Pathophysiology ch 42

A nurse is caring for a client who twisted his ankle while running. Tests reveal damaged connective tissue that connects the movable bones of the joint. Based on this finding, the nurse prepares to teach the client about which of the following anatomical structure that is injured?

Ligaments Explanation: Tendons and ligaments are dense connective tissue structures that connect muscles and bones. Tendons connect muscles to bones and ligaments connect the movable bones of joints. Page 1063

Which vitamin has little or no activity until it has been converted to physiologically active compounds?

Vitamin D Explanation: Vitamin D has little or no activity until it has been converted to hysiologically active compounds. The first step of the activation process occurs in the liver, and next in the kidneys. Page 1072

A client has developed bursitis of the right knee. Select all that apply.

-Bursitis develops where pressure is exerted. -Movement may be limited. -Swelling may occur. -Pain may develop.

The physical therapy student is studying how the knee moves. The instructor knows the student understands the structure when she states which of the following?

"Ligaments join one bone to its articulating mate." Explanation: The dense connective tissue found in tendons and ligaments has a limited blood supply. Tendons attach skeletal muscle to bone. Ligaments are fibrous thickenings of the articular capsule that join one bone to its articulating mate. Although most ligaments are considered inelastic, they are pliable enough to permit movement at joints. They tear rather than stretch when exposed to excess stress. Page 1063

The faculty member knows the student understands the function of bone cells when the student states which of the following?

"Osteoblasts are bone-building cells that synthesize and secrete the organic matrix of bone." Explanation: Osteoclasts are bone-building cells that sythesize and secrete organic matrix of bone. Osteoprogenitor cells are undifferentiated cells that differentiate into osteoblasts. Osteocytes are mature bone cells that function in the maintenence of bone matrix. Osteoclasts are bone cells responsible for the resorption of bone matrix. Page 1067

A nursing faculty member is explaining the function of red bone marrow to students. Which of the following statements made by a student indicates that teaching was successful?

"Red bone marrow is the site of blood cell formation." Explanation: Red bone marrow contains developing red blood cells and is the site of blood cell formation. Page 1066

A client recently diagnosed with an injury to the articular cartilage of the knee asks the nurse how long it will take the injury to heal. Which of the following statements is the best response from the nurse?

"Regeneration of most cartilage is slow. These injuries can take a long time to heal." Explanation: Regeneration of most cartilage is slow. It is accomplished primarily by growth that requires the activity of perichondrium cells. In articular cartilage, which has no perichondrium, superficial injuries heal slowly. Page 1074

A nurse is teaching a patient diagnosed with osteoarthritis about the joint capsule. Which of the following statements made by the patient indicates that teaching was successful?

"The synovial fluid in my joint capsule acts as a lubricant and helps the movement of the joint's articulating surfaces." Explanation: Synarthroses are joints in which bones are joined together by fibrous tissue, cartilage, or bone; they lack a joint cavity and have little or no movement. Synovial, or diarthrodial, joints are freely movable. The surfaces of the articulating ends of bones in synovial joints are covered with a thin layer of articular cartilage, and they are enclosed in a fibrous joint capsule. The joint capsule consists of two layers: an outer fibrous layer and an inner membrane, the synovium. The synovial fluid, which is secreted by the synovium into the joint capsule, acts as a lubricant and facilitates movement of the joint's articulating surfaces. Bursae, which are closed sacs containing synovial fluid, prevent friction in areas where tendons are deflected over bone or where skin must move freely over bony tissue. Menisci are fibrocartilaginous structures that develop from portions of the articular disk that occupied the space between articular cartilage surfaces during fetal development. The menisci may have a free inner border, or they may extend through the joint, separating it into two cavities. Page 1074

While explaining to the parents of a 5-year old why the child's fractured femur has so much swelling and bruising, the nurse will include which of the following statements?

"This bone is hollowed out and the inside of the shaft produces marrow where red blood cells are formed." Explanation: Long bones usually are narrow in the mid-portion and broad at the ends so that the weight they bear can be distributed over a wider surface. The shaft of a long bone is formed mainly of compact bone roughly hollowed out to form a marrow-filled medullary canal. The edema and bruising following femur fracture is due primarily to disruption of the shaft of the bone. Cartilage attaches at the end of long bones, not the shaft. Page 1065

A 70 year-old woman's family physician has recommended a vitamin D supplement. The woman states that she tries hard to take as few pills as possible and questions her physician on the rationale and necessity of the hormone. How can the physician most accurately reply to the client's concerns?

