Dental Hygienist Competency Exam! Quiz
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Questions and Answers
- 1.
The physiological concept that refers to the maintenance of a constant environment is
- A.
Hemostasis
- B.
Dynamic equilibrium
- C.
Homeostasis
- D.
Interdependence
- E.
Induction
Correct Answer
C. HomeostasisExplanation
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.Rate this question:
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- 2.
The organelles that contain enzymes capable of digesting and destroying cellular debris.
- A.
Endoplasmic reticulum
- B.
Golgi apparatus
- C.
Mitochondria
- D.
Lysosomes
- E.
Ribosomes
Correct Answer
D. LysosomesExplanation
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.Rate this question:
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- 3.
Transport of water across a cell membrane.
- A.
Osmosis
- B.
Facilitated diffusion
- C.
Active transport
- D.
Diffusion
Correct Answer
D. DiffusionExplanation
Diffusion is the movement of molecules from an area of high concentration to an area of low concentration, without the need for energy input. In the context of water transport across a cell membrane, diffusion refers to the movement of water molecules from an area of higher water concentration to an area of lower water concentration. This process occurs passively, driven by the concentration gradient, and does not require any energy expenditure by the cell. Therefore, diffusion is the correct answer for the given question.Rate this question:
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- 4.
The direction and rate of diffusion of an ion is influenced by the:
- A.
Concentration gradient
- B.
Hydrostatic pressure gradient
- C.
Electrical gradient
- D.
All of the above
Correct Answer
D. All of the aboveExplanation
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.Rate this question:
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- 5.
Active transport differs from facilitated diffusion in that active transport.
- A.
Moves a substance against a concentration gradient
- B.
Requires a carrier
- C.
Requires energy from magnesius adenosine triphosphate (Mg ATP)
- D.
Is exemplified by the movement of sodium and potassium across cell membranes
- E.
All of the above
Correct Answer
E. All of the aboveExplanation
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.Rate this question:
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- 6.
A patient has accidentally been given an intravenous solution that is extremely hypertonic. Which of the following well occur?
- A.
Fluid moves from cell to plasma
- B.
The cell shrink
- C.
Crenation is the term to describe the changes that occur
- D.
All of the above are true statements about the events that occur
Correct Answer
D. All of the above are true statements about the events that occurExplanation
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.Rate this question:
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- 7.
All of the following are derived from endoderm except
- A.
Epithelial parts of the respiratory system
- B.
Epithelial parts of the gastrointestinal system
- C.
Epithelium in the mouth
- D.
Epithelium of the pharynx
Correct Answer
C. Epithelium in the mouthExplanation
The correct answer is "epithelium in the mouth." The mouth is derived from the ectoderm, not the endoderm. The endoderm gives rise to the epithelial parts of the respiratory system, gastrointestinal system, and pharynx.Rate this question:
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- 8.
Which of the following is derived from mesoderm?
- A.
Epidermis
- B.
Nervous system
- C.
Adrenal medulla
- D.
Posterior lobe of the pituitary gland
- E.
Connective tissue
Correct Answer
E. Connective tissueExplanation
Connective tissue is derived from mesoderm. During embryonic development, the mesoderm layer gives rise to various tissues and organs, including connective tissue. Connective tissue provides support and structure to the body, as well as connecting and protecting different organs and tissues. It includes various types of tissue such as bone, cartilage, blood, and adipose tissue.Rate this question:
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- 9.
Muscles of mastication is derived from which branchial arch?
- A.
First
- B.
Second
- C.
Third
- D.
Fourth
- E.
Fifth
Correct Answer
A. FirstExplanation
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.Rate this question:
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- 10.
The developmental period in which teeth and the palate are most susceptible to teratogenic agents is the
- A.
Third through the fifth week
- B.
Fourth through the seventh week
- C.
Fourth through the eighth week
- D.
Eighth through the tenth week
Correct Answer
D. Eighth through the tenth weekExplanation
the most rapid developmental timeRate this question:
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- 11.
Gingiva and buccal mucosa
- A.
Simple squamous epithelium
- B.
