Lecture 16 Flashcards
What are the body cavities?
Thoracic cavity and Abdominal cavity
What is the lining of the thoracic cavity?
Pericardium and 2x pleura
What is the lining of the abdominal cavity?
Peritoneum
What are the two layers of the pleura?
Visceral pleura and parietal pleura
What is the mediastinum?
Area within the thoracic cavity which contains the heart, vessels and pericardium
What are the pleural cavities?
Area of the thoracic cavity which contains the lungs
What is the anterior boundary of the thoracic cavity?
Sternum
What is the posterior boundary of the thoracic cavity?
Thoracic vertebrae
What is the lateral boundary of the thoracic cavity?
Ribs
What is the superior boundary of the thoracic cavity?
Base of the neck
What is the inferior boundary of the thoracic cavity?
diaphragm
What is the pleural cavity?
The space between the parietal and visceral pleura which is filled with pleural fluid
Why are there two plural cavities, one for each lung?
So if one stops functioning the other can continue
What is boyle’s law?
Pressure is inversely proportional to volume
How is pressure measured?
The frequency of the collisions of particles against the contains walls
Where will air flow?
To a lower pressure space
When the lungs increase in volume where will air flow?
It flows in
When the lungs decrease in volume where will air flow?
It flows out
What type of cartilage joins the sternum to the ribs?
Costal cartilage (hyaline)
What are the three sternum to rib joints?
Sternocostal, costochondral, interchondral
What is the sternocostal joint?
A synovial joint (except first - cartilaginous) that connects the sternum to cartilage
What is the costochondral joint?
Cartilaginous joints between the ribs and cartilage
What is the interchondral joint?
A synovial joint that joins cartilage to cartilage
What are the two rib to vertebrae joints?
Costotransverse and costovertebral
What is the costotransverse joint?
A synovial joint articulating between the rib and transverse process of the vertebrae
What is the costovertebral joint?
A synovial joint articulating between the ribs and body of vertebrae
What are the primary muscles of respiration?
Diaphragm and intercostal muscles
What are the accessory muscles
Extra muscles involved in respiration that are only active when you need them
What is the diaphragm?
A sheet of skeletal muscle that separates the thorax from the abdomen. It is dome-shaped when relaxed and flattens when contracted to expand the thoracic cavity and compress abdomen
What are the intercostal muscles?
Skeletal muscle which attaches diagonally between ribs. External and internal intercostals
What is the function of the external intercostals?
To lift the ribcage and expand the cavity. Inspiration - quiet and forced
What is the function of the internal intercostals?
To depress the ribcage and decrease the cavity. Expiration - forced only
What are the accessory muscles?
Several muscles that attach to the thoracic cage. Some increase cavity volume for forced inspiration and other decrease the cavity volume for forced expiration
What happens during normal quiet inspiration?
The diaphragm contracts and flattens. External intercostals contract to lift ribs
What happens during active forced inspiration?
The diaphragm contracts and flattens. External intercostals contract to lift ribs. Plus accessory muscles contract to further expand cavity
What happens during normal quiet expiration?
Is a passive process. Diaphragm relaxes to return to dome shape. External intercostals relax and ribs fall
What happens during active forced expiration?
Diaphragm relaxes to return to dome shape. External intercostals relax and ribs fall. Internal intercostals contract to depress ribs and accessory muscles contract to further decrease cavity volume
What are the lungs made from?
Elastic tissue
What is the function of the pleura in terms of the expansion of the lungs?
It makes the lungs stuck to the thoracic wall, making them expand and recoil while breathing
What are the three layers of pleura?
Parietal, visceral and fluid space
Where does the visceral pleura lie?
On the lungs
Where does the parietal pleura lie?
On the thoracic wall
What is between the parietal and visceral pleura?
The pleural fluid that reduces friction from movement and causes the lungs to stick to the thoracic wall
