Musculoskeletal

Question 1

What are diagnostic features of gout?

Pseudogout?

Answer 1

Gout=Needle shaped monosodium urate crystals (not birefringent). Commonly in joint of big toe.
Pseudogout=Rhomboid shaped calcium pyrophosphate (CPPD) crystals, positively birifringent. Commonly in knee.

Question 2

What anatomical landmark is used when getting a lumbar puncture?

Answer 2

You use the iliac crests because they are at the level of L3-L5, where the cauda equina is. That’s where you want to get the CSF from.

Question 3

Describe the characteristics of the 3 main types of hernia.

Answer 3

Indirect Inguinal: Caused by incomplete obliteration of processus vaginalis.
Direct Inguinal: Acquired protrusion through Hesselbach triangle in abdominal wall. NOT through inguinal canal. Medial to inferior epigastric blood vessels.
Femoral: Aquired protrusion through weakness of femoral canal. Least common type.

Question 4

“Ragged red” muscle fibers are indicative of what types of disease?

Answer 4

Mitochondrial, maternal inheritance pattern.

Question 5

A person lacks t tubules in some muscles.

What is the purpose of the T tubule, and what is the result?

Answer 5

T tubules propogate the message throughout the entire muscle pretty much simultaneously.
If you lack them, the action potential will not be uniform, and you will have uncoordinated contraction of the muscle.

Question 6

A patient has a disease that is causing reactive oxygen species to go nuts in their body. What are 3 potential enzymes that could fight against this process?

Answer 6

1) Superoxide dismutase
2) Glutathione peroxidase
3) Catalase

Question 7

T or F?

African Americans have a lower bone density and are more susceptible to osteoporosis than whites?

Answer 7

False. African Americans have GREATER bone density than whites, less susceptible to osteoporosis.
This has been in 2 questions so far

Question 8

If a chest tube is placed between ribs along the mid axillary line, what muscles does it go through?

Answer 8

The serratus anterior muscles and the intercostal muscles.

NOT the latissimus dorsi.

Question 9

In melanoma, what is the embryological origin of the problem cell?

Answer 9

Melanocytes–neural crest cells

Question 10

What advantage does celecoxib have over other NSAIDs?

Answer 10

Celecoxib is a COX-2 inhibitor only. So they decrease inflammation (by blocking COX-2), but don’t cause any gastroduodenal toxicity (like normal NSAIDs that block both COX-1 and COX-2)

Question 11

For each gland type, give the manner in which they secrete and an example.
Apocrine
Holocrine
Merocrine

Answer 11

Apocrine: Secrete via membrane-bound vesicles. Ex=mammary glands
Holocrine: cell lysis, secretes entire contents of cypoplasm and cell membrane. Ex=sebaceous glands (acne), Meibornian glands (eyelids)
Merocrine: Secrete via exocytosis. Ex=salivary glands, eccrine sweat glands, apocrine sweat glands.

Question 12

A lady with lupus is started on prednisone. What change would you note in her CBC within the first few hours of initiation?

Answer 12

Increased neutrophils. This actually decreases the immune response of neutrophils, but it releases them from the vessel wall (called “demargination”)

Question 13

An abdominal injury involves the phrenic nerve. Where will there be referred pain?

Answer 13

C3-C5 shoulder region (Kehr sign).

Also look for hiccups, nausea.

Question 14

Long term treatment and indications for gout?

Answer 14

Xanthine oxidase inhibitors.

They are used in people who have issues with chronic gout or chronic renal stones or tophi.

Question 15

A patient sustains a mid shaft humerus fracture. What nerve and artery are most likely involved, and what lack of function should you see?

Answer 15

Radial Nerve.
Deep brachial artery.
You should see a wrist drop (complete loss of wrist extension ability)

Question 16

You diagnose somebody with myasthenia gravis (weakness in hands/eyelids). What tumor is likely present? From which embryological structure does this originate? What other structure comes from there?

Answer 16

A thymoma. Just an association to know.
Originates from the 3rd pharyngeal pouch, along with the inferior parathyroid glands.
*NOTE! The superior parathyroid glands actually come from the 4th pouch! Counterintuitive

Question 17

What is the difference between pemphigus vulgaris and bullous pemphigoid?

Answer 17

Vulgaris: IgG antibody against desmosomes. Ruptures blisters, including in the oral cavity. Separation of epidermis upon manual stroking of skin.
Pemphigoid: Less severe, spares oral mucosa. Antibodies against hemidesmosomes, the blisters remain in tact.

Question 18

What are the 3 types of antibodies that can be detected in SLE?

Answer 18

1) Antinuclear antibodies–>not specific
2) Anti-double stranded DNA–>specific
3) Anti-Smith antibodies–>specific, but only present in 20-30% of SLE patients

Question 19

What is the underlying issue in xeroderma pigmentosum (when the skin is hyperreactive to UV rays and hyperpigmented and thin)?

Answer 19

There is faulty nucleotide excision repair. Normally UV rays cause issues in DNA that are removed by excision repair, but if this process isn’t there then you get abnormal amount of pyrimidines or carcinogenic additions.

Question 20

A patient is having a severe allergic reaction and a cricothyrotomy procedure is needed. What layers will the incision pass through?

Answer 20

Superficial cervical fascia, Pretracheal fascia, Cricothyroid membrane