Stratified squamous epithelium
- C.
Cuboidal epithelium
- D.
Stratified columnar epithelium
- E.
None of the above
Correct Answer
B. Stratified squamous epitheliumExplanation
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.Rate this question:
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- 12.
What type of connective tissue is present in scar tissue?
- A.
Loose
- B.
Dense fibrous
- C.
Lymphatic
- D.
Reticuloendothelial
- E.
Adipose
Correct Answer
B. Dense fibrousExplanation
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.Rate this question:
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- 13.
What kind of cell types line the vascular channels of the body?
- A.
Stratified squamous epithelium
- B.
Endothelium
- C.
Mesothelium
- D.
Transitional epithelium
- E.
Pseudostratified columnar epithelium
Correct Answer
B. EndotheliumExplanation
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.Rate this question:
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- 14.
Pleura is a type of
- A.
Serous membrane
- B.
Mucous membrane
- C.
Visceral membrane
- D.
Parietal membrane
- E.
Synovial membrane
Correct Answer
A. Serous membraneExplanation
The pleura is a serous membrane that lines the thoracic cavity and covers the lungs. Serous membranes are thin, double-layered membranes that secrete a serous fluid, which reduces friction between organs and allows them to move smoothly. The pleura specifically helps to protect and cushion the lungs, allowing them to expand and contract during breathing.Rate this question:
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- 15.
In long bones, the process whereby cartilage cells are replaced by bone cells, organic matrix is laid down, and calcium and phosphate are deposited is known as
- A.
Intramembranous ossification
- B.
Endochondral ossification
- C.
Osteoporosis
- D.
Erythropoiesis
- E.
Diaphyseal formation
Correct Answer
B. Endochondral ossificationExplanation
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.Rate this question:
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- 16.
All of the following terms are associated with haversian systems in bone
- A.
Caniculi
- B.
Lamellae
- C.
Lacunae
- D.
Osteocytes
- E.
Periosteum
Correct Answer
E. PeriosteumExplanation
The periosteum is a term associated with haversian systems in bone. It is a dense layer of connective tissue that covers the outer surface of bones. It contains blood vessels, nerves, and cells involved in bone formation and repair. The haversian systems, also known as osteons, are the basic structural units of compact bone and consist of concentric rings of lamellae, which surround a central canal containing blood vessels and nerves. The lacunae are small spaces within the lamellae that house osteocytes, the mature bone cells. Canaliculi are tiny channels that connect the lacunae and allow for communication between osteocytes. Therefore, the periosteum is the correct term associated with haversian systems in bone.Rate this question:
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- 17.
What kind of joint, is described by the following: joint cavity present; bone ends covered by cartilage; may be separated by a disk; freely movable?
- A.
Synarthrotic
- B.
Diarthrotic
- C.
Cartilagenous
- D.
Synphysis
- E.
Synchondroses
Correct Answer
B. DiarthroticExplanation
The correct answer is diarthrotic. Diarthrotic joints, also known as synovial joints, have a joint cavity that allows for movement. The bone ends are covered by cartilage, which helps reduce friction. These joints may also have a disk separating the bone ends. Overall, diarthrotic joints are freely movable.Rate this question:
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- 18.
Which of the following is NOT associated with a skeletal muscle?
- A.
Sarcolemma
- B.
Myofibrils
- C.
Intercalated disk
- D.
Mitochondria
- E.
Actin and myosin
Correct Answer
C. Intercalated disk -
- 19.
Actin and myosin are proteins contained within a
- A.
Myofibril
- B.
Myofilament
- C.
Fiber
- D.
Sarcoplasmic reticulum
Correct Answer
A. MyofibrilExplanation
Actin and myosin are proteins that are primarily found within myofibrils. Myofibrils are long, cylindrical structures within muscle cells that are responsible for muscle contraction. They are composed of repeating units called sarcomeres, which contain actin and myosin filaments. These filaments slide past each other during muscle contraction, allowing the muscle to shorten and generate force. Therefore, the correct answer is myofibril.Rate this question:
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- 20.