"Vitamin D is important in order for your body to absorb the calcium that you consume in your diet." Explanation: Vitamin D facilitates intestinal absorption of calcium. It does not directly increase bone density and the liver does not independently produce vitamin D. Vitamin D does not decrease the rate of bone resorption. Page 1069

Which of the following individuals demonstrates a health problem with his or her axial skeleton?

A 40 year-old man who has a contusion to the left temporal bone of his skull following a motor vehicle accident. Explanation: The skull is considered to be part of the axial skeleton, while the arm, hips and pelvis are components of the appendicular skeleton. Page 1063

Which of the following individuals who have recently presented to a hospital emergency department is displaying an injury that involves his or her fibrocartilage?

A 78 year-old man who has fallen and is suspected of having a "slipped disc" in his back. Explanation: Intervertebral discs are constructed of fibrocartilage, while the ear is largely constructed of elastic cartilage. Cartilage of the respiratory system and joints is most often hyaline cartilage. Page 1064

In a child, the epiphyses and metaphysis are separated by which of the following?

A growth plate Explanation: A typical long bone has a shaft, or diaphysis, and two ends called epiphyses. In growing bones, the part of the bone shaft that funnels out as it approaches the epiphyses is called the metaphysis. In a child, the epiphyses is separated from the metaphysis by the cartilaginous growth plate. Trabeculae compose cancellous bone. Synarthroses are joints that lack a joint cavity. Page 1065

In the adult, red blood cell production decreases and red marrow is gradually replaced by yellow bone marrow. Yellow marrow is composed largely of which of the following?

Adipose cells Explanation: Yellow bone marrow is composed largely of adipose cells. Red bone marrow contains developing red blood cells. White blood cells and osteoprogenitor cells are not in yellow marrow. Page 1066

A client who has a fractured ankle is complaining of knee and hip pain. What is the most likely cause of these symptoms?

All nerves that cross articulations innervate each joint of an extremity. Explanation: The nerve supply to joints is provided by the same nerve trunks that supply the muscles that move the joints. These nerve trunks also supply the skin over the joints. All the peripheral nerves that cross the articulation innervate each joint of an extremity. Page 1075

In which of the following locations would a clinician expect to find a ligament?

Around the capsule that forms the knee joint. Explanation: Ligaments exist where a bone connects to its articulating mate, as in the case of the synovial joint between the tibia and femur that constitutes the knee. Ligaments do not connect the ribs to the sternum and the radius and biceps are connected by a tendon. The interfaces between skull plates are considered joints, but these are not ligaments. Page 1075

Which of the following describes the blood supply to a synovial joint?

Articulating areas are nourished indirectly by the synovial fluid. Explanation: The articulating cartilage is nourished indirectly by the synovial fluid. The synovial membrane has a rich blood supply and due to this the healing and repair of the synovial membrane is usually rapid and complete. Because of the many capillaries near the surface of the synovium, blood may escape into the synovial fluid after relatively minor injuries. Page 1075

The skeletal system is composed of bone and cartilage. Which of the following statements regarding the skeletal system is most accurate?

Bones provide protection for internal organs. Explanation: Cartilage, a semirigid and slightly flexible structure, plays an essential role in prenatal and childhood development of the skeleton. Bone provides protection for internal organs and serves as a reservoir for calcium and phosphate storage. Bone matrix is maintained by four types of cells. Page 1064

A 16-year-old hockey player is driven into the boards by an opposing player. The impact damages the client's knee, and fluid-filled sacs in the knee have been damaged. Where is this client's injury?

Bursae Explanation: Bursae are fluid-filled sacs that prevent friction. Articular cartilage covers the end of bones, and the synovium is the membrane that secretes the synovial fluid. Intraarticular menisci are fibrocartilage structures that develop from portions of the articular disk that occupied the space between articular cartilage surfaces during fetal development. Page 1075

In some diarthrotic joints, the synovial membrane forms sacs filled with synovial fluid that prevent friction on a tendon. These sacs are known as which of the following?

Bursae Explanation: In some diarthrotic joints, the synovial membrane forms closed sacs that are called bursae and are filled with synovial fluid. Menisci are fibrocartilage structures that develop from portions of the articular disk that occupied the space between articular cartilage surfaces during fetal development. Periosteum covers the bones and lacuna are areas containing osteocytes. Page 1075

The physician is reviewing lab results for his client with cancer and finds the client to be hypercalcemic. Which of the following will the physcian prescribe?

