An Interesting Quiz On Chapter 9 Anatomy

The gluteus maximus is the correct answer because it is the largest muscle in the body and is located in the buttocks. It plays a major role in hip extension and is responsible for the action of sitting.

The frontalis is the correct answer because it is a flat muscle that covers the forehead and is responsible for raising the eyebrows, which creates a surprised look. The zygomaticus is a muscle that controls smiling, the masseter is a muscle that controls chewing, and the buccinator is a muscle that controls the movement of the cheeks. Therefore, the frontalis is the only muscle listed that matches the given description.

The masseter muscle is responsible for chewing food. It is one of the main muscles involved in the process of mastication, along with other muscles of the jaw. When the masseter muscle contracts, it helps to close the jaw and move it in a grinding motion, allowing for the breakdown of food into smaller particles that can be easily swallowed and digested.

The sternocleidomastoid is not a facial muscle. It is a large muscle located in the neck that helps with head movement and is not involved in facial expressions. The other three options, orbicularis oculi, zygomaticus, and frontalis, are all facial muscles that are responsible for various facial expressions such as blinking, smiling, and raising the eyebrows.

The rotator cuff muscles are a group of muscles that move the arms at the shoulder. These muscles include the supraspinatus, infraspinatus, teres minor, and subscapularis. They work together to stabilize the shoulder joint and allow for various movements, such as rotating the arm and lifting it away from the body. These muscles are commonly involved in shoulder injuries and can be strengthened through specific exercises to improve shoulder stability and function.

The term "pectoralis" is commonly used to refer to the muscles located in the chest area. It is derived from the Latin word "pectus" which means chest. Therefore, out of the given options, "pectoralis" is the correct muscle word that refers to the chest.

The sternocleidomastoid muscle is responsible for turning the head to the left and right. It is a long muscle located on the side of the neck, originating from the sternum and clavicle and attaching to the mastoid process of the skull. When this muscle contracts on one side, it causes the head to rotate towards the opposite side. Therefore, when you turn your head to the left and right, you are primarily using the sternocleidomastoid muscle.

The muscle that attaches to the cranial aponeurosis and wrinkles the forehead is the frontalis muscle. This muscle is responsible for raising the eyebrows and creating horizontal wrinkles on the forehead. It is located at the front of the skull and is one of the muscles involved in facial expressions and conveying emotions.

The correct answer is cardiac. Cardiac muscles are striated, meaning they have a striped appearance, and they are involuntary, meaning they are not under conscious control. Smooth muscles, on the other hand, are also involuntary but they do not have a striped appearance. Skeletal muscles are striated but they are voluntary, meaning they are under conscious control. Aponeurosis, on the other hand, is not a muscle but a sheet-like tendon that connects muscles to bones or other structures.

Actin is a contractile protein that is called a thin filament. Actin is a major component of the cytoskeleton and is responsible for the contraction of muscle fibers. It forms a filamentous structure along with myosin, which is a thick filament, to enable muscle contraction. Actin filaments slide past myosin filaments during muscle contraction, resulting in the shortening of muscle fibers. Therefore, the correct answer is that actin is a contractile protein that is called a thin filament.

A sarcomere is a series of contractile units that make up each myofibril. Each sarcomere extends from one Z line to another Z line. This is the basic functional unit of a muscle, where the actin and myosin filaments interact to generate muscle contractions. The other options, synapse, fascicle, and sarcoplasmic reticulum, are not related to the contractile units of a myofibril.

Myosin is the correct answer because it is the protein responsible for forming crossbridges with actin during muscle contraction. These crossbridges allow for the sliding of actin and myosin filaments, leading to muscle contraction. The sarcoplasmic reticulum is responsible for storing and releasing calcium ions, which are necessary for muscle contraction, but it does not directly form crossbridges with actin. T-tubules are invaginations of the sarcolemma that help propagate action potentials, but they also do not form crossbridges with actin. Sarcolemma is the plasma membrane of muscle cells and does not directly interact with actin to form crossbridges.

A tendon is the correct answer because it is the cord of connective tissue that connects muscle to bone. Ligaments, on the other hand, connect bone to bone. Linea alba is a fibrous structure in the abdomen, and aponeurosis is a sheet-like tendon.

