NEET-PG 2012 Practice Questions

Q: Crural index is:

Length of tibia/femur x 100. ***Length of tibia/femur x 100*** - The **crural index** is a measure used in physical anthropology and comparative anatomy to describe the proportion of the lower leg to the thigh. - It is calculated by dividing the **length of the tibia** (lower leg bone) by the **length of the femur** (thigh bone) and multiplying by 100 to express it as a percentage. *Length of radius/humerus x 100* - This formula describes the **brachial index**, which measures the proportion of the forearm to the upper arm. - It does not represent the crural index, which refers specifically to the **lower limb**. *Length of fibula/tibia x 100* - This ratio compares the two bones within the lower leg but is not the definition of the **crural index**. - The crural index focuses on the relative length of the lower leg to the entire thigh, reflecting overall **limb proportions**. *Length of radius/ulna x 100* - This ratio compares the lengths of the two bones in the forearm and does not correspond to the **crural index**. - The crural index involves the **tibia** and **femur**, which are bones of the lower limb.

Q: What is the term for the time between infection and maximum infectivity?

Generation time. ***Generation time*** - This is the **time interval** between receipt of infection by a host and the moment of **maximum infectivity** of that same host. - It is a crucial parameter in epidemiology for understanding **disease transmission dynamics** and the speed at which an epidemic can spread. *Incubation period* - This refers to the time from **exposure to an infectious agent** until the **onset of symptoms**. - It does not directly account for the timing of viral shedding or peak infectivity. *Serial interval* - This is the time between **symptom onset in a primary case** and **symptom onset in a secondary case** it infects. - While related to transmission, it focuses on symptomatic presentation rather than peak infectivity. *Communicable period* - This is the time during which an infected individual is **capable of transmitting** the infectious agent to others. - It represents the entire duration of potential transmission, not specifically the peak infectivity.

Q: Which of the following is NOT considered a grievous injury?

Breast contusion. ***Breast contusion*** - A breast contusion, while painful, is generally a **minor injury** that typically resolves without long-term significant functional impairment or disfigurement. - It does not meet the criteria for a grievous injury under **IPC Section 320**, which requires severe, lasting physical harm or functional loss. *Multiple facial scars* - Multiple facial scars can lead to significant and **permanent disfigurement of the face**, which is explicitly listed as a grievous injury under IPC Section 320. - Such scarring can have profound psychological impacts and may require extensive reconstructive surgery. *Femur fracture* - A femur fracture is a **grievous injury** under IPC Section 320 as it constitutes a **"fracture or dislocation of a bone."** - Additionally, it results in **severe pain**, prolonged disability, and often requires extensive medical intervention including surgery, with potential for protracted loss of use of a limb. *Emasculation injury* - Emasculation refers to the **removal or destruction of male reproductive organs**, which is explicitly listed as a grievous injury under IPC Section 320. - This type of injury results in **permanent impairment of reproductive powers** and qualifies as privation of a member or joint.

Q: Neonatal conjunctivitis is caused by all of the following except:

Aspergillus. ***Aspergillus*** - **Fungal infections** of the eye, particularly by *Aspergillus*, are extremely rare in neonates and typically present as **keratitis** rather than conjunctivitis. - While *Aspergillus* can cause severe infections in immunocompromised individuals, it is not a common cause of neonatal conjunctivitis. *Gonococcus* - **_Neisseria gonorrhoeae_** is a well-known cause of **ophthalmia neonatorum** (gonococcal conjunctivitis), presenting as severe, purulent discharge usually within the first 2-5 days of life. - This infection can lead to **corneal ulceration** and blindness if untreated. *Chlamydia* - **_Chlamydia trachomatis_** is the most common bacterial cause of **neonatal conjunctivitis**, typically appearing 5-14 days after birth. - It causes a **mucopurulent discharge** and can be associated with **chlamydial pneumonia** in infants. *Pseudomonas* - **_Pseudomonas aeruginosa_** can cause severe and rapidly progressive **neonatal conjunctivitis** and **keratitis**, especially in premature infants or those exposed to contaminated solutions. - It is a highly aggressive pathogen that can lead to significant ocular morbidity.

