1.
Muscles are named by-(Select all that apply)Pg 183
Correct Answer(s)
A. Shape & Size
B. Bone they are near
C. Number of origins
D. Point of attachments
E. Directions of fibers
Explanation
Muscles can be named based on their shape and size, as different muscles can have distinct shapes and sizes. They can also be named based on the bone they are near, as muscles are often associated with specific bones in the body. The number of origins of a muscle, which refers to the number of attachment points on the bone, can also be used to name muscles. Additionally, the point of attachment of a muscle, where it connects to a bone or other structure, can be used for naming. Finally, the direction of the muscle fibers, which determines the orientation of the muscle, can also be considered when naming muscles.
2.
In order to create movement, muscle fibers usually _______.Pg 183
Correct Answer
B. Get shorter
Explanation
Muscle fibers usually get shorter in order to create movement. When a muscle contracts, the actin and myosin filaments within the muscle fibers slide past each other, causing the muscle to shorten. This contraction generates the force needed to move the bones and joints, resulting in movement.
3.
Attachment of muscle to bone that doesn't move when contraction occurs.Pg G-23
Correct Answer
A. Origin
4.
Attachment of muscle to bone that moves when contractions occur.Pg G-17
Correct Answer
B. Insertion
Explanation
The correct answer is "Insertion." In the context of muscle anatomy, the term "insertion" refers to the attachment point of a muscle to the bone that moves when the muscle contracts. The insertion is typically located distally from the origin, and it is the site where the muscle exerts its force to produce movement.
5.
Smooth muscle is also referred to as-(Check all that apply)Pg 156
Correct Answer(s)
C. Involuntary
D. Visceral
Explanation
Smooth muscle is referred to as involuntary because it is not under conscious control. It is controlled by the autonomic nervous system. Smooth muscle is also referred to as visceral because it is found in the walls of internal organs such as the stomach, intestines, and blood vessels. It is not referred to as skeletal, voluntary, or striated as these terms are used to describe skeletal muscle, which is under conscious control, found in the skeletal system, and has a striped appearance.
6.
Skeletal muscle is also referred to as-(Check all that apply)pg 156
Correct Answer(s)
A. Striated
C. Voluntary
Explanation
Skeletal muscle is referred to as striated because it has a striped appearance due to the arrangement of its contractile proteins. It is also referred to as voluntary muscle because it is under conscious control, meaning we can choose to contract or relax these muscles as needed.
7.
Have unique dark bands called intercalated disks where the plasma membranes of adjacent _____ fibers come in contact with each other.Pg 156
Correct Answer
B. Cardiac
Explanation
Cardiac fibers have unique dark bands called intercalated disks where the plasma membranes of adjacent fibers come in contact with each other. These intercalated disks play a crucial role in the coordinated contraction of cardiac muscle cells, allowing for efficient pumping of blood. This feature is specific to cardiac muscle and is not present in skeletal or smooth muscle fibers.
8.
Unique dark bands called _______ where the plasma membranes of adjacent cardiac fibers come in contact with each other.Pg 156
Correct Answer
intercalated disks
Explanation
Intercalated disks are unique dark bands where the plasma membranes of adjacent cardiac fibers come in contact with each other. These specialized structures play a crucial role in connecting cardiac muscle cells, allowing for coordinated contraction of the heart. Intercalated disks contain gap junctions, which facilitate the passage of electrical signals between cells, ensuring efficient transmission of impulses and synchronized contraction. Additionally, intercalated disks also contain desmosomes, which provide mechanical strength and prevent separation of adjacent cells during the forceful contractions of the heart.
9.
Fibers are cylindrical, branch frequently, and then recombine into a continuous mass of interconnected tissue.Pg 156
Correct Answer
B. Cardiac
Explanation
The given statement describes the structure of cardiac muscle fibers. Cardiac muscle fibers are cylindrical in shape and have a high degree of branching. They frequently branch and then recombine, forming a continuous mass of interconnected tissue. This unique structure allows for coordinated contraction and relaxation of the cardiac muscle, enabling it to pump blood effectively throughout the body.
