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Questions and Answers
Which muscle listed does NOT directly anchor to the ribs?
Which muscle listed does NOT directly anchor to the ribs?
- Internal oblique (correct)
- Serratus anterior
- Pectoralis major
- External oblique
In what direction are the fibers of the external intercostal muscles oriented?
In what direction are the fibers of the external intercostal muscles oriented?
- Inferolaterally
- Superomedially
- Inferomedially (correct)
- Superolaterally
What do the accessory muscles of respiration do to aid in breathing distress?
What do the accessory muscles of respiration do to aid in breathing distress?
- Increase abdominal pressure to aid exhalation.
- Inhibit intercostal muscle function.
- Loosen the pectoral girdle for increased mobility.
- Fix the pectoral girdle to allow muscles to act on the rib cage. (correct)
The external intercostal muscles extend from the posterior aspect around to which location?
The external intercostal muscles extend from the posterior aspect around to which location?
Which muscle is a direct continuation of the external intercostals, transitioning into it as it extends into abdomen?
Which muscle is a direct continuation of the external intercostals, transitioning into it as it extends into abdomen?
In a patient experiencing severe dyspnea, strategic manipulation of which structure would MOST directly facilitate the utilization of accessory respiratory muscles connected to the rib cage?
In a patient experiencing severe dyspnea, strategic manipulation of which structure would MOST directly facilitate the utilization of accessory respiratory muscles connected to the rib cage?
A surgeon performing a thoracotomy encounters a membranous structure during dissection along the anterior aspect of the rib cage. Damage to which structure would most likely compromise respiratory function?
A surgeon performing a thoracotomy encounters a membranous structure during dissection along the anterior aspect of the rib cage. Damage to which structure would most likely compromise respiratory function?
What is the primary function of the abdominal muscles described?
What is the primary function of the abdominal muscles described?
Which nerve type innervates the muscles of the abdominal wall?
Which nerve type innervates the muscles of the abdominal wall?
If a patient has difficulty flexing their trunk, which muscle group is MOST likely affected?
If a patient has difficulty flexing their trunk, which muscle group is MOST likely affected?
Damage to the ventral rami of the spinal nerves in the thoracoabdominal region would MOST directly affect:
Damage to the ventral rami of the spinal nerves in the thoracoabdominal region would MOST directly affect:
A patient presents with an abdominal hernia, potentially caused by weakened abdominal muscles. Which of the following activities would be MOST inadvisable for this patient during the initial recovery phase?
A patient presents with an abdominal hernia, potentially caused by weakened abdominal muscles. Which of the following activities would be MOST inadvisable for this patient during the initial recovery phase?
Which muscle layer within the intercostal space is the innermost?
Which muscle layer within the intercostal space is the innermost?
In what direction do the fibers of the internal intercostal layer run?
In what direction do the fibers of the internal intercostal layer run?
Which muscles are considered to be continuous with the transversus abdominis muscles of the anterior abdominal wall?
Which muscles are considered to be continuous with the transversus abdominis muscles of the anterior abdominal wall?
Where are the innermost intercostals primarily found?
Where are the innermost intercostals primarily found?
Which of the following best describes the function of the intercostal muscles as a whole?
Which of the following best describes the function of the intercostal muscles as a whole?
Which structures innervate the muscles of the intercostal spaces?
Which structures innervate the muscles of the intercostal spaces?
Besides innervating the intercostal muscles, what else do intercostal nerves provide?
Besides innervating the intercostal muscles, what else do intercostal nerves provide?
Which anatomical feature separates the innermost intercostals from the internal intercostals?
Which anatomical feature separates the innermost intercostals from the internal intercostals?
A surgeon is performing a thoracotomy and needs to make an incision that carefully separates muscle fibers rather than cutting through them, to minimize post-operative pain. Which muscle is LEAST suited for this approach?
A surgeon is performing a thoracotomy and needs to make an incision that carefully separates muscle fibers rather than cutting through them, to minimize post-operative pain. Which muscle is LEAST suited for this approach?
