The Muscular System Practice Quiz

The coccygeus muscle does not compress the abdomen. It is a small triangular muscle located in the pelvic region, attaching to the coccyx and the ischial spine. Its main function is to support the pelvic organs and assist in stabilizing the pelvis. Unlike the internal oblique, external oblique, and transversus abdominis muscles, which are all involved in compressing the abdomen, the coccygeus muscle has a different role and does not contribute to abdominal compression.

During muscle contraction, the two articulating bones do not move equally. One bone remains relatively stationary while the other bone moves, resulting in the desired movement. This is because muscles work in antagonistic pairs, where one muscle contracts while the other relaxes to produce movement. Therefore, the statement that the two articulating bones move equally during contraction is not true.

The suprahyoid muscles are a group of muscles that lie superior to the hyoid bone and help form the floor of the oral cavity. This means that they are located above the hyoid bone and assist in creating the bottom surface of the mouth. They play a role in various functions such as swallowing and speech production.

The hamstring muscles are responsible for flexing the knee. When these muscles are paralyzed, the individual would be unable to flex their knee.

The sternocleidomastoid muscle is a straplike muscle that is responsible for movements of the head and neck. When this muscle experiences spasms, it can lead to wryneck or torticollis, which is a condition characterized by the head being tilted to one side. The other muscles listed (serratus anterior, zygomaticus, platysma) do not have the same function or involvement in wryneck or torticollis.

The gracilis muscle is not a member of the hamstrings. The hamstrings consist of three muscles: semitendinosus, semimembranosus, and biceps femoris. The gracilis muscle is located in the inner thigh and is not part of the hamstring group.

When the term "levator" is part of the descriptive term for a muscle's action, it indicates that the muscle elevates and/or adducts a region. The term "levator" comes from the Latin word "levare," which means "to lift." Therefore, a muscle with "levator" in its name is responsible for lifting or elevating a body part and potentially adducting it towards the midline of the body.

The deltoid muscle is involved in abduction. Abduction refers to the movement of a body part away from the midline of the body. The deltoid muscle is located in the shoulder and is responsible for lifting the arm away from the body. It is a triangular-shaped muscle that covers the shoulder joint and provides strength and stability during abduction movements. The other muscles listed, such as subscapularis, teres major, and latissimus dorsi, are not primarily involved in abduction but rather have different functions in the shoulder and upper body.

The extensor carpi radialis brevis is a muscle that extends and abducts the wrist. It is also described as being short in length.

The correct answer is that there are over 600 muscles in the body. This is true because the human body contains a complex network of muscles that work together to facilitate movement and maintain posture. While the exact number of muscles can vary from person to person, it is generally accepted that there are well over 600 muscles in the body. These muscles are responsible for a wide range of functions, including voluntary movements such as walking and running, as well as involuntary movements such as digestion and breathing.

An agonist is a muscle that provides the major force for producing a specific movement. It contracts and causes the desired movement to occur. It works in coordination with other muscles to produce the movement.

Muscle classification can be based on various factors such as location, type of action they cause, and muscle shape. However, the type of muscle fibers is not a way of classifying muscles. Muscle fibers can be classified as either slow-twitch or fast-twitch based on their contraction speed and endurance capabilities. This classification is not used to categorize muscles as a whole, but rather to understand the different types of muscle fibers within a muscle.

When the term biceps, triceps, or quadriceps forms part of a muscle's name, it indicates the number of origins the muscle has. "Bi-" means two, "tri-" means three, and "quadri-" means four. Therefore, the correct answer is that the muscle has two, three, or four origins, respectively.

Geniohyoid, hyoglossus, and stylohyoid are all muscles that are involved in the movement and control of the tongue. They work together to help move and position the tongue during speech and swallowing. These muscles play a crucial role in the articulation of sounds and the manipulation of food in the mouth.

The orbicularis oris muscle is responsible for closing, pursing, and protruding the lips. This muscle is located around the mouth and is responsible for various movements of the lips, such as closing the lips together, puckering or pursing the lips, and pushing the lips forward or protruding them. These actions are important for various functions like speaking, eating, and expressing emotions through facial expressions.

