Dental Hygienist Competency Exam! Quiz

The functions conducted in the dorsal columns of the spinal cord, specifically in the fasciculus graciles and cuneatus, include a high degree of location, vibratory sense, fine gradations of pressure, and kinesthesia. These functions are all processed and transmitted through these specific regions of the spinal cord.

The gingiva and buccal mucosa are both areas in the oral cavity that are constantly exposed to mechanical stress and abrasion. Stratified squamous epithelium is the ideal tissue type for these areas as it provides protection against wear and tear. This type of epithelium consists of multiple layers of flattened cells that can withstand the constant friction and mechanical forces exerted during activities such as chewing and speaking. Simple squamous epithelium, cuboidal epithelium, and stratified columnar epithelium are not suitable for these areas as they do not possess the same level of durability and resilience. Therefore, the correct answer is stratified squamous epithelium.

An increase in parasympathetic activity can lead to various physiological changes in the body. It stimulates the salivary glands, resulting in increased salivation. It also enhances gastrointestinal activity, leading to increased digestion and absorption of nutrients. Additionally, parasympathetic activity slows down the heart rate, promoting relaxation and rest. Therefore, all of the given options are correct as they represent the effects of increased parasympathetic activity.

When a patient is given an extremely hypertonic intravenous solution, the concentration of solutes in the solution is higher than that inside the cells. As a result, fluid moves from the cells to the plasma in an attempt to balance the concentration. This causes the cells to shrink, a process known as crenation. Therefore, all of the above statements about the events that occur are true.

The direction and rate of diffusion of an ion is influenced by the concentration gradient, which refers to the difference in concentration between two areas. This gradient determines the direction in which the ion will move. Additionally, the hydrostatic pressure gradient, which is the difference in pressure between two areas, can also affect the ion's diffusion. Finally, the electrical gradient, which is the difference in charge between two areas, plays a role in determining the ion's movement. Therefore, all of the mentioned factors - concentration gradient, hydrostatic pressure gradient, and electrical gradient - influence the direction and rate of ion diffusion.

The pressoreceptor system responds to an increase in blood pressure at the area of the aortic arch and carotid bodies. It operates through the vasomotor center and responds by decreasing the heart rate, strength of contraction, and peripheral resistance. This means that all of the given statements are correct and contribute to the overall function of the pressoreceptor system.

Free nerve endings are the type of receptors that are sensitive to pain. These nerve endings are found throughout the body and are the most common type of pain receptors. They are responsible for detecting and transmitting pain signals to the brain, signaling the presence of tissue damage or injury. Unlike other types of receptors listed, such as Pacinian corpuscles or Meissner's corpuscles, which are sensitive to touch or pressure, free nerve endings specifically respond to painful stimuli.

The correct answer describes the correct sequence of blood flow through the heart and the circulatory system. It starts with the blood entering the heart through the inferior vena cava, then flowing into the right atrium. From there, it passes through the tricuspid valves into the right ventricle. The blood is then pumped into the pulmonary trunk, which leads to the pulmonary circulation. After oxygenation in the lungs, the blood returns to the heart through the pulmonary veins, specifically the left atrium. It then passes through the bicuspid valves into the left ventricle. Finally, the blood is pumped out of the heart through the ascending aorta, entering the systemic circulation.

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Amylase is the correct answer because it is an enzyme that specifically hydrolyzes polysaccharides. Polysaccharides are complex carbohydrates made up of multiple sugar molecules bonded together, and amylase breaks down these bonds to release individual sugar units. Lipase, protease, trypsin, and pepsin are enzymes that hydrolyze lipids, proteins, and peptides respectively, but they do not target polysaccharides. Therefore, amylase is the enzyme that is responsible for the hydrolysis of polysaccharides.

Homeostasis is the physiological concept that refers to the maintenance of a constant environment within the body. It involves the regulation of various internal processes, such as body temperature, pH levels, and blood sugar levels, to ensure optimal functioning. This concept is crucial for the overall health and survival of an organism as it allows the body to adapt and respond to changes in the external environment, maintaining stability and balance.

The hypothalamus is a small region in the brain that plays a crucial role in maintaining homeostasis and regulating various bodily functions. It contains temperature control centers, which help regulate body temperature. It also regulates visceral activity, such as digestion and heart rate. Additionally, the hypothalamus is responsible for the synthesis of hormonal releasing factors, which control the release of hormones from the pituitary gland. Lastly, the hypothalamus influences basic drives like sex, thirst, and hunger. Therefore, all of the above options accurately describe the functions of the hypothalamus.

