Anatomy And Physiology Exam 2 Practice Test

Osteoblasts are cells responsible for the formation of bone. They play a crucial role in bone development and remodeling by producing and secreting the proteins and other substances needed to build and mineralize bone tissue. Osteoblasts are derived from mesenchymal stem cells and are responsible for the synthesis and deposition of the bone matrix. They also regulate the activity of osteoclasts, which are responsible for bone resorption. Therefore, the correct answer is "Bone forming cells."

Straightening the leg at the knee involves increasing the angle between the thigh and the lower leg, which is known as extension. This movement is the opposite of flexion, which is the bending of the leg at the knee. Excursion refers to the movement of a body part away from the midline, support does not describe the specific movement of straightening the leg at the knee, and "none of the above" is not the correct answer as extension accurately describes the movement.

Synovial fluid is a lubricating fluid that is found within the joints of the body. Its main function is to reduce friction between the cartilaginous surfaces within the joint, allowing for smooth movement and preventing wear and tear. It also helps to nourish the cartilage and provide it with the necessary nutrients for proper function. Therefore, the statement that synovial fluid moistens and lubricates the cartilaginous surfaces within a joint is true.

The knee joint is a hinge joint that allows for flexion and extension movements. Flexion refers to bending the knee, while extension refers to straightening it. This is made possible by the basic structure of the knee joint, which includes the femur (thigh bone), tibia (shin bone), and patella (kneecap), as well as ligaments and tendons that provide stability and support.

Exercise has a positive impact on bones by causing them to thicken, which means an increase in bone density. This is because physical activity stimulates the production of new bone tissue, making the bones stronger and less prone to fractures. Additionally, exercise helps to strengthen bones by putting stress on them, which encourages the bones to become denser and more resistant to damage. Therefore, the effects of exercise on bones are to thicken them and to strengthen them.

The coxal bones refer to the hip bones in the human body. These bones consist of three parts: the ilium, ischium, and pubis. The ilium is the largest and uppermost part of the coxal bone, forming the prominence of the hip. The ischium is the lower and posterior part of the coxal bone, and it supports the body weight when sitting. The pubis is the anterior part of the coxal bone, which joins with the corresponding bone from the other side at the midline. Therefore, the correct answer is "all of the above" as all three bones mentioned are part of the coxal bones.

Bursae are closed, fluid-filled sacs that act as cushions. They are found near joints and help reduce friction between bones, tendons, and muscles during movement. Bursae also provide lubrication, allowing smooth and pain-free motion. Therefore, bursae is the correct answer to the question.

A motor unit is composed of a motor neuron and the muscle fibers it innervates. The motor neuron transmits signals from the central nervous system to the muscle fibers, causing them to contract. This allows for coordinated movement and control of muscle function. Therefore, the statement is true as it accurately describes the relationship between a motor neuron and the muscle fibers it controls.

The hip joint is indeed a ball and socket joint. This means that the rounded head of the femur bone fits into the cup-shaped socket of the pelvis. This type of joint allows for a wide range of motion, including flexion, extension, abduction, adduction, and rotation. The ball and socket joint structure provides stability to the hip joint while also allowing for smooth movement.

The skeletal system has multiple functions. It is responsible for the production of blood cells in the bone marrow. It also acts as a storage site for inorganic salts such as calcium and phosphorus. Additionally, the skeletal system provides protection to vital organs, especially in the head and thorax. Therefore, the correct answer is "all of the above" as it encompasses all the mentioned functions of the skeletal system.

The tarsal bones actually form the ankle, not the wrist. The wrist is formed by a group of eight small carpal bones. Therefore, the given statement is false.

The parietal bone of the skull is an example of an intramembranous bone. Intramembranous bones are formed directly from mesenchymal cells without the presence of a cartilage precursor. They are typically flat bones found in the skull, such as the parietal bone, and are involved in protecting vital organs. The phalanges of the fingers, humerus of the arm, and femur of the leg are examples of long bones that are formed through endochondral ossification, where a cartilage model is first formed and then replaced by bone tissue.

Myofibrils are the contractile units of muscle cells, responsible for muscle contraction. Actin and myosin are the two main proteins found in myofibrils. Actin forms thin filaments, while myosin forms thick filaments. These two proteins work together in a sliding filament mechanism to generate muscle contraction. Therefore, the correct answer is actin and myosin.