A single motor neuron and the muscle cells supplied by its axon branches is termed
- A.
An efferent neuron
- B.
A motor unit
- C.
A motor end plate
- D.
A sarcoplasmic reticulum
- E.
An annulospiral ending
Correct Answer
C. A motor end plateExplanation
A motor end plate is the correct answer because it refers to the specialized region of the muscle fiber membrane that forms a synapse with the axon terminal of a motor neuron. This synapse allows for the transmission of nerve impulses from the motor neuron to the muscle fiber, leading to muscle contraction. The motor end plate is essential for the communication between the nervous system and the muscles, making it a crucial component of the neuromuscular junction.Rate this question:
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- 21.
Which of the following glial cells are responsible for myelin formation in the central nervous system?
- A.
Ependymal cells
- B.
Oligodendrocytes
- C.
Microglia
- D.
Schwann cells
Correct Answer
B. OligodendrocytesExplanation
Oligodendrocytes are responsible for myelin formation in the central nervous system. Myelin is a fatty substance that forms a protective sheath around nerve fibers, allowing for faster and more efficient transmission of electrical signals. Oligodendrocytes extend their processes to wrap around multiple nerve fibers, forming myelin sheaths. In contrast, Schwann cells are responsible for myelin formation in the peripheral nervous system, and ependymal cells and microglia have other functions such as lining the ventricles and supporting immune responses in the brain, respectively.Rate this question:
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- 22.
Depolarization occurs with
- A.
Transfer of sodium ions to the inside of a neuron
- B.
Transfer of potassium ions to the outside of a neuron
- C.
A reversal of charge across the nerve cell membrane making the outside of the fiber positive with respect to the inside
Correct Answer
A. Transfer of sodium ions to the inside of a neuronExplanation
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.Rate this question:
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- 23.
Conduction occurs when a stimulus reduces the membrane potential to a critical level. This level is called
- A.
Summation
- B.
Threshold
- C.
Action potential
- D.
Facilitation
- E.
Refractory period
Correct Answer
B. ThresholdExplanation
Conduction occurs when a stimulus reduces the membrane potential to a critical level. This critical level is known as the threshold. At the threshold, an action potential is triggered and the nerve impulse is conducted along the neuron. The threshold is an important concept in understanding how neurons transmit signals and is the minimum level of depolarization required to initiate an action potential. It serves as a sort of "trigger point" for the conduction of nerve impulses.Rate this question:
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- 24.
Which tract exerts a facilitative influence on motor neurons in the anterior horn?
- A.
Lateral corticospinal tract
- B.
Ventral corticospinal tract
- C.
Lateral reticulospinal tract
- D.
medial reticulospinal tract
- E.
Ectospinal tract
Correct Answer
C. Lateral reticulospinal tractExplanation
The lateral reticulospinal tract exerts a facilitative influence on motor neurons in the anterior horn. This tract originates in the reticular formation of the brainstem and descends to the spinal cord. It primarily controls voluntary movements and helps to facilitate the activity of motor neurons in the anterior horn, which are responsible for initiating muscle contractions. This facilitative influence helps to coordinate and control voluntary movements.Rate this question:
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- 25.
If the ventral root of a spinal nerve were sectioned what would be the result in the regions supplied by the nerve?
- A.
Loss of sensation
- B.
Loss of motor control
- C.
Loss of sensation and movement
- D.
Partial loss of sensation and movement
- E.
Loss of sensation, movement, and control of the degree of constriction of blood vessels
Correct Answer
B. Loss of motor controlExplanation
If the ventral root of a spinal nerve were sectioned, the result would be a loss of motor control in the regions supplied by the nerve. The ventral root contains the motor fibers that transmit signals from the central nervous system to the muscles, allowing for voluntary movement. Therefore, if this root is severed, the ability to control and move the muscles in the regions supplied by the nerve would be lost. Sensation, on the other hand, is transmitted through the dorsal root of the spinal nerve, so it would not be affected in this case.Rate this question:
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- 26.
Corticospinal tract
- A.
Fibers are located in grey columns of the cord
- B.