The autonomic nervous system is responsible for regulating and controlling involuntary bodily functions. It has an influence on smooth muscle, which is found in organs such as the intestines and blood vessels, helping to control their contractions. It also affects glandular secretion, regulating the release of hormones and other substances from glands. Additionally, the autonomic nervous system controls cardiac muscle, which is responsible for the contraction of the heart. Therefore, the correct answer is "all of the above" as the autonomic nervous system exerts its influence on smooth muscle, glandular secretion, and cardiac muscle.

Aldosterone is responsible for the reabsorption of sodium ions and the secretion of potassium and hydrogen ions. It is a hormone that is released by the adrenal glands in response to low blood pressure or low blood volume. It acts on the kidneys to increase the reabsorption of sodium ions, which leads to water retention and increased blood volume. At the same time, it stimulates the secretion of potassium and hydrogen ions, which helps maintain electrolyte balance in the body. Therefore, aldosterone is the hormone that controls the reabsorption and secretion of these ions.

The cerebellum is responsible for coordinating muscular activity and maintaining balance and posture. Lesions in the cerebellum can disrupt these functions, leading to an inability to coordinate muscular activity. This can result in unsteady movements, difficulty with fine motor skills, and problems with balance and coordination. The somesthetic cortex is involved in processing sensory information related to touch and proprioception, but it does not directly control muscular coordination. Broca's area is involved in speech production, and the occipital lobe is responsible for visual processing.

The medulla is the correct answer because it is an important center for the control of respiration and cardiovascular function. It is located in the brainstem and plays a crucial role in regulating breathing, heart rate, and blood pressure. The medulla contains specialized neurons that respond to changes in blood oxygen levels, carbon dioxide levels, and blood pressure, allowing it to adjust these vital functions to maintain homeostasis.

type O = universal donor, type AB = universal recipient

Mean arterial blood pressure is regulated by neural mechanisms that control constriction of the arteries, principles of capillary dynamics, and renal and hormonal mechanisms. In addition, mean arterial pressure (the approximate average of systolic and diastolic pressures) is affected by the cardiac output. Cardiac output is the volume of blood the heart pumps per minute.

Scar tissue is formed during the process of wound healing, where the body repairs damaged tissue. Dense fibrous connective tissue is present in scar tissue because it provides strength and support to the healing area. This type of tissue is composed of densely packed collagen fibers, which form a strong and durable matrix. It helps to bridge the gap in the wound and restore the integrity of the damaged tissue.

The swallowing mechanism involves multiple cranial nerves, including the trigeminal, facial, glossopharyngeal, vagus, and hypoglossal nerves. These nerves work together to coordinate the complex process of swallowing, which involves the movement of muscles in the face, throat, and tongue. Each of these cranial nerves plays a specific role in different aspects of swallowing, such as sensory perception, motor control, and coordination. Therefore, all of the above cranial nerves are involved in the swallowing mechanism.

Active transport differs from facilitated diffusion in multiple ways. Firstly, active transport moves a substance against its concentration gradient, meaning it moves from an area of low concentration to an area of high concentration. Facilitated diffusion, on the other hand, moves substances down their concentration gradient. Secondly, active transport requires a carrier protein to transport the substance across the cell membrane, while facilitated diffusion uses channel or carrier proteins. Thirdly, active transport requires energy in the form of magnesium adenosine triphosphate (Mg ATP), whereas facilitated diffusion does not require energy. Lastly, the movement of sodium and potassium across cell membranes is an example of active transport. Therefore, all of the above statements are true and differentiate active transport from facilitated diffusion.

Cortisol is a hormone that plays a crucial role in various metabolic processes. It increases the flux of amino acids in the body, which helps in protein synthesis and tissue repair. Additionally, cortisol mobilizes stored fat, allowing it to be used as an energy source. Furthermore, cortisol promotes gluconeogenesis, the production of glucose from non-carbohydrate sources like amino acids and fats. Therefore, all of the given options (increases the flux of amino acids, mobilizes stored fat, and promotes gluconeogenesis) are correct statements about the effects of cortisol.

Thrombocyte is not a leukocyte because it is actually a type of blood cell called a platelet. Leukocytes, on the other hand, are white blood cells that play a role in the immune system and are involved in fighting infections and diseases. Therefore, thrombocyte does not belong to the category of leukocytes.

