NEET-PG 2015 - Anatomy Practice Questions

Q: Which of the following structures does NOT pass through Calot's triangle?

Portal vein. ***Portal vein*** - The **portal vein** is located within the **porta hepatis** and does not pass through Calot's triangle, making it the correct answer to this question. - It carries venous blood from the **gastrointestinal tract** and **spleen** to the liver and is positioned medial and posterior to the structures within Calot's triangle. *Right hepatic artery* - The **right hepatic artery** is a key structure that passes through Calot's triangle and forms one of its boundaries. - It typically gives rise to the **cystic artery** within or near the triangle, making it an important anatomical landmark during **cholecystectomy**. *Lymph node of Lund* - The **lymph node of Lund** (cystic lymph node) is consistently found within Calot's triangle and serves as an important landmark. - Its presence helps surgeons identify the **boundaries of the triangle** and assess for inflammation or malignancy related to the gallbladder. *Cystic artery* - The **cystic artery** is a consistent structure within Calot's triangle, typically arising from the **right hepatic artery**. - It is routinely **ligated during cholecystectomy** and is one of the key structures surgeons must identify within the triangle.

Q: What structure passes through the quadrangular space?

Axillary nerve. Axillary nerve - The axillary nerve and the posterior circumflex humeral artery are the primary structures that pass through the quadrangular space. - Compression or injury within this space can lead to deficits in the axillary nerve's distribution, affecting the deltoid and teres minor muscles. *Radial nerve* - The radial nerve passes through the triangular interval, not the quadrangular space. - It supplies the triceps muscle and all muscles in the posterior compartment of the forearm. *Median nerve* - The median nerve travels through the cubital fossa and then down the anterior forearm, supplying most of the forearm flexors and some hand muscles. - It does not pass through any of the posterior axillary spaces. *Brachial Artery* - The brachial artery is the main arterial supply to the arm and runs anteriorly in the arm, deep to the biceps brachii muscle. - It does not pass through the quadrangular space; rather, the posterior circumflex humeral artery (a branch of the axillary artery) traverses this space.

Q: Seminal colliculus is present in ?

Urethra. ***Correct: Urethra*** - The **seminal colliculus** (also known as the **verumontanum**) is a prominent ridge located on the posterior wall of the **prostatic urethra** - It contains the openings of the **ejaculatory ducts** and the **prostatic utricle** - This is a key anatomical landmark in the male urethra during endoscopic procedures *Incorrect: Prostate* - While the seminal colliculus is located within the portion of the urethra that passes through the prostate (prostatic urethra), it is not a structure *of* the prostate gland itself - The prostate is a gland that surrounds the urethra and contributes to seminal fluid - The seminal colliculus is an intraluminal urethral structure, not prostatic tissue *Incorrect: Testis* - The testis is the primary male reproductive organ responsible for **spermatogenesis** and hormone synthesis (testosterone) - It does not contain the seminal colliculus, which is located in the pelvic urethra *Incorrect: Scrotum* - The scrotum is an external dermal sac that houses the testes, epididymis, and lower spermatic cords - It provides temperature regulation for spermatogenesis - The seminal colliculus is an internal pelvic structure, not present in the scrotum

Q: Which of the following is not a derivative of foregut?

Cecum. ***Cecum*** - The **cecum** and the entire large intestine (except the distal third of the transverse colon) are derivatives of the **midgut** [1]. - The midgut is supplied by the **superior mesenteric artery**, differentiating it developmentally from the foregut. *First part of the duodenum* - The **first part of the duodenum** (from the pylorus to the major duodenal papilla) is derived from the **foregut**. - This section receives its blood supply from branches of the **celiac trunk**, consistent with its foregut origin. *Liver* - The **liver** develops as a budding from the distal foregut and is therefore a **foregut derivative** [2]. - It plays a crucial role in metabolism and detoxification, consistent with its early development from this segment. *Pancreas* - The **pancreas** develops from dorsal and ventral buds of the distal foregut, making it a **foregut derivative**. - Both its exocrine and endocrine functions are vital for digestion and glucose homeostasis.

Q: Which Brodmann's area is primarily associated with motor speech?