The group that is incorrect is "muscles involved in breathing: diaphragm, intercostals, hamstrings". The diaphragm and intercostals are indeed muscles involved in breathing, but the hamstrings are not. The hamstrings are muscles located in the lower extremities, not directly involved in the process of breathing.

The latissimus dorsi muscle is located on the posterior part of the body. It is a large, flat muscle that covers the lower and middle back. It originates from the lower spine and iliac crest, and it inserts into the upper arm bone. The latissimus dorsi muscle is responsible for various movements of the shoulder joint, such as extension, adduction, and medial rotation. It also assists in movements of the spine, including extension and lateral flexion.

The hamstrings are a group of muscles located on the posterior thigh. They consist of three muscles: the biceps femoris, semitendinosus, and semimembranosus. These muscles are responsible for flexing the knee joint and extending the hip joint. They play a crucial role in activities such as walking, running, and jumping.

The diaphragm is a dome-shaped muscle that separates the thoracic and abdominal cavities. It is the primary muscle responsible for breathing, contracting and relaxing to facilitate inhalation and exhalation. When the diaphragm contracts, it moves downward, creating more space in the chest cavity and allowing the lungs to expand and fill with air. When it relaxes, the diaphragm moves upward, compressing the lungs and forcing air out. Therefore, the diaphragm is not only the muscle that separates the thoracic and abdominal cavities but also the chief breathing muscle.

The rectus, transversus, internal oblique, and external oblique are all muscles that are located in the abdomen. These muscles play a crucial role in maintaining core stability, supporting the spine, and assisting in movements such as bending, twisting, and flexing the trunk. They are commonly referred to as the abdominal muscles and are responsible for giving the abdomen its shape and strength.

The correct answer is "lie along the thigh." The quadriceps femoris group and the hamstrings are both located in the thigh region of the leg. They are major muscle groups that play a crucial role in leg movement and stability. The quadriceps femoris group is responsible for extending the knee joint, while the hamstrings are responsible for flexing the knee joint. Therefore, it is accurate to say that these muscles lie along the thigh.

The deltoid muscle covers the shoulder like a shoulder pad. It is a triangular-shaped muscle that forms the rounded contour of the shoulder and provides stability and movement to the shoulder joint. It is responsible for raising the arm to the side, forward, and backward, as well as rotating the arm. The trapezius muscle is located in the upper back and neck region, the biceps brachii is a muscle in the upper arm, and the sternocleidomastoid is a muscle in the neck.

The vastus lateralis is located in the thigh. It is one of the four muscles that make up the quadriceps femoris group. The vastus lateralis is the largest and most powerful of the quadriceps muscles and is located on the outer side of the thigh. It plays a key role in extending the knee joint and is commonly targeted during exercises such as squats and lunges.

"Pumping iron" refers to the activity of weightlifting or strength training, which involves repeatedly contracting and relaxing muscles against resistance. This type of exercise is known to stimulate muscle growth and increase muscle size, a process called hypertrophy. Atrophy refers to the wasting or shrinking of muscles, which is unlikely to occur with regular weightlifting. Contracture formation refers to the permanent shortening or tightening of muscles or tendons, which is also not likely to occur with weightlifting. Muscular dystrophy is a genetic disorder characterized by progressive muscle weakness and degeneration, which is unrelated to weightlifting. Therefore, the most likely effect of "pumping iron" is hypertrophy.

The orbicularis oris muscle is responsible for surrounding the mouth. This muscle is located around the lips and plays a crucial role in various facial expressions, including puckering the lips, closing the mouth, and controlling the movement of the lips during speech and eating. It helps in actions such as smiling, kissing, and whistling.

The gastrocnemius and the soleus muscles are commonly referred to as the "toe dancer's muscles" because they are heavily involved in the movements and strength required for ballet and other forms of toe dancing. These muscles are responsible for pointing and flexing the foot, providing stability and control during toe stands and other intricate footwork.

The brachialis and brachioradialis muscles are responsible for flexing the arm at the elbow joint. When these muscles contract, they cause the forearm to move towards the upper arm, resulting in elbow flexion. This action allows for movements such as lifting or bending the arm at the elbow.

