ITEC A&p (Muscular System) 3 Q&a

The muscular system relies on the skeletal system for movement. The skeletal system provides a framework of bones that act as levers for the muscles to pull on, allowing for movement of the body. The muscles attach to the bones via tendons, and when the muscles contract, they pull on the bones, causing movement. Without the support and structure provided by the skeletal system, the muscles would not be able to generate the necessary force to produce movement.

Overheating is not a cause of strain because strain typically refers to the excessive or overuse of muscles or tendons, resulting in injury or discomfort. Overheating, on the other hand, refers to an increase in body temperature due to external factors such as hot weather or intense physical activity. While overheating can lead to other health issues, it is not directly related to the strain on muscles or tendons.

The muscular system relies on the skeletal system for leverage and movement. The skeletal system provides a framework for the muscles to attach to and allows for movement to occur. Without the skeletal system, the muscles would not have a structure to work against and movement would be impossible. Additionally, the skeletal system acts as a lever, allowing the muscles to generate force and produce movement.

Overheating is not a cause of strain because strain typically refers to the excessive force or tension placed on a muscle or tendon during physical activity. Overheating, on the other hand, is a condition that occurs when the body's core temperature rises above normal levels, usually due to external factors such as hot weather or intense physical exertion. While overheating can lead to other health issues, it is not directly related to the muscular strain caused by overuse, over stretching, or overexertion.

Glucose is a muscle fuel because it is the primary source of energy for muscles during physical activity. When glucose is broken down through a process called glycolysis, it produces ATP (adenosine triphosphate), which is used by the muscles for contraction. Glucose can be obtained from the breakdown of carbohydrates in the diet or from the storage form of glucose called glycogen in the liver and muscles.

Muscles fuel themselves by using glucose. Glucose is a type of sugar that is broken down by the body to produce energy. It is the primary source of fuel for muscles during exercise or physical activity. When glucose is consumed, it is converted into ATP (adenosine triphosphate), which is the energy currency of the body. This ATP is then used by the muscles to perform their functions. Therefore, glucose is the correct answer as it is the main fuel source for muscles.

Atrophy refers to the wasting away or decrease in size of a muscle. This can occur due to various reasons such as disuse, aging, or certain medical conditions. It is characterized by a loss of muscle mass and strength. Inflammation of a muscle, build up of lactic acid in a muscle, and injury to a joint are not accurate descriptions of atrophy.

Atrophy refers to the wasting away or shrinkage of a muscle due to a decrease in muscle mass. This can occur as a result of various factors such as disuse, immobilization, nerve damage, or certain medical conditions. Inflammation of a muscle, build-up of lactic acid in a muscle, and injury to a joint are not accurate descriptions of atrophy.

A strain is the over-stretching of a muscle causing soreness and localized pain.

The tendon of Achilles is formed by the Gastrocnemius and soleus muscles. These two muscles are located in the calf and are responsible for plantar flexion of the foot. The Gastrocnemius is the larger muscle of the two and is visible as the prominent calf muscle. The soleus muscle lies underneath the Gastrocnemius and helps to stabilize the ankle joint. Together, these muscles form the Achilles tendon, which attaches to the heel bone and allows for movement of the foot.

The muscles have various functions, including producing movement, maintaining posture, and producing heat. However, protecting organs is not a function of the muscles. The organs are typically protected by other structures such as bones, cartilage, and connective tissues.

Heat is not a cause of cramp because cramping typically occurs when muscles are overworked, fatigued, or lacking in certain nutrients. While heat can contribute to muscle fatigue and dehydration, it is not a direct cause of cramping. Cramps are more commonly associated with factors such as vigorous exercise, lack of calcium in the muscle, and dehydration.

The tendon of Achilles is located in the posterior lower leg. It connects the calf muscles to the heel bone and is the largest tendon in the body. This tendon is responsible for allowing the foot to point downward and providing the necessary force for activities such as walking, running, and jumping.

Supination is the correct answer because it refers to the movement of turning a limb to face upwards. This movement is commonly seen in the forearm, where the palm is turned to face upwards or towards the ceiling. It is the opposite movement of pronation, which is the turning of the palm to face downwards or towards the floor. Plantarflexion refers to the movement of pointing the foot downwards, while eversion refers to the movement of turning the foot outwards.

Lactic acid is a byproduct of anaerobic metabolism in muscles. When the muscles are working hard and there is not enough oxygen available, they switch to anaerobic metabolism, resulting in the production of lactic acid. Accumulation of lactic acid can lead to muscle fatigue and decrease the efficiency of muscle contraction. Therefore, lactic acid can cause the inability of a muscle to contract efficiently.