Area 44. Area 44 - **Brodmann Area 44** is primarily known as **Broca's area**, which is critical for **motor speech production** and language processing [1]. - Damage to this area typically results in **Broca's aphasia**, characterized by non-fluent speech and difficulty forming complete sentences [1]. Area 1, 2, 3 - These Brodmann areas constitute the **primary somatosensory cortex**, responsible for processing **tactile and proprioceptive information** from the body. - They are involved in sensory perception, not directly with motor speech production. Area 4, 6 - **Brodmann Area 4** is the **primary motor cortex**, involved in executing voluntary movements [2]. **Brodmann Area 6** is the **premotor and supplementary motor cortex**, involved in planning and coordinating movements [2]. - While these areas are crucial for motor control, they are not specifically associated as the primary center for motor speech in the same way Broca's area is. Area 40 - **Brodmann Area 40**, also known as the **supramarginal gyrus**, is part of the **parietal lobe** and is involved in phonological processing, language perception, and spatial cognition. - While it plays a role in language, it is not the primary area for motor speech production.

Q: In the context of blood pressure regulation, where are baroreceptors primarily located?

Tunica adventitia. ***Tunica adventitia*** - **Baroreceptors** are specialized mechanoreceptive nerve endings that detect changes in blood pressure by sensing arterial wall stretch. - These sensory nerve endings are primarily located in the **tunica adventitia** (outermost layer) of the **carotid sinus** and **aortic arch** [1]. - The adventitia contains the **nerve fibers and endings** (including baroreceptors), as well as the vasa vasorum and connective tissue supporting the vessel wall [1]. - The nerve terminals extend from the adventitia toward the adventitial-medial border where they sense wall tension changes. *Tunica media* - The **tunica media** is the middle layer composed of **smooth muscle cells** and elastic fibers. - While this layer responds to stretch and changes thickness with blood pressure variations, it does **not contain nerve endings or baroreceptors** [1]. - The media is responsible for vasoconstriction and vasodilation but lacks the sensory innervation needed for baroreception. *Tunica intima* - The **tunica intima** is the innermost layer lined by **endothelial cells**. - Its primary functions include providing a smooth surface for blood flow and regulating vascular permeability. - This layer does not house baroreceptors or other mechanoreceptive nerve endings. *None of the options* - This option is incorrect because **tunica adventitia** is indeed the correct location of baroreceptors. - The adventitia contains the neural elements necessary for blood pressure sensing in these specialized arterial regions [1].

Q: Which organ receives dual blood supply with both sources contributing to its primary metabolic function?

Liver. ***Liver*** - The liver receives blood from two sources: the **hepatic artery** (supplying oxygenated blood, ~25% of blood flow) and the **hepatic portal vein** (supplying nutrient-rich, deoxygenated blood from the gastrointestinal tract, ~75% of blood flow). - Both blood supplies are essential for the liver's primary metabolic functions, detoxification, and nutrient processing [1]. - This is the classic example of dual blood supply in medical education. *Heart* - The heart receives its blood supply primarily from the **coronary arteries**, which branch off the aorta. - While it has an extensive arterial network, it has a single primary source of blood supply. *Kidney* - The kidneys receive their blood supply exclusively from the **renal arteries**, which branch directly from the aorta. - Each kidney typically has a single renal artery supplying it for high-pressure filtration. *Lung* - The lungs do receive blood from two sources: **pulmonary arteries** (deoxygenated blood for gas exchange) and **bronchial arteries** (oxygenated blood for tissue nourishment, <5% of flow). - However, the primary function (gas exchange) is served by pulmonary circulation alone, while bronchial circulation only nourishes lung tissue. - The liver is the standard answer for dual blood supply where both sources serve the organ's primary function.

Q: Elastic fibers of tunica media are secreted by

Smooth muscle. Correct: Smooth muscle - Smooth muscle cells within the tunica media are primarily responsible for synthesizing and secreting elastic fibers along with collagen and proteoglycans [1] - This extracellular matrix provides elasticity and structural integrity to blood vessels, allowing them to stretch and recoil with blood flow [1] - In elastic arteries (like the aorta), smooth muscle cells produce fenestrated elastic membranes that are characteristic of the tunica media Incorrect: Endothelium - Endothelial cells form the innermost lining of blood vessels (tunica intima) and are involved in regulating vascular tone, blood clotting, and inflammation [1] - They do not typically secrete the bulk of elastic fibers found in the tunica media Incorrect: External lamina - The external lamina (or external basal lamina) is an extracellular matrix layer, not a cellular component that secretes elastic fibers - It is actually secreted by the smooth muscle cells themselves and serves as structural support around individual muscle cells Incorrect: Fibroblast - Fibroblasts are connective tissue cells that primarily produce collagen and other extracellular matrix components in many tissues - While they contribute to the tunica adventitia (outermost layer), the tunica media's elastic fibers are primarily produced by smooth muscle cells [1]

Q: Where do primitive red blood cells first originate during early embryonic development?

