Title: The Musculoskeletal System
Course: Question Banks

Q: What is a hydrostatic skeleton?
- an external skeleton that consists of a hard encasement on the surface of an organism (Incorrect. This is an exoskeleton.)
- a skeleton that consists of hard, mineralized structures located within the soft tissue of organisms (Incorrect. This is an endoskeleton.)
- a skeleton formed by a fluid-filled compartment within the body (Correct. A hydrostatic skeleton is a skeleton formed by a fluid-filled compartment within the body, called the coelom.)
A: a skeleton formed by a fluid-filled compartment within the body

Q: Movement in a hydrostatic skeleton is provided by muscles that surround the ________.
- ossicles (Incorrect. The ossicles are middle ear bones.)
- nephridiopore (Incorrect. This is an earthworm excretory organ.)
- coelom (Correct. The organs of the coelom are supported by the aqueous fluid, which also resists external compression.)
A: coelom

Q: Arthropods such as crabs and lobsters have exoskeletons that consist of 30–50 percent ________.
- calcium carbonate (Incorrect. The exoskeleton is further strengthened by calcium carbonate (in addition to chitin) in organisms such as the lobster.)
- dentin (Incorrect. This is one of the components of teeth.)
- chitin (Correct. Arthropods such as crabs and lobsters have exoskeletons that consist of 30–50 percent chitin, a polysaccharide derivative of glucose that is a strong but flexible material.)
A: chitin

Q: The function of the axial skeleton is ________.
- to transmit sounds from the air as vibrations to the fluid-filled cochlea (Incorrect. This is the auditory ossicles.)
- to protect the entrances to the digestive and respiratory tracts (Incorrect. This is the function of the facial bones.)
- to provide support and protection for the brain, the spinal cord, and the organs in the ventral body cavity (Correct.)
A: to provide support and protection for the brain, the spinal cord, and the organs in the ventral body cavity

Q: What is the function of the auditory ossicles?
- to protect the entrances to the digestive and respiratory tracts (Incorrect. This is the function of the facial bones.)
- to provides support and protection for the brain, the spinal cord, and the organs in the ventral body cavity (Incorrect. This is the function of the axial skeleton.)
- to transmit sounds from the air as vibrations to the fluid-filled cochlea (Correct. The auditory ossicles of the middle ear transmit sounds from the air as vibrations to the fluid-filled cochlea. They consist of six bones: two malleus bones, two incus bones, and two stapes on each side.)
A: to transmit sounds from the air as vibrations to the fluid-filled cochlea

Q: How many bones does the human cranial cavity have?
- four (Incorrect. The cranial bones are eight bones that form the cranial cavity)
- ten (Incorrect. The cranial bones are eight bones that form the cranial cavity)
- eight (Correct.)
A: eight

Q: What part of the skeleton is responsible for bearing the weight of the body?
- clavicles (Incorrect. The clavicles are S-shaped bones that position the arms on the body.)
- pectoral girdle (Incorrect. The pectoral girdle bones provide the points of attachment of the upper limbs to the axial skeleton.)
- pelvic girdle (Correct. The pelvic girdle attaches to the lower limbs of the axial skeleton, it is securely attached to the axial skeleton by strong ligaments.)
A: pelvic girdle

Q: What are the tarsals?
- the five bones of the foot (Incorrect. The metatarsals are the five bones of the foot.)
- the 14 bones of the toes (Incorrect. The phalanges are the 14 bones of the toes.)
- the seven bones of the ankle (Correct. The tarsals are the seven bones of the ankle. The ankle transmits the weight of the body from the tibia and the fibula to the foot.)
A: the seven bones of the ankle

Q: What is an articulation?
- flat, triangular bone that is located at the back of the pectoral girdle (Incorrect. The scapulae are flat, triangular bones that are located at the back of the pectoral girdle.)
- the largest and longest bone of the upper limb and the only bone of the arm (Incorrect. This is the humerus.)
- any place at which two bones are joined (Correct.)
A: any place at which two bones are joined