10.
An organ composed mainly of striated muscle fibers & connective tissue.Pg 157
Correct Answer
A. Skeletal
Explanation
The correct answer is "Skeletal." This is because the organ described in the question is composed mainly of striated muscle fibers and connective tissue, which is a characteristic of skeletal muscle. Skeletal muscles are responsible for voluntary movements and are attached to bones by tendons. They are under conscious control and play a vital role in locomotion and body movement.
11.
______ anchor muscles firmly to bones.Pg 157
Correct Answer
tendons
tendon
Explanation
Tendons are fibrous connective tissues that anchor muscles firmly to bones. They are strong and flexible, allowing for the transmission of forces generated by muscle contractions to the bones, enabling movement and stability. Tendons are composed of collagen fibers, which provide strength and resistance to tension. Without tendons, muscles would not be able to effectively exert force on bones, resulting in impaired movement and functionality.
12.
Made of dense, fibrous connective tissues in the shape of heavy cords.Pg 157
Correct Answer
tendons
tendon
Explanation
Tendons are made of dense, fibrous connective tissues and are shaped like heavy cords. They are responsible for connecting muscles to bones and transmitting the force generated by the muscles to the bones, allowing movement.
13.
Muscular movement occurs when chemical enery from nutrient molecules are transferred to protein filaments in each muscle fiber and then converted to mechanical energy that attempts to contract the muscle.Pg 155
Correct Answer
A. True
Explanation
The given statement states that muscular movement occurs when chemical energy from nutrient molecules is transferred to protein filaments in each muscle fiber and then converted to mechanical energy that attempts to contract the muscle. This statement is true as it accurately describes the process of muscle contraction, where the chemical energy from nutrients is used to power the movement of protein filaments, resulting in muscle contraction.
14.
Prefixes that refer to muscle-(Select all that apply)Pg 155
Correct Answer(s)
B. Myo-
D. Sarco-
Explanation
The prefixes "myo-" and "sarco-" both refer to muscles. "Myo-" is derived from the Greek word "mys" meaning muscle, while "sarco-" is derived from the Greek word "sarkos" also meaning flesh or muscle. These prefixes are commonly used in medical and scientific terminology to indicate muscle-related terms or structures. Therefore, the correct answer is myo- and sarco-.
15.
Each fine thread is a muscle is called a muscle cell or a muscle _____.Pg 156
Correct Answer(s)
fiber
Explanation
Muscle cells are often referred to as muscle fibers because they have a long and slender shape, similar to that of a thread or fiber. This term is commonly used to describe the individual units that make up skeletal muscles. These muscle fibers are responsible for contracting and generating force, allowing the muscles to perform their functions. Therefore, the correct answer is "fiber."
16.
Have a smooth appearance when viewed under the microscope.Pg 156
Correct Answer
C. Smooth
Explanation
Smooth muscle tissue has a smooth appearance when viewed under the microscope. This is because smooth muscle cells are spindle-shaped and lack striations, giving them a uniform and sleek appearance. In contrast, skeletal muscle tissue has a striated appearance due to the arrangement of actin and myosin filaments, while cardiac muscle tissue also has striations but with an intercalated disc structure. Therefore, the correct answer is smooth muscle tissue.
17.
Most ___muscles attach to two bones that have a movable joint between them.Pg 157
Correct Answer
skeletal
Explanation
Skeletal muscles are the correct answer because they attach to two bones that have a movable joint between them. These muscles are responsible for movement and provide support to the skeletal system. They work in pairs, with one muscle contracting while the other relaxes to allow for movement at the joint. This arrangement allows for the coordination and control of movement in the body.
18.
