bronchi. This is about the level of the sternal angle.
How do the right and left bronchi differ?
The right bronchus is more direct and divides before entering the right lung (ie. before the hilum). This results in two lobar bronchi being seen in a right lung hilar cross section.The left lung is less direct and curves upward slightly. It enters the left lung before branching (ie. after the hilum). This results in only one main bronchus being seen in a left lung hilar cross section.
Describe what the trachea branches into all the way until the alveoli.
Trachea > main bronchus > lobar bronchus > segmental bronchus > 25 branches later > alveoli
What can be said about how lobar bronchi are directed?
Each lobar bronchi divides into one lobe, 3 for the right lung, two for the left.
How do bronchi differ from bronchioles?
When bronchi lose their carilaginous support (tracheal rings), they are known as bronchioles.
What are respiratory bronchioles?
Bronchioles that open up directly to alveoli.
What happens in the lungs during athsma?
Smooth muscles of the lower airway spasm. As there are no tracheal rings here (bronchioles), they have no cartilaginous support to prevent collapse.Note - Cold air is thought to aggravate athsma (ie. winter)
How are the lobes of the right and left lung named? What are the names of the fissures that seperate each lobe?
Right lung has a superior, middle and inferior lobe.Superior and middle are seperated by the horizontal fissure, while the middle and inferior are seperated by the oblique fissure.Left lung has a superior and inferior lobe only.Superior and inferior are seperated by the oblique fissure.
Where is the apex of the lung, and why is it significant clinically?
It is located at the very superior end of the lung, and is significant because it is poorly protected by the thoracic cage, making it susceptible to injury and lung collapse.
Which lung does the heart occupy more, and what structure results as a consequence of this?
It occupies the left side more, and the cardiac notch is formed as a result.
