Muscular Practice Exam Part 3 - A & P Zoo 172 For Exam 1
This is a practice exam for the first Exam in Zoology 172 A& P for Nursing School at Miami University. This covers the muscularsystem.
Questions and Answers
- 1.
__________ are fibrous tendonous sheets that anchor certain muscles.
- A.
Tendons
- B.
Ligaments
- C.
Aponeuroses
- D.
Fascia
Correct Answer
C. AponeurosesExplanation
Aponeuroses are fibrous tendonous sheets that anchor certain muscles. They are flat and broad in shape, providing a strong attachment for muscles to bones or other structures. Unlike tendons, which connect muscles to bones, aponeuroses can connect muscles to other muscles or structures. Ligaments, on the other hand, connect bones to other bones, while fascia refers to a connective tissue that surrounds and separates muscles, organs, and other structures. Therefore, the correct answer is aponeuroses.Rate this question:
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- 2.
The CT sheath around a whole muscle is called the ____________.
- A.
Epimysium
- B.
Perimysium
- C.
Endomysium
- D.
Fascicle
Correct Answer
A. EpimysiumExplanation
The CT sheath around a whole muscle is called the epimysium. The epimysium is a dense connective tissue that surrounds the entire muscle, providing support and protection. It helps to maintain the shape and integrity of the muscle, and also connects it to surrounding structures. The epimysium contains blood vessels and nerves that supply the muscle, and it merges with the tendons at the ends of the muscle, allowing for the transmission of forces between the muscle and bones.Rate this question:
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- 3.
The CT that covers the fascicle of a muscle is the ___________.
- A.
Epimysium
- B.
Perimysium
- C.
Endomysium
- D.
Myofibril
Correct Answer
B. PerimysiumExplanation
The perimysium is the connective tissue that surrounds and covers the fascicle of a muscle. It provides support and protection to the muscle fibers within the fascicle. The perimysium also contains blood vessels and nerves that supply the muscle fibers, allowing for proper functioning of the muscle.Rate this question:
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- 4.
The CT that covers the individual muscle fibers is the _______________.
- A.
Epimysium
- B.
Perimysium
- C.
Endomysium
- D.
Myofibril
Correct Answer
C. EndomysiumExplanation
The endomysium is the connective tissue that covers the individual muscle fibers. It surrounds each muscle fiber, providing support and protection. It also contains blood vessels and nerves that supply the muscle fibers with nutrients and signals for contraction. The other options, such as epimysium, perimysium, and myofibril, are not the correct answer because they refer to different structures within the muscle, such as the outer covering of the entire muscle, the connective tissue surrounding bundles of muscle fibers, and the contractile units within the muscle fiber, respectively.Rate this question:
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- 5.
The part of the muscles levels that are NOT covered in CT are the ___________.
- A.
Fascicles
- B.
Muscles fibers
- C.
Whole muscles
- D.
Myofibrils
Correct Answer
D. MyofibrilsExplanation
CT, or computed tomography, is a medical imaging technique that uses X-rays to create detailed cross-sectional images of the body. It is particularly useful for visualizing bones, organs, and tissues, but it may not provide clear images of smaller structures within the muscles, such as myofibrils. Myofibrils are the contractile units of muscle fibers and are responsible for muscle contraction. Since CT scans focus on larger structures, they may not be able to capture the fine details of myofibrils. Therefore, myofibrils are the part of the muscle levels that are not covered in CT scans.Rate this question:
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- 6.
Skeletal muscle fibers are very large, single nucleated cells that change in size by increasing or decreasing their volume.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
They are multi-nucleatedRate this question:
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- 7.
__________ are the filaments that provide the muscle with its contractile quality.
- A.
Myosin
- B.
Myofibrils
- C.
Actin
- D.
Sarcolemma
Correct Answer
B. MyofibrilsExplanation
Myofibrils are the filaments that provide the muscle with its contractile quality. These long, cylindrical structures are found within muscle cells and are responsible for muscle contraction. They consist of two types of filaments, actin and myosin, which slide past each other to generate tension and shorten the muscle fiber. The arrangement and interaction of these myofibrils allow for the coordinated movement of muscles, enabling them to contract and generate force. Sarcolemma, on the other hand, is the cell membrane of muscle cells and is not directly involved in muscle contraction.Rate this question:
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- 8.