The agonist muscle refers to the muscle that is primarily responsible for producing a specific movement or action. It contracts and generates force to create movement at a joint. In contrast, the antagonist muscle is responsible for opposing or slowing down the movement produced by the agonist muscle. Therefore, the correct answer is "contracting muscle."

Skeletal muscle is the correct answer because it is the type of voluntary muscle that is under conscious control. This type of muscle is attached to the bones and allows for movement of the body. Smooth muscle, cardiac muscle, and unstriated muscle are all types of involuntary muscles that are not under conscious control.

Voluntary muscles, also known as skeletal muscles, have a specific structure. They are composed of striated fibers, which means they have alternating light and dark bands. These fibers have a membrane that surrounds them and a nucleus within each fiber. This structure allows voluntary muscles to contract and relax in response to conscious control, enabling movement in the body.

The agonist muscle refers to the muscle that is actively contracting to produce a specific movement. It is responsible for generating the force required to execute the desired action. In contrast, the antagonist muscle is the muscle that opposes the action of the agonist and relaxes while the agonist contracts. Therefore, the correct answer is "Contracting muscle" as it accurately describes the role of the agonist muscle in movement.

Voluntary muscles have a structure of striated fibers with a membrane and nucleus. Striated fibers refer to the alternating light and dark bands that give these muscles their striped appearance. The presence of a membrane and nucleus is essential for the functioning and maintenance of the muscle cells. This structure allows voluntary muscles to contract and relax in response to conscious control from the central nervous system.

The muscles have various functions in the body, including producing movement, maintaining posture, and producing heat. However, protecting organs is not a function of the muscles. Organs are typically protected by other structures such as bones, cartilage, and connective tissues.

The origin of a muscle refers to the fixed end of the muscle, where it attaches to a bone or other structure that does not move during contraction. This point serves as the anchor for the muscle, allowing it to exert force and create movement at the other end, known as the insertion.

Lactic acid is caused by insufficient oxygen to the muscle. When the muscles are not receiving enough oxygen, they switch to anaerobic metabolism, which produces lactic acid as a byproduct. This occurs during intense exercise or when the body is unable to supply enough oxygen to the muscles, leading to a buildup of lactic acid.

A sudden twist of a ligament is known as a sprain. This occurs when the ligament is stretched or torn, causing pain, swelling, and difficulty in moving the affected joint. A sprain typically happens due to sudden movements, such as twisting or turning, that put excessive stress on the ligament. It is different from a strain, which refers to the stretching or tearing of a muscle or tendon. Rupture refers to a complete tear or breakage of a ligament, while a cramp is a sudden and involuntary muscle contraction.

Superficial fascia is found under the skin. It is a layer of connective tissue that lies between the skin and the underlying muscles and organs. It provides support and protection to the structures underneath and also contains fat cells that help with insulation and energy storage.

The superficial fascia is found beneath the skin. This layer of connective tissue lies directly above the deep fascia and is composed of adipose tissue and loose areolar connective tissue. It serves as a protective layer, providing insulation and cushioning for the underlying structures such as muscles, blood vessels, and nerves. Additionally, the superficial fascia also plays a role in storing and distributing fat throughout the body.

The quadriceps muscle group consists of four muscles: vastus lateralis, rectus femoris, vastus intermedius, and vastus medialis. The biceps femoris, on the other hand, is not part of the quadriceps muscle group. It is actually a muscle located in the posterior compartment of the thigh and is one of the hamstring muscles.

The deltoid muscle has anterior, medial, and posterior fibers that give the shoulder its shape. These fibers cover the shoulder joint and contribute to the rounded appearance of the shoulder. The deltoid muscle is responsible for various movements of the arm, such as abduction, flexion, and extension, and its different fiber orientations help in providing stability and strength to the shoulder joint.

Dorsiflexion refers to the movement of pointing the foot upwards. It is the opposite of plantarflexion, which is the movement of pointing the foot downwards. Inversion refers to the movement of turning the foot inward, while eversion refers to the movement of turning the foot outward. Therefore, the correct answer is dorsiflexion.

Muscle is composed of 75% water, which is necessary for the proper functioning of muscle cells. It also contains 20% protein, which is essential for muscle growth and repair. Additionally, muscle contains 5% mineral salts, which help maintain electrolyte balance, fats, which provide energy for muscle contraction, and glycogen, which is a storage form of glucose used for energy during exercise.

