NEX Exam Dumps - Nursing Entrance Exam (Math, Science and Verbal)

Veins contain one-way valves that prevent blood from flowing backward as it returns to the heart. These valves are especially important in veins of the arms and legs, where blood must move against gravity. When muscles contract, they push blood forward toward the heart, and the valves close behind it to prevent backflow. Without these valves, blood could pool in the veins, leading to conditions such as varicose veins. The valves do not obstruct blood flow under normal conditions, nor do they prevent blood from leaking into surrounding tissues—that function is related to capillary walls. The NEX Science exam often emphasizes understanding how anatomical structures support physiological function, making venous valves a key cardiovascular concept.

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Hyperextension refers to movement at a joint that goes beyond the normal anatomical position in the sagittal plane, specifically in a posterior direction. For example, bending the head backward farther than upright posture is considered hyperextension. Option B correctly describes this movement. Option A describes abduction, which occurs in the frontal plane. Option C describes flexion, which is anterior movement. Option D describes extension back to anatomical position, not beyond it. The NEX Science exam frequently tests anatomical terminology related to joint movement, and understanding directional planes (sagittal, frontal, transverse) is essential. Hyperextension differs from extension because it exceeds the normal range of motion, which can increase injury risk.

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The lower esophageal sphincter (LES) is a ring of smooth muscle located at the junction between the esophagus and the stomach. Its primary function is to prevent gastric contents, including acid, from flowing back into the esophagus. The LES contracts to keep the stomach contents contained and relaxes to allow food to enter the stomach during swallowing. Dysfunction of the LES can lead to gastroesophageal reflux disease (GERD). The esophageal muscularis helps move food, the upper esophageal sphincter controls entry into the esophagus, and the angle of His is an anatomical feature rather than a muscular valve. The NEX Science exam frequently tests digestive system physiology and reflux prevention mechanisms.

Saltatory conduction is the rapid transmission of nerve impulses alongmyelinated axons. In myelinated neurons, the axon is covered with a fatty insulating layer called myelin, which is interrupted at gaps known as nodes of Ranvier. During saltatory conduction, the electrical impulse “jumps” from one node to the next, greatly increasing the speed of signal transmission. Unmyelinated axons conduct impulses more slowly because the signal must travel continuously along the entire membrane. Dendrites receive signals rather than transmit them over long distances, and muscle cells do not conduct nerve impulses in this manner. The NEX Science exam commonly tests nervous system physiology, particularly mechanisms that improve conduction speed, making myelinated axons the correct answer.

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Hydrochloric acid (HCl) is a strong acid. To neutralize an acid, a base must be added. Sodium hydroxide (NaOH) is a strong base that reacts with HCl to form water and a salt (sodium chloride). This neutralization reaction reduces the acidity of the solution. The other options—HNO₃, CH₃COOH, and H₂SO₄—are all acids and would increase acidity rather than neutralize it. The NEX Science exam often tests acid–base chemistry and emphasizes recognizing common acids and bases. Since NaOH is the only base listed, option C is correct.

This question tests knowledge of bacterial morphology, which is commonly assessed on the NEX Science exam. Bacteria are often classified based on their shape, which helps in identification and diagnosis. The image shows elongated, rod-shaped bacteria. This shape is characteristic ofbacilli. Bacilli are cylindrical or rod-like and are commonly found in many bacterial species, includingEscherichia coliandBacillus anthracis. Cocci are spherical in shape, spirochetes are long and spiral-shaped, and vibrios have a curved, comma-like appearance. None of these shapes match the straight rod-like structures shown in the image. Identifying bacterial shape is an important first step in microbiology before further tests such as Gram staining or biochemical analysis are performed. The NEX exam frequently uses images or descriptions to assess whether students can correctly distinguish between cocci, bacilli, spirilla/spirochetes, and vibrios based on visual characteristics. Recognizing bacilli as rod-shaped bacteria is a key foundational concept.

Codominance occurs when two different alleles are both expressed in a heterozygous organism. In this case, the red and white alleles combine to produce an intermediate pink phenotype. Non-disjunction refers to chromosome separation errors, multiple alleles involve more than two allele types, and mutations involve DNA changes. The NEX Science exam frequently tests inheritance patterns, including codominance and incomplete dominance.

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Structure number 1 in the diagram represents the lens of the eye. The lens plays a crucial role in focusing incoming light onto the retina so that clear images can be formed. It changes shape through a process called accommodation, allowing the eye to focus on objects at varying distances. Protection from debris is mainly the function of the cornea, eyelids, and eyelashes. Regulation of light entering the eye is controlled by the iris, which adjusts the size of the pupil. Picking up light stimuli is the role of rods and cones located in the retina. Because the lens is responsible for bending and focusing light precisely onto the retina, option A is correct. The NEX Science exam frequently tests the relationship between eye structures and their functions, particularly focusing mechanisms.

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