Blood cell formation occurs in (a) yellow bone marrow, (b) red bone marrow, (c) the matrix of bone tissue, (d) the ground substance of bones.
(b) red bone marrow
two-thirds of the weight of bone is accounted for by (a) crystals of calcium phosphate, (b) collagen fibers, (c) osteocytes, (d) calcium carbonate.
(a) crystals of calcium phosphate
The membrane found wrapping the bones, except when in the joint cavity, is the (a) periosteum, (b) endosteum, (c) perforating fibers, (d) a, b, and c are correct.
The basic functional unit of compact bone is the Haversian system or (a) osteocyte, (b) osteoclast, (c) osteon, (d) osseous matrix, (e) osseous lamellae
The vitamins essential for normal adult bone maintenance and repair are (a) A and E, (b) C and D3, (c) B and E, (d) B complex and K
(b) C and D3
The hormones that coordinate the storage, absorption, and excretion of calcium ions are (a) growth hormone and thyroxine, (b) calcitonin and parathyroid hormone, (c) calcitriol and cholecalciferol, (d) estrogens and androgens.
(b) calcitonin and parathyroid hormone
Classify the bones in the following diagram according to their shape.
a. long bone
b. flat bone
c. sutural bone
d. irregular bone
e. short bones
f. sesamoid bones
The presence of an epiphyseal line indicates (a) epiphyseal growth has ended, (b) epiphyseal growth is just beginning, (c) growth of bone diameter is just beginning, (d) the bone is fractured at the location, (e) no particular event.
(a) epiphyseal growth has ended
The primary reason that osteoporosis accelerates after menopause in women is (a) reduced levels of circulating estrogens, (b) reduced levels of vitamin C, (c) diminished osteoclast activity, (d) increased osteoblast activity.
(a) reduced levels of circulating estrogens
The nonpathological loss of bone that occurs with aging is called (a) osteomyselitis, (b), osteoporosis, (c) osteopenia, (d) ostetitis, (e) osteomalacia.
Name the major functions of the skeletal system.
2. Storage of minerals and lipids (yellow marrow)
5. Blood production (blood marrow)
Name the 4 distinctive cell populations of bone tissue.
1) Osteogenic cells
What are the primary parts of a typical long bone?
Diaphysis and Epiphysis, Compact bone, Medullary cavity, Epiphyseal Plate/Line, Metaphysis
What is the primary difference between endochondral ossification and intramembranous ossification?
In endochondral ossification, bone replaces existing cartilage. Then bone growth occurs through interstitial and appositional growth. In intramembranous ossification, bone develops directly from mesenchyme or fibrous connective tissue
List the organic and inorganic components of the bone matrix.
Inorganic compounds: Calcium phosphate, Ca3(PO4)2, calcium hydroxide, Ca(OH)2, crystals of hydroxyapatite, Ca10(PO4)6(OH)2
Organic compounds: the collagen and the ground substance (nonfibrillar)
What nutritional factors are essential for normal bone growth and maintenance?
Proper Vitamin D absorption (either through food or sun exposure), Calcitrol and Vitamin D3 , vitamin C, calcium and phosphorous (and other minerals), Vitamins A, K, and B12,
What hormonal factors are essential for normal bone growth and maintenance?
Growth hormone (produced by pituitary gland), Throxine (from thyroid gland), sex hormones (estrogen and testosterone), and Parathyroid Hormone (PTH) and Calcitonin
Which 3 organs or tissues interact to assist in the regulation of calcium ion concentration in body fluids?
Calcitonin, Kidneys, and Parathyroid Hormone (PTH)?
What are the major effects of parathyroid hormone (PTH)?
All three major effects increase the blood calcium ion level:
1) Stimulating osteoclast activity (indirectly)
2) Increasing the amount of calcium ions absorbed by the intestines by enhancing calcitriol secretion by the kidneys
3) Decreasing the amount of calcium ions excreted by the kidneys
Sutural Bones (Wormian bones)
small, flat, oddly shaped bones found between the flat bones of the skull
complex shapes with short, flat, notched, or ridged surfaces
boxlike in appearance
thin, parallel surfaces; provide protection for underlying soft tissues and offer an extensive surface area for the attachment of skeletal muscles
relatively long and slender; longer than they are wide
usually small, round, and flat
Which 2 bone markings are projections?