Calcitonin Explanation: Calcitonin is used to reduce serum calcium levels during hypercalcemic crises. PTH would increase serum calcium levels. Potassium chloride and estrogen are not utilized to treat calcium levels. Page 1072

Calcitonin has what relationship to bone growth?

Calcitonin lowers blood calcium levels. Explanation: Calcitonin lowers blood calcium levels. PTH increases blood calcium levels. Calcitonin is secreted by the parafollicular cells of the thyroid gland and inhibits the release of calcium from bone into the extracellular fluid. Page 1069

A group of student nurses are reviewing the bones in the human body. What is the name for spongy bone?

Cancellous Explanation: Cancellous (spongy) bone is found in the interior of bones and is composed of trabeculae, or spicules, of bone that form a lattice-like pattern. Cancellous bone is relatively light, but its structure is such that it has considerable tensile strength and weight-bearing properties. Page 1065

The student is studying the types of mature bones. The spongy bone found in the interior of bones and composed of spicules is which of the following?

Cancellous Explanation: There are two types of mature bones: compact and cancellous bone. Cancellous (spongy) bone is found in the interior of bones and is composed of trabeculae or spicules. Compact bone, which forms the outer shell of a bone, is more rigid than cancellous bone. Irregular and flat bones are classifications of bones. Page 1065

A 70-year-old female client comes to the clinic with back pain. An x-ray reveals vertebral fractures and she is diagnosed with osteoporosis. Which of the following factors most likely contributed to her condition?

Decreased estrogen levels Explanation: Estrogen reduces the number and function of the osteoclasts. Thus, the decrease in estrogen levels that occurs at menopause results in increased resorption of bone. Page 1069

During the first two decades of life, the skeleton undergoes general overall growth. Select the structure that promotes this process.

Epiphyseal growth plate Explanation: During the first two decades of life, the skeleton undergoes general overall growth. The long bones of the skeleton, which grow at a relatively rapid rate, are provided with a specialized structure called the epiphyseal growth plate. Metaphysis is the part of the bone shaft that funnels out as it approaches the epiphysis. Diaphysis is shaft of a long bone. Epiphysis is the rounded end of long bone. Page 1068

The radiologist knows that it is normal to see lamellar and woven bone in the adult skeleton.

False Explanation: There are two types of bone tissue: lamellar bone and woven bone. Lamellar bone is a strong, mature form of bone found in the adult skeleton. Anything other than lamellar bone in an adult skeleton is abnormal. Woven bone is found in the developing fetus, in areas surrounding tumors and infections, and as part of a healing fracture. Page 1066

The nurse is caring for a client with a fracture in his appendicular skeleton. Which of the following bones is in this skeleton?

Femur Explanation: The skeletal system consists of the axial and appendicular skeleton. The axial skeleton is composed of the bones of the skull (mandible), thorax (ribs) and vertebral column. The appendicular skeleton consists of the bones of the upper and lower extremities (femur). Page 1064

The elderly nursing home resident has a fractured humerus. In order to promote healing, the physician recommends which of the following?

Including fish in the diet on a routine basis Explanation: Older adults who are housebound or institutionalized frequently have low vitamin D levels. Vitamin D is a valuable hormone involved in bone mineralization. There are two sources of Vitamin D: intestinal absorption and skin production. The most important dietary sources of vitamin D are fish, liver and irradiated milk. With adequate exposure of the skin to sunlight, the amount of vitamin D produced by the skin is usually sufficient to meet physiologic requirements. Page 1072

A female tennis player has suffered an injury to her shoulder that has affected her bursae in the joint. Which of the following consequences would be most expected from this aspect of her injury?

Increased friction on the tendons of the shoulder joint. Explanation: The primary role of bursae is the reduction of friction on tendons. Damage to the bursae would not result in bone-to-bone contact, fusing of the joint or separation between normally-connected muscle and bone. Page 1075

The nurse is explaining to a client that there are "cushions" in his back to absorb any jarring movement of the spine. Which of the following anatomical structures is the nurse referring to?

Intervertebral disks Explanation: Intervertebral disks are elastic fibrocartilaginous plates that are intermediate between dense connective tissue and hyaline cartilage, which cushion the spine like shock absorbers and help it move. Page 1074

A client has a tendonitis. What will the nurse teach the client about this disorder?

It is caused by overuse. Explanation: Tendons have an outer connective tissue tube that is attached to the structures surrounding the tendon and an inner sheath that encloses the tendon. The space between the inner and outer sheath is filled with a fluid. Overuse of the tendon can result in tendonitis or inflammation of the tendon. The other answers are not true. Page 1075

Which statement is correct about hyaline cartilage?

