The Skeletal System: Bone Tissue Flashcards
is an organ made up of several different tissues working together
Bone
Bone is an organ made up of several different tissues working together:
- bone (osseous) tissue
- cartilage
- dense connective tissue
- epithelium
- adipose tissue
- nervous tissue
the entire framework of bones and their cartilages
Skeletal System
the study of bone structure and the treatment of bone disorders
Osteology
osteo means
bone
logy means
study of
Skeletal System: Functions
- support
- protection
- Assistance in movement
- Mineral homeostasis (storage and release)
- Blood cell production
- Triglyceride storage
what cells store triglycerides?
adipose cells
is one that has greater length than width
Long bone
A typical long bone consists of the following parts:
- Diaphysis
- Epiphyses
- Metaphyses
- Articular cartilage
- Periosteum
- Medullary cavity
- Endosteum
Diaphysis means
(growing between)
is the bone’s shaft or body
Diaphysis
the long, cylindrical, main portion of the bone
Diaphysis
Epiphyses means
growing over
are the proximal and distal ends of the bone
Epiphyses
meta means
between
are the regions between the diaphysis and the epiphyses
Metaphyses
a layer of hyaline cartilage that allows the diaphysis of the bone to grow in length
Epiphyseal (Growth) Plate
is a thin layer of hyaline cartilage covering the part of the epiphysis
Articular Cartilage
where the bone forms an articulation (joint) with another bone
Articular Cartilage
peri means
around
is a tough connective tissue sheath and its associated blood supply that surrounds the bone surface wherever it is not covered by articular cartilage.
Periosteum
periosteum has an
outer fibrous layer and inner osteogenic layer
medulla means
marrow, pith
other term for medullary cavity
Marrow Cavity
is a hollow, cylindrical space within the diaphysis that contains fatty yellow bone marrow and numerous blood vessels in adults
medullary cavity
endo means
within
is a thin membrane that lines the medullary cavity
Endosteum
contains a single layer of bone-forming cells and a small amount of connective tissue.
Endosteum
Extracellular Matrix is about
15% water, 30% collagen fibers, and 55% crystallized mineral salts
The most abundant mineral salt is
calcium phosphate [Ca3(PO4)2]
calcium phosphate [Ca3(PO4)2] combines with another mineral salt, ____________________________, to form crystals of hydroxyapatite [Ca10(PO4)6(OH)2].
calcium hydroxide
calcium phosphate [Ca3(PO4)2] combines with another mineral salt, calcium hydroxide, to form crystals of?
hydroxyapatite [Ca10(PO4)6(OH)2]
minerals crystallize and the tissue hardens
Calcification
it is initiated by bone-building cells called osteoblasts
Calcification
Calcification is initiated by bone-building cells called
osteoblasts
depends on the crystallized inorganic mineral salts
Bone’s Hardness
depends on its collagen fibers
Bone’s Flexibility
______________________ secrete enzymes and acids that break down both the mineral salts and the collagen fibers of the extracellular matrix of bone.
osteoclasts
Four types of cells are present in bone tissue:
- Osteoprogenitor cell
- Osteoblast
- Osteocyte
- Osteoclast
develops into an osteoblast
Osteoprogenitor cell
- unspecialized bone stem cells derived from mesenchyme
Osteoprogenitor cell
Osteoprogenitor cells are unspecialized bone stem cells derived from?
mesenchyme
they are the only bone cells to undergo cell division
Osteoprogenitor cell
Osteoprogenitor cells are found along:
- the inner portion of the periosteum
- in the endosteum
- in the canals within bone that contain blood vessels
the tissue from which almost all connective tissues are formed
Mesenchyme
bone-building cells
osteoblast
forms bone extracellular matrix
osteoblast
they synthesize and secrete collagen fibers and other organic components needed to build the extracellular matrix of bone tissue
osteoblast
initiates calcification.
osteoblast
as osteoblasts surround themselves with extracellular matrix, they become trapped in their secretions and become?
osteocytes
mature bone cells
osteocyte
maintains bone tissue
osteocyte
are the main cells in bone tissue and maintain its daily metabolism, such as the exchange of nutrients and wastes with the blood.
osteocyte
like osteoblasts, osteocytes _____________________________
do not undergo cell division
functions in resorption
Osteoclast
huge cells derived from the fusion of as many as 50 monocytes (a type of white blood cell) and are concentrated in the endosteum.
