Thoracic Wall Flashcards
What is the location of the thorax?
between neck and abdomen
What are the contents of the thorax?
heart, lungs, and structures passing between neck and abdomen
What is the shape of the thorax?
truncated cone with inlet and outlet
What is the inlet of the thorax?
superior thoracic aperture
What is the outlet of the thorax? What is it closed off by?
inferior thoracic aperture
respiratory diaphragm
What does the bony thorax consist of?
12 thoracic vertebrae, 12 pairs of costae (ribs and costal cartilages), and sternum
What are the boundaries of the superior thoracic aperture?
body of T1 vertebra posteriorly, 1st pair of costae laterally, and manubrium anteriorly
What are the boundaries of the inferior thoracic aperture?
body of T12 vertebra posteriorly, 11th and 12th costae laterally, and xiphoid process and costal cartilages of 7-`10 anteriorly
What separates the thorax from the abdomen?
respiratory diaphragm
What level does the dome of the diaphragm rise to on the right and left?
right - 5th intercostal space
left - 6th intercostal space
What does the manubrium articulate with?
clavicles - sternoclavicular joints
1st pair of ribs
2nd pair of ribs
body of the sternum at sternal angle
How many sternabrae in the body of the sternum?
4
What does the body of the sternum articulate with?
manubrium, costal cartilages 2-7, and xiphoid process
What is the movement of the manubriosternal joint? What does this allow?
hinge-like movement of the body of the sternum anteriorly and posteriorly
facilitates increased respiration by allowing expansion of the thoracic cavity
What level is the xiphisternal joint at?
T8 vertebra
Can you palpate the xiphoid process?
yes, with discomfort
Can you palpate the xiphisternal joint?
yes
What is the length of the xiphoid process?
variable
What are the 3 types of ribs?
true ribs (1-7) false ribs (8-10) floating ribs (11-12)
What are true ribs?
costal cartilages attach directly to the sternum
What are false ribs?
costal cartilage attach indirectly to the sternum
What are floating ribs?
do not have any attachment to sternum
What are the intercostal muscles?
external intercostals, internal intercostals, innermost intercostals
What is the most superficial layer of intercostal muscles?
external intercostals
Where do the external intercostal muscles extend?
from the tubercles of the ribs to the junction of the costal cartilages with the bony ribs
What passes from the anterior margin of external intercostals to the lateral border of the sternum?
external intercostal membrane
What is the orientation of muscle fibers for external intercostal muscles?
inferomedial orientation
What is the action of the external intercostal muscles?
elevate ribs for inspiration
What is the middle layer of intercostal muscles?
internal intercostal muscles
Where does the internal intercostal muscles extend?
sternum to mid-axillary line
What passes from the lateral margin of the internal intercostal muscles to the region of the vertebral column to fuse with the superior costotransverse ligaments?
internal intercostal membrane
What orientation do the internal intercostal muscles run?
inferolateral
What is the action of the internal intercostal muscles?
rib depression for exhalation
What is the deepest layer of the intercostal muscles?
innermost intercostal muscles
Where do the innermost intercostal muscles extend?
from the angles of the ribs to just anterior of the mid-axillary line
What passes from the anterior border of the innermost intercostal muscles to the lateral border of the transversus thoracis muscle?
innermost intercostal membrane
What orientation do the innermost intercostal muscle fibers run?
inferolateral
What is the action of the innermost intercostal muscles?
rib depression for exhalation
Where do the transversus thoracis muscles extend?
from the posterior surface of the lower half of the body of the sternum and xiphoid process to the costochondral junction of ribs 3-6
What is the action of the transversus thoracis muscles?
depress the ribs for exhalation
What are the intercostal nerves?
ventral primary rami of T1-T11
What do the motor branches of the intercostal nerves innervate?
external intercostal muscles, internal intercostal muscles, innermost intercostal muscles, and transversus thoracis muscles
What do the cutaneous branches fo the intercostal nerves innervate?
skin on the lateral and anterior surfaces of the thorax
What intercostal nerves continue into the abdominal wall? What do they do?
T1-T7
provide motor and cutaneous branches to the muscles and skin of the abdomen region
Where are the posterior intercostal arteries located?
between the internal intercostal muscles and innermost intercostal muscles from the descending aorta in intercostal spacees 3-11
What do the posterior intercostal arteries supply?
intercostal, pectoral, and serratus anterior muscles
What is the blood supply for the breast in females?
lateral branches from posterior intercostal arteries in ICS 3-5
Where does the supreme thoracic artery branch from?
axillary A
What does the supreme thoracic artery supply?
intercostal spaces 1-2
What does the supreme intercostal arteries branch from?
costocervical trunk
What do the supreme intercostal arteries supply?
intercostal spaces 1-2
What do the anterior intercostal arteries branch from?
internal thoracic A
Where are the anterior intercostal arteries found?
intercostal spaces 1-6
What do the anterior intercostal arteries supply?
skin, intercostal muscles, breasts, and thymus gland
Where is the thymus gland located?
anterior mediastinum
Where does the musculophrenic artery branch from?
terminal branch of internal thoracic artery
What does the musculophrenic artery supply?
anterior intercostal arteries to intercostal spaces 7-9
What does the parietal pleura line?
pleural cavity
What are the surfaces of the parietal pleura? What are they attached to?
costal pleura - ribs and intercostal spaces
mediastinal pleura - mediastinum
diaphragmatic pleura - superior surface of the respiratory diaphragm
cervical pleura - pleural cavity above 1st ribs, in the root of the neck
What does the visceral pleura cover?
surface of the lungs and structures that pass into the lungs (bronchi, pulmonary vessels, nerves, lymphatics)
Where is the vertebral reflection?
where the costal and mediastinal pleurae become continuous posteriorly
Where is the sternal reflection?
where the costal and mediastinal pleurae become continuous anteriorly
Where is the costal reflection?
wehre the costal and diaphragmatic pleurae become continuous inferiorly
What are the 3 pleural recesses?
right costodiaphragmatic recess
left costodiaphragmatic recess
left costomediastinal recess
Where is the right costodiaphragmatic recess located?
laterally along the costal reflection
Where is the left costodiaphragmatic recess located?
laterally along the costal reflection
Where is the left costomediastinal recess located?
anteriorly along the sternal reflection
Do the lungs normally occupy recesses?
no
What may collect in the recess during respiratory infections?
pus, fluid, or dead cells
What is the pleural cavity?
potential space located between the pleural layers of the parietal and visceral pleura
What do pleuaral cavities contain?
fluid produced by pleural membranes to lubricate surface and prevent adhesion
What are intercostal nerve sensory fibers for?
pain and irritation to costal pleura in addition to supplying the periphery of the respiratory diaphragm
What do the phrenic nerves supply?
fibers for pain and irritation to the mediastinal pleura and diaphragmatic pleura
What is the pleural sac?
Location where the lungs are found contained within the visceral pleura