It joins the ribs to the sternum. Explanation: Hyaline cartilage is the most abundant type of cartilage. It forms much of the cartilage of the fetal skeleton. In the adult, hyaline cartilage forms the costal cartilages that join the ribs to the sternum and vertebrae, many of the cartilages of the respiratory tract, the articular cartilages, and the epiphyseal plates. There are three different types of cartilage: elastic cartilage, hyaline cartilage, and fibrocartilage. Page 1064

A client with a spinal cord injury has experienced contractures and destructive changes in the joints of the lower extremities. The nurse determines which of the following is the most likely cause?

Loss of proprioception and reflex control of the muscles Explanation: The tendons and ligaments of the joint capsule are sensitive to position and movement, particularly stretching and twisting. These structures are supplied by the large sensory nerve fibers that form proprioceptor endings. Loss of proprioception and reflex control of muscular support lead to destructive changes in the joint. Page 1075

Select the statement that best describes a synovial or diarthrodial joint. The joint:

Moves freely Explanation: Synovial or diarthrodial joints are those that move freely and are located throughout the body. Synarthrosis joints are connected to the bone by hyaline cartilage and have little or no movement. Page 1074

Bone formation occurs in two stages. Which of the following stages involves the formation of prebone or unmineralized bone?

Ossification Explanation: Bone formation occurs in two stages: ossification and calcification. Ossification involves the formation of osteoid or prebone. Calcification of bone involves the depostion of calcium salts in the osteoid tissue. Resorption involves removing the mineral content and organic matrix of bones. Osteoclasts, by virtue of their phagocytic lineage, ingest minute particles of bone matrix and crystals. Page 1067

What type of cell is responsible for building bone in the body?

Osteoblasts Explanation: Osteoblasts are bone building cells. They are responsible for the formation of the bone matrix. Osteoprogenitor cells are found in the periosteum and they differentiate into osteoblasts. Osteocytes are mature bone cells that maintain the bony matrix. Page 1067

Following a fall, an 83-year-old male has fractured his femoral head. His care provider has stated that the healing process is occurring at a reasonable pace, and that the man will regain full function after healing and rehabilitation. Which cells are most responsible for restoring the integrity of the man's broken bone?

Osteoblasts Explanation: The osteoblasts, or bone-building cells, are responsible for the formation of the bone matrix and would participate in the healing process. Osteocytes are mature bone cells while osteoclasts reabsorb bone cells. An osteoma is a bone tumour. Page 1067

A client has developed increased resorption of bone with removal of mineral content. This is most likely the result of:

Osteoclasts Explanation: Osteoclasts are responsible for resorption of bone with removal of mineral content. Osteoprogenitor cells continually replace worn-out bone; osteocytes maintain bony structure; and osteoblasts are bone-building cells that secrete the bone matrix. Page 1067

A client experienced a tibial fracture several days ago and his bone is now healing. Which physiologic process will contribute to the client's healing?

Osteoprogenitor cells may be activated for remodeling Explanation: Osteoprogenitor cells differentiate into osteoblasts and are active during normal growth. They may also be activated in adult life during healing of fractures and other injuries. Osteoblasts, or bone-building cells, are responsible for the formation of the bone matrix; inhibition would slow the healing process. Osteocytes are mature bone cells, not the cause of remodelling process. Osteoclasts are "bone-chewing" cells that function in the resorption of bone, removing the mineral content and the organic matrix. Page 1066

The nurse recognizes that parathyroid Hormone (PTH) has what relationship to bone formation?

PTH is a regulator of calcium and phosphate. Explanation: PTH is one of the important regulators of calcium and phosphate levels in the blood. Additionally, PTH has been found to be advantageous in increasing fracture healing if given supplementally to people with fractures. Page 1069

The student is comparing the actions of parathyroid hormone (PTH) and calcitonin. Which of the following statements is most correct?

Parathyroid hormone produces a prompt increase in serum calcium levels. Explanation: PTH produces a prompt increase in serum calcium levels and increases the renal excretion of phosphate. Calcitonin increases the renal excretion of calcium and decreases bone resorption. Page 1069

An adolescent asks the nurse about peak bone mass. The most appropriate response would be:

Peak mass occurs in early adulthood. Explanation: Peak bone mass is achieved during early adulthood. It is determined by a number of factors, including the type of vitamin D receptor inherited, nutrition, level of physical activity, age, and hormonal status. Page 1068

Which of the following covers bones and has an inner layer that contains osteoprogenitor cells?