Q: The bones of the human skeleton are classified by ________.
- composition (Incorrect. The bones of the human skeleton are classified by their shape: long bones, short bones, flat bones, sutural bones, sesamoid bones, and irregular bones.)
- size (Incorrect. The bones of the human skeleton are classified by their shape: long bones, short bones, flat bones, sutural bones, sesamoid bones, and irregular bones.)
- shape (Correct. The bones of the human skeleton are classified by their shape: long bones, short bones, flat bones, sutural bones, sesamoid bones, and irregular bones.)
A: shape

Q: What is the diaphysis?
- the rounded end of long bones (Incorrect. The epiphyses is the rounded end of a long bone, the diaphysis is the central shaft.)
- a bone that develops inside tendons and may be found near joints at the knees, hands, and feet (Incorrect. This is a sesamoid bone, the diaphysis is the central shaft of long bones.)
- the central shaft of long bones (Correct. Long bones are longer than they are wide and have a shaft and two ends. The diaphysis, or central shaft, contains bone marrow in a marrow cavity.)
A: the central shaft of long bones

Q: Where are sutural bones found?
- near joints at the knees, hands, and feet (Incorrect. Sesamoid bones develop inside tendons and may be found near joints at the knees, hands, and feet.)
- in the wrist and ankle (Incorrect. Bones of the wrist (carpals) and ankle (tarsals) are short bones.)
- between the flat bones of the skull (Correct. Sutural bones are small, flat, irregularly shaped bones that can be found between the flat bones of the skull.)
A: between the flat bones of the skull

Q: What type of bone cells are responsible for bone formation?
- osteoclasts (Incorrect. They remove bone structure by releasing lysosomal enzymes and acids that dissolve the bony matrix.)
- osteocytes (Incorrect. Osteocytes maintain normal bone structure by recycling the mineral salts in the bony matrix.)
- osteoblasts (Correct. Osteoblasts synthesize and secrete the organic part and inorganic part of the extracellular matrix of bone tissue, and collagen fibers.)
A: osteoblasts

Q: What are osteons?
- structures that form the hard external layer of all bones (Incorrect. Compact bone forms the hard external layer of all bones. Osteons are structures that contain a mineral matrix and living osteocytes.)
- lamellae that are arranged as rods or plates (Incorrect. Trabeculae are lamellae that are arranged as rods or plates.)
- structures that contain a mineral matrix and living osteocytes (Correct. Osteons are cylindrical structures that contain a mineral matrix and living osteocytes connected by canaliculi, which transport blood.)
A: structures that contain a mineral matrix and living osteocytes

Q: What does the Haversian canal contain?
- only the bone’s blood vessels (Incorrect. The Haversian canal contains the bone’s blood vessels and nerve fibers.)
- spongy bone tissue (Incorrect. The Haversian canal contains the bone’s blood vessels and nerve fibers.)
- the bone’s blood vessels and nerve fibers (Correct. The Haversian canal (osteonic canal) contains the bone’s blood vessels and nerve fibers.)
A: the bone’s blood vessels and nerve fibers

Q: What is ossification?
- the process of bone resorption by osteoclasts (Incorrect. This is part of bone remodeling which is the replacement of old bone tissue by new bone tissue. Ossification is the process of bone formation by osteoblasts.)
- the addition of bone tissue at the epiphyseal plate (Incorrect. Ossification is the process of bone formation by osteoblasts.)
- the process of bone formation by osteoblasts (Correct. Osteoblasts synthesize and secrete the organic part and inorganic part of the extracellular matrix of bone tissue, and collagen fibers.)
A: the process of bone formation by osteoblasts

Q: What is the region between the diaphysis and epiphysis that is responsible for growth?
- the primary ossification center (Incorrect. This is the first area of a bone to start ossifying, the epiphyseal plate is the region between the diaphysis and epiphysis.)
- the articular cartilage (Incorrect. The epiphyseal plate (growth plate) is the region between the diaphysis and epiphysis that is responsible for the lengthwise growth of long bones.)
- the epiphyseal plate (Correct. The epiphyseal plate (growth plate) is the region between the diaphysis and epiphysis that is responsible for the lengthwise growth of long bones.)
A: the epiphyseal plate

