Skin
The role of osteocytes is to
a. Secrete chemicals required for bone maintenance
b. Differentiate into osteoblasts
c. Deposit bone until they are trapped and become osteoblasts
d. Break down bone matrix by secreting hydrogen ions and enzymes
a. Secrete chemicals required for bone maintenance
If excessive growth hormone is secreted before the closure of the epiphyseal plate during childhood, which condition may occur?
a. Acromegaly
b. Osteogenesis imperfecta
c. Achondroplasia
d. Gigantism
e. Rickets
d. Gigantism
The outermost surface of a bone is
a. Endosteum, a thin layer of fibrous connective tissue
b. Compact bone
c. Periosteum, a layer of dense irregular connective tissue richly supplied with blood vessels and nerves
d. Lamellae
c. Periosteum, a layer of dense irregular connective tissue richly supplied with blood vessels and nerves
Which of these methods may be used to prevent osteoporosis?
a. Engaging in weight-baring exercises
b. Avoiding high cholesterol
c. Avoiding habits that put pressure on bones, like cracking joints, or sitting in one position for too long
d. Removing the tumor that causes it
a. Engaging in weight-baring exercises
Which of these describes the nail matrix?
a. A part of the nail with actively dividing epithelial cells
b. The most obvious part of the nail
c. The most lateral part of the nail
d. The slightly more opaque region near the proximal nail fold
a. A part of the nail with actively dividing epithelial cells
If blood calcium is too low, which of the following will happen?
a. Parathyroid hormone will be released, promoting bone resorption by stimulating osteoblasts
b. Parathyroid hormone will be released, promoting bone deposition by stimulating osteoclasts
c. Parathyroid hormone will be released, promoting bone resorption by stimulating osteoclasts
d. Calcitonin will be released, promoting bone resorption by stimulating osteoclasts
e. Calcitonin will be released, promoting bone deposition by stimulating osteoblasts
c. Parathyroid hormone will be released, promoting bone resorption by stimulating osteoclasts
In general, the most dangerous type of skin cancer is
a. Basal cell carcinoma
b. Malignant melanoma
c. Squamous cell carcinoma
d. Colorectal cancer
e. Benign mole
b. Malignant melanoma
Which of the following statements is false?
a. Albinism results in a lack of skin pigmentation and a greatly increased risk of keratinocyte DNA damage from UV radiation
b. Keratinocytes play a critical role in protecting the skin from UV radiation
c. The dermis is highly vascular
d. One of the functions of the skin is vitamin D synthesis
e. The skin accounts for 10-15% of the body's weight
b. Keratinocytes play a critical role in protecting the skin from UV radiation
The primary component of the inorganic matrix is
a. hydroxyapatite crystals
b. osteoid
c. proteoglycans, glycosaminoglycans and glycoproteins
d. collagen fibers
a. hydroxyapatite crystals
Which of the following statements is INCORRECT?
a. Osteoporosis is more common among women because of hormonal changes after reaching menopause
b. The rule of nines can estimate the severity of a patient's burns
c. Parathyroidism is a disorder in which the parathyroid glands secrete too much PTH. A symptom of this disease would be lowered blood Ca2+ levels.
d. Severe hypoxia can cause a purple or blue color in the skin, called cyanosis
c. Parathyroidism is a disorder in which the parathyroid glands secrete too much PTH. A symptom of this disease would be lowered blood Ca2+ levels.
The most significant determination of skin color is
a. Genetics determine the amount of melanocytes in the skin
b. Melanocyte activity and variable amounts of eumelanin and pheomelanin
c. How much time is spent in the sun
d. The thickness of the epidermis and dermis of the skin
e. The activity of keratinocytes
b. Melanocyte activity and variable amounts of eumelanin and pheomelanin
Which of the following statements is incorrect?
a. Your eyebrows, eyelashes, and the hair on your head all grow at different rates
b. The arrector pili is a skeletal muscle that attaches to the dermal root sheath and contracts in response to cold or strong emotions such as fear
c. The melanocytes in a person with blonde hair produce less melanin than a person with brown hair
d. Botox contains a toxin that temporarily paralyzes facial muscles, causing the skin over them to appear smoother
e. The distal part of the nail is attached to the underlying nail bed by an accumulation of stratum corneum referred to as the hyponychium
b. The arrector pili is a skeletal muscle that attaches to the dermal root sheath and contracts in response to cold or strong emotions such as fear
Which of the following is true?
a. Appositional growth is the lengthening of a long bone and occurs at the epiphyseal plate
b. Both spongy bone and compact bone obtain their nutrients and oxygen from a central canal
c. Osteoporosis is a disease in which defective osteoclasts do not break down bone, resulting in abnormally grown and dense bone
d. Spongy bone contains trabeculae which do not contain osteons, but do contain osteocytes
d. Spongy bone contains trabeculae which do not contain osteons, but do contain osteocytes