Bile is formed in the liver and stored in the gallbladder

Lysosomes are organelles that contain enzymes capable of digesting and destroying cellular debris. They function as the recycling centers of the cell, breaking down waste materials such as old organelles, proteins, and foreign substances. Lysosomes play a crucial role in maintaining cellular homeostasis and removing harmful substances from the cell. This explanation fits with the given correct answer, which is lysosomes.

Insulin is the hormone that promotes glucose transport from the blood into the cells. It is produced by the pancreas and helps regulate blood sugar levels by facilitating the uptake of glucose into cells, where it can be used for energy or stored for later use. Insulin also plays a role in the metabolism of fats and proteins.

The respiratory tidal volume refers to the amount of air that is exchanged in the lungs with a normal breath. It represents the volume of air that is inhaled and exhaled during each breath. This measurement is typically around 1 liter, although it can vary depending on factors such as age, sex, and physical condition. The tidal volume is an important parameter in assessing lung function and can be used to diagnose respiratory disorders.

The oculomotor nerve is responsible for the constriction of the pupil of the eye. This nerve controls the muscles that regulate the size of the pupil, allowing it to constrict or dilate in response to changes in light intensity. The optic nerve, abducens nerve, and vagus nerve are not directly involved in pupil constriction.

The autonomic nervous system regulates various involuntary functions in the body. Heart rate, digestive secretion, glandular secretion, and blood pressure are all examples of autonomic effects. However, skeletal muscle tone is not directly regulated by the autonomic nervous system. Instead, it is controlled by the somatic nervous system, which is responsible for voluntary movements.

The rate of gastric emptying is affected by multiple factors. Firstly, the quantity of liquid in chyme plays a role in determining the rate of emptying. Secondly, neural and hormonal reflexes from the small intestine also influence gastric emptying. Finally, the quantity of chyme present in the small intestine affects the rate of emptying as well. Therefore, all of the above options have an impact on the rate of gastric emptying.

Depolarization occurs when there is a transfer of sodium ions to the inside of a neuron. This transfer of positive ions causes a reversal of charge across the nerve cell membrane, making the outside of the fiber positive with respect to the inside. This change in charge is an important step in the generation of an action potential, which allows for the transmission of signals within the nervous system.

Parathyroid hormone and calcitonin are responsible for maintaining calcium homeostasis. Parathyroid hormone acts to increase blood calcium levels by stimulating the release of calcium from bones and promoting the reabsorption of calcium in the kidneys. Calcitonin, on the other hand, acts to decrease blood calcium levels by inhibiting the release of calcium from bones and promoting the excretion of calcium in the kidneys. Together, these hormones work in a coordinated manner to regulate the levels of calcium in the body and ensure its balance.

Amylase is an enzyme that hydrolyzes carbohydrates.

The glomerulus is the tuft of capillaries in Bowman's capsule where water, electrolytes, amino acids, glucose, urea, and other small molecular size constituents are filtered from blood. The capillaries of the glomerulus unite to form the outgoing efferent arteriole.

The correct answer is superior cervical ganglion. The sympathetic innervation to the face and head structures is transmitted via nerves that have cells of origin in the superior cervical ganglion. This ganglion is located in the neck, near the base of the skull, and it plays a crucial role in regulating various functions such as pupil dilation, blood vessel constriction, and sweat gland activity in the face and head.

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Cardiac output refers to the amount of blood pumped by the heart per minute. It is calculated by multiplying the heart rate (number of heartbeats per minute) with the stroke volume (amount of blood pumped by each heartbeat). This means that the heart rate and stroke volume are the two factors that determine the cardiac output. The heart rate represents the speed at which the heart beats, while the stroke volume represents the amount of blood pumped with each heartbeat. Therefore, the correct answer is heart rate and stroke volume.

The thalamus is a structure located in the brain that acts as a relay station for sensory information. It receives sensory impulses from various parts of the body and then sends them to the cerebral cortex, which is responsible for processing and interpreting these signals. Therefore, almost all sensory impulses pass through the thalamus on their way to the cerebral cortex. The basal ganglia, corpus striatum, hypothalamus, and corpus callosum are not directly involved in the transmission of sensory impulses to the cerebral cortex.

The adult liver performs various important functions, including bile formation, reticuloendothelial activity, glycogenesis, glycogenolysis, and glucogenesis, and detoxication. However, erythropoiesis, which is the process of red blood cell production, does not occur in the liver. This function primarily takes place in the bone marrow.