Q: What is the fibrocartilaginous callus?
- the formation of clotted blood at the site of a bone break (Incorrect. This is a hematoma, the fibrocartilaginous callus is the repair tissue between the broken bone ends.)
- the central shaft of long bones (Incorrect. This is the diaphysis, or central shaft, the fibrocartilaginous callus is the repair tissue between the broken bone ends)
- the repair tissue between broken bone ends (Correct. The repair tissue between the broken bone ends is called the fibrocartilaginous callus, as it is composed of both hyaline and fibrocartilage.)
A: the repair tissue between broken bone ends

Q: Synarthroses joints ________.
- allow light movement (Incorrect. These joints are amphiarthroses, immovable joints are synarthroses.)
- allow for free movement (Incorrect. These joints are diarthroses, immovable joints are synarthroses.)
- are immovable (Correct.)
A: are immovable

Q: Joints in which the bones are connected by a band of connective tissue are ________.
- gomphoses (Incorrect. Gomphoses occur between teeth and their sockets; the term refers to the way the tooth fits into the socket like a peg. Syndesmoses are joints in which the bones are connected by a band of connective tissue.)
- sutures (Incorrect. Sutures are found only in the skull and possess short fibers of connective tissue that hold the skull bones tightly in place. Syndesmoses are joints in which the bones are connected by a band of connective tissue.)
- syndesmoses (Correct. Syndesmoses are joints in which the bones are connected by a band of connective tissue, allowing for more movement than in a suture.)
A: syndesmoses

Q: What joints are held together by fibrous connective tissue?
- cartilaginous joints (Incorrect. Cartilaginous joints are joints in which the bones are connected by cartilage.)
- synovial joints (Incorrect. Synovial joints are the only joints that have a space between the adjoining bones.)
- fibrous joints (Correct. The bones of fibrous joints are held together by fibrous connective tissue.)
A: fibrous joints

Q: What is rotational movement?
- the movement produced when the angle between the bones of a joint changes (Incorrect. Angular movements are produced when the angle between the bones of a joint changes whereas rotational movement is movement of a bone as it rotates around its longitudinal axis.)
- the movement that occurs as relatively flat bone surfaces move past each other (Incorrect. Gliding movements occur as relatively flat bone surfaces move past each other whereas rotational movement is movement of a bone as it rotates around its longitudinal axis.)
- the movement of a bone as it rotates around its longitudinal axis (Correct. Rotation can be toward the midline of the body, which is referred to as medial rotation, or away from the midline of the body, which is referred to as lateral rotation.)
A: the movement of a bone as it rotates around its longitudinal axis

Q: What type of angular movement occurs when the angle between bones decreases?
- extension (Incorrect. Extension is the opposite of flexion in that the angle between the bones of a joint increases.)
- hyperextension (Incorrect. Extension past the regular anatomical position is referred to as hyperextension whereas flexion occurs when the angle between the bones decreases.)
- flexion (Correct. Flexion, or bending, occurs when the angle between the bones decreases.)
A: flexion

Q: What special movement refers to bending at the ankle such that the toes are lifted toward the knee?
- supination (Incorrect. Supination is the movement of the radius and ulna bones of the forearm so that the palm faces forward, whereas dorsiflexion is the bending at the ankle such that the toes are lifted toward the knee.)
- pronation (Incorrect. Pronation is the opposite movement of supination in which the palm faces backward, whereas dorsiflexion is the bending at the ankle such that the toes are lifted toward the knee.)
- dorsiflexion (Correct.)
A: dorsiflexion

Q: Which type of joints have bones with articulating surfaces that are flat or slightly curved?
- hinge (Incorrect. Pivot joints consist of the rounded end of one bone fitting into a ring formed by the other bone. This structure allows rotational movement.)
- pivot (Incorrect. In hinge joints, the slightly rounded end of one bone fits into the slightly hollow end of the other bone.)
- planar (Correct. Planar joints are found in the carpal bones in the hand and the tarsal bones of the foot.)
A: planar

Q: What type of movement does a condyloid joint allow?
- rotational movement, as the rounded bone moves around its own axis (Incorrect. Pivot joints consist of the rounded end of one bone fitting into a ring formed by the other bone.)
- gliding movements (Incorrect. This is a planar joint.)
- angular movement along two axes (Correct)
A: angular movement along two axes

