Anatomy
6 questionsWhat is the posterior relation of the neck of the pancreas?
Hilton's law primarily relates to which of the following?
The incudomalleolar joint is a?
Which of the following nerves does NOT contribute to the sensory supply of the tongue?
Which muscle of the arm has additional supinator action?
Which Brodmann's area is primarily associated with motor speech?
NEET-PG 2015 - Anatomy NEET-PG Practice Questions and MCQs
Question 161: What is the posterior relation of the neck of the pancreas?
- A. IVC
- B. Aorta
- C. Common bile duct
- D. Origin of portal vein (Correct Answer)
Explanation: ***Origin of portal vein*** - The **neck of the pancreas** is intimately associated with the formation of the **hepatic portal vein** [1]. - The **superior mesenteric vein** and **splenic vein** unite behind the pancreatic neck to form the **hepatic portal vein** [1]. *IVC* - The **inferior vena cava (IVC)** lies posterior to the **head of the pancreas**, not the neck. - While it's in proximity, it does not directly relate to the neck in the same way the portal vein does. *Aorta* - The **abdominal aorta** lies posterior to the **body** and **tail of the pancreas**, further superior and to the left. - It is not a direct posterior relation of the pancreatic neck. *Common bile duct* - The **common bile duct** passes through a groove on the posterior surface of the pancreatic **head**, sometimes even embedded within it. - It is not a direct posterior relation of the pancreatic neck, which is a different segment.
Question 162: Hilton's law primarily relates to which of the following?
- A. Nerve innervation only
- B. Nerve supply of joints, muscles moving them, and overlying skin (Correct Answer)
- C. Blood supply to joints
- D. None of the above
Explanation: ***Nerve supply of joints, muscles moving them, and overlying skin*** - **Hilton's law** states that the nerve supplying a joint also supplies the muscles that move the joint and the skin overlying the insertions of those muscles - This anatomical principle is clinically significant as it explains **referred pain patterns** from joints to surrounding structures - The law demonstrates the **functional integration** between joint innervation, muscle control, and cutaneous sensation *Nerve innervation only* - While Hilton's law involves nerve innervation, this option is too vague and incomplete - The law specifically describes the **relationship between three components**: joint nerves, muscle nerves, and cutaneous nerves - Simply stating "nerve innervation only" misses the **clinical significance** of the anatomical pattern *Blood supply to joints* - This refers to the vascular supply of joints (articular arteries), which is important for joint nutrition - However, **Hilton's law** specifically addresses **nerve supply patterns**, not vascular anatomy - Blood supply to joints follows different anatomical principles *None of the above* - This is incorrect because Hilton's law clearly relates to the integrated nerve supply pattern described in the correct option - The law is a fundamental principle in anatomy explaining the **functional relationship** between joint, muscle, and skin innervation
Question 163: The incudomalleolar joint is a?
- A. Saddle joint (Correct Answer)
- B. Pivot joint
- C. Ellipsoid joint
- D. Hinge joint
Explanation: ***Saddle joint*** - The **incudomalleolar joint** is classified as a **saddle joint** (also called a **sellar joint**), which is a type of synovial joint. - It has reciprocally concave-convex articular surfaces that fit together like a rider on a saddle. - This joint allows **slight gliding movements** between the head of the malleus and the body of the incus during sound transmission. - Standard anatomy texts including **Gray's Anatomy** classify this as a saddle joint based on its structural characteristics. *Pivot joint* - A **pivot joint** allows rotation around a single axis, such as the **atlantoaxial joint** (atlas rotating around the dens of axis) or the **proximal radioulnar joint**. - While the ossicular chain as a whole undergoes rotatory movement during sound transmission, the **incudomalleolar joint itself** is not classified as a pivot joint anatomically. *Ellipsoid joint* - An **ellipsoid joint** (condyloid joint) allows movement in two planes (flexion/extension and abduction/adduction) but restricts rotation. - Examples include the **radiocarpal joint** and **metacarpophalangeal joints** of the fingers. - The incudomalleolar joint has a different articular surface configuration. *Hinge joint* - A **hinge joint** permits movement primarily in one plane (flexion and extension), like a door hinge. - Examples include the **elbow joint**, **knee joint**, and **interphalangeal joints**. - This does not match the structural or functional characteristics of the incudomalleolar joint.