Circular muscles are the muscles that are found at openings of the body. These muscles are arranged in a circular pattern around the openings and are responsible for controlling the opening and closing of these passages. They contract and relax to regulate the flow of substances in and out of the body. Examples of circular muscles include the muscles of the digestive system, such as the muscles of the esophagus, stomach, and intestines, as well as the muscles of the respiratory system, such as the muscles of the bronchioles and the iris of the eye.

Tennis players commonly experience pain in the arm that swings the racquet. The muscle that is usually strained under these conditions is the brachioradialis. This muscle is located in the forearm and is responsible for flexing the forearm at the elbow joint. The repetitive swinging motion in tennis can put strain on the brachioradialis, leading to pain and discomfort.

The frontal belly of the epicranius muscle is responsible for producing horizontal wrinkles in the forehead. This muscle is located in the frontalis muscle, which covers the forehead and extends from the eyebrows to the scalp. When the frontal belly of the epicranius contracts, it pulls the scalp forward, causing the skin of the forehead to wrinkle horizontally. This muscle is commonly used in facial expressions such as raising the eyebrows or showing surprise.

The supraspinatus muscle is responsible for stabilizing the shoulder joint and preventing the downward displacement of the humerus. It also assists in abduction, which is the movement of the arm away from the body. This muscle plays a crucial role in maintaining the proper alignment and function of the shoulder joint during various arm movements.

The tibialis anterior muscle is involved in inversion at the ankle joint. Inversion refers to the movement of the foot inwards, towards the midline of the body. The tibialis anterior muscle is located on the front of the lower leg and is responsible for dorsiflexion (lifting the foot upwards) and inversion of the foot. When the tibialis anterior muscle contracts, it helps to turn the sole of the foot inward, causing inversion at the ankle joint.

Paralysis of the iliopsoas and rectus femoris muscles would make an individual unable to flex the thigh. These muscles are responsible for flexing the hip joint, which allows for movement of the thigh towards the abdomen. If these muscles are paralyzed, the individual would not be able to bring their thigh upwards towards their abdomen.

When exhaling forcibly, the internal intercostals and diaphragm contract. The diaphragm is a dome-shaped muscle located at the base of the lungs, and when it contracts, it moves downward, pushing against the abdominal organs and causing exhalation. The internal intercostals are muscles that are located between the ribs, and when they contract, they pull the ribs downward, further aiding in exhalation. Therefore, the correct answer is internal intercostals and diaphragm.

The major factor controlling the manner in which levers work is the difference in the positioning of the effort, load, and fulcrum. This refers to the relative distances and positions of these three components in a lever system. The position of the effort, load, and fulcrum determines the mechanical advantage and efficiency of the lever. By adjusting the positioning, the leverage can be increased or decreased, allowing for easier or more powerful movement of the load.

The buccinator muscle is responsible for the sucking action in nursing infants as well as the muscle used for whistling in adults. This muscle is located in the cheek area and helps with actions such as blowing, sucking, and whistling. The other options, platysma, masseter, and zygomaticus, are not involved in the sucking or whistling actions described in the question.

The adductor magnus, adductor longus, and adductor brevis are muscles that are located in the medial compartment of the thigh. These muscles are responsible for adduction, or bringing the thigh towards the midline of the body. They also assist in flexion and extension of the hip joint.

A muscle group that works with and assists the action of a prime mover is called a synergist. Synergists help to stabilize joints and provide additional support to the prime mover muscle during movement. They work together to produce a coordinated and efficient movement.

The triceps brachii acts as an antagonist in flexing the forearm at the elbow. When the biceps brachii contracts to flex the forearm, the triceps brachii relaxes and lengthens to allow for this movement. The triceps brachii is responsible for extending the forearm at the elbow, so it acts in opposition to the biceps brachii during flexion.

The popliteus muscle does not act in plantar flexion. It is a small muscle located in the back of the knee joint and its main function is to unlock the knee joint by internally rotating the tibia. Plantar flexion, on the other hand, refers to the movement of pointing the foot downward, which is primarily performed by the gastrocnemius and soleus muscles in the calf, as well as the tibialis posterior and flexor digitorum longus muscles in the lower leg.

The scalenes are a group of muscles that are responsible for flexing and rotating the neck. They are located on the sides of the neck and connect the cervical vertebrae to the first and second ribs. When these muscles contract, they help to tilt the head to the side and rotate it. They also assist in deep inhalation by elevating the first and second ribs. Therefore, the scalenes are the correct answer for the group of muscles that flex and rotate the neck.