The biceps brachii muscle is the correct answer because it lies along the anterior surface of the humerus and works together with the brachialis and brachioradialis muscles to flex the arm at the elbow. The deltoid muscle is not involved in flexing the arm at the elbow, but rather in shoulder abduction and flexion. The triceps brachii muscle is responsible for extending the arm at the elbow, not flexing it. The latissimus dorsi muscle is primarily involved in shoulder extension and adduction, not elbow flexion.

The T-tubule is a structure that extends from the sarcolemma or cell membrane into the muscle fibers. It plays a crucial role in muscle contraction by carrying the electrical signal, known as an action potential, from the surface of the muscle to the deepest parts of the muscle. This allows for synchronized and coordinated contraction of the muscle fibers. The T-tubules are essential for transmitting the signal to the sarcoplasmic reticulum, which then releases calcium ions, initiating the muscle contraction process.

The group "types of striated muscle: skeletal, cardiac, smooth" is incorrect because smooth muscle is not striated. Striated muscles have a striped appearance due to the arrangement of their contractile proteins, while smooth muscles lack this characteristic. The correct group should include only skeletal and cardiac muscles as types of striated muscle.

The rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius are all muscles that make up the quadriceps femoris. They work together to extend the leg at the knee joint. Therefore, the correct answer is that these muscles are the muscles of the quadriceps femoris.

The levator palpebrae superioris is a muscle located in the upper eyelid. Its main function is to raise the eyelids, allowing us to open our eyes. This muscle plays a crucial role in the movement and control of the eyelids, helping us to blink, maintain eye contact, and protect our eyes. It is not involved in actions such as pursing the lips, whistling, or wiggling the nose.

The adductors are a group of muscles located on the inner surface of the thigh. They are responsible for moving the thigh towards the midline of the body, a movement known as adduction. This is in contrast to the other options listed, such as the gastrocnemius (a calf muscle) and quadriceps femoris (a group of muscles on the front of the thigh) which are not involved in adduction. The sartorius muscle, although located in the thigh, is primarily responsible for flexing and rotating the hip and knee, not adducting the thigh.

The correct answer is gastrocnemius because the Achilles tendon connects the soleus and gastrocnemius muscles to the calcaneus. The sartorius muscle is not involved in this connection, and the quadriceps femoris and vastus lateralis muscles are located in the thigh, not the lower leg where the Achilles tendon is located.

The biceps femoris, semitendinosus, and semimembranosus are collectively known as the hamstrings. They are a group of muscles located on the posterior thigh. These muscles play a crucial role in knee flexion and hip extension. They are also involved in the stabilization of the knee joint.

The zygomaticus muscle is responsible for smiling. When this muscle contracts, it pulls the corners of the mouth upward, creating a smile. The buccinator muscle is located in the cheek and is involved in activities such as chewing and blowing air. The frontalis muscle is located in the forehead and is responsible for raising the eyebrows and creating forehead wrinkles. The orbicularis oris muscle is responsible for puckering the lips and closing the mouth. Therefore, the correct answer is zygomaticus.

The trapezius muscle is located in the upper back and posterior neck region. When this muscle contracts, it causes you to look up at the sky. The pectoralis major is a muscle in the chest, the sternocleidomastoid is a muscle in the neck that allows for head rotation, and the diaphragm is a muscle involved in breathing. Therefore, the correct answer is trapezius.

The intercostal muscles are located between the ribs and play a crucial role in breathing. They help to expand and contract the rib cage during inhalation and exhalation, allowing for the movement of air in and out of the lungs. Without the intercostal muscles, the rib cage would not be able to move effectively, leading to difficulty in breathing.

The triceps brachii is the correct answer because it is a muscle that lies along the posterior surface of the upper arm. It is responsible for extending the forearm and is commonly used to bear weight in crutch walking. The biceps brachii, biceps femoris, and deltoid are not involved in these actions and do not lie along the posterior surface of the upper arm.

The peroneus longus muscle is located in the lower extremities. It is a muscle in the leg that runs along the outer side of the lower leg and connects to the foot. This muscle is responsible for ankle eversion, which is the movement of the foot away from the midline. It also helps to stabilize the foot and maintain balance during walking and running.

