Chapter 6 (I) Flashcards
what type of cartilage contains no blood vessels or nerves?
skeletal cartilage
what does water lend in skeletal cartilage?
lend resiliency
what surrounds the skeletal cartilage and contains blood vessels for nutrient delivery?
perichondrium
what does perichondrium resist?
outward expansion
all skeletal cartilages contain ______ in lacunae and extracellular matrix.
chondrocytes
what cartilage provides support, flexibility, and resilience?
hyaline cartilage
what fibers do hyaline cartilage contain?
collagen ONLY
what type of cartilage is found in the articular, costal (ribs), respiratory, and nasal cartilage?
hyaline cartilage
what fibers do elastic cartilage contain?
elastic fibers
what cartilage is found in the external ear and epiglottis?
elastic cartilage
what type of cartilage do fibrocartilage have?
thick collagen fibers
what cartilage is found in the menisci of knee and vertebral discs?
fibrocartilage
what cartilage growth has cells secrete matrix against external face of existing cartilage?
appositional growth
what cartilage growth has chondrocytes divide and secrete new matrix, expanding cartilage from within?
interstitial growth
what occurs during normal bone growth and hardens cartilage?
calcification
what shapes are bones classified by?
long, short, flat, irregular
what are the functions of bones?
mineral and growth factor storage blood cell formation in red marrow fat storage in bone cavities hormone production support, protection, movement
what regulates bone formation, protects against obesity, glucose intolerance, and diabetes mellitus?
osteocalcin
how are bones considered organs?
contain different types of tissues
what are 2 different bone textures?
compact and spongy
what bone has a dense outer layer that is smooth and solid?
compact bone
what bone has a honeycomb of flat pieces of bone deep to compact called trabeculae?
spongy bone
what structure of bone does this describe?
thin plates of spongy covered by compact
plates sandwiched btwn connective tissue membrane
no shaft/epiphyses
bone marrow throughout spongy
hyaline cartilage covers articular surfaces
short, irregular, and flat bones
what structure of bone does this describe?
tubular shaft forms long axis
compact surround medullary cavity
diaphysis long bone
what structure of bone does this describe?
bone ends
external compact, internal spongy
articular cartilage covers articular surface
btwn epiphyseal line
epiphyses long bone
what is a epiphyseal line
remnant of childhood bone growth at epiphyseal plate
what has a white, double layered membrane and many nerve fibers and blood vessels?
periosteum
what does the periosteum cover?
external surfaces except joint surfaces
what does the outer layer of the periosteum have?
dense irregular connective tissue
sharpey’s fibers
what does the osteogenic layers of the periosteum contain?
primitive stem cells (osteogenic cells)
periosteum is an anchoring point for ______ and ______.
anchoring point for tendons and ligaments
what layer abuts the bone?
osteogenic layer
what fiber secures the bone matrix?
sharpey’s fibers
what has a delicate connective tissue membrane covering internal bone surfaces?
endosteum
what does the endosteum cover?
what does the endosteum line?
covers trabeculae of spongy bone
lines canals that pass through compact bone
what cells do endosteum contain and what can they do?
contain osteogenic cells and can differentiate into other bone cells
what is found within trabecular cavities of spongy bone and diploe of flat bones?
red marrow
where is red marrow found in newborns?
medullary cavities and spongy bones
where is red marrow found in adult bones?
femur and humerus
which bones have little red marrow?
adult long bones
where is red marrow most active?
diploe and irregular bones
yellow marrow can be converted to what when necessary?
red marrow
what are sites of muscle, ligament, and tendon attachment on external surfaces?
bone markings
what are the 3 categories of bone markings?
projections
depressions
openings
what are conduits for blood vessels and nerves?
bone markings
what bone marking indicates stresses created by muscle pull or joint modifications?
projections
what bone marking usually allows nerves and blood vessels to pass?
depressions and openings
what are the 5 major cells of bone tissue?
