Diaphragm, Respiration, and Pericardium Flashcards
What does the diaphragm separate?
thorax and abdomen
Why is the right dome higher than the left dome of the diaphragm?
it overlies the liver
What are the two parts of the diaphragm?
muscular and central tendon
What are the points of origin of the muscular part of the diaphragm?
sternal: xiphoid process
costal: lower 6 costal cartilages
lumbar: lumbar vertebrae 1-3, medial and lateral arcuate ligaments
What are the three openings in the diaphragm?
caval opening, esophageal hiatus, and aortic hiatus
What vertebral level is the caval opening and what are its contents?
tv 8 and the inferior vena cava and the right phrenic nerve
What is firmly attached to the central tendon around the caval opening and facilitates venous return to heart during inspiration?
inferior vena cava
What is the vertebral level of the esophageal hiatus and what are its contents?
tv 10 and the esophagus, and anterior/posterior vagal trunks
What is the vertebral level of aortic hiatus and what are its contents?
tv 12 and the aorta, thoracic duct, and the azygos vein
What is the blood supply to the diaphragm?
musculophrenic, pericardiacophrenic, superior phrenic, and inferior phrenic arteries
What is the innervation to the diaphragm?
Phrenic nerve (C3,4,5) and intercostal nerves
What causes a hiatial hernia?
weakness in the diaphragmatic wall around the esophageal hiatus
What causes a hiatal hernia?
weakness in the diaphragmatic wall around the esophageal hiatus
What happens when the upper part of the stomach slides up into the thoracic cavity through the esophageal hiatus?
hiatal hernia
What is a major cause of gastroesophageal reflux, including belching and epigastric pain?
hiatal hernia
What movement is when the diaphragm contracts, pulling the domes inferiorly into the abdomen, resulting in an increase in the vertical diameter of the thorax?
piston movement
Which movement elevates the lower ribs (7-10) about an antero-posterior axis, resulting in an increase in the transverse diameter of the thorax?
bucket handle movement
What does the pump handle movement do?
elevates upper ribs (2-6) about a transverse axis, resulting in an increase in antero-posterior diameter of thorax
The elevation of the ribs in both the bucket handle and pump handle movements are due to the contraction of what muscles?
external intercostal muscles
What happens in normal expiration?
diaphragm and external intercostal muscles relax and air is expelled passively
What happens in forced expiration?
the internal intercostals, innermost intercostals, and muscles of the anterior abdominal wall contract
What happens to the intrathoracic volume and pressure in inspiration?
volume increases, pressure decreases
What happens to the intrathoracic volume and pressure in expiration?
volume decreases, pressure increases
What happens to the abdominal volume and pressure when the diaphragm is contracted during inspiration?
volume is decreased, pressure increased
What are hiccups a result of?
spasmodic contraction of diaphragm
What is the pericardium?
fibroserous sac which encloses the heart and great vessels
What are the layers of the pericardium?
fibrous pericardium, parietal layer of the serous pericardium, and visceral layer of the serous pericardium
What is a potential space between the parietal and visceral layers of the serous pericardium that contains serous fluid?
pericardial cavity
What is another name for the sternopericardial ligaments that attach the fibrous pericardium to the back of the sternum?
cardiac seat belt
What are the layers of the pericardium of the heart?
epicardium, myocardium, endocardium, chambers
What is a cardiac temponade?
fluid leaks rapidly into pericardial cavity compressing the heart and superior vena cava making the external jugular veins become enlarged and prominent
What are the pericardial sinuses?
transverse pericardial sinus and the oblique pericardial sinus
What is the blood supply to the pericardium?
pericardiacophrenic (main supply), bronchial, esophageal, and coronary (visceral layer) arteries
What nerves innervate the heart?
phrenic nerve (sensory), sympathetic trunk (vasomotor), and the vagus nerve
Where is pericardial pain felt?
behind the sternum, although less sensitive to pain than pleura
What is inflammation to the pericardium?
pericarditis (very life threatening)
When listening to the heart and holding their breath, what should you hear for percardial friction rub?
The sound will continue when breath is held, if sound stops then it is pleural friction rub