During a physiology experiment, researchers selectively blocked the function of the subcostal muscles in a test subject. Knowing the anatomy of the thoracic wall, what compensatory change would you predict to observe during forced inspiration, assuming all other respiratory muscles function normally?
During a physiology experiment, researchers selectively blocked the function of the subcostal muscles in a test subject. Knowing the anatomy of the thoracic wall, what compensatory change would you predict to observe during forced inspiration, assuming all other respiratory muscles function normally?
Which of the following accurately describes the innervation of the posterior (dorsal) aspect of the skin?
Which of the following accurately describes the innervation of the posterior (dorsal) aspect of the skin?
What is the origin of the arterial supply to the muscles of the intercostal space?
What is the origin of the arterial supply to the muscles of the intercostal space?
Which of the following vessels directly contribute to the venous drainage of the intercostal spaces?
Which of the following vessels directly contribute to the venous drainage of the intercostal spaces?
What anatomical structure is formed by the external oblique's aponeurosis doubling back on itself?
What anatomical structure is formed by the external oblique's aponeurosis doubling back on itself?
Which of the following accurately describes the arrangement of muscle layers forming the anterolateral abdominal wall?
Which of the following accurately describes the arrangement of muscle layers forming the anterolateral abdominal wall?
Which structure passes through the superficial ring of the inguinal canal?
Which structure passes through the superficial ring of the inguinal canal?
What is the orientation of the external oblique muscle fibers relative to the external intercostal muscles?
What is the orientation of the external oblique muscle fibers relative to the external intercostal muscles?
Which muscle of the anterolateral abdominal wall has a free posterior border that does NOT fuse with the lumbar fascia?
Which muscle of the anterolateral abdominal wall has a free posterior border that does NOT fuse with the lumbar fascia?
A surgeon is operating in the intercostal space and needs to ligate the intercostal arteries to control bleeding. If the internal thoracic artery is compromised, which vessel would provide collateral circulation via anastomosis?
A surgeon is operating in the intercostal space and needs to ligate the intercostal arteries to control bleeding. If the internal thoracic artery is compromised, which vessel would provide collateral circulation via anastomosis?
A patient presents with referred pain along the T10 dermatome following a splenic injury. Which of the following structures is MOST directly responsible for this pattern of pain referral?
A patient presents with referred pain along the T10 dermatome following a splenic injury. Which of the following structures is MOST directly responsible for this pattern of pain referral?
Which anatomical structure is formed by the aponeuroses of the three sheet-like abdominal muscles?
Which anatomical structure is formed by the aponeuroses of the three sheet-like abdominal muscles?
What is the primary function of the three sheet-like abdominal muscles acting together?
What is the primary function of the three sheet-like abdominal muscles acting together?
Which layer of the abdominal muscles has the smallest extent and fuses posteriorly with the lumbar fascia?
Which layer of the abdominal muscles has the smallest extent and fuses posteriorly with the lumbar fascia?
What is the arcuate line?
What is the arcuate line?
Which muscles can flex and rotate the trunk?
Which muscles can flex and rotate the trunk?
What abdominal muscle exhibits tendinous intersections that attach to the anterior rectus sheath?
What abdominal muscle exhibits tendinous intersections that attach to the anterior rectus sheath?
Which of the following abdominal muscles has the most significant deficiency in its aponeurosis around the inguinal canal?
Which of the following abdominal muscles has the most significant deficiency in its aponeurosis around the inguinal canal?
How does the arrangement of the aponeuroses of the sheet-like abdominal muscles change at the arcuate line?
How does the arrangement of the aponeuroses of the sheet-like abdominal muscles change at the arcuate line?
Considering the anatomical arrangement of the abdominal wall, which structure is most immediately posterior to the rectus abdominis muscle at the level below the arcuate line?
Considering the anatomical arrangement of the abdominal wall, which structure is most immediately posterior to the rectus abdominis muscle at the level below the arcuate line?