- osteogenic cells
- osteoblasts
- osteocytes
- bone lining cells
- osteoclasts
osteogenic cells (osteoprogenitor cells)
mitotically active stem cells in periosteum and endosteum
what happens when osteogenic cells are stimulated?
differentiate into osteoblasts or bone lining cells or some persist as osteogenic cells
osteoblasts
bone forming cells
actively mitotic
what do osteoblasts secrete?
unmineralized bone matrix or osteoid
includes collagen and calcium binding proteins
osteocytes
mature bone cells in lacunae
what do osteocytes monitor and maintain?
bone matrix
what cells act as stress or strain sensors?
osteocytes
what cells respond to and communicate mechanical stimuli to osteoblasts and osteoclasts so bone remodeling can occur?
osteocytes
bone lining cells
flat cells on bone surfaces
help maintain matrix
periosteal cells (bone lining cells) are located on what?
external bone surface
endosteal cells (bone lining cells) line what?
line internal substances
where are osteoclasts derived from? and what do they become?
derived from hematopoietic cells
become macrophages
osteoclasts
giant, multinucleate cells for bone resorption
when actively resorbing (breaking down) bone, where do osteoclasts lie?
lie in a shallow depression they have carved out
what cell has a distinctive ruffled border that increases surface area for enzyme degradation of bone and seals off area from surrounding matrix?
osteoclasts
what is the structural unit of the compact bone?
osteon
what is an elongated cylinder that is parallel to the long axis of bone?
osteon
what are the hollow tubes of bone matrix called?
lamellae
why do collagen fibers in adjacent rings of lamellae run in different directions?
to withstand stress and resist twisting
what runs through the core of the osteon and contains blood vessels/nerve fibers?
central canal or haversian canal
what canals are lined with endosteum at right angles to the central canal?
perforating (volkmann’s) canals
what do perforating (volkmann’s) canals do?
connect blood vessels and nerves to periosteum, medullary cavity, and central canal
what are small cavities that contain osteocytes?
lacunae
what are hairlike canals that connect lacunae to each other and central canal?
canaliculi
how do osteoblasts secreting bone matrix maintain contact with each other and osteocytes?
cell projections with gap junctions
when do the canaliculi form?
when matrix hardens and cell are trapped
what allows communication and permits nutrients and wastes to be relayed from 1 osteocytes to another throughout osteon?
canaliculi
what is an incomplete lamellae, not part of a complete osteon?
interstitial lamellae
interstitial lamellae either fills gap between ______ or are remnants of ______ that have been cut through by bone remodeling.
fills gap between forming osteons
remnants of osteons that have been cut through by bone remodeling
what is located just deep to periosteum, superficial to endosteum, and extend around entire surface of diaphysis?
circumferential lamellae
what does circumferential lamellae do?
resist twisting of long bone
which bone appears to be poorly organized?
spongy
where do trabeculae align?
align along lines of stress
which bone has no osteons?
spongy
which bone has irregularly arranged lamellae and osteocytes interconnected by canaliculi?
spongy
what do capillaries in the endosteum supply?
nutrients
what is an osteoid and what is it made of?
what is it: 1/3 of organic bone matrix
what is it made of: ground substance and
collagen fibers
what do osteoids provide?
structure, strength, flexibility
resilience of bone is due to ______ in or between collagen molecules.
sacrificial bonds
why do sacrificial bonds stretch and break easily on impact?
to dissipate energy and prevent fracture
what happens to sacrificial bonds if there is no additional trauma?
bonds re-form
what does the organic component of the bone contain?
cells and osteoid
what does the inorganic component of the bone contain?
hydroxyapatites (mineral salts)
what are hydroxyapatites (mineral salts) mainly made of?
tiny calcium phosphate in/around collagen fibers
what are hydroxyapatites (mineral salts) responsible for?
hardness/resistance to compression
what is half as strong as steel in resisting compression?
what is as strong as steel in resisting tension?
bone
why do bones last long after death?
mineral composition
what do bones reveal?
info about ancient people
what do bones display?
growth arrest lines- horizontal lines on bones that provide proof of illness
