Chapter 6 Flashcards
_____ is accomplished by osteoclasts. Osteoclasts crawl along the bone surfaces, essentially digging pits as they break down the bone tissue.
Bone resorption
This type of fractice is when the epiphysis separates from the diaphysis along the epiphyseal plate. It tends to occur when cartilage cells are dying and calcification of the matrix is occuring
Epiphyseal fracture
_____ hormones modulate the effects of growth hormone, ensuring that the skeleton retains its proper proportions as it grows.
Thyroid
This type of fracture occurs when the bone breaks incompletely. Only one side of the shaft breaks; the other side bends. Common in children, whose bones have relatively more organic matrix and are more flexible than those of adults
Greenstick fracture
_____ also called _____, lie at right angles to the central angles to the central canals and connect the blood and nerve supply of the periosteum to that of the central canals and the marrow cavity
Perforating canals, Volkmann’s canals
Cartilage is a connective tissue that consists of cells called ____.
Chondrocytes
______ is accomplished by osteoblasts, these cells lay down organic osteoid on bone surfaces, and calicium salts crystallize within this osteoid.
Bone deposition
This type of fracture is when the bone is crushed. It is common in porous bones (ie osteoporotic bones) subjected to extreme trauma, as in a fall.
Compression
______ is characterized by low bone mass and a deterioration of microscopic architecture of the bony skeleton
Osteoporosis
Between the diaphysis and each epiphysis of an adult long bone is _____
an epiphyseal line
A connective tissue membrane called the _____ covers the entire outer surface of each bone expect on the ends of the epiphyses, wehre articular cartilage occurs
periosteum
In the adult skelton, bone is deposited and removed primarily at the endosteal surface. Together, these two processes constitute ______. This process involves _____ and_____
bone remodeling
osteoblasts and osteoclasts
Notes from lecture: bones are dynamic. Cancellous bone of the skeleton is replaced every 3-4 years. Compact bone replaced every 10 years, A lot of calicium leaves the bone every day (500 mg?)
The very center of the diaphysis of long bones contains no bone tissue at all and is called the _______
medullary cavity
What are the 6 functions of bone?
- Support
- Movement
- Protection
- Mineral Storage
- Blood cell formation and energy storage
- Energy metabolism
A layer of dense irregular connective tissue which acts like a girdle to resist outward expansion whent the cartilage is subjected to pressure. This also functions in the growth and repair of cartilage.
Perichonodrium
The chemical composition of bone: ___% organic components composed of cells, fibers, and organic substances abudant with ___.
___% inorganic mineral salts, primarily ____. This composition resists compression.
35%; collagen
65%; calcium phosphate
If you wish to slow bone loss, the activity of which cells in bone tissue should be targeted?
Osteoclasts
The external layer is _____ bone. Internal to this is _____ bone, also called ______, a honeycomb of small need-like or flat pieces called ______.
compact
spongy
trabecular bone
trabeculae
These cells differentiate into bone-forming osteoblasts
Osteogenic cells
In cartilage tissue each chondrocyte is located in a space in the matrix called _____.
lacuna
Short, irregular, and flat bones are both periosteum-covered compact spongy bone externally and endosteum-covered spongy bone internally. However, because these bones are not cylindrical, they have no _____
diaphysis.
Bone-forming osteoblasts derive from ____ cells. Osteoclasts, which also form in the bone marrow, arise from immature blood cells called _____ stem cells, and they may be related to macrophages
mesenchyme cells
hematopoietic stem cells
Other bones develop as hyaline cartilage, which is replaced through a process called _______. These bones are called ____.
endochondral ossification
endocohondral bones
Growth of a bone by the addition of bone tissue to its surface is called _______
appoositional growth
The mature bone cells, the osteocytes, are spider shaped. Their bodies occupy small cavities in the solid matrix called ____ and their “spider legs” occupy thinn tubes callred _____
lacunae, canaliculi
The three types of cartilage are:
- Hyaline cartilage
- Elastic cartilage
- Fibrocartilage
The long axis of a long bone
Diaphysis
This type of fracture is when bone fragments into three or more pieces, its particularly common in the aged, whose bones are more brittle.