If a surgeon makes an incision precisely along the midline of the abdomen, extending superiorly from the pubic symphysis to the xiphoid process, which structure is MOST likely being incised?
If a surgeon makes an incision precisely along the midline of the abdomen, extending superiorly from the pubic symphysis to the xiphoid process, which structure is MOST likely being incised?
Which of the following muscles are primarily involved in respiration?
Which of the following muscles are primarily involved in respiration?
Which thoracic muscle is primarily responsible for inspiration?
Which thoracic muscle is primarily responsible for inspiration?
Flashcards
"Orange peel" appearance
"Orange peel" appearance
Advanced breast carcinoma symptom where the skin has a dimpled appearance.
Rib Anchored Muscles
Rib Anchored Muscles
Muscles anchored by ribs, including those from the upper limb, abdomen, and back.
Accessory Respiratory Muscles
Accessory Respiratory Muscles
Examples include pectoralis major/minor and serratus anterior.
Lateral Trunk Wall Muscles
Lateral Trunk Wall Muscles
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Intercostal Muscles
Intercostal Muscles
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External Intercostals
External Intercostals
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Inferomedially
Inferomedially
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External Oblique Muscles
External Oblique Muscles
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Abdominal muscle function
Abdominal muscle function
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Abdominal wall muscles
Abdominal wall muscles
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Abdominal wall muscle innervation
Abdominal wall muscle innervation
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Abdominal Wall Nerve Supply
Abdominal Wall Nerve Supply
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Thoracoabdominal nerves
Thoracoabdominal nerves
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Dermatome
Dermatome
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Anterior & Posterior Intercostal Arteries:
Anterior & Posterior Intercostal Arteries:
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Cutaneous Branches of Intercostal Arteries
Cutaneous Branches of Intercostal Arteries
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Intercostal Veins
Intercostal Veins
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External Oblique
External Oblique
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Inguinal Ligament
Inguinal Ligament
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Superficial Ring of the Inguinal Canal
Superficial Ring of the Inguinal Canal
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Inguinal Canal
Inguinal Canal
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Internal Oblique
Internal Oblique
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Spermatic Cord
Spermatic Cord
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Transversus Thoracis
Transversus Thoracis
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Innermost Intercostals
Innermost Intercostals
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Subcostals
Subcostals
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Function of Intercostal Muscles
Function of Intercostal Muscles
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Intercostal Nerves
Intercostal Nerves
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Cutaneous Branches
Cutaneous Branches
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Third Muscle Layer
Third Muscle Layer
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Transversus Thoracis Attachment
Transversus Thoracis Attachment
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Transversus Abdominis
Transversus Abdominis
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Inguinal Canal Deficiency
Inguinal Canal Deficiency
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Intra-abdominal Pressure Role
Intra-abdominal Pressure Role
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Rectus Abdominis
Rectus Abdominis
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Rectus Sheath
Rectus Sheath
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Arcuate Line
Arcuate Line
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Tendinous Intersections
Tendinous Intersections
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Study Notes
- In advanced carcinoma stages, the breast may show a "dimpled" or orange peel appearance
Anterior Thoracic Wall I
- Ribs serve as anchor points for muscles from the upper limb, abdomen, and back
- Muscles anchored to the ribs include pectoralis major and minor (upper limb), external oblique (abdomen), and serratus anterior (back)
- These muscles can act as accessory respiration muscles in breathing distress by stabilizing pectoral girdles allowing them to act on the rib cage
Lateral Wall Muscles of the Trunk
- The muscles that make up the lateral walls of the thorax and abdomen are paired oblique and transverse muscle groups
- These three layers are found in both the thorax and abdomen, but study begins by looking at the thorax
Muscles of the Thoracic Wall
- The intercostal muscles fill the spaces between the ribs and are organized into three layers
- External intercostals fibers extend inferomedially (like putting your hands into your pockets) from posterior around to the costochondral junction, where they become the anterior intercostal membrane
The external intercostals
- Continuous with the fibers of the external oblique mm of the anterior abdominal wall.
