INI-CET 2024

125 Questions — Page 3 of 13

Anatomy

2 questions

Q21

Which of the following statements is true regarding the anatomy of the breast?

Q22

At which vertebral level is the ischial spine located?

INI-CET 2024 - Anatomy INI-CET Practice Questions and MCQs

Question 21: Which of the following statements is true regarding the anatomy of the breast?

A. The superior medial quadrant has more tissue
B. The nipple is located at the level of the fourth intercostal space in most women
C. There are 15-20 lobules present
D. The axillary tail of Spence crosses the anterior axillary fold (Correct Answer)

Explanation: ***The axillary tail of Spence crosses the anterior axillary fold*** - The **axillary tail of Spence** is an extension of breast glandular tissue that passes superolaterally from the main breast body and often **penetrates the deep fascia** in the axilla [3]. - Its presence crossing the **anterior axillary fold** is relevant for physical examination and surgical considerations, as it can be a site for breast pathologies. *The superior medial quadrant has more tissue* - The **superior lateral quadrant** of the breast typically contains the **most glandular tissue** and lymphatics, making it the most common site for breast cancers. - This anatomical distribution is crucial for understanding the **etiology and metastasis** of breast malignancies. *The nipple is located at the level of the fourth intercostal space in most women* - The **nipple** typically lies at the level of the **fourth rib (not intercostal space)** in nulliparous women, but its position can vary significantly based on individual factors like breast size, age, and parity [1]. - Topographical landmarks such as the **midclavicular line** are often used for more consistent localization. *There are 15-20 lobules present* - Each breast typically contains **15-20 lobes**, not lobules, arranged radially around the nipple [1]. - Each **lobe** consists of numerous smaller **lobules**, which are the functional units of milk production, draining into ducts that converge at the nipple [2].

Question 22: At which vertebral level is the ischial spine located?

A. L4
B. S2 (Correct Answer)
C. S3-S5
D. Coccygeal region

Explanation: ***S2*** - The **ischial spine** is a bony projection located on the posterior border of the ischium [1]. - It is anatomically located at the vertebral level of **S2**, which is a crucial landmark especially in obstetrics for assessing the station of the fetal head during labor [1]. *L4* - The **L4 vertebral level** is generally associated with the **iliac crests** and is a common site for lumbar punctures. - It lies significantly superior to the ischial spine and is not a relevant landmark for its location. *S3-S5* - The vertebral levels **S3 to S5** primarily contribute to the formation of the lower sacrum and the coccyx. - While they are inferior to S2, they are not directly associated with the precise anatomical level of the ischial spine. *Coccygeal region* - The **coccygeal region** consists of the fused coccygeal vertebrae, forming the tailbone. - This region is located inferior to the sacrum and is distinct from the level of the ischial spine, which is situated higher on the pelvis.

Anesthesiology

1 questions

Q21

Which of the following is a second-generation laryngeal mask airway (LMA)?

Biochemistry

2 questions

Q21

Select the correct sequence of events in the cAMP signaling pathway.

Q22

Which of the following is not an amino acid-derived neurotransmitter?

INI-CET 2024 - Biochemistry INI-CET Practice Questions and MCQs

Question 21: Select the correct sequence of events in the cAMP signaling pathway.

A. Adenylyl cyclase converts ATP to cAMP, which activates PKA. (Correct Answer)
B. PKA is activated before cAMP is formed.
C. Adenylyl cyclase activates PKA before producing cAMP.
D. cAMP directly activates adenylyl cyclase to produce more cAMP.

Explanation: ***Adenylyl cyclase converts ATP to cAMP, which activates PKA.*** - **Adenylyl cyclase** is an enzyme that catalyzes the conversion of **ATP (adenosine triphosphate)** into **cyclic AMP (cAMP)**, a crucial second messenger. - Subsequently, **cAMP** binds to and activates **Protein Kinase A (PKA)**, which then phosphorylates various target proteins to mediate cellular responses. *PKA is activated before cAMP is formed.* - **cAMP formation** is a prerequisite for **PKA activation**; PKA cannot be activated independently before cAMP is produced. - The binding of **cAMP** to the regulatory subunits of **PKA** is what causes the dissociation and activation of its catalytic subunits. *Adenylyl cyclase activates PKA before producing cAMP.* - **Adenylyl cyclase's** sole function in this pathway is to synthesize **cAMP** from ATP; it does not directly activate PKA. - **PKA activation** is mediated by **cAMP**, not directly by adenylyl cyclase. *cAMP directly activates adenylyl cyclase to produce more cAMP.* - While **cAMP** is a critical messenger, it does not directly activate **adenylyl cyclase** to produce more of itself in a positive feedback loop. - **Adenylyl cyclase** is typically activated by **G-protein coupled receptors (GPCRs)** binding to their ligands, which then stimulate G proteins to activate adenylyl cyclase.

