True or false (if false, give the correct information):
the pleural lining is a double layered structure, however its abdominal continuation, the peritoneum, is single layered.
False. Both the pleural lining of the pleural cavities and its abdominal continuation, the peritoneum, are serous membranes. All serous membranes have a visceral and a parietal layer and each layer is composed of a layer of mesothelium and connective tissue (generally areolar).
What structures make up the superior aperture of the thorax?
The superior surface of the manubrium
the median margins of the 1st ribs
the medial margins of the 1st costal cartilages
the anterior surface of the 1st thoracic vertebra
True or false (if false, give the correct information):
Pectoralis major is not a muscle of the thoracic wall, but pectoralis minor and subclavius are.
FALSE. None of them are muscles of the thoracic wall.
True or false (if false, give the correct information):
the 8th - 10th ribs are false ribs and the 11th and 12th ribs are floating ribs
TRUE (the 11th and 12th ribs are both false ribs and floating ribs).
Which two of the following statements are true regarding breathing:
A) C3, C4, and C5 are the spinal levels of one of the most important muscles involved in breathing
B) The external intercostals are most active during expiration, during which they move the ribs inferiorly and medially
C) The diaphragm contracts down into the abdomen during inhalation and expands up into the thorax during exhalation
D) Compression of the abdominal contents pushes the diaphragm up into the thorax during inhalation
A&C
Describe the superior attachments of the internal intercostals and innermost intercostal muscles and state the anatomical significance of this relationship.
The internal intercostals attach to the lateral margin of the inferior surface of the rib above (lateral margin of the costal groove) and the innermost intercostals attach to the medial margin of the inferior surface of the rib above. This spacial relationship allows the intercostal vessels and nerves run in the costal groove between the internal and innermost intercostal muscles.
What best distinguishes thoracic vertebrae from cervical and lumbar vertebrae?
All thoracic vertebrae articulate with at least one pair of ribs.
Which six surfaces articulate to form the typical COMPREHENSIVE (i.e., involving the the maximum number of articulations possible for a costovertebral joint) costovertebral joint? State which surfaces articulate with each other and whether they are from their "own" corresponding structure or from the structure above or below.
There are three articulating surfaces on the ribs and three on the thoracic vertebrae to form a typical costovertebral joint:
1) the superior costal facet on the vertebra articulates with the inferior vertebral facet on the head of the vertebra's own rib.
2) the inferior costal facet on the vertebra articulates with the superior vertebral facet on the head of the rib below the reference vertebra.
3) the transverse costal facet on the vertebra articulates with the tubercle of the vertebra's own rib.
Describe the exceptions to the general articulation pattern between the thoracic vertebrae and the ribs and state how each bone varies from the norm.
TI & 1st rib: The 1st rib articulates only with the TI vertebra and not with the vertebra above. The TI vert is normal in terms of the number of costal facets it has (meaning that it has superior and inferior facets), but the 1st rib has only one set of vertebral facets.
TX (and sometimes TIX) and the 10th rib (and sometimes rib IX): The 10th (and sometimes the 9th) vertebrae articulate only with their own ribs and not with the ribs below. So TX vert (and sometimes TIX) does not have an inferior costal facet. This means that the 10th rib is normal (assuming that the 9th vert & rib are normal) but the 11th rib does not have what would normally be called a superior vertebral facet (because TX does not have an inferior costal facet and it articulate only with its own rib [#10])
TXI& TXII and ribs XI and XII: The 11th and 12th vertebrae articulate only with their own ribs and only at their superior costal facet because they do not have an inferior or transverse costal facets. This means that they articulate with their own rib only at the superior costal facet and the ribs have neither transverse vertebral facets AND they don't have what are normally called superior vertebral facets (because TX also articulates only with its own rib).
True or false (if false, give the correct information):
The floating ribs do not have tubercle articular facets.
TRUE.
True or false (if false, give the correct information):
All of the sternocostal joints are non-synovial joints.
FALSE. Only the joint between the 1st costal cartilage and the manubrium is a non-synovial joint.
Trace the primary blood supply of the posterior portion of the 1st intercostal space back to the arch of the aorta on the left side of the body
1st posterior intercostal artery/supreme intercostal artery/costocervical trunk/1st part of subclavian artery/arch of the aorta
Trace the primary blood supply of the anterior portion of the 9th intercostal artery back to the arch of the aorta on the right side of the body.
9th anterior intercostal artery/musculophrenic artery/internal thoracic artery/1st part of subclavian artery/brachiocephalic trunk/arch of the aorta
Which muscles (may) function to depress the costal cartilages?
The transversus thoracic muscles
Describe the movement of the diaphragm and the thorax during expiration. Include which thoracic muscles are active.
During expiration the diaphragm relaxes and moves upward into the thorax (decreasing the potential volume of the thorax and increasing the pressure in the lungs). The volume of the thorax decreases, meaning that (roughly) ribs 2-8 rotate inferior and medially, ~9&10 ribs generally slide slightly superiorly (returning to the normal position) and the lowest ribs [~11-12] stay put or move to their original location, slightly superiorly]). ALL of the thoracic muscles are active (because they all act to change the volume of the thorax). However, the internals and innermost are the most active to move the ribs medially and inferiorly and the subcostals and transversus thoracics may also be most active during exhalation to depress the ribs and the costal cartilages, respectively).