Tendon ______ enclose some tendons.Pg 157
Correct Answer
sheaths
sheath
Explanation
The correct answer is "sheaths, sheath". The word "tendon" is a noun referring to a tough band of fibrous connective tissue that connects muscle to bone. In this context, the word "enclose" suggests that there is a need for a plural form of the noun "sheath" to indicate that multiple tendons are being enclosed. Therefore, the correct answer is "sheaths". However, it is worth noting that "sheath" is also a valid singular form of the noun, so the combination of "sheaths, sheath" covers both possibilities.
19.
Thick & thin myofilaments are formed by proteins called-Pg 157
Correct Answer
B. Myosin & Actin
Explanation
Thick and thin myofilaments are formed by proteins called myosin and actin. These proteins are responsible for the contraction of muscles. Myosin is a thick filament, while actin is a thin filament. During muscle contraction, myosin and actin interact with each other, causing the filaments to slide past each other and shorten the muscle. This interaction is regulated by the presence of calcium ions. Oxygen is not involved in the formation of myofilaments.
20.
Thick myofilaments are made from a protein called-Pg 157
Correct Answer
B. Myosin
Explanation
Thick myofilaments are made from a protein called myosin. Myosin is a motor protein that plays a crucial role in muscle contraction. It interacts with thin filaments made of actin to generate the force required for muscle contraction. This interaction between myosin and actin allows for the sliding of the filaments, leading to muscle contraction and movement. Therefore, myosin is the correct answer as it is the protein responsible for the formation of thick myofilaments in muscle cells.
21.
Thin myofilaments are made from a protein called-Pg 157
Correct Answer
A. Actin
Explanation
Thin myofilaments are made from a protein called actin. Actin is a globular protein that forms long chains and is an essential component of muscle contraction. It is responsible for the sliding movement of the thin filaments past the thick filaments during muscle contraction. Actin filaments are thin and flexible, allowing them to interact with myosin filaments and generate the force required for muscle contraction. Myosin, on the other hand, is a thick myofilament that interacts with actin during muscle contraction but is not the correct answer in this case.
22.
What is the smallest functional unit of muscle?Pg 157-159
Correct Answer
sarcomere
Explanation
The sarcomere is the smallest functional unit of muscle. It is a highly organized structure within the muscle fiber that is responsible for muscle contraction. It is composed of actin and myosin filaments, which slide past each other during muscle contraction. The sarcomere is bounded by Z-discs, which anchor the actin filaments, and the H-zone, which contains only myosin filaments. The interaction between actin and myosin within the sarcomere is what allows muscles to generate force and produce movement.
23.
Of all the muscles contracting simultaneously, the one that is manily responsible for producing a particular movment is called the _______________.Pg 159
Correct Answer
A. Prime mover
Explanation
The prime mover is the muscle that is primarily responsible for producing a particular movement. It is the main muscle that contracts and generates the force needed to perform the desired action. Synergists are muscles that assist the prime mover in performing the movement, while antagonist muscles oppose or reverse the action of the prime mover. The prime mover is the key muscle that initiates and carries out the movement.
24.
The other muscles that helps in producing the movement are called ___.Pg 159
Correct Answer
B. Synergists
Explanation
Synergists are the other muscles that assist in producing movement. They work together with the prime mover muscle to create a coordinated and efficient movement. While the prime mover is primarily responsible for the movement, synergists help to stabilize the joint and provide additional force or control. Antagonist muscles, on the other hand, work in opposition to the prime mover and help to control the speed and precision of the movement.
25.
When muscles contract simultaneously, the other muscles that relax are called ____.Pg 159
Correct Answer
C. Antagonist muscles
Explanation
When muscles contract simultaneously, the other muscles that relax are called antagonist muscles. These muscles work in opposition to the prime mover muscles, which are responsible for the main movement. The antagonist muscles help to control and stabilize the movement by relaxing and allowing the prime mover muscles to contract effectively. Synergists, on the other hand, are muscles that assist the prime mover muscles in producing a specific movement.
26.