When a limb is immobilized in a cast for an extended period of time, the muscles in that limb are not being used or exercised. This lack of use leads to disuse atrophy, which is the wasting away or shrinking of the muscles due to inactivity. In this case, Joey's leg appears smaller than the uninjured leg because the muscles in his leg have experienced disuse atrophy during the time it was in a nonweight-bearing cast.

The sarcoplasmic reticulum is a specialized organelle found in muscle cells that is responsible for storing and releasing calcium ions. It surrounds the myofibrils, which are the contractile units of muscle cells that contain sarcomeres. The sarcomeres are the functional units of muscle contraction, composed of actin and myosin filaments. Therefore, the sarcoplasmic reticulum envelopes the sarcomere-containing myofibrils, allowing for the regulation and coordination of muscle contraction.

When a muscle contracts, calcium ions are released from the sarcoplasmic reticulum, allowing actin and myosin to interact and cause muscle contraction. However, for the muscle to relax, calcium ions need to be removed from the sarcomere. This is done by pumping calcium back into the sarcoplasmic reticulum. Therefore, the correct answer is that calcium is pumped back into the sarcoplasmic reticulum for muscle relaxation.

Tetany describes a muscle that remains in a contracted state. It is a condition characterized by prolonged and involuntary muscle contractions. These contractions can be caused by a variety of factors, such as low levels of calcium or magnesium in the blood. Tetany can lead to muscle spasms, cramps, and stiffness. It can affect any muscle in the body and may cause pain and discomfort. Treatment usually involves addressing the underlying cause and restoring the balance of electrolytes in the body.

The deltoid muscle is responsible for the movement of the arm and shoulder, particularly for raising the arm away from the body. When someone "makes like a scarecrow," they often extend their arms out to the sides, resembling the pose of a scarecrow. This movement engages the deltoid muscle, making it the correct answer. The frontalis muscle is located in the forehead and is responsible for raising the eyebrows, while the trapezius and latissimus dorsi muscles are located in the back and are responsible for various movements of the shoulder and upper back.

Acetylcholine is a neurotransmitter that is released from the prejunctional membrane in response to a nerve impulse. Nerve impulses, also known as action potentials, are electrical signals that travel along neurons to transmit information. When a nerve impulse reaches the prejunctional membrane, it triggers the release of acetylcholine into the synaptic cleft. Acetylcholine then binds to receptors on the postjunctional membrane, leading to various physiological responses, such as muscle contraction or nerve signal transmission. Therefore, the release of acetylcholine is directly linked to the occurrence of a nerve impulse.

The force of muscle contraction is most related to the numbers of crossbridges formed between actin and myosin. When a muscle contracts, the myosin heads on the thick filaments form crossbridges with the actin molecules on the thin filaments. The interaction between myosin and actin allows for the sliding of the filaments, resulting in muscle contraction. The more crossbridges that are formed, the stronger the force of contraction. Therefore, the numbers of crossbridges formed between actin and myosin directly determine the force of muscle contraction.

Recruitment refers to the process of activating more motor units within a muscle to generate a stronger contraction. When more motor units are recruited, more muscle fibers are stimulated, resulting in an increased force of contraction. This can be achieved by increasing the frequency of nerve impulses to the muscle or by activating additional motor units. Therefore, recruitment is the correct answer as it directly increases the force of contraction of a whole muscle.

The release of neurotransmitter (ACh) from the somatic motor neuron comes first in skeletal muscle contraction. This neurotransmitter is released at the neuromuscular junction and binds to the receptors on the muscle fiber, leading to the activation of the muscle. This activation then triggers a series of events, including the release of calcium from the sarcoplasmic reticulum, which allows for crossbridge formation between actin and myosin. Therefore, the release of ACh is the initial event that starts the process of skeletal muscle contraction.

The correct answer is sarcoplasmic reticulum. The sarcoplasmic reticulum is a specialized organelle found in muscle cells that is responsible for storing and releasing calcium ions. During muscle relaxation, calcium ions are actively pumped back into the sarcoplasmic reticulum, reducing their concentration in the cytoplasm and allowing the muscle to relax. The T-tubules, on the other hand, are invaginations of the muscle cell membrane that help propagate action potentials deep into the muscle fiber, but they do not store calcium ions.