The ___________ is the membrane of the myofibril.
- A.
Sarcomere
- B.
Sarcolemma
- C.
Sarcoplasmic reticulum
- D.
Titin
Correct Answer
B. SarcolemmaExplanation
The sarcolemma is the correct answer because it is the membrane that surrounds each individual muscle fiber. It acts as a barrier and controls the movement of substances in and out of the muscle cell. The sarcolemma is essential for muscle contraction and plays a crucial role in transmitting electrical impulses throughout the muscle fiber.Rate this question:
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- 9.
Myofibrils are composed of the proteins myosin and _________.
- A.
Actin
- B.
Perimysium
- C.
Titin
- D.
Troponin
- E.
Tropomyosin
Correct Answer
A. ActinExplanation
Myofibrils are composed of the proteins myosin and actin. Actin is a protein that is responsible for the contraction of muscles. It forms thin filaments that interact with thick filaments made of myosin. The interaction between actin and myosin allows muscles to contract and generate force. Therefore, actin is an essential component of myofibrils and plays a crucial role in muscle function.Rate this question:
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- 10.
Myosin myofibrils are the _________filaments that provide the active process in contraction.
- A.
Thick
- B.
Thin
Correct Answer
A. ThickExplanation
Myosin myofibrils are the thick filaments that provide the active process in contraction. These filaments are responsible for generating force during muscle contraction. They contain the protein myosin, which interacts with the thin filaments (actin) to produce the sliding movement that shortens the muscle fibers. The thick filaments are composed of multiple myosin molecules, which have a unique structure that allows them to bind to actin and generate the necessary force for muscle contraction.Rate this question:
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- 11.
Actin myofibrils are the __________ filaments that provide an anchor against which the myosin pulls.
- A.
Thick
- B.
Thin
Correct Answer
B. ThinExplanation
Actin myofibrils are the thin filaments that provide an anchor against which the myosin pulls. These thin filaments are composed of actin proteins and are responsible for the sliding movement of the myofibrils during muscle contraction. The myosin filaments grab onto the actin filaments and pull them closer together, causing the muscle to contract. Therefore, the correct answer is "thin".Rate this question:
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- 12.
_________ are the shared zig zag connections between adjacent sacromeres.
- A.
I bands
- B.
A bands
- C.
Z lines
- D.
M lines
Correct Answer
C. Z linesExplanation
Z lines are the shared zig zag connections between adjacent sarcomeres. They are made up of proteins called actin and connect the thin filaments of one sarcomere to the thin filaments of the next sarcomere. Z lines play a crucial role in maintaining the structural integrity of the sarcomere and in coordinating the contraction of muscle fibers.Rate this question:
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- 13.
_________ are light colored and are composed entirely of actin (thin filaments).
- A.
I bands
- B.
A bands
- C.
Z lines
- D.
M lines
- E.
Sarcomere
Correct Answer
A. I bandsExplanation
I bands are light colored and are composed entirely of actin (thin filaments). The I bands are found in the sarcomere, which is the basic structural unit of a muscle fiber. The I bands are responsible for the light appearance of the muscle under a microscope due to their composition of actin filaments. These filaments are responsible for muscle contraction and play a crucial role in the sliding filament theory, which explains how muscles contract.Rate this question:
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- 14.
__________ are dark colored and are located in the central part of the sarcomere.
- A.
I bands
- B.
A bands
- C.
Z lines
- D.
M lines
Correct Answer
B. A bandsExplanation
A bands are dark colored and are located in the central part of the sarcomere. The A band is composed of thick filaments made of myosin, which are responsible for muscle contraction. These filaments overlap with thin filaments made of actin in the region called the H zone, creating the dark appearance of the A band. The A band is an important structural component of the sarcomere and plays a crucial role in muscle contraction.Rate this question:
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- 15.
The __________ binds the myosin bundles togther and is located in the center of the A band.
- A.
I band
- B.
Z line
- C.
M line
- D.
Titin
- E.