Tension during muscle lengthening is often called ___ ___.Page 159
Correct Answer
eccentric contraction
Explanation
Tension during muscle lengthening is often referred to as eccentric contraction. This type of contraction occurs when the muscle is actively lengthening while still generating force. It is called eccentric because the muscle fibers are lengthening under tension, as opposed to concentric contraction where the muscle fibers are shortening under tension. Eccentric contractions are important for controlling movement and decelerating forces, such as when lowering a weight during a bicep curl. This type of contraction also causes more muscle damage, leading to greater muscle soreness and adaptation.
27.
What is required for contraction in the sliding filament model?Pg 158(Select all that apply)
Correct Answer(s)
A. Calcium
C. Oxygen
E. Adenosine triphosphate
Explanation
In the sliding filament model, contraction requires calcium, oxygen, and adenosine triphosphate (ATP). Calcium is necessary for the binding of myosin to actin, which initiates the contraction process. Oxygen is needed for cellular respiration, which produces ATP, the energy source for muscle contraction. ATP is responsible for providing the energy required for the myosin heads to attach and detach from the actin filaments during muscle contraction. Carbon and hydrogen are not mentioned as necessary components for contraction in the sliding filament model.
28.
Functions of skeletal muscles-Pg 159(Select all that apply)
Correct Answer(s)
A. Movement
C. Heat Production
D. Posture
Explanation
The skeletal muscles have multiple functions, including movement, heat production, and maintaining posture. Skeletal muscles are responsible for generating movement by contracting and relaxing, allowing us to perform various actions such as walking, running, and lifting objects. They also play a role in heat production, as muscle contractions generate heat, which helps to maintain our body temperature. Additionally, skeletal muscles help to maintain posture by providing support and stability to our skeletal system, allowing us to stand and sit upright.
29.
When maintain body posture because of continuous, low-strenght muscle contractions called ______ contractions.Pg 160
Correct Answer(s)
tonic
Explanation
Continuous, low-strength muscle contractions are known as tonic contractions. These contractions help maintain body posture by providing a constant level of muscle tension without causing any movement. Tonic contractions are important for activities such as standing or sitting upright, as they help stabilize the body and prevent it from collapsing.
30.
Any decrease below normal temperature is called-Pg 160
Correct Answer
B. Hypothermia
Explanation
Hypothermia is the correct answer because it refers to any decrease below normal body temperature. This condition occurs when the body loses heat faster than it can produce, causing the body temperature to drop below 95 degrees Fahrenheit (35 degrees Celsius). Hypothermia can be caused by exposure to cold temperatures, prolonged immersion in cold water, or certain medical conditions. Symptoms of hypothermia include shivering, confusion, drowsiness, and loss of coordination. If left untreated, severe hypothermia can be life-threatening.
31.
Any increase above normal temperature is called-Pg 160
Correct Answer
A. Hyperthermia
Explanation
Hyperthermia refers to an increase in body temperature that is above normal. This can be caused by various factors such as heat stroke, prolonged exposure to high temperatures, or certain medical conditions. Hyperthermia can be dangerous and may lead to symptoms such as dizziness, rapid heartbeat, and even organ damage if not promptly treated.
32.
If muscle fibers are stimulated repeatedly without adequate periods of rest, the strength of the muscle contraction decreases, resulting in _____.Pg 160
Correct Answer
fatigue
Explanation
When muscle fibers are stimulated repeatedly without enough rest, they become fatigued. This means that they are unable to contract with the same force and strength as before. Fatigue occurs due to the depletion of energy stores, build-up of waste products like lactic acid, and the inability of the muscle fibers to effectively transmit electrical signals. As a result, the muscle contraction becomes weaker, leading to a decrease in strength.
33.
Muscle fibers are stimulated by a nerve fiber called a __________.Pg 161
Correct Answer
B. Motor neuron
Explanation
Muscle fibers are stimulated by a nerve fiber called a motor neuron. Motor neurons are responsible for transmitting signals from the central nervous system to the muscles, causing them to contract. These neurons release neurotransmitters, such as acetylcholine, at the neuromuscular junction, which then bind to receptors on the muscle fibers, initiating muscle contraction. This process allows for voluntary movement and control of muscles in the body.
