Deck II

Question 1

What embryological abnormality results in an annular pancreas?

Answer 1

Abnormal migration of the ventral pancreatic bud.

Question 2

What does an annular pancreas encircle?

Answer 2

The descending part of the duodenum.

Question 3

The left ureter lies immediately anterolateral to what structure in the true pelvis?

Answer 3

Left internal illiac artery.

Question 4

Describe the position of the ureters in relation to other vasculature in the area.

Answer 4

Ureters cross over the common/external iliac vessels and under the gonadal vessels (and uterine vessels in females); they lie anterolateral to the internal iliac vessels and medial to the ovarian vessels within the true pelvis.

Question 5

What is most likely to be punctured due to insertion of a needle along the upper border of the 10th rib at the right midaxillary line?

Answer 5

The liver.

Question 6

Where should a thoracocentesis be performed?

Answer 6

Above the 7th rib in midclavicular line, the 9th rib along the midaxillary line, and the 11th rib along the posterior scapular line.

Question 7

What structure may be punctured due to thoracosentesis penetration on the inferior margin of the rib?

Answer 7

The subcostal neurovascular bundles

Question 8

What artery is most likely to be damaged due to fracture of the humeral shaft?

Answer 8

Deep brachial artery (runs with the radial nerve)

Question 9

What is the underlying cause of Myasthenia Gravis?

Answer 9

Circulating antibodies against acetylcholine cell surface receptors of the NMJ.

Question 10

What celluluar processes occur in lymphoid germinal centres?

Answer 10

Germinal centres are the site of B cell proliferation during an immune response. The majority of activated B cells in the germinal centres transform into antibody secreting plasma cells (i.e. undergo isotype switching).

Question 11

Describe the Type I IgE Hypersensitivity response.

Answer 11

Reaction is triggered by cell surface bound IgE bridging by antigen.

Question 12

What does a giardia lamblia trophozoite look like on peripheral smear?

Answer 12

Pear shaped, bilaterally symmetric organisms with four pairs of flagella and two nuclei

Question 13

What deficiency is likely in a patient with recurrent Giardia lamblia infections?

Answer 13

IgA deficiency.

Question 14

What is the key factor in the elimination of and host defense against mycobacterial infections?

Answer 14

IFN-y.

Question 15

What type of immunodeficiency is implicated by recurrent otitis media infections from strep. Pneumo, H. influenzae, and Moraxella?

Answer 15

Humoral immunodeficiency.

Question 16

What type of immunodeficiency is implicated by pneumocystic infections and chronic mucocutaneous candidiasis?

Answer 16

T cell deficiency.

Question 17

What is the candida skin test used to assess?

Answer 17

Cell mediated response (T-cell and NK cell activity)

Question 18

What type of hypersensitivity reaction can be mediated by sulfonamides?

Answer 18

Type III

Question 19

What immunologic deficiency is characteristic of a type III hypersensitivity serum sickness reaction?

Answer 19

Low C3 levels 5-10 days after intravascular exposure to an antigen.

Question 20

What immunologic impairment can be expected in a patient with a defective Fas gene product?

Answer 20

Activation of T lymphocyte death.

Question 21

What is the function of the Fas receptor?

Answer 21

Initiation of the extrinsic pathway of apoptosis.

Question 22

How do eosinophils contribute to host defenses in parasitic infection?

Answer 22

By destroying the parasite via antibody dependent cellular cytotoxicity (ADCC) with enzymes from their cytoplasmic granules.

Question 23

What abnormal immunologic ratio is characteristic of sarcoidosis?

Answer 23

Intraalveolar and interstitial accumulation of CD4+ T cells results in a high CD4:CD8 ratio.

Question 24

What is likely to appear on biopsy in a patient with chronic organ rejection?

Answer 24

Obliterative vascular fibrosis due to antibody mediated damage to the graft endothelium. This causes obliterative intimal smooth muscle hypertrophy and fibrosis.

Question 25

What immunologic process mediates Graft vs Host disease?

Answer 25

T lymphocytes of the donor tissue attack MHC antigens of the recipient. Skin, liver, and intestine are commonly involved.

Question 26

What cytokine is typically involved in mediating the accumulation of pus?

Answer 26

IL-8.

Question 27

What comprises an MHC Class I molecule?

Answer 27

A single heavy chain and an associated B2 microglobulin.

Question 28

What cell types possess MHC class II peptides?

Answer 28

Antigen presenting cells only.

Question 29

How is antigen and APC loaded onto MHC class II peptides?

Answer 29

Antigen is taken into the APC by phagocytosis or endocytosis and is loaded onto MHC Class II within acidified endosomes.

Question 30

How does the influenza vaccine attenuate flu-symptoms?

Answer 30

By impairing virus entry into cells.