Osteoclasts are indeed large cells that are responsible for the breakdown of osseous tissue. They play a crucial role in bone remodeling and resorption, as they secrete enzymes and acids that dissolve the mineralized matrix of bone. This process allows for the removal of old or damaged bone tissue and the subsequent formation of new bone. Therefore, the statement is true.

Joints serve multiple functions in the body. They not only bind skeletal parts together, but also allow bone growth to occur and enable body parts to move. Therefore, the correct answer is "all of the above."

The ball and socket joint allows the most possible movements because it is a highly mobile joint that allows for flexion, extension, abduction, adduction, rotation, and circumduction. This joint consists of a rounded bone (ball) that fits into a cup-like socket, allowing for a wide range of movements in multiple directions. In contrast, a condyloid joint allows for flexion, extension, abduction, adduction, and circumduction, but not rotation. A hinge joint allows for flexion and extension in one plane, while a pivot joint allows for rotation around a single axis.

The xyphoid process is a small, cartilaginous extension at the lower end of the sternum. It serves as an attachment point for muscles and ligaments in the abdomen, and helps protect the underlying organs. The sternum is a flat bone that runs down the center of the chest and forms the front part of the rib cage. Therefore, the correct answer is sternum.

Articular cartilage is the correct answer because it is the white substance that reduces friction found at the ends of bones. It acts as a cushion and allows smooth movement between bones in a joint. The epiphysis refers to the rounded end of a long bone, while the periosteum is the outer layer of bone and the endosteum is the inner layer. However, neither of these substances specifically reduce friction or are found at the ends of bones.

The correct answer is Periosteum. The periosteum is a tough, fibrous tissue that covers the outer surface of long bones. It provides protection, nourishment, and support for the bone. It also serves as an attachment point for ligaments and tendons. Ligaments are strong bands of connective tissue that connect bones to other bones, while the stapes is one of the three small bones in the middle ear.

Cartilaginous joints are connected by hyaline cartilage or fibrocartilage. These types of joints allow for limited movement and are found in areas such as the spine and the pubic symphysis. Hyaline cartilage is a smooth, flexible connective tissue that covers the ends of bones, allowing them to glide against each other. Fibrocartilage, on the other hand, is a tough, dense connective tissue that acts as a shock absorber and provides stability to the joint. Both hyaline cartilage and fibrocartilage help to cushion the joint and reduce friction during movement.

The correct answer is skeletal muscle fibers. Transverse tubules and sarcoplasmic reticulum are well developed in skeletal muscle fibers. Transverse tubules are invaginations of the sarcolemma that allow for the rapid transmission of action potentials deep into the muscle fiber. Sarcoplasmic reticulum is a specialized type of endoplasmic reticulum in muscle cells that stores and releases calcium ions, which are essential for muscle contraction. Smooth muscle fibers do not have a well-developed system of transverse tubules and sarcoplasmic reticulum.

Short muscle cells with centrally located nuclei are smooth muscle fibers. Smooth muscle fibers are found in the walls of hollow organs such as the stomach, intestines, and blood vessels. Unlike skeletal muscle fibers which are long and multinucleated, smooth muscle fibers are shorter and have a single centrally located nucleus. This arrangement allows for coordinated contractions and relaxation of smooth muscle, enabling the movement of substances through the organs they are found in. Rough muscle fibers are not a recognized term in muscle physiology.

The endomysium is a connective tissue layer that surrounds individual muscle fibers. It provides support and protection to the muscle fibers, while also allowing for flexibility and movement. This layer helps to separate and isolate each muscle fiber, allowing them to function independently within the muscle. Therefore, the statement that the endomysium separates individual muscle fibers is correct.

The hard palate is the bony structure that forms the roof of the mouth. It is composed of two main bones, the maxillary and palatine bones. The maxillary bone is the largest facial bone and forms the majority of the hard palate. The palatine bone is a smaller bone located towards the back of the hard palate. Together, these bones provide a sturdy and rigid structure for the roof of the mouth, allowing for proper speech and chewing.

Bursae are fluid-filled sacs that are located between the skin and underlying bony prominences. They serve as cushions to reduce friction and provide protection to the bones, tendons, and muscles. Ligaments are fibrous tissues that connect bones to other bones, while menisci are cartilage structures found in the knee joint. Therefore, the correct answer is bursae.