34.
Formation of ____ results in a rapid consumption of oxygen & nutrients.Pg 160
Correct Answer
B. More ATP
Explanation
The formation of more ATP results in a rapid consumption of oxygen and nutrients. ATP is the primary source of energy for cellular processes, and when more ATP is being produced, it indicates that the cells are in an active state and require more oxygen and nutrients to sustain the increased energy demand.
35.
The term _____ describes the continued increased metabolism that must occur in a cell to remove excess lactic acid that accumulates during prolonged exercise.Pg 160
Correct Answer
oxygen debt
Explanation
During prolonged exercise, the body may not be able to supply enough oxygen to the muscles, resulting in the production of lactic acid. This lactic acid buildup leads to an oxygen debt, which refers to the increased metabolism required by the cell to remove the excess lactic acid. The body needs to break down this lactic acid and convert it back into glucose, which requires additional oxygen. Therefore, the term "oxygen debt" accurately describes the process of increased metabolism needed to eliminate lactic acid after prolonged exercise.
36.
The shutting off of impulses to certain skeletal muscles results in ______.Pg 160
Correct Answer
paralysis
Explanation
When impulses to certain skeletal muscles are shut off, it leads to paralysis. Paralysis is the loss of muscle function in part of the body, resulting in the inability to move or control the affected muscles. This can occur due to various reasons such as nerve damage, spinal cord injury, or certain medical conditions.
37.
The ____ of muscle fibers produces most of the heat required to maintain body temperature.Pg 160
Correct Answer
contraction
Explanation
Muscle fibers undergo contraction, which refers to the shortening and tightening of the muscle fibers. This contraction generates heat, which is essential for maintaining the body temperature. Therefore, the contraction of muscle fibers is responsible for producing most of the heat required to regulate body temperature.
38.
Chemicals called _____ are released by the motor neuron in response to a nervous impulse.Pg 161
Correct Answer
C. Neurotransmitters
Explanation
Neurotransmitters are chemicals released by the motor neuron in response to a nervous impulse. They play a crucial role in transmitting signals between nerve cells and are responsible for the communication and coordination of various functions in the body. Neurotransmitters are released into the synapse, the gap between two nerve cells, and bind to receptors on the receiving cell, transmitting the signal and initiating a response.
39.
A single motor neuron, with the muscle fibers it innervates is called a ________/Pg 161
Correct Answer
Motor unit
motor unit
Explanation
A single motor neuron, along with the muscle fibers it innervates, is referred to as a motor unit. This term describes the functional unit of the neuromuscular system, where the motor neuron transmits signals to multiple muscle fibers, causing them to contract simultaneously. The motor unit plays a crucial role in coordinating and controlling muscle movements in the body.
40.
The neuromuscular junction is where ________ meets.Pg 161
Correct Answer
B. Nerve & muscles
Explanation
The neuromuscular junction is the point of connection between a nerve and a muscle. It is where the nerve endings release neurotransmitters that stimulate the muscle fibers, causing them to contract. This allows for the transmission of signals from the nervous system to the muscles, enabling movement and coordination.
41.
The minimal level of stimulation required to cause a fiber to contract is called the ____ stimulus. Pg 162
Correct Answer
threshold
Explanation
The minimal level of stimulation required to cause a fiber to contract is called the threshold stimulus. This is the point at which the fiber becomes excitable and initiates a response. It is the minimum amount of stimulation needed to activate the muscle fiber and trigger a contraction.
42.
Muscle fibers are said to respond ______.Pg 162
Correct Answer
C. All or none
Explanation
Muscle fibers are said to respond "all or none." This means that when a muscle fiber is stimulated by a nerve impulse, it will contract fully or not at all. There is no partial contraction. This principle is important for muscle function and coordination, as it allows for precise control of movement. If all muscle fibers within a muscle are stimulated, the entire muscle contracts. If only some fibers are stimulated, only those fibers will contract while the rest remain relaxed.
