INI-CET 2022 - Anatomy Practice Questions

Q: A 50-year-old male patient presented with left -sided hemiparesis. Damage to which part of the internal capsule leads to this presentation?

Posterior limb. ***Posterior limb*** - The **posterior limb** of the internal capsule contains the **corticospinal tracts**, which carry motor commands from the primary motor cortex to the spinal cord. - Damage to this area results in **contralateral hemiparesis** or hemiplegia, explaining the patient's left-sided weakness from right brain damage. *Anterior limb* - Contains **frontopontine fibers** and **anterior thalamic radiations**, which connect the frontal cortex to pontine nuclei and thalamus. - Lesions here typically cause **dysarthria**, **behavioral changes**, or **executive dysfunction**, not motor weakness. *Retrolentiform* - Contains the **optic radiations** (visual pathways) and some **auditory fibers** from the temporal lobe. - Damage results in **contralateral homonymous hemianopia** or **visual field deficits**, not hemiparesis. *Sublentiform* - Contains **auditory radiations** from the medial geniculate body and **temporopontine fibers**. - Lesions cause **auditory processing deficits** or **conduction aphasia** if dominant hemisphere affected, not motor weakness.

Q: Identify the cell marked in the image below

Mast cell. ***Mast cell*** - The cell indicated by the arrow displays characteristic features of a **mast cell**, including its large size, prominent central nucleus, and cytoplasm densely packed with numerous large, basophilic (darkly stained) granules. - These granules contain powerful inflammatory mediators like **histamine** and **heparin**, which are key in allergic reactions and inflammation. *Macrophage* - Macrophages are typically larger than mast cells with an **irregular shape**, a kidney-shaped nucleus, and often contain phagocytosed material in their cytoplasm, which is not clearly visible here. - While they are also immune cells, they lack the characteristic dense, uniform basophilic granulation seen in the indicated cell. *Plasma cell* - Plasma cells are characterized by an **eccentric nucleus** with **chromatin clumping** (cartwheel or clock-face appearance) and a prominent Golgi apparatus (perinuclear halo), none of which are evident in the marked cell. - Their cytoplasm is typically basophilic but lacks the distinct large granules. *Fibroblast* - Fibroblasts are typically **spindle-shaped** or stellate cells with elongated nuclei and a sparse cytoplasm, responsible for producing extracellular matrix. - They do not possess the abundant, dense cytoplasmic granules that are a hallmark of the cell shown.

Q: Identify which of the following structure is a sebaceous gland:

2. ***Correct: (2) Sebaceous gland*** - The structure labeled (2) is a **sebaceous gland**, characterized by its **multicellular alveolar structure** typically associated with a hair follicle - Sebaceous glands are **holocrine glands** where the entire cell disintegrates to release sebum (oily secretion) - These glands are found throughout the body except on palms and soles, and produce **sebum for lubrication** of hair and skin - Histologically identified by **grape-like clusters of cells** with foamy cytoplasm due to lipid content *Incorrect: (3) Inner root sheath* - The structure labeled (3) represents the **inner root sheath** of the hair follicle - This is a **structural component**, not a glandular structure - Functions to provide support and guidance to the developing hair shaft - Composed of three layers: Henle's layer, Huxley's layer, and the cuticle *Incorrect: (4) Hair matrix* - The structure labeled (4) indicates the **hair matrix**, located at the base of the hair follicle - This is a **proliferative zone** with actively dividing cells responsible for hair growth - Not a glandular structure, but rather the germinative region where hair cells differentiate - Contains melanocytes that provide pigment to the growing hair *Incorrect: (1) Hair shaft* - The structure labeled (1) is the **hair shaft**, the visible keratinized portion of the hair - This is the **final product** of the hair follicle, composed of dead, keratinized cells - Not a glandular structure, but rather a modified epidermal structure - Extends from the hair follicle through the skin surface

Q: Fingerprint first develops in how many weeks of intrauterine life?

12-16. ***12-16*** - **Fingerprint patterns**, specifically the **friction ridges** on the fingers, begin to form between 12 and 16 weeks of gestation. - This period marks the development of the **dermal papillae** and epidermal ridges that create the unique patterns. *20-24* - By 20-24 weeks, the fingerprint patterns are already **well-established** and clearly visible. - This stage is beyond the initial developmental period when the patterns first emerge. *28-32* - At 28-32 weeks, the fingerprint patterns are **fully formed** and permanent. - This timeframe is too late for the initial development of these unique dermal features. *32-36* - By 32-36 weeks, the fetus is nearing full term, and the **fingerprint morphology** is complete and stable. - The initial formation process has long since concluded before this stage.

Q: Froment's sign (book test) is used to assess the function of adductor pollicis. Which of the following nerves supplies this muscle?

Ulnar nerve. The adductor pollicis muscle is primarily innervated by the deep branch of the ulnar nerve [1]. This muscle is crucial for thumb adduction, and its function is assessed by the Froment's sign (often referred to as the book test) to detect ulnar nerve palsy. The radial nerve primarily innervates the muscles of the posterior compartment of the arm and forearm, responsible for wrist and finger extension [1]. It does not supply any intrinsic muscles of the hand, including the adductor pollicis [1]. The posterior interosseous nerve is a terminal branch of the deep radial nerve, supplying most of the extensors in the forearm [1]. It does not innervate any of the intrinsic hand muscles. The median nerve innervates most of the flexors of the forearm and the thenar muscles of the hand (abductor pollicis brevis, opponens pollicis, and superficial head of flexor pollicis brevis) [1]. It does not supply the adductor pollicis muscle; median nerve palsy would affect thumb opposition and abduction, not adduction [1].

Question 1

A 50-year-old male patient presented with left -sided hemiparesis. Damage to which part of the internal capsule leads to this presentation?

Accepted Answer

Posterior limb

Answer

Anterior limb

Answer

Retrolentiform

Answer

Sublentiform

Question 2

Identify the cell marked in the image below

Accepted Answer

Mast cell

Answer

Macrophage

Answer

Plasma cell

Answer

Fibroblast

Question 3

Identify which of the following structure is a sebaceous gland:

Accepted Answer

2

Answer

3

Answer

4

Answer

1

Question 4

Fingerprint first develops in how many weeks of intrauterine life?

Accepted Answer

12-16

Answer

20-24

Answer

28-32

Answer

32-36

Question 5

Froment's sign (book test) is used to assess the function of adductor pollicis. Which of the following nerves supplies this muscle?

Accepted Answer

Ulnar nerve

Answer

Radial nerve

Answer

Posterior interosseous nerve

Answer

Median nerve

INI-CET 2022 — Anatomy