Question 164: Which of the following nerves does NOT contribute to the sensory supply of the tongue?
- A. Vagus nerve
- B. None of the options
- C. Glossopharyngeal nerve
- D. Lingual nerve
Explanation: ***None of the options*** - All three nerves listed (Vagus, Glossopharyngeal, and Lingual) **DO contribute to the sensory supply of the tongue**, making this the correct answer. - Since the question asks which nerve does **NOT contribute**, and all listed nerves actually do contribute, none of them is the correct choice. *Vagus nerve* - The **vagus nerve (CN X)** provides **both general sensation and taste** to the **posterior-most part of the tongue** (base of tongue and region around vallate papillae) via the **internal laryngeal branch** of the superior laryngeal nerve [1]. - It also supplies sensory innervation to the **epiglottis and vallecula** [1]. *Glossopharyngeal nerve* - The **glossopharyngeal nerve (CN IX)** supplies both **general sensation and taste sensation** to the **posterior one-third of the tongue** [1]. - It also provides motor innervation to the **stylopharyngeus muscle** and parasympathetic innervation to the **parotid gland**. *Lingual nerve* - The **lingual nerve**, a branch of the **mandibular nerve (CN V3)**, provides **general sensation** (touch, pain, temperature) to the **anterior two-thirds of the tongue** [1]. - It also carries **taste fibers from the chorda tympani** (branch of facial nerve, CN VII) for the anterior two-thirds of the tongue [1].
Question 165: Which muscle of the arm has additional supinator action?
- A. Brachialis
- B. Biceps (Correct Answer)
- C. Coracobrachialis
- D. Triceps
Explanation: ***Biceps*** - The **biceps brachii** powerfully supinates the forearm, especially when the elbow is flexed, due to its distal attachment on the **radial tuberosity**. - Its two heads originate from the scapula, contributing to both **flexion** at the elbow and supination. *Brachialis* - The **brachialis muscle** is the primary and most powerful flexor of the elbow joint. - It inserts onto the **ulna** and does not have any rotational or supinator action. *Coracobrachialis* - The **coracobrachialis** muscle primarily functions in adduction and flexion of the arm at the shoulder joint. - It has no attachments that allow for supination of the forearm. *Triceps* - The **triceps brachii** is the sole extensor of the elbow joint, located on the posterior aspect of the arm. - It is an antagonist to the biceps and has no supinator action.
Question 166: Which Brodmann's area is primarily associated with motor speech?
- A. Area 1, 2, 3
- B. Area 4, 6
- C. Area 40
- D. Area 44 (Correct Answer)
Explanation: 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.
Physiology
4 questionsSpermatogenesis begins at -
During the sympathetic fight-or-flight response, what is the primary cardiovascular effect of epinephrine and norepinephrine on skeletal muscle vasculature?
Which of the following neurons in the cerebellar cortex is primarily excitatory?
What is the total surface area of the respiratory membrane in a healthy adult human?
NEET-PG 2015 - Physiology NEET-PG Practice Questions and MCQs
Question 161: Spermatogenesis begins at -
- A. Birth
- B. 5 years
- C. Puberty (Correct Answer)
- D. 18 years
Explanation: ***Puberty*** - **Spermatogenesis**, the process of sperm production, is initiated and sustained by the surge of **gonadotropin-releasing hormone (GnRH)**, which begins at puberty. - This hormonal signal leads to the secretion of **luteinizing hormone (LH)** and **follicle-stimulating hormone (FSH)**, crucial for testicular function and sperm development. *Birth* - At birth, the male testes contain **spermatogonia**, but these cells remain dormant and do not begin active sperm production. - Hormonal levels at birth are not conducive to initiating spermatogenesis. *5 years* - While some hormonal changes occur in early childhood, they are not sufficient to trigger the full process of spermatogenesis. - The reproductive system is still in a quiescent state before puberty. *18 years* - By 18 years, spermatogenesis is typically well-established and has been ongoing for several years, having started at puberty. - This age marks a period of full reproductive maturity, not the initiation of sperm production.