Troponin
Correct Answer
C. M lineExplanation
The M line binds the myosin bundles together and is located in the center of the A band. It provides structural support and stability to the sarcomere during muscle contraction.Rate this question:
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- 16.
The ____________ is the section of the muscle fiber that extends from one Z line to the next.
- A.
Sarcomere
- B.
Sarcolemma
- C.
Sarcoplasma
- D.
Fascicle
Correct Answer
A. SarcomereExplanation
The sarcomere is the section of the muscle fiber that extends from one Z line to the next. It is the basic functional unit of a muscle and is responsible for muscle contraction. The sarcomere contains the contractile proteins actin and myosin, which slide past each other during contraction. The Z lines mark the boundaries of the sarcomere and anchor the actin filaments. The sarcomere shortens during muscle contraction, resulting in overall muscle shortening and movement. The sarcolemma is the cell membrane of a muscle fiber, sarcoplasm is the cytoplasm of a muscle fiber, and a fascicle is a bundle of muscle fibers.Rate this question:
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- 17.
________ molecules hold the myosin filaments in place by attaching to the Z line and the end of the myosin like a spring.
- A.
Troponin
- B.
Actin
- C.
Titin
- D.
Tropomyosin
- E.
Myosin
Correct Answer
C. TitinExplanation
Titin is a large protein found in muscle cells that acts as a molecular spring. It spans from the Z line to the end of the myosin filament, providing structural support and holding the myosin filaments in place. This allows for the proper alignment and organization of the contractile proteins in the muscle, enabling efficient muscle contraction and force generation. Therefore, titin is the molecule that attaches to the Z line and the end of the myosin filament, acting like a spring.Rate this question:
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- 18.
Tropomyosin on the actin filament is pulled off of the binding site so the myosin can attach by the globular protein __________.
- A.
Titin
- B.
Troponin
- C.
Aponeuroses
- D.
Osteon
Correct Answer
B. TroponinExplanation
When muscle contraction occurs, myosin needs to attach to the binding site on the actin filament. However, this binding site is initially blocked by tropomyosin. In order for myosin to attach, tropomyosin needs to be pulled off of the binding site. This is where troponin comes in. Troponin is a globular protein that is associated with tropomyosin on the actin filament. When calcium ions are released during muscle contraction, they bind to troponin, causing a conformational change. This change in troponin position allows tropomyosin to move away from the binding site, making it available for myosin to attach and initiate muscle contraction.Rate this question:
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- 19.
During an AP, _____ is released into the sarcoplasm which causes troponin to pull tropomyosin off of the actin binding sites.
- A.
K+
- B.
Ca++
- C.
Na+
- D.
Cl-
Correct Answer
B. Ca++Explanation
During an action potential (AP), Ca++ is released into the sarcoplasm. This influx of Ca++ ions causes troponin to bind to the actin filament, causing a conformational change that pulls tropomyosin away from the actin binding sites. This allows myosin to bind to actin and initiate muscle contraction.Rate this question:
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- 20.
Each myofibril is wrapped in an interlaced __________ which stores and evenly distributes the Ca++ upon an AP arriving.
- A.
Transverse tubule
- B.
Sarcoplasmic reticulum
- C.
Tropomyosin
- D.
Perimysium
Correct Answer
B. Sarcoplasmic reticulumExplanation
The sarcoplasmic reticulum is a network of membrane-bound tubules found within muscle cells. It plays a crucial role in muscle contraction by storing and releasing calcium ions (Ca++) upon the arrival of an action potential (AP). When an AP reaches the sarcoplasmic reticulum, it releases Ca++ into the surrounding cytoplasm, which then binds to proteins involved in muscle contraction. This allows the muscle to contract and generate force. The sarcoplasmic reticulum also helps in evenly distributing Ca++ throughout the muscle cell, ensuring efficient muscle contraction.Rate this question:
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- 21.
__________ are extensions of the sarcolemma that penetrate into the myofibril transversly and transmit extracellular fluid and the action potential into the core of the myofibril.
- A.
Sarcoplasmic reticulum
- B.
Cisternae
- C.
T-tubules
- D.