Process and Ramus
projection or bump
part of a bone that forms an angle with the rest of the structure (projection)
Which bone markings are depressions?
Sulcus and fossa
Narrow groove (depression)
Shallow depression (depression)
Which bone markings are openings?
Sinus, Foramen, Fissure, Meatus, and Canal
Chamber within a bone, normally filled with air (opening)
Rounded passageway for blood vessels and/or nerves (opening)
Deep furrow, cleft, or slit (opening)
Passage or channel, especially the opening of a canal (opening)
Duct or channel (opening)
Which bone markings are projections where muscles, tendons, or ligaments attach?
Trochanter, Crest, Spine, Line, Tubercle, and Tuberosity
Large, rough projection (attachment projection)
Prominent ridge (attachment projection)
Pointed process (attachment projection)
Low ridge (attachment projection)
Small, rounded projection (attachment projection)
Rough projection (attachment projection)
What are the bone markings for projections for forming joints?
Head, neck, facet, condyle, trochlea
Expanded articular end of an epiphysis, often separated from the shaft by a narrower neck (joint projection)
Narrow connection between the epiphysis and the diaphysis (joint projection)
Small, flat articular surface (joint projection)
Smooth, rounded articular process (joint projection)
Smooth, grooved articular process shaped like a pulley (joint projection)
Extended tubular shaft of a long bone
The expanded area at polar ends of the long bone
A narrow zone that connects the diaphysis and the epiphysis
What are the two types of bone tissue?
Compact bone and spongy bone (trabecular bone)
Relatively dense and solid; forms a sturdy protective layer that surrounds the medullary cavity. A layer of compact bone is called a cortex.
Spongy bone (Trabecular bone)
Open network of struts and plates called trabecula. Within the holes are red marrow or yellow marrow. A layer of spongy bone is called Diploë
for lipid storage
Red bone marrow
for blood cell formation
an envelope that surrounds bone tissue
Crystals of calcium salts formed in the bone matrix; cause stiffness of bones
Differentiate into osteoblasts
Synthesize new bone matrix by osteogensis or ossification
Mature bone cells located in lacunae; maintain the surrounding matrix and assist bone repair
Interconnect osteocytes adjacent to ones located in lacunae
Dissolve the bony matrix through osteolysis
If spongy bone has no osteons, how do nutrients reach the osteocytes?
Nutrients reach the osteocytes in spongy bone by diffusing along canaliculi that open into the surface of the trabeculae
Why are stresses or impacts to the side of the shaft in a long bone more dangerous than stress applied to the long axis of the shaft?
The osteons are aligned parallel to the long axis of the shaft, which does not bend when forces are applied to either end. Stresses or impacts to the side of the shaft can lead to a fracture
Why do extended periods of inactivity cause degenerative changes in the skeleton?
The lack of physical stress during inactivity leads to the removal of calcium salts from bones. Up to 1/3 of the bone mass can be lost in this manner, causing the bones to become thing and brittle
What are the functional relationships between the skeleton, on the one hand, and the digestive and urinary systems, on the other?
The digestive and urinary (kidneys) systems play important roles in providing the calcium and phosphate materials needed for bone growth. In return, the skeleton provides protection and acts as a reserve of calcium, phosphate, and other minerals that can compensate for changes in the dietary supplies of these ions
Why would a physician be concerned about the growth patterns of a young child request an x-ray of the hand?
There are many long bones in the hand, each of which has an epiphyseal cartilage. Measuring the width of these plates will provide clues to the hormonal control of growth in a child
Why does a second fracture in the same bone tend to occur at a site different from that of the first fracture?
Once a bone fracture has been repaired, the bone at the fracture site tends to be stronger and thicker than normal.
The process of bone growth at the epiphyseal cartilage is similar to (a) intramembranous ossification (b) endochondral ossification, (c) process of osteopenia, (d) the process of healing a fracture, (e) the process of calcification
(a) endochondrol ossification
How might bone markings be useful in identifying the remains of an individual who was shot and killed years ago?
Bone markings give clues as to the size, age, sex, and general appearance of an individual