Comminuted
______ is a form of bone cancer.
Osteosarcoma
“growth from within” The chondrocytes within the cartilage divide and secrete new matrix
Interstitial growth
Some bones, called ____, develop from a mesenchymal membrane through a process called _____.
membrane bones, intramembranous ossification
This type of cartilage resists strong compression and tension between hyaline cartilage and dense regular connective tissue
Fibrocartilage
The internal spongy bone is called _____.
diploe
“Growth from the outside” cartilage forming cells (chondroblasts) in the surrounding perichondrium produce the new cartilage tissue by actively secreting matrix
Appositional growth
These cells are responsible for the resorption of bone are the fourth type of cell found within bone tissue. They break down bone by secreting hydrochloric acid, which disovles the mineral component of the matrix, and lysosomal enaymes, which digest the organic components
osteclasts
The periosteum is secured to the underlying bone by ______, thick bundles of collagen that run from the periosteum into the bone matrix
Perforating fibers (Sharpey’s fibers)
The joint surface of each epiphysis is covered with a thin layer of hyaline cartilage called the
articular cartilage
This type of cartilage is in the epiglottis and outer ear; bendy
Elastic cartilage
What makes the extracellular matrix durable and resilient but not brittle?
Combination of organic collagen and incorganic mineral content.
These cells actively produce and secrete the organic components of the bone matrix: the ground substance and the collagen fibers. The bone matrix secreted by these cells is called osteoid
Osteoblasts
This type of fracture is when a ragged break occurs when execessive twisting forces are applied to a bone. It’s common in sports fractures.
Spiral
______ is characterized by excessive rates of bone deposition and bone resorption.
Paget’s diease
The bone ends
epiphyses
Lying between the osteons are groups of incomplete lamellae called ____. These are simply the remains of old osteons that have been cut through by bone remodeling.
interstial lamellae
_______ occur in the external and internal surfaces of the layer of compact bone; each of these lamellae extends around the entire circumference of the diaphysis.
circumferential lamellae, this effectively resist twisting of the entire long bone.
Structurally, an osteon is a group of concentric tubes resembling the rings of a treek trunk the cross section. Each of the tubes is a ___, a lyer of bone matrix in which the collagen fibers and mineral crystals align and run in a single direction.
lamella
What time of cartilage has spherical condrocytes, provides support through flexibility and resilience
Hyaline Cartilage
An important structural component of the compact bone is the ____ or _____ system
osteon, Haversian (system)
The ____ hormones, such as _____ and _____, first promote bone growth in the growth spurt at adolescence and later induce the epiphyseal plates to close, ending growth
sex
androgens and estrogens
What are the four classifications of bones?
- Long bones
- Short bones
- Flat bones
- Irregular bones
Bone growth is regulated by several hormones, primarily ______, which stimulates the epiphyseal plates to grow and stimulated by the _____.
growth hormone
pituitary gland
At what age do bones begin to ossify?
At what age does bone mass begin to decline?
Week 8
40 years
Whereas periosteum covers the external surface of bones, internal bone surfaces are covered by a much thinner connective tissue membrane called
endosteum, specifically the endosteum covers the trabeculae of spongy bone; it also lines the central canals of osteons.
This type of fracture is when a broken bone portion is pressed inward. It is typical of a skull fracture
Depressed fracture
____ and _____ are both names for the process of bone-tissue formation.
Osteogenesis; ossification
The phases of healing of a simple fracture (4)
- Hematoma formation
- FIbrocartilaginous callus formation
- bony callus formation
- bone remodeling
Through the core of each osteon runs a canal called the ____ or ______.
central canal, Haversian canal
The term ____ applies to a number of disorders in adults in which the bones are inadequately mineralized. ____ is the analogous disease in children. These are both caused by inadequate amounts of _____ or ____ in the diet.
Osteomalacia
Rickets
Vitamin D or Calcium Phosphate