Cross-bridges
Correct Answer
C. T-tubulesExplanation
T-tubules are extensions of the sarcolemma that penetrate into the myofibril transversely. They transmit extracellular fluid and the action potential into the core of the myofibril.Rate this question:
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- 22.
The structure in a muscle fiber that consists of 2 sarcoplasmic reticula and one T-tubule is called a __________.
- A.
Cisternae
- B.
Triad
- C.
Olympiad
- D.
Motor unit
Correct Answer
B. TriadExplanation
The structure in a muscle fiber that consists of 2 sarcoplasmic reticula and one T-tubule is called a triad. The triad plays a crucial role in muscle contraction by allowing the transmission of electrical impulses deep into the muscle fiber. It is formed by the close association of two terminal cisternae of the sarcoplasmic reticulum and a T-tubule, creating a specialized microenvironment for the release and uptake of calcium ions. This calcium release is essential for the interaction between actin and myosin filaments, leading to muscle contraction.Rate this question:
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- 23.
The neurotransmitter that is used to control skeletal muscle is ___________.
- A.
Troponin
- B.
Acetylcholine
- C.
Actin
- D.
Creatine phosphate
Correct Answer
B. AcetylcholineExplanation
Acetylcholine is the correct answer because it is the neurotransmitter responsible for transmitting signals from motor neurons to skeletal muscles. When acetylcholine is released at the neuromuscular junction, it binds to receptors on the muscle fibers, triggering a series of events that ultimately lead to muscle contraction. This neurotransmitter plays a crucial role in controlling skeletal muscle movement and is essential for proper muscle function.Rate this question:
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- 24.
After ACh is released across the synaptic cleft and combines with receptor sites on the motor end plate, a __________- gated response takes place.
- A.
Chemically
- B.
Voltage
Correct Answer
A. ChemicallyExplanation
After ACh is released across the synaptic cleft and combines with receptor sites on the motor end plate, a chemically-gated response takes place. This means that the response is initiated by the binding of a specific chemical (ACh) to the receptor sites, which then triggers a series of biochemical reactions leading to the opening or closing of ion channels. This allows ions to flow in or out of the cell, resulting in a change in the membrane potential and the generation of an electrical signal. Therefore, the correct answer is chemically.Rate this question:
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- 25.
After the End Plate Potential is initiated, channels are opened and the motor end plate depolarizes due to the influx of ___________.
- A.
Na+
- B.
K+
- C.
Ca+
- D.
Cl-
Correct Answer
A. Na+Explanation
After the End Plate Potential is initiated, channels are opened and the motor end plate depolarizes due to the influx of Na+. This is because the opening of Na+ channels allows sodium ions to move into the cell, which leads to a change in the membrane potential and depolarization. The influx of Na+ ions is responsible for the initiation of an action potential, which then triggers muscle contraction.Rate this question:
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- 26.
After the influx of Na+ into the motor end plate, __________ - gated channels open to allow Na+ into the sarcolemma and it depolarizes beyond threshold, which initiates a full-blown all-or-nothing AP to travel through it to the T-tubules.
- A.
Chemically
- B.
Voltage
Correct Answer
B. VoltageExplanation
After the influx of Na+ into the motor end plate, voltage-gated channels open to allow Na+ into the sarcolemma and it depolarizes beyond threshold, which initiates a full-blown all-or-nothing AP to travel through it to the T-tubules. The term "voltage" refers to the fact that the opening of these channels is dependent on the voltage or potential difference across the membrane.Rate this question:
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- 27.
After an AP travels through the sarcolemma into the T-tubules it causes the cisternae (in which the T-tubules lay) to release _________ into the sarcoplasm.
- A.
Na+
- B.
Ca++
- C.
K+
- D.
Cl-
Correct Answer
B. Ca++Explanation
When an action potential (AP) travels through the sarcolemma and reaches the T-tubules, it triggers the release of calcium ions (Ca++) from the cisternae into the sarcoplasm. This release of calcium ions is a crucial step in muscle contraction. Calcium ions bind to the protein troponin, causing a conformational change that allows the myosin heads to bind to actin and initiate the sliding filament mechanism. This ultimately leads to muscle contraction.Rate this question:
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- 28.