ATPase is an enzyme that hydrolyzes ATP to ADP and inorganic phosphate, releasing energy in the process. Myosin is a protein involved in muscle contraction and ATPase activity is essential for its function. The ATPase activity of myosin occurs in the globular head portion of the myosin molecule. This is where ATP binds to myosin, and the hydrolysis of ATP powers the movement of myosin along actin filaments during muscle contraction. Therefore, the statement that ATPase occurs in the globular portion of myosin molecules is true.

The formation of endochondral bone involves several steps, including the development of hyaline cartilage in the shape of the future bone, the formation of periosteum from connective tissue on the outside of the developing bone, and the deposition of osseous tissue by osteoblasts in place of the disintegrating cartilage. However, hyaline cartilage changing to adipose tissue is not a step in the formation of endochondral bone.

All of the listed movements - extension, rotation, and adduction - can occur at the hip joint. Extension refers to the movement of the leg backward, rotation refers to the inward or outward turning of the leg, and adduction refers to the movement of the leg toward the midline of the body. Therefore, all of these movements are possible at the hip joint.

The process of ossification refers to the formation of bone tissue. At birth, not all bones are fully ossified. As a child grows, the bones continue to ossify and develop. By the age of 25, most individuals have reached skeletal maturity, meaning that all their bones have completed the process of ossification. Therefore, the correct answer is 25 years.

During anaerobic respiration, glucose molecules are converted into lactic acid. This process occurs in the absence of oxygen and is also known as fermentation. In anaerobic conditions, the glucose molecule is broken down into pyruvate through glycolysis. Pyruvate is then converted into lactic acid by the enzyme lactate dehydrogenase. This process allows cells to generate energy in the absence of oxygen, although it is less efficient compared to aerobic respiration. Lactic acid is produced in muscles during intense exercise, leading to muscle fatigue and soreness.

The presence of a cartilaginous epiphyseal disk indicates that the bone length is increasing. The epiphyseal disk is a layer of cartilage located at the ends of long bones, where growth occurs. It allows for the growth and elongation of the bone by the process of ossification. As long as the epiphyseal disk is present, it indicates that the bone is actively growing in length. Once the bone reaches its full length and the epiphyseal disk is replaced by bone tissue, the bone length is no longer increasing.

The joints between the bodies of the vertebrae of the backbone are described as slightly movable because while they do allow for a small amount of movement, they are primarily designed to provide stability and support for the spine. These joints, known as cartilaginous joints, are connected by fibrocartilage discs called intervertebral discs, which act as shock absorbers and allow for limited flexion, extension, and rotation of the spine. However, the range of motion in these joints is relatively small compared to freely movable joints found in other parts of the body.

The movements permitted by the elbow joint are flexion and extension. Flexion refers to the movement that decreases the angle between the forearm and upper arm, while extension refers to the movement that increases this angle. These two movements allow for the bending and straightening of the arm at the elbow joint. The other options mentioned in the question, such as adduction, rotation, and circumduction, are not possible at the elbow joint.

The proximal epiphysis is an expanded portion of the bone that articulates with another bone. This means that it is the part of the bone that forms a joint with another bone, allowing movement and providing stability. The epiphysis is typically located at the ends of long bones and is composed of spongy bone tissue. It contains red bone marrow, which is responsible for producing blood cells.

Rotational movement is possible in a ball and socket joint. This type of joint allows for a wide range of motion in multiple directions, including rotation. The rounded end of one bone fits into the cup-like socket of another bone, allowing for smooth movement and rotation. This type of joint is found in the shoulder and hip, enabling movements such as swinging the arm or rotating the leg. Condyloid joints and hinge joints, on the other hand, do not allow for rotational movement. Condyloid joints allow for movement in two planes, while hinge joints only allow for movement in one plane, like a door hinge.

Hyaline cartilage is the correct answer because it is the specific type of cartilage that makes up articular cartilage. Articular cartilage is found on the ends of bones in joints and acts as a smooth, slippery surface that allows for easy movement and reduces friction between bones. Hyaline cartilage is characterized by its glassy appearance and is the most common type of cartilage in the body. It is flexible and resilient, making it ideal for cushioning and protecting joints.

The appendicular skeleton consists of parts that support and protect the limbs, rather than the head, neck, and trunk. The appendicular skeleton includes the bones of the arms, legs, shoulders, and pelvis. These bones provide support and facilitate movement in the limbs, while the axial skeleton, which includes the skull, vertebral column, and ribcage, supports and protects the head, neck, and trunk. Therefore, the statement that the appendicular skeleton consists of parts that support and protect the head, neck, and trunk is false.