Fibers come from neuron cell bodies located in the spinal cord
- C.
Fibers synapse with neurons in the cerebellar cortex
- D.
Fibers are descending fibers from the cells in the primary motor cortex of the frontal lobe
- E.
Nonfunctionng is one cause of loss of sensation
Correct Answer
D. Fibers are descending fibers from the cells in the primary motor cortex of the frontal lobeExplanation
The corticospinal tract fibers are descending fibers from the cells in the primary motor cortex of the frontal lobe. This means that they originate from the motor cortex and travel down the spinal cord to synapse with neurons in the grey columns. These fibers are responsible for transmitting motor signals from the brain to the muscles, allowing voluntary movement. If the corticospinal tract is nonfunctioning, it can lead to a loss of sensation due to the inability to transmit motor signals effectively.Rate this question:
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- 27.
The primary motor area of the brain is the
- A.
Precentral gyrus
- B.
Postcentral gyrus
- C.
Temporal lobe
- D.
Occipital lobe
- E.
Hypothalamus
Correct Answer
A. Precentral gyrusExplanation
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.Rate this question:
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- 28.
Which of the following functions are conducted in the dorsal columns of the spinal cord, that is, in the fasciculus graciles and cuneatus?
- A.
High degree of location
- B.
Vibratory sense
- C.
Fine gradations of pressure
- D.
Kinesthesia
- E.
All of the above
Correct Answer
E. All of the aboveExplanation
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.Rate this question:
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- 29.
Damage to the precental gyrus of the cerebral cortex
- A.
Spastic paralysis
- B.
Sensory loss
- C.
Intention tremor
- D.
Tremor at rest
- E.
Loss of simple reflexes
Correct Answer
A. Spastic paralysisExplanation
Damage to the precentral gyrus of the cerebral cortex can result in spastic paralysis. The precentral gyrus is responsible for controlling voluntary movements, and when it is damaged, the signals from the brain to the muscles are disrupted. This leads to increased muscle tone and stiffness, causing spastic paralysis. Other symptoms such as sensory loss, intention tremor, tremor at rest, and loss of simple reflexes may also be present depending on the extent and location of the damage.Rate this question:
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- 30.
Almost all sensory impulses pass through what structure on their way to the cerebral cortex?
- A.
Basal ganglia
- B.
Corpus striatum
- C.
Hypothalamus
- D.
Corpus callosum
- E.
Thalamus
Correct Answer
E. ThalamusExplanation
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.Rate this question:
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- 31.
Inability to coordinate muscular activity can be due to a lesion in the
- A.
Cerebellum
- B.
Somesthetic cortex
- C.
Broca's area
- D.
Occipital lobe
Correct Answer
A. CerebellumExplanation
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.Rate this question:
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- 32.
Which of the following describes the function of the hypothalamus?
- A.
Temperature control centers
- B.
Regulation of visceral activity
- C.
Synthesis of hormonal releasing factors
- D.
Influencing basic drives like sex, thirst, hunger
- E.
All to the above describe hypothalamic functhions
Correct Answer
E. All to the above describe hypothalamic functhionsExplanation
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.Rate this question:
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- 33.
Important centers for control of respiration and dardiovascular function are located in the
- A.
Pons
- B.
Medulla
- C.
Midbrain
- D.
Thalamus
Correct Answer
B. MedullaExplanation
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.Rate this question:
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- 34.
Which of the following is/are not necessary for any of the responses referred to as reflexes?
- A.
Autonomic nerves
- B.
Cerebral cortex
- C.
Effectors
- D.
Receptors
- E.
Synapses
Correct Answer
B. Cerebral cortexExplanation
The cerebral cortex is not necessary for any of the responses referred to as reflexes. Reflexes are involuntary and rapid responses to stimuli that do not involve conscious thought. The cerebral cortex is responsible for higher cognitive functions, such as decision-making and voluntary movements, but it is not involved in reflex actions. Reflexes are mediated by the spinal cord and lower parts of the brain, bypassing the cerebral cortex.Rate this question:
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- 35.
