Ch 6 A&P
The adult skeleton contains ________ major bones.
206
Where is articular cartilage found, and how is it nourished?
Articular cartilage is found covering both epiphyseal portions of articulating bone and nutrients diffuse from synovial fluid within the joint.
A transverse fracture of the wrist that may be comminuted is called a ________ fracture.
Colles
How does calcitonin act to lower blood calcium? (Module 6.11C)
Decreases osteoclast break down of bone matrix, decreases calcitriol production, decreases intestinal absorption, and increases renal excretion
Define endochondral ossification. (Module 6.7A)
Endochondral ossification is the replacement of a cartilage model with bone.
Compare gigantism with acromegaly. (Module 6.9C)
Gigantism results from an overproduction of growth hormone before puberty, whereas acromegaly results from an overproduction of growth hormone after puberty.
Which of the following is not true of the skeletal system?
It interacts with the lymphatic system to regulate calcium levels.
Describe the functions of osteocytes. (Module 6.4B)
Osteocytes are mature bone cells that maintain the bone matrix.
Describe the functions of osteogenic cells and osteoblasts. (Module 6.4A)
Osteogenic cells are stem cells that form osteoblasts. Osteoblasts are immature bone cells that secrete the organic components of bone matrix.
All the following result in decreased calcium levels in the bloodstream EXCEPT __________.
PTH stimulation of osteoclasts
Ankle fractures that affect both bones of the leg are called __________.
Pott's fractures
Describe the axial and appendicular divisions of the skeleton. (Module 6.1A)
The axial skeleton consists of the bones of the skull, vertebral column, and thorax. The appendicular skeleton consists of the bones of the limbs, pectoral girdle and pelvic girdle.
If osteoclast activity exceeds osteoblast activity in a bone, how will bone mass be affected? (Module 6.4D)
The bone mineral content will decrease and thus bone mass will decrease.
Describe the function of the medullary cavity.
The medullary cavity contains the red bone marrow and the yellow bone marrow.
Excessive growth hormone after puberty could result in
acromegaly.
In compact bone, the osteons are
arranged in concentric lamellae.
The central canal of an osteon contains
blood vessels.
Elevated levels of calcium ion in the blood stimulate the secretion of the hormone
calcitonin.
The most abundant mineral in the human body is
calcium
Which substance accounts for almost two-thirds of the weight of bone?
calcium salts
Endochondral ossification begins with the formation of a(n)
cartilage model.
A ________ fracture produces shattered bone fragments.
comminuted
An open, or ________, fracture projects through the skin.
compound
The fracture of vertebrae subjected to extreme vertical stress is called a ________ fracture.
compression
The smooth, rounded articular process of a bone is termed a
condyle
A prominent ridge, as seen on the pelvis, is a
crest.
The shaft of a long bone is called the
diaphysis.
The lining of the medullary cavity is called the
endosteum
Identify the structure labeled "2."
epiphysis
List the major parts of a long bone. (Module 6.3A)
epiphysis, metaphysis, diaphysis, and medullary cavity
A rib is an example of a ________ bone.
flat
Identify the six broad categories for classifying a bone according to shape. (Module 6.2A)
flat, sutural, long, irregular, sesamoid, short
A ________ is a rounded passageway for passage of blood vessels and/or nerves.
foramen
A rounded hole through a bone is termed a
foramen.
A shallow depression on a bone is termed a
fossa
Damage to a bone because of extreme load, sudden impact, or stresses applied from an unusual direction is called a
fracture.
Which of the following describes spiral fractures?
fractures that are produced by twisting stresses that spread along the length of the bone
The expanded articular end of an epiphysis that is separated from the shaft by a narrower neck is termed a
head
What type of tissue occurs at "1"?
hyaline cartilage
Which of the following is true for parathyroid hormone?
inhibits calcitonin secretion.
All the following are characteristics of periosteum EXCEPT __________.
it is an incomplete cellular layer that lines the medullary cavity
The humerus is an example of a(n) ________ bone.
long
Fat is stored within the
medullary cavity.
The region of a long bone between the end and the shaft is known as the
metaphysis.
The opening in the diaphysis through which blood vessels provide oxygen to osteons is named the ________ foramen.
nutrient
The lacunae of osseous tissue contain
osteocytes.
Identify the hormone that stimulates the release of calcium ions from bone matrix. Explain its mechanism of action. (Module 6.11A)
parathyroid hormone; increases osteoclast break down of bone matrix
Identify the structure at "4."
periosteum
A projection at an angle on a bone is termed a
ramus.
What process is shown at "6"?
secondary ossification
Which class of bones develops inside tendons and is most commonly located near joints at the knees, the hands, and the feet?
sesamoid bones
The carpal bones are examples of ________ bones.
short
A chamber within a bone normally filled with air is a
sinus.
A ________ fracture is produced by twisting stresses applied to the bone.
spiral
Which of the following is not a function of the skeletal system?
temperature regulation
Which of the following are not components of the skeletal system?
tendons
Secondary ossification centers occur in
the epiphyses.
A small rough bump on bone where a tendon attaches is called a
tuberosity.