Q: What joint allows the greatest range of motion?
- saddle joint (Incorrect. Saddle joints allow angular movements similar to condyloid joints but with a greater range of motion. The organization of the ball-and-socket joint allows the greatest range of motion, as all movement types are possible in all directions.)
- planar joint (Incorrect. The range of motion is limited in planar joints and does not involve rotation whereas the organization of a ball-and-socket joint allows the greatest range of motion.)
- ball-and-socket joints (Correct. Ball-and-socket joints possess a rounded, ball-like end of one bone fitting into a cuplike socket of another bone. This organization allows the greatest range of motion, as all movement types are possible in all directions.)
A: ball-and-socket joints

Q: How is smooth muscle tissue distinguished from other types?
- It has striations. (Incorrect. Smooth muscle has no striations, cardiac and skeletal muscle has striations.)
- It is consciously controlled. (Incorrect. Smooth muscle has no striations and is not under voluntary control, whereas skeletal muscle is consciously controlled.)
- It has no striations. (Correct. Smooth muscle has no striations, is not under voluntary control, has only one nucleus per cell, is tapered at both ends, and is called involuntary muscle.)
A: It has no striations.

Q: Where does the action potential conduction which triggers muscle contraction take place?
- myofibrils (Incorrect. Myofibrils are long cylindrical structures that lie parallel to the muscle fiber and run the entire length of the muscle fiber, the sarcolemma is the site of action potential conduction.)
- sarcomeres (Incorrect. Sarcomeres are the functional units of skeletal muscle and the sarcolemma is the site of action potential conduction.)
- sarcolemma (Correct. The sarcolemma is the site of action potential conduction, which triggers muscle contraction.)
A: sarcolemma

Q: What is the primary component of thin filaments?
- tropomyosin (Incorrect. The primary component of thin filaments is the actin protein, other components include tropomyosin and troponin.)
- troponin (Incorrect. The primary component of thin filaments is the actin protein, other components include tropomyosin and troponin.)
- actin (Correct. The primary component of thin filaments is the actin protein.)
A: actin

Q: When a muscle contracts, ________ is pulled along myosin toward the center of the sarcomere.
- the myofibril (Incorrect. When a muscle contracts, actin is pulled along myosin toward the center of the sarcomere until the actin and myosin filaments are completely overlapped.)
- calcium (Incorrect. When a muscle contracts, actin is pulled along myosin toward the center of the sarcomere until the actin and myosin filaments are completely overlapped.)
- the actin (Correct. When a muscle contracts, actin is pulled along myosin toward the center of the sarcomere until the actin and myosin filaments are completely overlapped.)
A: the actin

Q: When the muscle is fully contracted, the ________ is no longer visible.
- the myosin filaments (Incorrect. The H zone becomes smaller and smaller due to the increasing overlap of actin and myosin filaments, and the muscle shortens. Thus when the muscle is fully contracted, the H zone is no longer visible.)
- actin filaments (Incorrect. The H zone becomes smaller and smaller due to the increasing overlap of actin and myosin filaments, and the muscle shortens. Thus when the muscle is fully contracted, the H zone is no longer visible.)
- H zone (Correct. The H zone becomes smaller and smaller due to the increasing overlap of actin and myosin filaments, and the muscle shortens. Thus when the muscle is fully contracted, the H zone is no longer visible.)
A: H zone

Q: In the sliding filament model of contraction, the actin and myosin filaments ________.
- increase in length (Incorrect. The actin and myosin filaments themselves do not change length, but instead slide past each other.)
- decrease in length (Incorrect. The actin and myosin filaments themselves do not change length, but instead slide past each other.)
- do not change length (Correct. The actin and myosin filaments themselves do not change length, but instead slide past each other.)
A: do not change length

Q: What is the source of energy for muscle shortening?
- actin (Incorrect. The motion of muscle shortening occurs as myosin heads bind to actin and pull the actin inwards. This action requires energy, which is provided by ATP.)
- myosin (Incorrect. The motion of muscle shortening occurs as myosin heads bind to actin and pull the actin inwards. This action requires energy, which is provided by ATP.)
- ATP (Correct. The motion of muscle shortening occurs as myosin heads bind to actin and pull the actin inwards. This action requires energy, which is provided by ATP.)
A: ATP

Q: What happens during the power stroke?
- A new molecule of ATP attaches to the myosin head causing cross-bridge to detach. (Incorrect. Energy is expended as the myosin head moves through the power stroke; at the end of the power stroke, the myosin head is in a low-energy position. After the power stroke, ADP is released.)
- The movement of the myosin head back to its original position. (Incorrect. This is called the recovery stroke.)
- The myosin head bends and the ADP and phosphate are released. (Correct. Energy is expended as the myosin head moves through the power stroke; at the end of the power stroke, the myosin head is in a low-energy position. After the power stroke, ADP is released.)
A: The myosin head bends and the ADP and phosphate are released.