Ca++ ions from the cisternae diffuse passively into the sarcoplasm and combine with the globular protein __________.
- A.
Tropomyosin
- B.
ATP
- C.
ACh
- D.
Troponin
Correct Answer
D. TroponinExplanation
When Ca++ ions from the cisternae diffuse passively into the sarcoplasm, they combine with the globular protein troponin. Troponin is a regulatory protein found in muscle fibers that plays a crucial role in muscle contraction. When Ca++ ions bind to troponin, it causes a conformational change in the troponin-tropomyosin complex, exposing the myosin binding sites on the actin filament. This allows for the interaction between actin and myosin, leading to muscle contraction. Therefore, troponin is the correct answer as it is directly involved in the regulation of muscle contraction.Rate this question:
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- 29.
After Ca++ combines with troponin on the actin filaments, the troponin changes shape causing tropomyosin to be pulled from the binding sites on the actin filaments which allows access by myosin ___________.
- A.
Molecules
- B.
Cross-bridges
- C.
Sarcomeres
- D.
Channels
Correct Answer
B. Cross-bridgesExplanation
After Ca++ combines with troponin on the actin filaments, the troponin changes shape causing tropomyosin to be pulled from the binding sites on the actin filaments. This exposes the binding sites on the actin filaments, allowing myosin cross-bridges to attach and initiate muscle contraction.Rate this question:
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- 30.
When myosin cross-bridges bind with the actin binding sites, the cross-bridges flex in the power stroke and cause the filaments to slide past each other. This causes the sarcomere to ___________.
- A.
Open
- B.
Lengthen
- C.
Shorten
- D.
Close
Correct Answer
C. ShortenExplanation
When myosin cross-bridges bind with the actin binding sites, they undergo a power stroke where they flex and pull the actin filaments towards the center of the sarcomere. This movement causes the filaments to slide past each other, resulting in the shortening of the sarcomere.Rate this question:
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- 31.
Ca++ is removed from the troponin by ___________ back into the sarcoplasmic reticulum.
- A.
Taxi
- B.
Passive transport
- C.
Concentration gradient
- D.
Active transport
Correct Answer
D. Active transportExplanation
Active transport is the process by which Ca++ is actively removed from the troponin and transported back into the sarcoplasmic reticulum. This process requires the expenditure of energy to move ions against their concentration gradient. Therefore, active transport is the most appropriate explanation for the given answer.Rate this question:
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- 32.
All of the following are inhibitory effects or effectors at the neuromuscular junction EXCEPT __________.
- A.
Botulism
- B.
Organophosphates
- C.
Myasthenia Gravis
- D.
Acromegaly
Correct Answer
D. AcromegalyExplanation
Acromegaly is not an inhibitory effect or effector at the neuromuscular junction. Acromegaly is a hormonal disorder caused by excessive growth hormone production, typically due to a pituitary gland tumor. It leads to the enlargement of bones and tissues, but it does not directly affect the neuromuscular junction or its inhibitory effects.Rate this question:
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- 33.
ATP is necessary for both muscle contraction and relaxation.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
ATP (adenosine triphosphate) is the primary source of energy for muscle contraction. It is required for the myosin heads to bind to actin filaments and generate force, leading to muscle contraction. Additionally, ATP is also needed for the relaxation of muscles after contraction. It is used to pump calcium ions back into the sarcoplasmic reticulum, allowing the muscle to relax. Therefore, ATP is necessary for both muscle contraction and relaxation, making the statement true.Rate this question:
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- 34.
The initial souce of ATP for muscle contraction that is short-term is _____________.
- A.
Acetylcholine
- B.
Glycolysis
- C.
Creatine phosphate
- D.
Electron transport chain
Correct Answer
C. Creatine phosphateExplanation
Creatine phosphate is the initial source of ATP for short-term muscle contraction. During intense exercise or muscle contraction, ATP is rapidly used up. Creatine phosphate then donates a phosphate group to ADP, regenerating ATP quickly and providing a rapid source of energy for muscle contraction. This process is known as the creatine phosphate system and is used for short bursts of high-intensity activity, such as weightlifting or sprinting. Acetylcholine is a neurotransmitter involved in muscle contraction, not a source of ATP. Glycolysis and the electron transport chain are involved in long-term energy production, not immediate ATP regeneration.Rate this question:
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- 35.