A type of receptor which is sensitive to pain is
- A.
Pacinian corpuscle
- B.
Meissener's corpuscle
- C.
Free nerve endings
- D.
End bulb of Krause
- E.
Ruffin endings
Correct Answer
C. Free nerve endingsExplanation
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.Rate this question:
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- 36.
Referred pain is
- A.
Initiated in skin and referred to viscera or muscle
- B.
Initiated in viscera and referred to the contralateral dermatome
- C.
Due to converging the pain fibers with other sensory fibers in nuclei of the somesthetic cortex
- D.
Due to converging of pain fibers with other sensory fibers in the cord and thalamus
Correct Answer
D. Due to converging of pain fibers with other sensory fibers in the cord and thalamusExplanation
Referred pain occurs when pain signals from one part of the body are perceived in another part. This can happen because pain fibers from different areas converge and share pathways with other sensory fibers in the spinal cord and thalamus. As a result, the brain may interpret the pain signals as coming from a different location than the actual source. This phenomenon helps explain why, for example, a heart attack can cause pain in the left arm or jaw.Rate this question:
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- 37.
The autonomic nervous system exerts its influence on
- A.
Smooth muscle
- B.
Glandular secretion
- C.
Cardiac muscle
- D.
All of the above
Correct Answer
D. All of the aboveExplanation
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.Rate this question:
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- 38.
The neurotransmitter substance released at the postganglionic terminal of the parasympathetic division of the autonomic nervous system is
- A.
Norepinephrine
- B.
Epinephrine
- C.
Cholinesterase
- D.
Acetylcholine
- E.
Gamma-aminobutyric acid
Correct Answer
D. AcetylcholineExplanation
The correct answer is acetylcholine. Acetylcholine is the neurotransmitter substance released at the postganglionic terminal of the parasympathetic division of the autonomic nervous system. It is responsible for transmitting signals across the synapse to activate target cells and elicit parasympathetic responses in various organs and tissues. Acetylcholine is involved in regulating processes such as digestion, heart rate, and glandular secretion.Rate this question:
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- 39.
Norepinephrine and epinephrine are released from
- A.
Preganglionic and postganglionic fibers of the sympathetic nervous system
- B.
Neuromyal junction
- C.
Postganglionic fibers of the sympathetic nervous system and the adrenal medulla
- D.
All of the above
Correct Answer
C. Postganglionic fibers of the sympathetic nervous system and the adrenal medullaExplanation
Norepinephrine and epinephrine are both released from postganglionic fibers of the sympathetic nervous system and the adrenal medulla. The sympathetic nervous system is responsible for the "fight or flight" response in the body, and these neurotransmitters play a crucial role in this response. The release of norepinephrine and epinephrine helps to increase heart rate, blood pressure, and blood flow to muscles, preparing the body for action. The adrenal medulla, which is part of the adrenal glands located on top of the kidneys, also releases these hormones into the bloodstream in response to stress or danger. Therefore, the correct answer is that norepinephrine and epinephrine are released from postganglionic fibers of the sympathetic nervous system and the adrenal medulla.Rate this question:
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- 40.
All of the following are autonomic effects on the body except regulation of
- A.
Heart rate
- B.
Digestive secretion
- C.
Skeletal muscle tone
- D.
Glandular secretion
- E.
Blood pressure
Correct Answer
C. Skeletal muscle toneExplanation
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.Rate this question:
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- 41.
Extreme excitement in a patient may have the following effects on organ systems:
- A.
Increased blood pressure
- B.
Increases gastrointestinal activity
- C.
Relaxation of smooth muscles in bronchi
- D.
A and C
- E.
B and C
Correct Answer
D. A and CExplanation
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.Rate this question:
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- 42.
An increase in parasympathetic activity
- A.
Increase salivation
- B.
Increases gastrointestinal activity
- C.
Decreases heart rate
- D.
All of the above
Correct Answer
D. All of the aboveExplanation
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.Rate this question:
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- 43.
Hormones
- A.
Catalyze intracellular biochemical reactions
- B.
Enter into chemical reactions without being degraded or depleted
- C.