Q: Each myosin head has two binding sites: once for actin and one for ________.
- thin filaments (Incorrect. Each myosin head has two binding sites: one for ATP and another for actin. The binding of ATP to a myosin head detaches myosin from actin, thereby allowing myosin to bind to another actin molecule.)
- myosin (Incorrect. Each myosin head has two binding sites: one for ATP and another for actin. The binding of ATP to a myosin head detaches myosin from actin, thereby allowing myosin to bind to another actin molecule.)
- ATP (Correct. Each myosin head has two binding sites: one for ATP and another for actin. The binding of ATP to a myosin head detaches myosin from actin, thereby allowing myosin to bind to another actin molecule.)
A: ATP

Q: What is the muscle side of the synaptic cleft called?
- cross-bridge (Incorrect. The area of the sarcolemma on the muscle fiber that interacts with the neuron is called the motor end plate.)
- myosin (Incorrect. The area of the sarcolemma on the muscle fiber that interacts with the neuron is called the motor end plate.)
- motor end plate (Correct. The area of the sarcolemma on the muscle fiber that interacts with the neuron is called the motor end plate.)
A: motor end plate

Q: What is the synaptic cleft?
- the cross-bridge between actin and myosin (Incorrect. A small space called the synaptic cleft separates the synaptic terminal from the motor end plate.)
- the area of the sarcolemma on the muscle fiber that interacts with the neuron (Incorrect. A small space called the synaptic cleft separates the synaptic terminal from the motor end plate.)
- the small space that separates the synaptic terminal from the motor end plate (Correct. A small space called the synaptic cleft separates the synaptic terminal from the motor end plate.)
A: the small space that separates the synaptic terminal from the motor end plate

Q: What is the neurotransmitter released by motor neurons that binds to receptors in the motor end plate?
- somatostatin (Incorrect. This neurotransmitter binds to somatostatin receptor, ACh binds to receptors in the motor end plate.)
- adenosine (Incorrect. This neurotransmitter binds to the adenosine receptor, ACh binds to receptors in the motor end plate.)
- acetylcholine (ACh) (Correct.)
A: acetylcholine (ACh)

Q: What are fast twitch fibers?
- They generate lower amounts of force but can do so for longer periods of time. (Incorrect. This are slow twitch fibers, fast twitch fibers generate high force for brief periods of time.)
- They are also called Type I fibers. (Incorrect. Slow twitch fibers are also called Type I fibers, fast twitch fibers are also called Type II fibers.)
- They generate high force for brief periods of time. (Correct.)
A: They generate high force for brief periods of time.

Q: Muscles that have a predominance of slow fibers are sometimes referred to as ________.
- white muscles (Incorrect. Muscles that have a predominance of fast fibers are referred to as white muscles.)
- type II fibers (Incorrect. Fast twitch fibers are also called Type II fibers and can sometimes be referred to as white muscles.)
- red muscles (Correct. Slow twitch fibers are surrounded by capillary networks that supply oxygenated blood contain a red pigment called myoglobin. Because of the reddish color of myoglobin these fibers are often called red muscle fibers.)
A: red muscles

Q: What happens during the relaxation phase in muscle contraction?
- release of acetylcholine and depolarization of the motor end plate (Incorrect. During the lag phase an action potential moves to the end of the motor neuron and results in release of acetylcholine and depolarization of the motor end plate.)
- cross-bridges between actin and myosin form (Incorrect. This is the contraction phase.)
- calcium is actively transported back into the sarcoplasmic reticulum using ATP (Correct.)
A: calcium is actively transported back into the sarcoplasmic reticulum using ATP