Isotonic muscle contraction occurs when the length of the muscle changes while the tension remains the same. In this type of contraction, the muscle shortens or lengthens against a constant resistance. This allows for movement and is commonly seen during activities such as weightlifting or walking.

The muscle found on the lateral front of the lower leg is the Tibialis anterior.

The semimembranosus muscle is located in the back of the thigh and is responsible for extending the hip, not flexing it. Flexing the hip involves bringing the thigh towards the abdomen, which is done by muscles such as the iliopsoas (which includes the iliacus muscle), sartorius, and rectus femoris. Therefore, the correct answer is Semimembranosus.

Isotonic muscle contraction occurs when the length of the muscle changes while the tension in the muscle remains the same. This type of contraction is commonly seen during activities such as weightlifting or performing a bicep curl, where the muscle shortens as it contracts against a constant resistance.

Eversion describes the action of turning the foot to face outwards. This means that the sole of the foot is moving away from the midline of the body. It is the opposite of inversion, which is the action of turning the foot to face inwards towards the midline of the body.

The correct answer is Myositis. Myositis refers to the inflammation of a muscle. It can be caused by various factors such as infection, injury, or autoimmune diseases. Symptoms of myositis may include muscle pain, weakness, and swelling. Fibrositis, on the other hand, refers to the inflammation of fibrous connective tissue, not specifically muscles. Spasticity refers to the condition of increased muscle tone and stiffness, while rupture refers to the tearing or breaking of a muscle or tendon.

Isometric contraction involves the muscle contracting without any movement. This means that the muscle is generating tension and force, but there is no change in the length or position of the muscle. Isometric contractions are commonly used in exercises such as planks or wall sits, where the muscle is contracted and held in a static position without any movement occurring. This type of contraction helps to build strength and stability in the muscle.

The action of the Middle deltoid is abduction. Abduction refers to the movement of a body part away from the midline of the body. In the case of the Middle deltoid, it is responsible for moving the arm away from the body laterally. This action is commonly used when raising the arm to the side, such as during lateral raises or when performing certain overhead movements.

The action of the hamstring muscle group is to flex the knee and extend the hip. This means that when the hamstrings contract, they bend the knee joint and straighten the hip joint. This motion is important for activities such as walking, running, and jumping.

Atony refers to the lack of tone in a muscle. This means that the muscle lacks the normal firmness and strength, resulting in weakness and flabbiness. It can be caused by various factors such as nerve damage, muscle disuse, or certain medical conditions. Myositis refers to inflammation of the muscle, atrophy refers to the wasting away or shrinking of muscle, and rupture refers to the tearing or breaking of a muscle.

The gastrocnemius muscle is responsible for both plantarflexion of the foot and flexion of the knee. Plantarflexion refers to pointing the toes downward, while flexion of the knee involves bending the knee joint. The gastrocnemius muscle is located in the calf and is one of the major muscles involved in walking and running.

The origin of a muscle refers to the point where the muscle attaches to a stationary bone or structure. This is the starting point of the muscle and is usually located closer to the body's midline. The attachment of the muscle to tendons refers to the point where the muscle connects to the tendons that allow it to move. The main body of the muscle refers to the bulk of the muscle tissue. The moving end of the muscle refers to the point where the muscle attaches to a bone that moves when the muscle contracts. Therefore, the correct answer is "The end of the muscle that is stationary."

The muscle positioned on the inside front of the thigh is the Vastus medialis. This muscle is one of the four quadriceps muscles and is located on the inner side of the thigh. It plays a role in extending the leg and stabilizing the knee joint.

The rectus femoris is a muscle located in the front of the thigh that crosses both the hip and knee joints. It is one of the four muscles that make up the quadriceps group. The main function of the rectus femoris is to extend the knee joint. When the muscle contracts, it helps to straighten the leg and lift the foot off the ground. Therefore, the rectus femoris is the correct answer to the question.

The structure of a tendon is composed of white fibrous inelastic cords. Tendons are strong, flexible cords of connective tissue that attach muscles to bones. They are made up of collagen fibers, which provide strength and stability to the tendon. The inelastic nature of the cords allows them to transmit the force generated by the muscle to the bone, enabling movement and providing stability to the joints.

The correct answer is Gracilis. The Gracilis muscle is positioned on the inner thigh. It is one of the muscles that make up the adductor muscle group and runs from the pubic bone to the tibia. It helps to adduct and flex the hip, as well as assist in knee flexion. The Biceps femoris and Vastus lateralis are not positioned on the inner thigh, while the duplicate option of Gracilis is incorrect.