43.
A quick, jerky response to stimulus.Pg 162
Correct Answer
A. Twitch
Explanation
A twitch refers to a quick and jerky response to a stimulus. This is a brief contraction of a muscle fiber that occurs in response to a single nerve impulse. It is characterized by a rapid and short-lived contraction and relaxation of the muscle. This type of muscle contraction is different from tetanic contraction, isotonic contraction, and isometric contraction, which involve sustained or constant muscle contractions.
44.
A more sustained and steady response than a twitch.Pg 162
Correct Answer
A. Tetanic contraction
Explanation
A tetanic contraction refers to a sustained and steady muscle contraction that occurs when a muscle is stimulated rapidly and at a high frequency. This type of contraction results in a continuous and smooth movement, unlike a twitch which is a brief and jerky contraction. Isotonic contraction refers to a muscle contraction where the muscle changes length and moves a load, while isometric contraction refers to a muscle contraction where the muscle does not change length but generates tension. Therefore, the correct answer is tetanic contraction.
45.
In most cases produces movement of a joint.pg 162
Correct Answer
B. Isotonic contraction
Explanation
Isotonic contraction is the correct answer because it refers to a type of muscle contraction where the muscle changes length and produces movement of a joint. During isotonic contractions, the tension in the muscle remains constant while the muscle shortens or lengthens, resulting in movement. This is in contrast to isometric contractions, where the muscle does not change length and no movement occurs. The information provided on page 162 further supports this explanation.
46.
In a type of isotonic contraction called ____, the insertion end moves towards the point of origin.Pg 162
Correct Answer
A. Concentric
Explanation
In a concentric contraction, the muscle shortens as it generates force, causing the insertion end to move towards the point of origin. This type of contraction is commonly seen in activities such as lifting weights or doing bicep curls, where the muscle contracts to overcome resistance and move a load.
47.
A type of isotonic contraction wherea muscle produces tension as it lengthens and thus insertion moves away from the origin.Pg 162
Correct Answer
B. Eccentric contraction
Explanation
An eccentric contraction refers to a type of isotonic contraction where a muscle produces tension as it lengthens. In this type of contraction, the insertion point of the muscle moves away from its origin. This is different from a concentric contraction, where the muscle shortens as it produces tension. The information provided on page 162 supports the answer of eccentric contraction.
48.
A contraction that does not always produce movement. Sometimes it increases the tension within a muscle but does not shorten it.Pg 162
Correct Answer
B. Isometric contraction
Explanation
An isometric contraction refers to a type of muscle contraction where there is an increase in tension within the muscle, but no change in its length or movement. This means that the muscle remains static while exerting force against an immovable object or resisting an external force. In this case, the contraction increases the tension within the muscle, but does not cause any movement.
49.
During prolonged inactivity, muscles usually shrink in mass, a condition called ____.Pg 164
Correct Answer
disuse atrophy
Explanation
Disuse atrophy refers to the shrinking of muscles that occurs when they are not used or active for an extended period of time. This condition is commonly observed in individuals who are bedridden or have limited mobility, as their muscles are not being regularly stimulated through movement and exercise. Lack of muscle activity leads to a decrease in muscle size and strength, resulting in muscle wasting or shrinkage. This can have detrimental effects on overall physical health and functionality.
50.
Muscle hypertrophy can be enhanced by-Pg 164
Correct Answer
B. Strength training
Explanation
Muscle hypertrophy refers to the increase in muscle size. This can be achieved through strength training, which involves resistance exercises that target specific muscle groups. Strength training causes micro-tears in muscle fibers, which then repair and grow larger and stronger during the recovery process. On the other hand, aerobic training primarily focuses on cardiovascular fitness and endurance, rather than muscle growth. Therefore, strength training is the more effective method for enhancing muscle hypertrophy.