Week 2 Lecture Flashcards
bone in greek is…
osto!
what are the 3 basic components of connective tissue?
- specialized cells
- extracellular protein fibers
- ground substance (fluid)
what 2 components make up the matrix?
extracellular protein fibers and ground substance (fluid)
what are the main functions of connective tissue
structural framework of the body
transports fluids
stores energy
protects organs
surrounds supports and connects other tissues
defends the body from microorganisms
what are the three types of connective tissue?
connective tic cue proper
fluid connective tissue
supporting connective tissue
what are fixed cells
stationary cells involved with local maintenance repair and energy storage
what are wandering cells
repair and defend damaged tissues
what are the three types of loose connective tissue?
areolar tissue
adipose tissue
reticular tissue
what is the function of dense regular connective tissue, and where is it located?
provides firm attachment; conducts pull of muscles
located between skeletal muscles and skeletal and between bones or stabilizing positions of internal organs
what is the function of irregular connective tissue? where is it located?
provides strength to resist forces applied from many directions
located in capsules of visceral organs, nerve and muscle sheaths
what are supportive connective tissue functions?
support
smooth sliding surfaces
resists compressive forces
model for future bones
intervertebral cushioning
what are the steps of appositional growth?
- cells in perichondrium differentiate into chondroblasts
- chondroblasts secrete new matrix
- new matrix enlarges & chondroblasts differentiate into chondrocytes
interstitial growth
- chondrocytes divide in a lacuna surrounded by matrix
- daughter cells secrete matrix. cells move apart creating cartilage from within
what are the three types of cartilage
hyaline
elastic
fibrous
what is the function of hyaline cartilage?
tough and flexible (weakest)
reduces friction between bony surfaces
where is hyaline cartilage located?
between tips of ribs and bones of sternum supporting the larynx, trachea, bronchi
what are some histological facts about hyaline cartilage?
hard to see collagen fibers because they are tightly packed
the matrix is translucent
what is the function of elastic cartilage?
provides support, tolerates distortion and returns to original shape
where is elastic cartilage located?
auditory canal
epiglottis
larynx
what are some histological facts about elastic cartilage?
cells are closely packed together and visible between the chondrocytes
elastic fibers in matrix, chondrocytes in lacunae
what is the function of fibrous cartilage?
resists compression
prevents bone to bone compact
absorbs shocks
where is fibrous cartilage located?
pads within knee joint (menisci)
between the pubic bones of the pelvis
intervertebral discs
what are some histological facts about fibrous cartilage?
chondrocytes are relatively dense
collagen fibers!
what are the function of the bones?
structural support
storage of minerals
hematopoeisis
protection
leverage
what are 4 types of bone cells?
osteocytes
osteoblast
osteoprogenitor cells
osteoclast
function of osteocytes
maintain the protein and mineral content of the matrix
responsible for the deposition of calcium into the surrounding matrix
where are osteocytes located
sit in depressions called lacunae
function of osteoblasts
secrete organic components of the matrix
responsible for osteogenesis - the production of new bone
where are osteoblasts located?
found in the inner or outer surfaces of bones
what is the function of osteoprogenitor cells?
heavily involved in repair of bones after a fracture
- stem cell that divides to produce osteoblasts
where are osteoprogenitor cells located?
found in the innermost layer of the periosteum
what is the function of an osteoclast?
secrete acids which dissolve bone matrix and release calcium into the blood (this process is called osteolysis
where are osteoclasts located?
located on the bone surface in lacunae
what are the two types of osseous Tissue?
compact bone and spongy (trabecular/cancellous) bone
what are characteristics of compact bone?
- dense and solid
- consists of osteons
what are characteristics of spongy (trabecular/cancellous) bone?
open network of plates, lightweight
surrounds the medullary cavity
arranged in parallel struts, forms trabeculae
what is an osteon?
a functional unit of bone
what is the function of the periosteum?
surrounds the bone and protects and communicates with other systems
what does the endosteum do?
lines the medullary cavity
describe the diaphysis
shaft or middle of the bone transfers stress from the hip to the knee
describe the epiphysis
ends of the bone, filled with spongy bone
what is the metaphysis
the neck of the bone just before the epiphysis
what are osteons parallel to?
the longitudinal axis of the body
what is ossification
process of replacing other tissue with bone
what is osteogenesis?
bone formation
what is calcification?
deposition of calcium ions into the bone tissue
what are the steps of intramembranous ossification?
(4 steps)
- differentiation of mesenchymal cells to osteoblasts
- differentiation to osteocytes & formation of spicules
- entrapment of blood vessels
- formation of spongy bone
what are the steps of Endochondral Ossification? (4 steps)
- chondrocytes enlarge
- blood vessels grow around cartilage
- blood supply to periosteum increases
- shaft fills with spongy bone
what is the difference between appositional growth and longitudinal growth?
appositional growth adds to the thickness of a tissue, while longitudinal growth adds to its length.
what factors regulate bone growth?
- nutrition
- hormones
- exercise
