Thorax Lymphatic Flashcards
Trachea
• Between larynx and tracheal bifurcation
Description:
• Rigid tube held open by a series of “C-shaped” cartilaginous rings (open end of rings directed posteriorly)
• Cartilaginous rings connected by anular ligaments of trachea
• Posterior aspect of tracheal rings closed by fibroelastic trachealis muscle
Also known as:
• “Windpipe”
Comment:
• Tracheotomy is surgical procedure to open trachea in neck to bypass an airway obstruction
Mediastinal lymph nodes
Description:
• Lymph node clusters found along trachea, bronchi, and great vessels
• Small, oval or round, encapsulated lymphoid organs
Right main bronchus
Description:
• Formed at bifurcation of trachea
• Shorter, wider, and more vertical than left main bronchus
• Component of root and hilum of right lung
Comment:
• Foreign bodies that enter trachea tend to pass to right main bronchus
Left main bronchus
Description:
• Formed at bifurcation of trachea
• Longer, more narrow, and less vertical than right main bronchus
• Component of root and hilum of left lung
Diaphragm
Action:
• Dome of diaphragm flattens during inspiration
• Contraction increases vertical dimension of thoracic cavity
Innervation:
• Phrenic nerve
Comment:
• Primary muscle of respiration
• Contraction (flattening) decreases intrathoracic pressure and increases intra-abdominal pressure
Liver
Location:
• Immediately inferior to diaphragm
• In upper abdominal quadrants; in epigastric and right hypochondriac regions
Description: • Accessory digestive organ • Four lobes: right, left, quadrate, and caudate • Largest visceral organ • Suspended from diaphragm by peritoneum
Function:
• Produces and secretes bile and plasma proteins
• Stores glycogen, minerals, and vitamins
• Detoxifies drugs and alcohol
• Modifies hormones
• Removes (phagocytizes) bacteria
Comment:
• Adult liver typically does not project inferior to costal margin
• Alcoholism, drug abuse, and liver disease can lead to destruction of hepatocytes (liver cells) resulting in cirrhosis
Azygos v.
Drainage:
• Posterior walls of thorax and abdomen
• Mediastinal structures (except heart)
Course:
• Ascends in posterior mediastinum on anterolateral aspect of thoracic vertebral bodies
Comment:
• Azygos venous system forms collateral pathway between superior and inferior vena cavae
Descending aorta
Course:
• Has thoracic and abdominal parts that parallel vertebral column
• Thoracic part shifts from left side of vertebral column to midline position as it descends
• Passes through aortic hiatus (diaphragm) at level of T12 vertebra
Distribution: • Thoracic, abdominal, and pelvic walls • Mediastinal viscera (excluding heart) • Diaphragm • Abdominal and pelvic viscera • Perineum • Back, spinal cord, and meninges • Lower limb
Cisterna chyli
Description:
• Small, irregular-shaped lymph sac
Function:
• Receives lymph from abdomen, pelvis, and lower limbs
Comment:
• Origin of thoracic duct
Thoracic Duct
• Between thoracic aorta and azygous vein
Description:
• Originates from cysterna chyli
• Deviates to left side as it ascends along thoracic vertebral bodies
• Arches anteriorly to end at junction of left internal jugular and subclavian veins
Function:
• Receives lymph from body inferior to diaphragm, and left side of thorax, upper limb, neck, and head
Comment:
• Lymph from right side of thorax, right upper limb, and right side of head and neck enters right lymphatic duct, which empties into junction of right internal jugular and subclavian veins
Remnant of thymus
Description:
• Large, bilobed gland in children that atrophies during adolescence
• Remnant in adults consists primarily of fibrous and adipose tissue
Function:
• Secretes thymopoietin and thymosins that stimulate and promote differentiation, growth and maturation of T-lymphocytes
• Site for maturation and differentiation of T-lymphocytes (primarily in young individuals)