Question 22: Which of the following is not an amino acid-derived neurotransmitter?

A. Dopamine
B. GABA
C. Serotonin
D. Creatine (Correct Answer)

Explanation: ***Creatine*** - **Creatine** is an organic compound that helps supply energy to cells, primarily muscle cells, but it does **not** function as a neurotransmitter. - It is synthesized from **amino acids** like arginine, glycine, and methionine, but it is not itself an amino acid-derived neurotransmitter. *Dopamine* - **Dopamine** is a **catecholamine neurotransmitter** derived from the amino acid **tyrosine**. - It plays crucial roles in **motivation**, reward, motor control, and various other brain functions. *GABA* - **GABA** (gamma-aminobutyric acid) is the **primary inhibitory neurotransmitter** in the central nervous system, derived from the amino acid **glutamate**. - It works to reduce neuronal excitability throughout the nervous system. *Serotonin* - **Serotonin** (5-hydroxytryptamine or 5-HT) is a **monoamine neurotransmitter** derived from the amino acid **tryptophan**. - It regulates mood, appetite, sleep, and numerous other physiological processes.

Physiology

2 questions

Q21

The interpretation of the following ABG value is: pH = 7.5, pCO2 = 50 mm Hg, HCO3 = 30 mEq/L

Q22

Which of the following statements about cardiac muscle is incorrect?

INI-CET 2024 - Physiology INI-CET Practice Questions and MCQs

Question 21: The interpretation of the following ABG value is: pH = 7.5, pCO2 = 50 mm Hg, HCO3 = 30 mEq/L

A. Respiratory acidosis
B. Metabolic acidosis
C. Metabolic alkalosis (Correct Answer)
D. Normal acid-base balance

Explanation: ***Metabolic alkalosis (partially compensated)*** - The **pH of 7.5** indicates **alkalosis**, and the elevated **bicarbonate (HCO3) of 30 mEq/L** is the primary driver of this high pH. - The elevated **pCO2 of 50 mm Hg** represents **partial respiratory compensation**, where the body retains CO2 to lower the pH toward normal. - Since the pH remains elevated (not normalized to 7.35-7.45), this is **partially compensated** rather than fully compensated. *Respiratory acidosis* - This would be characterized by a **low pH** and an **elevated pCO2**, which is not seen here as the pH is high. - Although pCO2 is elevated, the **high pH** and **high bicarbonate** rule out primary respiratory acidosis. *Metabolic acidosis* - This would present with a **low pH** and a **low bicarbonate** concentration. - The given values show a **high pH** and **high bicarbonate**, which is the opposite of metabolic acidosis. *Normal acid-base balance* - A normal acid-base balance would have a **pH between 7.35-7.45**, a **pCO2 between 35-45 mm Hg**, and an **HCO3 between 22-26 mEq/L**. - All three values are outside of their normal ranges, indicating an acid-base disturbance.

Question 22: Which of the following statements about cardiac muscle is incorrect?

A. Cardiac muscle has a short refractory period. (Correct Answer)
B. Cardiac muscle obeys the all or none law.
C. Cardiac muscle exhibits the Frank-Starling mechanism
D. Cardiac muscle has automaticity and rhythmicity

Explanation: ***Cardiac muscle has a short refractory period.*** - This statement is **incorrect** because cardiac muscle has a **long refractory period** (~250 ms), which prevents summation and tetanus by ensuring that the muscle relaxes completely before another action potential can be initiated. - The long refractory period is crucial for maintaining the heart's **pumping efficiency** and preventing arrhythmias. *Cardiac muscle obeys the all or none law.* - This statement is **correct**. Individual **cardiac muscle cells** obey the **all-or-none law**; when a stimulus reaches threshold, the cell contracts fully. - The heart as a whole organ can grade its contraction force through recruitment of more fibers and the Frank-Starling mechanism, but at the cellular level, the all-or-none principle applies. *Cardiac muscle exhibits the Frank-Starling mechanism* - This statement is **correct**. The **Frank-Starling mechanism** describes the heart's ability to increase its force of contraction and stroke volume in response to an increase in **venous return** or end-diastolic volume. - This intrinsic regulatory mechanism allows the heart to match its output to the venous return, optimizing cardiac efficiency. *Cardiac muscle has automaticity and rhythmicity* - This statement is **correct**. **Automaticity** refers to the ability of specialized cardiac cells (e.g., in the sinoatrial node) to spontaneously generate action potentials without external nervous stimulation. - **Rhythmicity** is the regular, cyclical discharge of these action potentials, which drives the rhythmic beating of the heart.

Surgery

3 questions

Q21

During thyroidectomy, which nerve, if damaged, can cause a hoarse voice?