Q: What is the most common cause of vitreous hemorrhage in diabetic retinopathy?

Proliferative diabetic retinopathy. ***Proliferative diabetic retinopathy*** - **Neovascularization** is the hallmark of proliferative diabetic retinopathy (PDR), where new, fragile blood vessels grow on the surface of the retina and optic disc. - These delicate vessels can easily rupture and bleed into the vitreous humor, leading to a **vitreous hemorrhage**. *Non-proliferative diabetic retinopathy* - This stage is characterized by **microaneurysms**, hemorrhages, and cotton wool spots, but typically lacks significant neovascularization. - While it involves retinal vascular damage, the absence of **newly formed, fragile vessels** makes vitreous hemorrhage less common. *Severe non-proliferative diabetic retinopathy* - This stage shows extensive microvascular abnormalities, including numerous hemorrhages and venular beading, but generally **still no new vessel formation**. - Without the presence of **fragile neovascular membranes**, the risk of significant vitreous hemorrhage is lower compared to PDR. *Diabetic macular edema* - This condition involves **fluid leakage** from damaged retinal vessels into the macula, causing vision loss. - While it's a common complication of diabetes, it primarily causes **macular swelling** and does not directly lead to vitreous hemorrhage.

Q: When should breastfeeding be initiated after a normal delivery?

Immediately after delivery. **Correct: Immediately after delivery** - Initiating breastfeeding **within the first hour** of birth (early initiation) is crucial for establishing **successful lactation** and promoting optimal infant health. - This early initiation allows for **skin-to-skin contact**, which helps stabilize the newborn's temperature, heart rate, and breathing, and facilitates **bonding** between mother and baby. - Aligned with **WHO and UNICEF recommendations** for best practice in postpartum care. *Incorrect: 2 hours after delivery* - While earlier is generally better, waiting two hours misses the **optimal window** for initiating feeding and bonding. - The newborn's **alert period** is typically strongest in the first hour post-birth, making it an ideal time for the first latch. *Incorrect: 4 hours after delivery* - Delaying breastfeeding by four hours can make it more challenging for the baby to latch effectively as they may have passed their **initial alert state** and become sleepy. - This delay can also hinder the establishment of the mother's **milk supply**, as stimulation from early feeding is important for prolactin release. *Incorrect: 6 hours after delivery* - Waiting six hours significantly **misses the critical window** for early initiation and can lead to increased difficulties with breastfeeding. - Prolonged delays may necessitate supplementation, potentially interfering with exclusive breastfeeding and establishing a **strong milk supply**.

Q: What is the iodine content percentage in amiodarone?

20 - 40%. ***20 - 40%*** - **Amiodarone** is highly lipophilic and contains a significant amount of **iodine**, typically comprising around **37.5%** of its molecular weight. - This high iodine content is responsible for many of its **adverse effects**, particularly those related to thyroid dysfunction. *10 - 20%* - This range is too low; the actual iodine content in **amiodarone** is considerably higher, making it a prominent feature of the drug's chemical structure. - A lower iodine percentage would likely result in fewer **thyroid-related side effects**. *40 - 60%* - While amiodarone has a high iodine content, 40-60% is slightly above the generally accepted range. - Iodine constitutes a substantial but not an overwhelming majority of the drug's molecular mass. *60 - 80%* - This range is significantly higher than the actual iodine content in **amiodarone**. - Such a high percentage would imply an even greater propensity for **iodine-induced adverse effects**.

Q: Which enzyme is irreversibly inhibited by aspirin?

