USMLE3

Card Set Information

Author:
rere_girl4ever
ID:
292999
Filename:
USMLE3
Updated:
2015-01-15 12:29:01
Tags:
USMLE
Folders:

Description:
USMLE3
Show Answers:

Home > Flashcards > Print Preview

The flashcards below were created by user rere_girl4ever on FreezingBlue Flashcards. What would you like to do?


  1. Which cells contribute to the development of centriacinar emphysema?
    Heavy smoing causes neutrophils and macrophages  to release proteases: elastase, cathepsins, matrix metalloproteinases which destroys elastic fibers.
  2. What is the function of Club/ Clara cells?
    • 1. Secrete component of surfactant
    • 2. Detoxify inhaled substances (eg tobacco smoke) by cytochrome P450 mechanism
  3. Label the diagram
  4. Which structures does the truncus arteriosus give rise to?
    Ascending aorta and pulmonary trunk
  5. What structure does the cardinal veins give rise to?
    • Superior vena cava
    • R.common and R.anterior cardinal vein
  6. Which embryonic structure gives rise to the SVC?
    R.common and R.anterior cardinal vein
  7. Which embryonic structure gives rise to the ascending aorta?
    Truncus arteriosus
  8. Which embryonic structure gives rise to the pulmonary trunk?
    Truncus arteriosus
  9. Describe the presentation of obstructive sleep apnea
    • Excessive daytime sleepiness (MCC)
    • Bed partners kept awake (snoring)
    • Morning headaches
    • Depression
  10. What causes obstructive sleep apnea?
    • In adults: excess parapharyngeal tissue
    • In children: adenotonsillar hypertrophy
    • Patient continues to contract the diaphragm in an attempt to breathe but airflow is impeded by upper airway obstruction

  11. What is obesity hypoventilation syndrome (aka Pickwickian syndrome)?
    • Obesity BMI>30 impeded the expansion of the chest and abdominal wall during breathing.
    • Underventilation of lungs during all  hours -> Chronically elevated PaCO2 during sleep and waking hours
    • Decreased PaO2
  12. What is central sleep apnea?
    CNS injury/ toxicity- no drive to initiate breathing
  13. The 47,XXY karyotype is diagnostic of?
    • Klinefelter syndrome
    • The extra chromosome is acquired due to meiotic nondisjunction.
  14. 45,XO karyotype is diagnostic of ?
    Turner syndrome
  15. Calcitonin is secreted by?
    Parafollicular or C cells of the thyroid
  16. What is the function of calcitonin?
    Decreased bone resorption of calcium (osteoclast inhibition)
  17. Label 1-4
  18. Describe the passage of a penetrating injury to the right ventricle.
    • Penetrating injury at the left sternal boarder at the level of the 4th intercostal space
  19. Describe the penetrating injury to the left ventricle.
    Penetrating injury t the 4th intercostal space in midclavicular line, only after passing through a bulk of the lung

  20. Describe the penetrating injury to the pulmonary trunk.
    • Penetrating injury to 2nd intercostal space at left sternal boarder
  21. At what level does the IVC penetrate the diaphragm?
    At T8
  22. How does HIV enter the target cell?
    • 1. gp120 binds CD4 and CCR5 ( on macrophages (early infection))/ CXCR4 (on T cells (late infection))
    • 2. The virus enters the cell by fusion with the cell membrane (gp41)
  23. What role does the CCR5 coreceptor play in HIV infection?
    gp120 binds CD4 as well as a coreceptor CCR5 on macrophages (early infection).
  24. What role does CXCR4 play in HIV infection?
    gp120 binds CD4 as well as coreceptor CXCR4 in T cells (late infection)
  25. Deletion of both alleles of the gene that codes for CCR5 indicates?
    Homozygous CCR5 mutation= immunity/ resistant to HIV
  26. What happens if cells do not express the CCR5 protein on their membrane?
    HIV binds CD4 but is unable to enter the cell.
  27. What is the importance of fibronectin?
    • High molecular weight glycoprotein that is synthesized in the liver and plays a role in wound healing.
    • Component of cryoprecipitate used to treat coagulation deficiencies involving fibrinogen and factor 8
  28. What are cadherins?
    • Calcium dependent adhesion proteins responsible for cellular adhesion.
    • Loss of E-cadherin promotes metastasis.
  29. Downregulation in the gene that codes for E-cadherin is implicated in?
    Cancer progression and metastasis
  30. What are calcium-dependent adhesion proteins?
    Cadherins- important for cellular adhesion
  31. What are the effects of ethanol (alcohol) on gluconeogenesis?
    • Ethanol metabolism increases the NADH/NAD ratio in the liver causing the conversion of:
    • Oxaloaxetate to malate (prevents gluconeogenesis -> Fasting hypoglycemia)

What would you like to do?

Home > Flashcards > Print Preview