Are chemical substances that are produced by endocrine glands, travel through the circulatory system, and exert their influence on specific structures
- D.
All of the above
Correct Answer
C. Are chemical substances that are produced by endocrine glands, travel through the circulatory system, and exert their influence on specific structuresExplanation
Any time during a test, if you don't know the right answer: 1. find a answer that grammatically fits better with the question
2. the longest answer
3. or just pick CRate this question:
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- 44.
A topic hormone
- A.
Stimulates growth and secretion of a specific glandular tissue
- B.
Acts by positive feedback control
- C.
Is produced by the gonads
- D.
Two of the above
Correct Answer(s)
A. Stimulates growth and secretion of a specific glandular tissue
D. Two of the aboveExplanation
The correct answer is "stimulates growth and secretion of a specific glandular tissue, two of the above." This is because a topic hormone can indeed stimulate the growth and secretion of a specific glandular tissue. Additionally, it can act by positive feedback control. However, it is not necessarily produced by the gonads, so only two of the given options are correct.Rate this question:
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- 45.
Calcium homeostasis is maintained by
- A.
Mineralocorticoids and adrenocorticotropic hormone (ACTH)
- B.
Aldosterone and parathyroid hormone
- C.
Parathyroid hormone and calcitonin
- D.
Calcitonin and glucagon
Correct Answer
C. Parathyroid hormone and calcitoninExplanation
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.Rate this question:
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- 46.
Calcitonin
- A.
Potentiates the effect of parathyroid hormone
- B.
Is secreted by the thyroid gland
- C.
Is released in response to excess serum calcium
- D.
All of the above
- E.
Only B and C are correct descriptions
Correct Answer
E. Only B and C are correct descriptionsExplanation
Calcitonin is a hormone that is secreted by the thyroid gland. It is released in response to excess serum calcium levels in the body. It helps to lower blood calcium levels by inhibiting the activity of osteoclasts, cells that break down bone tissue. Therefore, the correct descriptions for calcitonin are that it is secreted by the thyroid gland and it is released in response to excess serum calcium.Rate this question:
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- 47.
Which hormone promotes glucose transport from blood into cell?
- A.
Insulin
- B.
Glucagon
- C.
Epinephrine
- D.
Pancreatin
Correct Answer
A. InsulinExplanation
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.Rate this question:
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- 48.
Which hormone is LESS involved in a stress reaction?
- A.
Epinephrine
- B.
Norepinephrine
- C.
Cortisone
- D.
Thyroxin
- E.
Adrenocorticotropin
Correct Answer
D. ThyroxinExplanation
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.Rate this question:
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- 49.
Cortisol
- A.
Increases the flux of amino acids in the body
- B.
Mobilizes stored fat
- C.
Promotes gluconeogenesis
- D.
All of the above
- E.
Only A and C are correct
Correct Answer
D. All of the aboveExplanation
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.Rate this question:
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- 50.
Insulin has all of the following effects EXCEPT
- A.
Promotes glucose entry into cells, therefore has a hypoglycemic effect
- B.
Promotes transport of amino acids into cells, therefore increases protein synthesis
- C.
Promotes transport of fatty acids into cells, therefore has a lipogenic effect
- D.
Promotes liver glycogenolysis, therefor has a hyperglycemic effect
- E.
Promotes potassium entry into cells, therefore has a hypokalemic effect
Correct Answer
D. Promotes liver glycogenolysis, therefor has a hyperglycemic effectExplanation
Insulin is a hormone that is released by the pancreas in response to high blood glucose levels. It helps regulate glucose levels by promoting glucose entry into cells, which lowers blood glucose levels and has a hypoglycemic effect. Insulin also promotes the transport of amino acids into cells, increasing protein synthesis. It promotes the transport of fatty acids into cells, which has a lipogenic effect. Additionally, insulin promotes potassium entry into cells, leading to a hypokalemic effect. However, insulin does not promote liver glycogenolysis, which is the breakdown of glycogen into glucose. Therefore, it does not have a hyperglycemic effect.Rate this question:
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