Cyclooxygenase. ***Cyclooxygenase*** - **Aspirin** irreversibly inhibits **cyclooxygenase (COX-1 and COX-2)** by acetylating a serine residue in the enzyme's active site. - This irreversible inhibition prevents the production of **prostaglandins, thromboxane**, and **prostacyclin**, thereby reducing inflammation, pain, fever, and platelet aggregation. *Lipooxygenase* - **Lipooxygenase** is involved in the synthesis of **leukotrienes**, which are mediators of inflammation and allergic responses. - Aspirin does not directly inhibit lipooxygenase; rather, it primarily targets the COX pathway. *Thromboxane synthase* - **Thromboxane synthase** is an enzyme downstream of COX, responsible for converting prostaglandin H2 into **thromboxane A2**. - While aspirin's effect on platelet aggregation is due to reduced thromboxane A2 synthesis via COX inhibition, it does not directly inhibit thromboxane synthase itself. *Phospholipase* - **Phospholipase A2** is responsible for releasing **arachidonic acid** from cell membrane phospholipids, which is the initial step in both the cyclooxygenase and lipooxygenase pathways. - Aspirin does not directly inhibit phospholipase A2; its action occurs later in the cascade.

Q: A wave in ERG is due to activity of:

Rods and cones. ***Rods and cones*** - The **electroretinogram (ERG)** measures the electrical responses of various retinal cells to light stimuli. - The **a-wave** of the ERG primarily reflects the activity of the **photoreceptors (rods and cones)** as they hyperpolarize in response to light. *Pigmented epithelium* - The **retinal pigmented epithelium (RPE)** plays a crucial role in photoreceptor health and function but does not directly generate the primary electrical waves measured by the standard ERG. - Its dysfunction can lead to secondary changes in ERG, but its activity is not the direct source of the a-wave. *Ganglion cell* - **Ganglion cells** are the output neurons of the retina, transmitting visual information to the brain. - Their activity is generally not well-represented in the standard ERG, which primarily assays outer and middle retinal layers. *Bipolar cell* - **Bipolar cells** transmit signals from photoreceptors to ganglion cells and contribute to the **b-wave** component of the ERG. - The b-wave, not the a-wave, is largely generated by the depolarizing activity of bipolar cells and Müller cells.

Question 1

Crural index is:

Accepted Answer

Length of tibia/femur x 100

Answer

Length of radius/humerus x 100

Answer

Length of fibula/tibia x 100

Answer

Length of radius/ulna x 100

Question 2

What is the term for the time between infection and maximum infectivity?

Accepted Answer

Generation time

Answer

Communicable period

Answer

Incubation period

Answer

Serial interval

Question 3

Which of the following is NOT considered a grievous injury?

Accepted Answer

Breast contusion

Answer

Multiple facial scars

Answer

Femur fracture

Answer

Emasculation injury

Question 4

Which of the following statements about Haemophilus influenzae is true?

Accepted Answer

Encapsulated strains are the most common cause of severe H. influenzae diseases

Answer

It is not capsulated

Answer

Invasive strain causes severe diseases but is less common than non-invasive strains

Answer

Typically grown on chocolate agar in CO2-enriched environment but not clinically relevant to severe diseases

Question 5

Neonatal conjunctivitis is caused by all of the following except:

Accepted Answer

Aspergillus

Answer

Chlamydia

Answer

Pseudomonas

Answer

Gonococcus

Question 6

What is the most common cause of vitreous hemorrhage in diabetic retinopathy?

Accepted Answer

Proliferative diabetic retinopathy

Answer

Non-proliferative diabetic retinopathy

Answer

Severe non-proliferative diabetic retinopathy

Answer

Diabetic macular edema

Question 7

When should breastfeeding be initiated after a normal delivery?

Accepted Answer

Immediately after delivery

Answer

2 hours after delivery

Answer

4 hours after delivery

Answer

6 hours after delivery

Question 8

What is the iodine content percentage in amiodarone?

Accepted Answer

20 - 40%

Answer

10 - 20%

Answer

40 - 60%

Answer

60 - 80%

Question 9

Which enzyme is irreversibly inhibited by aspirin?

Accepted Answer

Cyclooxygenase

Answer

Lipooxygenase

Answer

Thromboxane synthase

Answer

Phospholipase

Question 10

A wave in ERG is due to activity of:

Accepted Answer

Rods and cones

Answer

Pigmented epithelium

Answer

Ganglion cell

Answer

Bipolar cell

NEET-PG 2012

Anatomy

Community Medicine

Forensic Medicine

Microbiology

Ophthalmology

Pediatrics

Pharmacology

Physiology