Periosteum Explanation: The periosteum covers the bones, except at their articular ends. The periosteum has an outer fibrous layer and an inner layer that contains osteoprogenitor cells. The endosteum is the membrane that lines the spaces of spongy bone, the marrow cavities, and the Haversian canals of compact bone. The pericondrium is a layer of fibrous connective tissue that covers the free surface of most hyaline cartilage. Fibrocartilage is found in intervertebral disks and in the symphysis pubis. Page 1065

Each joint capsule has tendons and ligaments. What are the tendons and ligaments of the joint capsule sensitive to?

Position and movement Explanation: The tendons and ligaments of the joint capsule are sensitive to position and movement, particularly stretching and twisting. The other answers are incorrect. Page 1075

A 30 year-old woman has just given birth to boy. How will the mother's bone marrow differ from that of her son?

Proportionately, the infant will have more red marrow and less yellow marrow than his mother. Explanation: At birth, nearly all of the marrow is red and hematopoietically active. As the need for red blood cell production decreases during postnatal growth, red marrow is gradually replaced with yellow bone marrow in most of the bones. Page 1066

While reviewing the role of the parathyroid hormone in the balance of calcium and phosphate levels, the nursing faculty will emphasize that the kidney responds to parathyroid stimulation by:

Reducing the reabsorption of phosphate. Explanation: In the kidney, PTH stimulates tubular reabsorption of calcium while reducing the reabsorption of phosphate. The latter effect ensures that increased release of phosphate from bone during mobilization of calcium does not produce an elevation in serum phosphate levels. Page 1069

The radiology student is studying x-rays of the wrist. The instructor explains that these irregularly shaped bones are known as which of the following?

Short bones Explanation: Long bones are found in the upper and lower extremities. Short bones are irregularly shaped bones located in the ankle and wrist. Flat bones are found in areas such as the skull and rib cage or scapula. Irregular bones include bones such as the vertebrae and bones of the jaw. Page 1065

A client has sustained an injury to a synarthrotic joint. Where is a possible site of the client's injury?

Skull Explanation: The coronal suture of the skull is a synarthrosis. The knee, elbow, and temporomandibular joints are all synovial joints. Page 1074

While reviewing the bones in anatomy class, the instructor discusses this type of bone that protects the underlying structures. A good example of a flat bone is:q

Skull. Explanation: Flat bones are composed of a layer of cancellous bone between two layers of compact bone. They are found in areas such as the skull and rib cage, where extensive protection of underlying structures is needed, or as in the scapula, where a broad surface for muscle attachment must be provided. Vertebrae are irregular bones while the metatarsal bones and the femur are long bones. Page 1065

The joint capsule in a diarthrodial joint consists of two layers. Which of the following is one of these layers?

Synovium Explanation: The joint capsule consists of two layers: an outer fibrous layer and an inner membrane, the synovium. The periosteum covers the bones, except at their articular ends. The endosteum is the membrane that lines the spaces of spongy bone, the marrow cavities, and the Haversian canals of compact bone. The pericondrium covers free surfaces of most hyaline cartilage, with the exception of articular cartilage. Page 1074

A client has experienced trauma of the musculoskeletal structure that connects muscle to bone. The nurse interprets this as an injury of the:

Tendon Explanation: Tendons connect skeletal muscles to bone. Ligaments join one bone to its articulating mate. Periosteum is a membrane that covers the outer surface of all bones; metaphysis is the part of the bone shaft that funnels out as it approaches the epiphysis. Page 1065

A nurse is caring for a client who injured her knee while playing basketball. Tests reveal a torn connective tissue that connects muscles to bones. Based on this finding, the nurse prepares to teach the client about which of the following anatomical structure that is injured?

Tendons Explanation: Tendons and ligaments are dense connective tissue structures that connect muscles and bones. Tendons connect muscles to bones and ligaments connect the movable bones of joints. Page 1065

What part of the bone assists in protecting the bone?

The compact bone Explanation: The compact bone is the outer shell of the bone and protects the bone. The spongy interior, periosteum, and cartilage do not prevent the bone from damage. Page 1065

Which of the following is the best example of a diarthrodial joint?

The interphalangeal joint between the proximal and middle phalanges of the fingers. Explanation: Interphalangeal joints are examples of diarthrodial, or synovial joints, which are characterized by free movement. The joints at epiphyseal plates, between skull bones and at the symphysis pubis do not meet this criterion. Page 1074