True or false (if false, give the correct information):
The right crus of the diaphragm is anchored to the L3, the left crus is anchored to L2 and the posterior crus is also anchored to L3.
FALSE. The posterior crus does not exist.
True or false (if false, provide the correct information): The azygos vein drains only the posterior intercostal veins on the left side of the body.
FALSE. The azygos vein drains the posterior intercostal veins on the right and the left sides. It is located on the right posterior thorax and directly drains the right posterior intercostals. The hemiazygos and accessory hemiazygos veins are located on the left side of the thorax and drain the posterior intercostals on the left side. They drain into the azygos vein, so the azygos vein directly or indirectly ends up draining all of the posterior intercostal veins.
If the internal thoracic arteries were blocked on both sides, would the primary blood supply of the diaphragm be impacted? Explain your answer in full (e.g., include the names of the relevant arteries where necessary).
Yes, it would be compromised. The primary blood supply of the diaphragm comes from the musculophrenic arteries, the pericardcophrenic arteries and the inferior phrenic arteries. Musculophrenic and pericardiophrenic are branches of the internal thoracic artery
If the thoracic aorta were blocked, other than the fact that you would be dead, would the primary blood supply of the rectus abdominis muscle be completely blocked? Explain your answer.
No, it would not be completely blocked because part of the primary blood supply of rectus abdominis comes from the superior epigastric arteries, which are terminal branches of the internal thoracic arteries, which come from the subclavian arteries, directly or indirectly off of the arch of the aorta. So the thoracic aorta is not involved in the derivation of the part of the primary blood supply coming from internal thoracic. However, it is involved in the inferior primary blood supply, which comes from inferior epigastric artery, off of the external iliac artery (from common iliac / abdominal aorta / thoracic aorta).
list the seven common functions of the muscles of the abdominal wall (this is the only time I will ask this question).
1) Maintain the integrity of abdominal cavity
2) Protect the abdominal cavity
3) Protect the abdominal viscera
4) Maintain the position of abdominal viscera while standing erect
5) Assist in respiratory functions
6) Assist with functions requiring increases in abdominal pressure (e.g., child birth, defecation, urination)
7) Compression of the abdominal contents
Describe the composition of the anterior and posterior walls of the rectus sheath in a) its upper 3/4th and b) its lower 1/4th
Anterior wall, upper 3/4th: aponeuroses of external obliques and internal obliques
posterior wall, upper 3/4th: aponeuroses of the internal obliques and transversus abdominis
anterior wall, lower 1/4th: aponeuroses of all three muscles
posterior wall, lower 1/4th: not present
True or false (if false, provide the correct information): intraperitoneal organs are embedded within the extraperitoneal fascia.
FALSE: intraperitoneal organs are suspended from the abdominal wall by visceral peritoneal while some retroperitoneal organs are embedded within the extraperitoneal fascia posterior to the parietal peritoneum.
When an individual is rotating to the right, which abdominal muscles are active? Provide the name of the muscle and the side on which it is active (L, R, or both)
This is kind of a bananas question, but it is a good test of your understanding of this area.
B&C
Which of the following accurately reflect a potential sympathetic (efferent) impulse pathway (assume paths reflect start and end points, do not worry about specific nerves): A) Lateral grey horn @ L3 / lateral white column @ L3 / Anterior root @ L3 / anterior ramus @ L3 /spinal nerve @ L3 / white ramus communicant / ganglion @ L3 / *synapse occurs* / grey ramus communicant / anterior ramus @ L3 / peripheral nerve / smooth muscle in stomach B) Lateral grey horn @ T5 / lateral white column @ T5 /Anterior root @ T5 / posterior ramus @ T5 / spinal nerve @ T5 / white ramus communicant / ganglion @ T5 / *synapse occurs* / grey ramus communicant / anterior ramus / posterior ramus @ T5 / peripheral nerve / cutaneous gland C) Lateral grey horn @ T8 / lateral white column @ T8 / Anterior root @ T8 / anterior ramus @ T8 / spinal nerve @ T8 / white ramus communicant / ganglion @ T8 / *synapse occurs* / sphlanchnic nerve / nerve plexus to target organ D) Lateral grey horn @ T7 / lateral white column @ T7 / Anterior root @ T7 / spinal nerve @ T7 / anterior ramus @ T7 / white ramus communicant / ganglion @ T7 / sphlanchnic nerve / collateral ganglion / *synapse occurs* / nerve plexus to target organ E) Lateral grey horn @ T7 / lateral white column @ T7 / Anterior root @ T7 / spinal nerve @ T7 / posterior ramus @ T7 / white ramus communicant / ganglion @ T7 / sphlanchnic nerve (autonomic nerve) / collateral ganglion / *synapse occurs* / nerve plexus to target organ
This is kind of a bananas question, but it is a good test of your understanding of this area.
D
Identify and correct the error in the following impulse path:
Lateral grey horn @ T3 / lateral white column @ T3 / Anterior root @ T3 / spinal nerve / anterior ramus @ T3 / white ramus communicant / ganglion @ T3 / superior cervical ganglion / *synapse occurs * / peripheral nerve to target in the eye
The error in the path occurs at the beginning: all sympathetic impulses bound for the head emerge from T1. To correct this error, simply change all of the T3 levels to T1.