Chapter 6 Pre Test Flashcards
Which of the following is not a function of the skeletal system?
leverage
blood cell production
*mineral absorption
calcium storage
Which type of bones provides protection of underlying soft tissues?
irregular bones
sutural bones
sesamoid bones
*flat bones
Which of the following is a characteristic of spongy bone?
consists of a network of trabeculae
does not possess lamellae
consists of parallel osteons
possesses capillaries and venules in its matrix
*consists of a network of trabeculae
does not possess lamellae
consists of parallel osteons
possesses capillaries and venules in its matrix
Structures that connect osteons with one another, and which radiate through the lamellae of bone, are called:
lacunae.
central canals.
*canaliculi.
trabeculae.
During appositional bone growth, which of the following are deposited?
Howship’s lacunae
circumferential lamellae
concentric lamellae
interstitial lamellae
Howship’s lacunae
*circumferential lamellae
concentric lamellae
interstitial lamellae
During endochondral ossification, fibroblasts migrating with blood vessels differentiate into which structures?
osteoprogenitor cells
*osteoblasts
osteoclasts
osteocytes
Near the end of the endochondral ossification process, the:
epiphyses are filled with compact bone.
epiphyses are filled with fibrous cartilage.
*epiphyses are filled with spongy bone.
diaphyses are filled with elastic cartilage.
Intramembranous ossification:
occurs in most long bones of the human skeleton.
occurs as chondrocytes cluster together and start to secrete the bony matrix.
*starts during approximately the eighth week of embryonic development.
requires a hyaline cartilage precursor.
Acromegaly results from which of the following?
*growth hormone levels rising abnormally after epiphyseal cartilages close
when, under abnormal conditions, mesenchymal stem cells in the connective tissue around bone develop into osteoblasts
Marfan syndrome
an overproduction of growth hormone before puberty
Bones do not contain most of the body’s ______.
*potassium
calcium
carbonate
phosphate
Accounting for most of the cell population in bone,
X are mature bone cells that occupy pockets sandwiched between layers of matrix.
osteocytes???
_____ are passageways, other than the central canals, that extend roughly perpendicular to the surface of the bone. (2 words)
perforating canals
Inadequate production of growth hormones leads to reduced epiphyseal cartilage activity and abnormally short bones in the condition known as
pituitary growth failure
Parathyroid hormone (PTH) stimulates the increased release of ______ by the kidneys, enhancing its effects on the intestines and resulting in an increase in the rate of intestinal calcium absorption.
not calcitriol…?
In a _______ fracture, the affected area of the bone is shattered into a multitude of bony fragments.
comminuted
_____ bones are small, flat irregularly shaped bones that are typically found between the flat bones of the skull.
sutural
_____ is a highly vascular tissue that fills the medullary cavity. (3 words)
red bone marrow
Osteogenic cells are mesenchymal cells present in the inner layer, or _____, that lines medullary cavities.
endosteum
The endosteum consists of a simple flattened layer of cells that covers the ______, generally without any intervening connective tissue fibers. (2 words)
medullary cavity
In intramembranous ossification, the developing bone grows outward from the ossification center in small struts called
spicules
A rare single-gene mutation results in the deposition of bone around skeletal muscles.
Fibrodysplasia ossificans progressiva (FOP)
Inadequate production of growth hormone leads to reduced epiphyseal cartilage activity and abnormally short bones.
Pituitary growth failure
Abnormal increase of growth hormone levels after epiphyseal cartilages close results in thicker, not longer, bones, especially those in the face, jaw, and hands.
Acromegaly
Overproduction of growth hormone before puberty results in very tall individuals.
Gigantism
Excessive cartilage formation at the epiphyseal cartilages results in very tall individuals whose limbs are very long and slender.
Marfan syndrome
The epiphyseal cartilages of the long bones grow unusually slowly and are replaced by bone early in life.
Achondroplasia
calcium effect of PTH stimulates osteoclasts so that they accelerate their erosion of bone matrix.
Calcium is released into body fluids.
calcium effect of PTH stimulates the increased release of calcitriol by the kidneys and enhances the effects of calcitriol on the intestines
Calcium is absorbed quickly.
calcium effect of Calcitriol is continuously secreted by the kidneys at low levels sufficient to keep pace with the rate of calcium ion reabsorption at the kidneys.
Calcium is conserved.
calcium effect of Calcitonin inhibits osteoclasts but does not affect osteoblasts, which continue to deposit calcium ions within the bone matrix.
Calcium is stored.
calcium effect of Increased calcitonin secretion causes decreasing PTH or calcitriol levels, resulting in a decrease in the rate of calcium ion absorption from the intestines.
Calcium is absorbed slowly.
calcium effect of Increased calcitonin levels have an inhibitory effect on the kidneys and suppress calcium ion reabsorption.
Calcium is excreted.