Oxygen debt occurs when the cardiovascular system cannot supply adequate oxygen to the muscles and _________ is formed - this is caused by anaerobic glycolysis.
- A.
Lactic acid
- B.
Glycerine
- C.
Acetylcholine
- D.
Pyruvic acid
Correct Answer
A. Lactic acidExplanation
During intense exercise, the cardiovascular system may not be able to deliver enough oxygen to the muscles, resulting in oxygen debt. This leads to anaerobic glycolysis, a process in which glucose is broken down without the presence of oxygen. As a byproduct of anaerobic glycolysis, lactic acid is formed. Therefore, the correct answer is lactic acid.Rate this question:
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- 36.
More motor units are required for different degrees of strength of contraction, or force, this is called multiple motor unit summation, or __________.
- A.
Contraction
- B.
Bundle
- C.
Recruitment
- D.
Isotonic
Correct Answer
C. RecruitmentExplanation
Recruitment refers to the process of activating additional motor units in order to generate a stronger muscle contraction. When more force is required, the brain sends signals to activate more motor units, which are groups of muscle fibers controlled by a single motor neuron. This allows for a greater number of muscle fibers to contract simultaneously, resulting in a stronger contraction. Therefore, recruitment is the correct term to describe the phenomenon of requiring more motor units for different degrees of strength of contraction.Rate this question:
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- 37.
There are two types of tetany: fused and unfused.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
The statement is true because there are indeed two types of tetany: fused and unfused. Fused tetany refers to sustained muscle contractions that do not have any relaxation periods in between, while unfused tetany refers to muscle contractions that have intermittent relaxation periods. These two types of tetany can occur due to various factors such as electrolyte imbalances, hyperventilation, or certain medical conditions.Rate this question:
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- 38.
_________ is an advanced form of summation where the muscle undergoes full contraction with no discernable amount of relaxation.
- A.
Strength
- B.
Tetany
- C.
Tertiary
- D.
Isometric
Correct Answer
B. TetanyExplanation
Tetany is an advanced form of summation where the muscle undergoes full contraction with no discernable amount of relaxation. This means that the muscle remains contracted for an extended period of time without any relaxation or rest. It is often seen in conditions such as hypocalcemia, where there is a decrease in calcium levels in the body. Tetany can cause muscle spasms, cramps, and twitching, and can be a result of overstimulation of the muscle fibers.Rate this question:
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- 39.
______ contraction is when the force of contraction stays the same, but the muscle length changes.
- A.
Isotonic
- B.
Isometric
- C.
Isotoners
- D.
Iced tea
Correct Answer
A. IsotonicExplanation
Isotonic contraction refers to a type of muscle contraction where the force of contraction remains constant, but the length of the muscle changes. This means that the muscle is actively shortening or lengthening while maintaining the same level of force. Isometric contraction, on the other hand, refers to a type of muscle contraction where the muscle length remains constant, but the force exerted by the muscle increases. Isotoners and iced tea are not related to muscle contractions and are therefore incorrect options.Rate this question:
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- 40.
___________ contractions is when the length stays the same, but the force of contraction changes.
- A.
Isotonic
- B.
Isometric
- C.
Isotoners
- D.
Iced tea
Correct Answer
B. IsometricExplanation
Isometric contractions refer to a type of muscle contraction where the length of the muscle stays the same while the force exerted by the muscle changes. This means that there is no movement or change in joint angle during the contraction. Isometric contractions are commonly used in exercises like planks or wall sits, where the muscles are engaged and holding a static position without any movement.Rate this question:
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- 41.
Slow twitch muscles (type I) are ________ in color.
- A.
Blue
- B.
Dark red
- C.
White
- D.
Yellow
Correct Answer
B. Dark redExplanation
Slow twitch muscles (type I) are dark red in color due to their high concentration of myoglobin, a protein that stores oxygen in muscle cells. Myoglobin gives the muscles a darker appearance, as it has a deep red color. This pigment helps slow twitch muscles efficiently use oxygen for sustained contractions, making them well-suited for endurance activities.Rate this question:
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- 42.
