PRINCIPLES OF MEDICINE MIDTERM EXAM

Question 1

most common malignant tumor of the oral cavity?

Answer 1

Squamous cell carcinoma

Question 2

most common histological type of oral cancer is:

Answer 2

Squamous cell carcinoma

Question 3

hallmarks of cancer allows cancer cells to divide indefinitely?

Answer 3

Enabling replicative immortality

Question 4

Dysplasia is best described as

Answer 4

A pre-cancerous condition with abnormal cell appearance and disorganized tissue architecture

Question 5

A tumor is composed of both parenchyma and stroma. What is the primary role of the parenchyma in a tumor?

Answer 5

It determines the biological behavior and name of the tumor

Question 6

A pre-cancerous oral lesion appearing as a white patch on the mucosa is called:

Answer 6

Leukoplakia

Question 7

A cancer that is confined to its tissue of origin, without lymph node involvement or metastasis, is classified as

Answer 7

Stage I

Question 8

Which of the following is the main hallmark of neoplasia?

Answer 8

Uncontrolled and persistent cell division

Question 9

The two basic components of a tumor are:

Answer 9

Parenchyma and stroma

Question 10

What is the role of the stroma in a tumor?

Answer 10

It carries the blood supply and provides structural support

Question 11

What is the MAIN characteristic that distinguishes benign tumors from malignant tumors?

Answer 11

) Malignant tumors invade and metastasize, while benign tumors do not

Question 12

Which hallmark of cancer allows malignant cells to spread to distant organs?

Answer 12

Activating invasion and metastasis

Question 13

Which of the following statements regarding cancer is FALSE?

Answer 13

Cancer cells maintain their normal cell-to-cell adhesion and architecture

Question 14

Which of the following is NOT a risk factor for oral cancer?

Answer 14

High vitamin C intake

Question 15

Which statement about benign and malignant tumors is TRUE?

Answer 15

Benign tumors are well-differentiated and do not spread

Question 16

A 55-year-old smoker with a long history of alcohol consumption develops a non-healing ulcer on the lateral border of the tongue. The lesion is persistent for more than three weeks and is firm on palpation. Which of the following is the most appropriate next step?

Answer 16

Perform a biopsy of the lesion for histopathologic examination

Question 17

In the TNM staging system, what does ‘N’ represent?

Answer 17

Lymph node involvement

Question 18

What is the final stage of the cell cycle, where actual cell division occurs?

Answer 18

M

Question 19

Which of the following findings is most characteristic of hereditary spherocytosis?

Answer 19

Spherocytes on peripheral smear

Question 20

Iron-deficiency anemia is most commonly caused by:

Answer 20

Hemorrhage

Question 21

What is the primary defect in Chronic Granulomatous Disease (CGD)?

Answer 21

Defective oxidative (respiratory) burst

Question 22

Which anticoagulant specifically targets the intrinsic coagulation pathway?

Answer 22

Heparin

Question 23

Which of the following is NOT a stage of hemostasis?

Answer 23

Coagulation degradation

Question 24

Which of the following best describes the primary function of hemoglobin in red blood cells?

Answer 24

Transporting oxygen from the lungs to tissues and facilitating carbon dioxide removal

Question 25

Prothrombin Time (PT) assesses

Answer 25

Extrinsic pathway

Question 26

Which clotting factor is absent in hemophilia A

Answer 26

Factor VIII

Question 27

Aplastic anemia is characterized by:

Answer 27

Decreased production of RBCs, WBCs, and platelets

Question 28

What does an INR of greater than 5 indicate?

Answer 28

Increased risk of bleeding

Question 29

Which laboratory test is the gold standard for diagnosing CGD?

Answer 29

Flow cytometric oxidative (respiratory) burst assay

Question 30

Which type of anemia is characterized by large, immature RBCs?

Answer 30

Megaloblastic anemia

Question 31

Which white blood cell type is most abundant in a normal blood smear?

Answer 31

. Neutrophils

Question 32

A high eosinophil count suggests:

Answer 32

Parasitic infection

Question 33

What hormone regulates RBC production?

Answer 33

. Erythropoietin

Question 34

What is the primary function of blood?