The internal intercostals
- Run at right angles to the external layer - inferoposterior in direction and extend from the sternum around to the angle of the ribs where they become the internal intercostal membrane
The third layer of muscles
- Consists of three muscles linked in a membrane and won't be seen until the thorax is opened and the lungs are removed.
The transversus thoracis
- Attach to the back of the sternum and xiphoid process oriented inferoposteriorly
- May skip up to two ribs before reattaching and is considered to be continuous with the transversus abdominis mm. of the anterior abdominal wall
The innermost intercostals
- Found along the mid-axillary line direction similar to the internal intercostals
- May be considered a subset separated by the intercostal neurovascular bundle
The subcostals
- Most posterior near the angle of the ribs
- Typically crosses one rib before reattaching
- All these muscles function in elevating the ribs, expanding the thoracic diameter, and keeping the intercostal spaces rigid to prevent the lungs pushing the muscle outward
- The muscles receive their arterial supply from branches of the anterior and posterior intercostal arteries
- Intercostal muscles are innervated segmentally by the ventral rami of the spinal nerves from T1-T12 called intercostal nerves.
Venous drainage
- Through intercostal veins that drain either to the internal thoracic veins anteriorly
- The azygous/hemiazygous system (posteriorly)
- Intercostal nerves give rise to lateral and anterior cutaneous br that supply the overlying skin in a band-like fashion (dermatome)
- Dorsal aspect is supplied segmentally by the dorsal rami of the spinal nerves.
Muscles of the Anterolateral Abdominal Wall
- Three muscle players that form the anterolateral abdominal wall are external oblique, the internal oblique, and the transversus abdominis
- The external oblique is most extensive layer with fibers extending inferoanteriorly/medially originated from the lower 8 ribs a free posterior border that does not fuse with the lumbar fascia
- The aponeurosis (extensive anterior) of the external oblique doubles back between the anterior superior iliac and the pubic tubercle to form the inguinal ligament
- A deficiency exists in the lower medial aspect of the aponeurosis known as the superficial ring of the inguinal canal
- Above the arcuate line all 3 aponeuroses contribute to the anterior aspect of the sheath forming the anterior sheets
- Below the arcuate line you have the external oblique aponeurosis in front (anterior) and fascia transversalis behind (posterior)
The internal oblique
- The internal oblique is the middle layer with the lumbar fascia posteriorly
- Fibers extend supero-anteriorly similar to those of the internal intercostal, also exhibiting a deficiency in its aponeurosis in the region of the inguinal canal.
The transversus abdominis
- It is innermost smallest extent and fuses posteriorly with the lumbar fascia as aponeurosis extends anteriorly to the midline
- Participates with the two overlying oblique mm in the sheath of the rectus abdominis and exhibits a deficiency in the region of the inguinal canal
Rectus Abdominis
- The rectus abdominis is strap-like and enclosed in a sheath formed by the aponeuroses of the 3 sheet-like abdominal muscles (external oblique, internal oblique, and transversus abdominis)
- The rectus exhibits tendinous intersections that attach to the posterior aspect of the anterior sheath
- Sheet-like muscles support the trunk and protect the abdominal viscera and can increase intra-abdominal pressure as required during defecation, micturition, and childbirth
- The external and internal obliques can flex and rotate the trunk
- The muscles of the abdominal wall are innervated segmentally by the ventral rami of the spinal (thoracoabdominal) nerves
Arcuate Line
- Is below the umbilicus between the umbilicus and the pubic crest where the posterior aspect of the rectus sheath becomes deficient leaving only fascia transversalis
- All 3 aponeuroses contribute to the anterior aspect of the sheath.
- Transversus Abdominis fuses posteriorly with the lumbar fascia and its aponeurosis extends anteriorly to the midline.
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Description
Explore the muscles involved in respiration, including their attachments, functions, and clinical significance. Covers intercostals, accessory muscles, and related anatomical structures. Understanding these muscles aids in diagnosing respiratory distress and performing surgical procedures.