Osteoclast
Osteoclast are derived from the fusion of as many as 50 of what certain type of white blood cell?
monocyte
The breakdown of bone extracellular matrix
resorption/bone resorption
is part of the normal development, maintenance, and repair of bone
resorption/bone resorption
what percentage of the skeleton is compact bone?
80%
what percentage of the skeleton is spongy bone?
20%
strongest form of bone tissue
compact bone
Found beneath the periosteum of all bones
compact bone
makes up the bulk of the diaphyses of long bones
compact bone
Provides protection and support and resists the stresses produced by weight and movement
compact bone
Composed of repeating structural units called osteons, or haversian systems
compact bone
compact bone is composed of repeating structural units called
osteons, or haversian systems
circular plates
Concentric Lamellae
small spaces between the concentric lamellae
Lacunae
canaliculi or
small channels
are filled with extracellular fluid
canaliculi
spongy bone can also be called
trabecular or cancellous bone
do spongy bone contain osteon?
NO
- always located in the interior of a bone, protected by a covering of compact bone
spongy bone
spongy bone consists of ____________________ that are arranged in an irregular pattern of thin columns called trabeculae
lamellae
trabeculae or
little beams
irregular pattern of thin columns
trabeculae
filled with red bone marrow and yellow bone marrow (in other bones)
Macroscopic Spaces
Spongy bone tissue is ______________, which reduces the overall weight of a bone.
light
support and protect the red bone marrow
Trabeculae of Spongy Bone Tissue
is the only site where red bone marrow is stored
Spongy bone in the hip bones, ribs, sternum (breastbone), vertebrae, and the proximal ends of the humerus and femur
the site where hemopoiesis (blood cell production) occurs in adults.
Red Bone Marrow
blood cell production
Hemopoiesis
Blood and Nerve Supply of Bone
- Periosteal arteries
- Nutrient artery
- Metaphyseal arteries
- Epiphyseal arteries
enter the diaphysis through many interosteonic canals and supply the periosteum and outer part of the compact bone.
Periosteal arteries
passes through a hole in compact bone called the nutrient foramen
Nutrient artery
Nutrient artery passes through a hole in compact bone called the
nutrient foramen
enter the metaphyses of a long bone
Metaphyseal arteries
enter the epiphyses of a long bone
Epiphyseal arteries
carry blood away from long bones
Veins
Veins that carry blood away from long bones are evident in three places:
- One or two nutrient veins accompany the nutrient artery and exit through the diaphysis
- Numerous epiphyseal veins and metaphyseal veins accompany their respective arteries and exit through the epiphyses and metaphyses, respectively
- many small periosteal veins accompany their respective arteries and exit through the periosteum
what veins accompany the nutrient artery and exit through the diaphysis?
One or two nutrient veins
what veins accompany their respective arteries and exit through the epiphyses and metaphyses, respectively
Numerous epiphyseal veins and metaphyseal veins
what veins accompany their respective arteries and exit through the periosteum
many small periosteal veins
One or two nutrient veins accompany the nutrient artery and exit through the
diaphysis
Numerous epiphyseal veins and metaphyseal veins accompany their respective arteries and exit through the
epiphyses and metaphyses
many small periosteal veins accompany their respective arteries and exit through the
periosteum
is the ongoing replacement of old bone tissue by new bone tissue
Bone remodeling
the removal of minerals and collagen fibers from bone by osteoclasts
Bone Resorption
the addition of minerals and collagen fibers to bone by osteoblasts
Bone Deposition
Bone Resorption is the removal of minerals and collagen fibers from bone by ?
osteoclasts
Bone Deposition is the addition of minerals and collagen fibers to bone by?
osteoblasts
At any given time, about ______ of the total bone mass in the body is being remodeled.
5%
also takes place at different rates in different regions of the body
Remodeling
The distal portion of the femur is replaced about
every four months