Endochondral ossification involves the process of forming bone by replacing hyaline cartilage. This means that during endochondral ossification, the bones develop by replacing a cartilage model. On the other hand, intramembranous ossification involves forming bone by replacing connective tissue. In this process, bone develops directly from mesenchyme or fibrous connective tissue, without the presence of a cartilage model.

The correct answer is "all of the above" because a neuromuscular junction is indeed composed of a junction between a motor neuron and muscle fiber. It is also a site where there is a gap or cleft between the neuron and muscle, known as the synaptic cleft. Additionally, it is a site where neurotransmitters are released into the synaptic cleft from the motor neuron. Therefore, all the statements mentioned in the options are true and describe a neuromuscular junction accurately.

The origin of a muscle refers to the point of attachment that is relatively immovable. It is the fixed point from which the muscle begins its contraction. In contrast, the insertion of a muscle is the point of attachment that moves when the muscle contracts. Therefore, the correct answer is "origin" as it correctly describes the muscle end attached to a relatively immovable part.

Creatine phosphate serves as a source of high-energy phosphate groups that can be transferred to ADP molecules, converting them into ATP. This process is known as phosphorylation and is a crucial step in the synthesis of ATP, the main energy currency in cells. By providing these phosphate groups, creatine phosphate helps replenish ATP levels, ensuring a constant supply of energy for cellular processes.

Both acetylcholine and norepinephrine are neurotransmitters that can affect smooth muscle contraction. Acetylcholine is released by cholinergic neurons and activates receptors on smooth muscle cells, leading to muscle contraction. Norepinephrine, on the other hand, is released by sympathetic neurons and binds to adrenergic receptors on smooth muscle cells, also causing contraction. Therefore, both acetylcholine and norepinephrine can influence smooth muscle contraction.

The outermost layer of connective tissue surrounding a skeletal muscle is called the epimysium. This layer provides support and protection to the muscle, as well as helps to maintain its shape and integrity. It also connects the muscle to the surrounding structures and allows for proper transmission of forces generated during muscle contraction. The epimysium is made up of dense irregular connective tissue and is continuous with tendons, which attach the muscle to bones.

The correct answer is sarcomere arrangement. The striated appearance of skeletal muscle is due to the arrangement of sarcomeres, which are the basic contractile units of muscle fibers. Sarcomeres are made up of thick and thin filaments that slide past each other during muscle contraction, giving the muscle its striated appearance. The transverse tubule pattern, sarcoplasmic reticulum network, and cisternae placement are all important components of muscle function, but they do not directly contribute to the striated appearance.

The anaerobic phase of respiration, also known as glycolysis, occurs in the cytoplasm of the cell, not in the mitochondria. In glycolysis, glucose is broken down into pyruvate, producing a small amount of ATP. The pyruvate then enters the mitochondria for further processing in the aerobic phase of respiration, which occurs in the presence of oxygen. Therefore, the statement that the anaerobic phase of respiration occurs primarily in the mitochondria is false.

Rigor mortis is the stiffening of muscles after death. This occurs due to a decrease in ATP (adenosine triphosphate), which is the energy source for muscle contraction, and an increased permeability to calcium. Calcium is necessary for muscle contraction, and when ATP levels decrease, calcium is released into the muscle cells, causing them to contract and become rigid. Therefore, the correct answer is a decrease of ATP and increased permeability to calcium.

A suture is an example of a fibrous joint because it is a type of joint where two bones are held together by fibrous connective tissue. Sutures are found in the skull and are immovable, providing stability and protection to the brain.

The refractory period refers to the brief moment following stimulation when the muscle remains unresponsive to additional stimulation. During this period, the muscle is unable to contract again, allowing it to rest and recover before it can be stimulated again. This period is important for preventing overstimulation and ensuring that the muscle can function properly.

A gomphosis is a type of fibrous joint where a tooth is anchored into its socket in the jawbone by strong connective tissue called periodontal ligaments. This joint provides stability and allows for minimal movement, making it an example of a fibrous joint. Fibrous joints are characterized by the presence of dense fibrous connective tissue between the bones, which limits their range of motion and provides strength and stability to the joint.

Smooth muscle is a type of muscle tissue that is found in the walls of internal organs and blood vessels. Compared to skeletal muscle, smooth muscle contracts more slowly and relaxes more slowly. This is because smooth muscle cells have a different structure and organization compared to skeletal muscle cells. Smooth muscle contractions are also typically involuntary and can be sustained for longer periods of time.