Yolk sac. ***Yolk sac*** - The **yolk sac** is the primary site of **hematopoiesis** during the first few weeks of embryonic development. - Primitive erythroid cells (red blood cells) originate here to supply the developing embryo with oxygen. *Liver* - The **liver** takes over as the main hematopoietic organ from about the 6th week of gestation, after the yolk sac [1]. - While it produces various blood cells, it is not the *first* site of primitive red blood cell formation. *Bone marrow* - **Bone marrow** becomes the primary site of hematopoiesis during the **fetal period** (around the 20th to 24th week) and continues throughout postnatal life [2]. - It is not involved in the initial production of primitive red blood cell formation in early embryogenesis. *Spleen* - The **spleen** plays a minor role in fetal hematopoiesis, mainly producing lymphoid cells and some myeloid cells, and can take on myeloid functions if the bone marrow is compromised. - It is not the initial site of red blood cell production in the early embryo.

Q: Intercalated disc is present in:

Cardiac muscle. ***Cardiac muscle*** - **Intercalated discs** are unique structures found only in cardiac muscle, forming specialized cell-cell junctions [1]. - These discs contain **gap junctions** for electrical coupling and **desmosomes** for strong adhesion, allowing the heart muscle to contract in a coordinated fashion. *Smooth muscle* - **Smooth muscle cells** are spindle-shaped and lack striations and organized sarcomeres. - They do not possess intercalated discs; instead, communication and coordination are often mediated by **gap junctions** scattered along the cell membranes [2]. *Skeletal muscle* - **Skeletal muscle cells** are long, multinucleated, and highly organized with prominent striations [3]. - They do not have intercalated discs as individual muscle fibers are innervated separately and generally do not directly communicate via specialized junctions for coordinated contraction. *All of the options* - As **intercalated discs** are characteristic features *only* of **cardiac muscle**, this option is incorrect. - Their presence in all three muscle types would contradict the specific cellular organization of smooth and skeletal muscle.

Question 1

Which of the following structures does NOT pass through Calot's triangle?

Accepted Answer

Portal vein

Answer

Right hepatic artery

Answer

Lymph node of Lund

Answer

Cystic artery

Question 2

What structure passes through the quadrangular space?

Accepted Answer

Axillary nerve

Answer

Radial nerve

Answer

Median nerve

Answer

Brachial Artery

Question 3

Seminal colliculus is present in ?

Accepted Answer

Urethra

Answer

Testis

Answer

Prostate

Answer

Scrotum

Question 4

Which of the following is not a derivative of foregut?

Accepted Answer

Cecum

Answer

Liver

Answer

Pancreas

Answer

First part of the duodenum

Question 5

Which Brodmann's area is primarily associated with motor speech?

Accepted Answer

Area 44

Answer

Area 1, 2, 3

Answer

Area 4, 6

Answer

Area 40

Question 6

In the context of blood pressure regulation, where are baroreceptors primarily located?

Accepted Answer

Tunica adventitia

Answer

Tunica intima

Answer

None of the options

Answer

Tunica media

Question 7

Which organ receives dual blood supply with both sources contributing to its primary metabolic function?

Accepted Answer

Liver

Answer

Heart

Answer

Kidney

Answer

Lung

Question 8

Elastic fibers of tunica media are secreted by

Accepted Answer

Smooth muscle

Answer

Endothelium

Answer

External lamina

Answer

Fibroblast

Question 9

Where do primitive red blood cells first originate during early embryonic development?

Accepted Answer

Yolk sac

Answer

Liver

Answer

Bone marrow

Answer

Spleen

Question 10

Intercalated disc is present in:

Accepted Answer

Cardiac muscle

Answer

Smooth muscle

Answer

Skeletal muscle

Answer

All of the options

NEET-PG 2015 — Anatomy