The primary motor area of the brain is located in the precentral gyrus. This region of the brain is responsible for initiating voluntary movements in the body. It receives signals from other areas of the brain and sends commands to the muscles, allowing us to perform various motor tasks. The precentral gyrus is specifically involved in the control and coordination of fine motor skills, such as precise movements of the fingers and hands.

Ovulation is dependent on a high concentration of LH in the blood. LH, or luteinizing hormone, is responsible for triggering the release of an egg from the ovary during ovulation. When LH levels rise, it signals the ovaries to release a mature egg, which can then be fertilized by sperm. Therefore, the presence of a high concentration of LH in the blood is necessary for ovulation to occur.

Carbon dioxide is carried in the blood in three main forms: as dissolved gas, as carbaminohemoglobin (bound to hemoglobin), and as bicarbonate ions. Carbonic acid is not a direct form in which carbon dioxide is carried in the blood. Carbon dioxide combines with water in the blood to form carbonic acid, which then quickly dissociates into bicarbonate ions and hydrogen ions. Therefore, the correct answer is "as carbonic acid."

The muscles of mastication are derived from the first branchial arch. During embryonic development, the first branchial arch gives rise to various structures in the head and neck region, including the muscles responsible for chewing or mastication. These muscles include the masseter, temporalis, medial pterygoid, and lateral pterygoid muscles. They play a crucial role in the movement and function of the jaw, allowing for biting, chewing, and grinding of food.

Endochondral ossification is the correct answer because it refers to the process in long bones where cartilage cells are replaced by bone cells, organic matrix is laid down, and calcium and phosphate are deposited. This process is essential for bone growth and development. Intramembranous ossification is a different process that occurs in flat bones, where bone forms directly from mesenchymal cells without the presence of cartilage. Osteoporosis is a condition characterized by a decrease in bone density, erythropoiesis is the production of red blood cells, and diaphyseal formation refers to the development of the shaft of a long bone.

Thyroxin is the hormone that is less involved in a stress reaction. While epinephrine, norepinephrine, cortisone, and adrenocorticotropin are all hormones that are released in response to stress, thyroxin is not directly involved in the stress response. Thyroxin is primarily responsible for regulating metabolism and energy levels in the body.

The sinoatrial node is considered the normal pacemaker of the heart because it possesses all the mentioned characteristics. It has a lower difference between resting membrane potential and threshold, which allows it to initiate depolarization more easily. Additionally, it has a more rapid "sodium leakage," which leads to spontaneous depolarization before other areas. Lastly, the sinoatrial node recovers from the previous refractory period more rapidly than other areas. Therefore, all of these factors contribute to the sinoatrial node's role as the normal pacemaker of the heart.

Secretin is a gastrointestinal hormone that controls the secretion of water and bicarbonate by acinar cells of the pancreas. When secretin is released into the bloodstream, it stimulates the pancreas to produce and release bicarbonate-rich pancreatic juice. This helps to neutralize the acidic chyme that enters the small intestine from the stomach, creating a more favorable environment for digestion and absorption. Secretin also stimulates the liver to produce bile, which aids in the digestion and absorption of fats. Therefore, secretin plays a crucial role in regulating pancreatic and liver secretions to maintain optimal digestive function.

Endothelium is the correct answer because it is the type of cell that lines the vascular channels of the body. Endothelial cells form a thin layer of epithelial tissue that lines the interior surface of blood vessels, lymphatic vessels, and the heart. They play a crucial role in regulating blood flow, controlling the exchange of substances between the blood and surrounding tissues, and maintaining the integrity of the vascular system.

Extreme excitement in a patient can lead to increased blood pressure and relaxation of smooth muscles in the bronchi. Increased blood pressure is a common physiological response to excitement and can be caused by the release of stress hormones. Relaxation of smooth muscles in the bronchi can result in bronchodilation, allowing for increased airflow and improved breathing. These effects on the cardiovascular and respiratory systems are often observed in individuals experiencing extreme excitement.

Digestion refers to the process of breaking down large chemical compounds present in food into simpler substances. This is achieved through hydrolysis, which involves the addition of water molecules to break the bonds holding the compounds together. The end products of digestion, which are smaller in molecular weight, can then be absorbed into body fluids for further use. Therefore, the correct answer is "only A and C" as both options A (splitting large chemical compounds in foods into simpler substances that can be absorbed) and C (hydrolysis) are involved in digestion.