Lecture 16: Anatomy of the Thorax and Breathing Flashcards
What lines our body’s cavities?
serous membranes
What are serous membranes?
double layer of secretory tissue with fluid between the layers
What are the two layers of serous membranes and where are they?
- visceral layer on the organ
- parietal layer on the body wall
What are the two serous membranes in the thoracic cavity?
pericardium
pleura
What is the mediastinum?
where the heart, pericardium and major vessels are found
Inside the pleural cavities there are the
lungs
What bones indicate the boundaries of the thoracic cavity?
- anterior
- posterior
- inferior
- superior
- lateral
- anterior: sternum
- posterior: 12 thoracic vertebrae
- lateral: ribs
- superior: base of neck
- inferior: diaphragm
What is inside the thoracic cavity?
the left and right pleural cavity
What is inside the pleura?
pleural fluid
Where does the visceral pleura sit?
On the lung itself
Where does the parietal pleura sit?
against the ribs
What is the purpose of the pleural fluid?
to create frictionless movement so the lungs don’t get damaged when they expand and rub against the ribs
Breathing is driven by
pressure changes within the thoracic cavity
Inspiration causes the volume to _____ and the pressure to ________
increase
decrease
Expiration causes the volume to _____ and the pressure to ________
decrease
increase
What is Boyle’s Law
P = 1/V
Pressure is measured by
the number of collisions
How does the number of collisions affect the pressure?
the increased number of collisions, the higher the pressure
Air moves to the ____ pressure space
lower
By changing the volume fo the thorax, we can change the
pressure
In between breathing, there is no
pressure gradient
Describe the flow of air when breathing in and why
When breathing in, the volume of the thoracic cavity increases so pressure decreases so air flows in
Describe the flow of air when breathing out and why
When breathing out, the volume of the thoracic cavity decreases so pressure increases so air flows out
How do the ribs attach to the costocartilage?
Via costochondral joints
What type of joint are costochondral joints?
Cartilaginous joints
What is the name of the joints attaching the sternum to the ribs?
sternocostal joints