Q22

A 55-year-old man has a history of difficulty swallowing and frequent choking while eating. A barium swallow shows a posterior pharyngeal diverticulum. What is the most likely diagnosis?

Q23

Patients requiring immediate life-threatening care are categorized under which of the following triage?

INI-CET 2024 - Surgery INI-CET Practice Questions and MCQs

Question 21: During thyroidectomy, which nerve, if damaged, can cause a hoarse voice?

A. Recurrent laryngeal; loops under aorta/subclavian (Correct Answer)
B. Superior laryngeal; with superior thyroid artery
C. Glossopharyngeal; along posterior thyroid
D. Hypoglossal; inferior to thyroid

Explanation: ***Recurrent laryngeal; loops under aorta/subclavian*** - The **recurrent laryngeal nerve (RLN)** innervates most of the intrinsic muscles of the larynx, including the **posterior crico-arytenoid muscle**, which is responsible for abducting the vocal cords. - Damage to the RLN during thyroidectomy can lead to **vocal cord paralysis**, resulting in a hoarse voice, stridor, or aspiration. *Superior laryngeal; with superior thyroid artery* - The **superior laryngeal nerve (SLN)** branches into external and internal laryngeal nerves. The **external laryngeal nerve** runs with the **superior thyroid artery** and innervates the **cricothyroid muscle**, which is responsible for tensioning the vocal cords. - Damage to the SLN can cause subtle changes in voice pitch and reduced vocal range but typically does not cause hoarseness or vocal cord paralysis, which is more characteristic of RLN injury. *Glossopharyngeal; along posterior thyroid* - The **glossopharyngeal nerve (CN IX)** provides sensory innervation to the posterior third of the tongue, tonsils, pharynx, and middle ear, and motor innervation to the stylopharyngeus muscle. - It is not directly related to vocal cord function or hoarseness as a result of thyroid surgery. *Hypoglossal; inferior to thyroid* - The **hypoglossal nerve (CN XII)** innervates all extrinsic and intrinsic muscles of the tongue, controlling tongue movement. - Damage to the hypoglossal nerve would affect speech articulation and swallowing but not directly cause hoarseness or vocal cord paralysis.

Question 22: A 55-year-old man has a history of difficulty swallowing and frequent choking while eating. A barium swallow shows a posterior pharyngeal diverticulum. What is the most likely diagnosis?

A. Zenker's diverticulum (Correct Answer)
B. Esophageal stricture
C. GERD
D. Achalasia

Explanation: ***Zenker's diverticulum*** - A **Zenker's diverticulum** is a **pseudodiverticulum** that occurs due to herniation of the pharyngeal mucosa at Killian's triangle, often causing dysphagia and regurgitation in older adults. - The **barium swallow** revealing a **posterior pharyngeal diverticulum** is a classic finding for Zenker's, and the symptoms of difficulty swallowing and choking are consistent with food lodging in the pouch. *Esophageal stricture* - An **esophageal stricture** is a narrowing of the esophagus, which would cause difficulty swallowing (dysphagia), but typically wouldn't lead to a **posterior pharyngeal diverticulum** on barium swallow. - While strictures can cause choking, the primary finding described in the barium swallow points away from a simple stricture. *GERD* - **Gastroesophageal reflux disease (GERD)** can cause dysphagia due to **esophagitis** or stricture formation, but it is not typically associated with a **posterior pharyngeal diverticulum**. - The main symptoms of GERD include **heartburn** and acid regurgitation, though atypical symptoms exist, the diverticulum is not characteristic. *Achalasia* - **Achalasia** is a motility disorder characterized by impaired relaxation of the **lower esophageal sphincter** and loss of peristalsis in the esophageal body, leading to dysphagia and regurgitation. - A barium swallow in achalasia typically shows a **dilated esophagus** with a "bird's beak" appearance at the LES, not a posterior pharyngeal diverticulum.

Question 23: Patients requiring immediate life-threatening care are categorized under which of the following triage?

A. Black
B. Yellow
C. Red (Correct Answer)
D. Green

Explanation: ***Red*** - The **red tag** is assigned to patients with immediate, life-threatening injuries or illnesses who have a high probability of survival with prompt medical intervention. - This category signifies that the patient needs **critical care** and immediate transport to a medical facility to stabilize their condition. *Black* - The **black tag** is reserved for patients who are deceased or whose injuries are so severe that survival is unlikely, even with extensive medical care. - This category indicates that resources should be allocated to those with a higher chance of survival. *Yellow* - The **yellow tag** is for patients with significant injuries that require medical attention but are not immediately life-threatening. - These patients can usually wait for a few hours before receiving definitive treatment. *Green* - The **green tag** is for patients with minor injuries or illnesses that are not life-threatening and who can often care for themselves or wait for medical attention for several hours. - They are considered the "walking wounded" and usually require minimal medical intervention.