Question 162: During the sympathetic fight-or-flight response, what is the primary cardiovascular effect of epinephrine and norepinephrine on skeletal muscle vasculature?
- A. Increased blood flow to muscles (Correct Answer)
- B. Increased blood flow to the skin
- C. Bronchoconstriction
- D. Decreased heart rate
Explanation: ***Increased blood flow to muscles*** - **Epinephrine** and **norepinephrine** cause **vasodilation** in skeletal muscle arterioles, shunting blood toward tissues critical for immediate physical action. - This response ensures that muscles have adequate **oxygen** and **nutrients** to support intense activity, enabling a quick escape or confrontation. *Increased blood flow to the skin* - During fight-or-flight, the body prioritizes essential organs, causing **vasoconstriction** in the skin to redirect blood flow away from non-essential areas. - This redirection helps to conserve blood and reduce potential blood loss from surface injuries. *Bronchoconstriction* - **Epinephrine** and **norepinephrine** actually cause **bronchodilation**, leading to the relaxation of airway smooth muscles. - This effect increases the diameter of the airways, allowing more air to enter and exit the lungs, thereby enhancing **oxygen intake** and carbon dioxide expulsion. *Decreased heart rate* - The primary effect of **epinephrine** and **norepinephrine** is to **increase heart rate** and myocardial contractility. - This cardiac acceleration enhances **cardiac output**, ensuring rapid and efficient delivery of oxygenated blood throughout the body to meet the demands of stress.
Question 163: Which of the following neurons in the cerebellar cortex is primarily excitatory?
- A. Purkinje
- B. Basket
- C. Golgi
- D. Granule cells (Correct Answer)
Explanation: ***Granule cells*** - **Granule cells** are the only neurons in the cerebellar cortex that are **excitatory**, utilizing glutamate as their neurotransmitter. - They receive input from **mossy fibers** and project their parallel fibers to Purkinje cells and other interneurons. *Purkinje* - **Purkinje cells** are the primary output neurons of the cerebellar cortex and are **inhibitory**, releasing GABA. - They integrate vast amounts of information and project to the **deep cerebellar nuclei**. *Basket* - **Basket cells** are **inhibitory interneurons** located in the molecular layer of the cerebellum. - They synapse on the somata of **Purkinje cells**, providing potent inhibition. *Golgi* - **Golgi cells** are **inhibitory interneurons** found in the granular layer of the cerebellum. - They receive excitatory input from **parallel fibers** and inhibit granule cells, forming an important feedback loop.
Question 164: What is the total surface area of the respiratory membrane in a healthy adult human?
- A. 30 m2
- B. 50 m2
- C. 75 m2 (Correct Answer)
- D. 100 m2
Explanation: ***75 m²*** - The **total surface area** of the respiratory membrane in a healthy adult human is approximately **70-80 m²**, with 75 m² being the most accurate estimate among the given options. - This large surface area is primarily attributed to the presence of approximately **300-500 million alveoli**, which are crucial for efficient gas exchange. - Modern measurements using **stereological techniques** have refined earlier estimates and established this range as the current standard. *100 m²* - This value represents an **older estimate** that has been revised downward with more accurate measurement techniques. - While historically cited in older textbooks, current physiological data supports a **smaller surface area** of approximately 70-80 m². *30 m²* - This value is significantly **underestimated** for the total respiratory membrane surface area. - Such a small surface area would result in highly **inefficient gas exchange**, leading to severe respiratory compromise and inability to meet metabolic demands. *50 m²* - While larger than 30 m², this is still an **underestimation** of the full respiratory membrane surface area. - It does not adequately account for the extensive and intricate branching of the **respiratory bronchioles** and the vast number of alveolar sacs.