Fast twitch muscles (type II) are __________ in color.
- A.
Blue
- B.
Dark red
- C.
White
- D.
Yellow
Correct Answer
C. WhiteExplanation
Fast twitch muscles (type II) are white in color because they have a lower concentration of myoglobin, a protein that stores oxygen in muscle cells. Myoglobin is responsible for the red color in slow twitch muscles (type I) which have a higher oxygen supply. Since fast twitch muscles rely on anaerobic metabolism and have less oxygen available, they appear white in color.Rate this question:
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- 43.
Intercalated discs are found in _________ muscle.
- A.
Smooth
- B.
Cardiac
- C.
Strong
Correct Answer
B. CardiacExplanation
Intercalated discs are specialized structures found in cardiac muscle. These discs play a crucial role in connecting individual cardiac muscle cells, allowing them to synchronize their contractions and function as a coordinated unit. This unique feature is not present in smooth or strong muscle, making cardiac muscle the correct answer.Rate this question:
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- 44.
Torque is the tendency of a force to cause straight acceleration.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
angular accelerationRate this question:
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- 45.
Second class levers are always _________ in terms of force.
- A.
Advantaged
- B.
Disadvantaged
Correct Answer
A. AdvantagedExplanation
Second class levers are always advantaged in terms of force because the load is located between the fulcrum and the effort. This positioning allows for a greater mechanical advantage, meaning that a smaller effort force can move a larger load. In second class levers, the effort arm is always longer than the load arm, resulting in a force multiplication effect. This makes it easier to lift heavy objects or apply force to a resistance.Rate this question:
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- 46.
The _________ is the immovable end of the muscle and has no tendon in most cases.
- A.
Insertion
- B.
Origin
- C.
Ligament
- D.
Tendon
Correct Answer
B. OriginExplanation
The origin of a muscle is the immovable end of the muscle and in most cases, it does not have a tendon. The origin is the point of attachment of the muscle to a bone that remains fixed during muscle contraction. This is in contrast to the insertion, which is the movable end of the muscle that attaches to the bone that moves during muscle contraction. Ligaments are fibrous connective tissues that connect bones to other bones, while tendons connect muscles to bones.Rate this question:
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- 47.
The insertion is the end of the muscle that moves the associated bone toward the origin.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
The statement is true because the insertion point of a muscle is where it attaches to the bone that it moves. When the muscle contracts, it pulls on the bone, causing movement towards the origin point of the muscle. Therefore, the insertion point does indeed move the associated bone towards the origin.Rate this question:
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- 48.
_______________ are muscles that are responsible for the principal activity of a particular movement. Also called agonists.
- A.
Prime movers
- B.
Synergists
- C.
Antagonists
Correct Answer
A. Prime moversExplanation
Prime movers are muscles that are responsible for the principal activity of a particular movement. They are the main muscles that generate the force needed to perform the movement. Synergists are muscles that assist the prime movers in performing the movement, while antagonists are muscles that oppose or inhibit the action of the prime movers. Therefore, the correct answer is prime movers.Rate this question:
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- 49.
_________ are muscles that assist, stabilize, guide, or coordinate the agonist.
- A.
Prime movers
- B.
Synergists
- C.
Antagonists
Correct Answer
B. SynergistsExplanation
Synergists are muscles that work together with the agonist to assist, stabilize, guide, or coordinate movements. They help to enhance the action of the agonist and ensure smooth and efficient movement. Unlike prime movers, which are primarily responsible for generating movement, synergists provide additional support and control. Antagonists, on the other hand, oppose or inhibit the action of the agonist. Therefore, the correct answer for this question is synergists.Rate this question:
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- 50.
___________ are muscles that act in an opposite manner, and usually direct the agonist.
- A.
Prime movers
- B.
Synergists
- C.
Antagonists
Correct Answer
C. AntagonistsExplanation
Antagonists are muscles that act in an opposite manner to the agonist. They work to relax and lengthen while the agonist contracts, allowing for smooth and controlled movement. This opposing action helps to stabilize joints and prevent excessive or uncontrolled movements.Rate this question:
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