Answer 34

Transport of gases, nutrients, and waste B. Regulation of body temperature C. Defense against infections D. (All of the above)

Question 35

Hodgkin lymphoma is characterized by the presence of:

Answer 35

Reed-Sternberg cells

Question 36

Which of the following is NOT a component of blood?

Answer 36

Myosin

Question 37

Which of the following best differentiates Gram-positive from Gram-negative bacteria?

Answer 37

The retention of crystal violet dye due to a thick peptidoglycan layer

Question 38

Dermatophytes require which of the following for survival?

Answer 38

Keratin

Question 39

An infectious agent that causes severe disease but does not easily spread from host to host would be described as having:

Answer 39

High virulence, low infectivity

Question 40

Which of the following is a hallmark sign of sepsis?

Answer 40

Hypotension, organ failure, and shock

Question 41

Tinea capitis is primarily diagnosed through:

Answer 41

Examination of plucked hairs on potassium hydroxide (KOH) wet mount

Question 42

Case: A new strain of influenza virus spreads rapidly among a population but causes only mild symptoms in most infected individuals. Scientists analyzing the virus note that almost everyone exposed develops an infection, but severe complications are rare. Which of the following best describes this new strain?

Answer 42

High infectivity, low virulence

Question 43

The development of acute necrotizing ulcerative gingivitis is most strongly associated with which of the following conditions?

Answer 43

Poor oral hygiene and stress

Question 44

Which of the following is a defining characteristic of obligate intracellular bacteria?

Answer 44

They require host cells for replication and survival.

Question 45

Which of the following statements about dermatophytoses is FALSE?

Answer 45

They primarily affect internal organs.

Question 46

Ludwig’s angina is a serious bacterial infection primarily affecting which anatomical regions?

Answer 46

Sublingual, submandibular, and submental spaces

Question 47

Case: A 5-year-old child develops a high fever, cough, and runny nose. A week earlier, he had attended a birthday party where another child was later diagnosed with measles. The physician explains that measles spreads through airborne particles that can linger in the air for hours. What mode of transmission is responsible for the spread of measles in this case?

Answer 47

Aerosol transmission

Question 48

Case: A 23-year-old woman presents with painful urination, frequent urge to urinate, and lower abdominal discomfort. A urinalysis reveals elevated white blood cells and bacteria. What type of infection is most likely responsible for her symptoms?

Answer 48

Urinary tract infection (UTI)

Question 49

A patient develops a fungal infection after sharing contaminated towels. This mode of transmission is:

Answer 49

Indirect contact

Question 50

The ability of an infectious agent to survive outside the host in adverse conditions is referred to as:

Answer 50

Survivability in the environment

Question 51

Case: A 55-year-old man with poorly controlled diabetes presents with white, curd-like patches on his tongue and inner cheeks that can be scraped off, revealing red, inflamed tissue beneath. He reports a burning sensation in his mouth. What is the most likely cause of his condition?

Answer 51

Oral candidiasis (thrush)

Question 52

Which of the following correctly describes the sequence of events required for a microbe to establish infection?

Answer 52

Contamination → Adherence → Colonization → Invasion → Pathogenic Effects

Question 53

Which of the following is a hallmark sign of sepsis?

Answer 53

Hypotension, organ failure, and shock

Question 54

The development of acute necrotizing ulcerative gingivitis is most strongly associated with which of the following conditions?

Answer 54

Poor oral hygiene and stress

Question 55

A patient with a history of HIV presents with white patches on the buccal mucosa that can be scraped off. The most likely diagnosis is:

Answer 55

Candidiasis

Question 56

Oral candidiasis commonly occurs due to:

Answer 56

Overuse of antibiotics or immunosuppressive drugs

Question 57

Which characteristic of an infectious agent refers to its ability to cause disease in a host?

Answer 57

Pathogenicity

Question 58

Which of the following is an example of indirect transmission?

Answer 58

A person contracts influenza after shaking hands with an infected individual

Question 59

A 72-year-old man with a history of diabetes is admitted to the ICU with confusion, low blood pressure, and rapid breathing. His blood tests show a very high white blood cell count and elevated lactate levels. Despite antibiotic therapy, his condition worsens, leading to organ dysfunction.

Answer 59

Septic shock

Question 60

Which microbial infection is caused by Candida albicans and commonly presents as white patches on the oral mucosa?

Answer 60

Oral candidiasis (thrush)