The correct answer is infraspinatus. The question asks for a muscle located on the dorsal side of the body. The pectoralis minor, rectus femoris, and rectus abdominis are all muscles located on the ventral side of the body, while the infraspinatus is a muscle located on the dorsal side.

A first-class lever is demonstrated by scissors. In a first-class lever, the fulcrum is located between the effort and the load. In the case of scissors, the fulcrum is the pivot point where the two blades are joined together. The effort is applied by squeezing the handles together, and the load is the object being cut. This lever arrangement allows for the force to be magnified or redirected, making it easier to cut through materials.

The vastus lateralis muscle is a common intramuscular injection site, particularly in infants. This muscle is located on the lateral side of the thigh and is easily accessible for injections. It is often chosen for injections in infants because it has a thick muscle belly and is less likely to cause damage to surrounding structures. Additionally, the vastus lateralis muscle has a large surface area, allowing for the dispersion of medication and reducing the risk of complications.

In a pennate muscle, the fascicles are short and attach obliquely to a central tendon that runs the length of the muscle. This arrangement allows for a greater number of muscle fibers to be packed into a smaller area, resulting in increased strength. The oblique attachment of the fascicles to the tendon also allows for a larger range of motion and force generation. This arrangement is different from circular, triangular, or fusiform arrangements, which have different patterns of muscle fiber organization.

The correct answer is the gastrocnemius. The gastrocnemius muscle is a large muscle located at the back of the lower leg. It inserts into the calcaneal tendon, also known as the Achilles tendon, which attaches to the calcaneus bone in the heel. This muscle is responsible for plantar flexion of the foot, which is the movement that allows us to stand on tiptoes.

When a lever operates at a mechanical disadvantage, it means that the load is far from the fulcrum and the effort is applied near the fulcrum. This means that the load is located at a greater distance from the fulcrum compared to the effort. As a result, a greater effort is required to move the load, making the lever system less efficient.

The sartorius muscle is involved in crossing one leg over the other while in a sitting position. This muscle is located in the thigh and is the longest muscle in the human body. It runs diagonally across the front of the thigh and helps to flex and rotate the hip joint. When crossing one leg over the other, the sartorius muscle contracts to bring the leg across the midline of the body.

In a pennate muscle pattern, the muscles look like a feather. This is because the fascicles of the muscle fibers are arranged at an angle to the tendon, giving it a feather-like appearance. This arrangement allows the muscle to generate a greater force, making it well-suited for tasks that require strength and power.

The genioglossus muscle is responsible for protruding and retracting the tongue. In this scenario, the child stuck her tongue out, indicating the use of the genioglossus muscle.

The extensor digitorum longus muscle has a unipennate fascicle arrangement. This means that the muscle fibers are arranged on one side of a central tendon, resembling a feather. This arrangement allows for greater strength and force production in a specific direction, which is important for extending the toes.

The adductor magnus is a muscle that is responsible for flexing the thigh. It is located in the inner thigh and helps to bring the thigh closer to the body's midline. The tibialis posterior is a muscle in the lower leg that is responsible for inversion and plantar flexion of the foot. The vastus lateralis is a muscle in the quadriceps group that is responsible for extending the leg at the knee joint. The gluteus maximus is a muscle in the buttocks that is responsible for extending the thigh.

The fibularis tertius muscle is responsible for keeping your toes from dragging when walking. This muscle is located in the lower leg and helps to lift the foot and toes during the swing phase of walking. It works in conjunction with other muscles to maintain proper foot positioning and prevent the toes from dragging on the ground.

First-class levers in the body can operate at a mechanical advantage or mechanical disadvantage, depending on the specific location. This means that depending on where the load, fulcrum, and effort are positioned, the lever can either multiply the force applied (mechanical advantage) or require more effort to move the load (mechanical disadvantage). This flexibility allows the body to perform a variety of movements efficiently, such as lifting heavy objects or performing delicate tasks with precision.

The power of a muscle is primarily determined by the number of neurons innervating it. Neurons are responsible for transmitting electrical signals from the brain to the muscles, causing them to contract. The more neurons that innervate a muscle, the more forceful and powerful its contractions can be. Therefore, the number of neurons plays a crucial role in determining the power of a muscle.