BIO 141 Ch. 6 Bones
What do cells secrete in appositional growth? Where do they secrete it?
what-chondroblast cells in perichondrium secrete matrix where-matrix is secreted against the external face of existing cartilage
What is the difference between the endosteum and the endochondrium?
...
What are the five steps in endochondral ossification?
1) a bone collar forms around the existing hyaline cartilage structure (kind of makes a mold) 2) cartilage in the center of the diaphysis calcifies and then develops cavities 3) the periosteal bud invades the cavities, supplying blood and nutrients into the cavities, so that spongy bone can form 4) the diaphysis elongates and a medullary cavity forms 5) secondary ossification centers appear in the epiphyses 6) the cartilage in the epiphyses calcifies; hyaline cartilage remains only in the epiphyseal plates and the articular cartilage
What two times of life does calcification of cartilage occur?
1) during normal bone growth 2) in old age
Name the two types of ossification.
1) intramembranous 2) endochondral
What are the four steps in intramembranous ossification?
1) ossification center appears in the fibrous membrane 2) osteoblasts secrete bone matrix within the membrane 3) woven bone and periosteum (outer covering) form 4) a bone collar of compact bone forms and red marrow appears
Osteogenesis/ossification occurs three times during life. Name them.
1) when the bony skeleton forms in the embryo 2) throughout childhood into early adulthood 3) to repair and remodel bones during life
__________ ___________ requires breakdown of hyaline cartilage prior to ossification.
Endochondral ossification
Name the 6 bone markings that are depressions or openings.
FFFMSG fossa, foramen, fissure, meatus, sinus, groove
What type of tissue does bone form from in intramembranous ossification? What do you call the bone that forms in this type of ossification?
Fibrous membrane develops into bone. Bones that originate from fibrous membranes are called membrane bones.
What is the difference between the periosteum and the perichondrium?
Periosteum-a membrane that lines the outer surface of all bones, except at the joints of long bones. Perichondrium-a layer of dense irregular connective tissue which surrounds the cartilage of developing bone; Once vascularized, the perichondrium becomes the periosteum.
Name the 8 bone markings that are sites of ligament and muscle attachment.
TTTCLEPS tuberosity, tubercle, trochanter, crest, line, epicondyle, process, spine
What are the perforating canals in compact bone called?
Volkmann's canals
When cartilage grows in thickness, this is called ____________ growth.
appositional growth
What are the two types of cartilage growth? How are they different?
appositional growth and interstitial growth; appositional is growth from the outside, interstitial is growth from the inside
Which type of cell is responsible for appositional growth?
appositional-chondroblasts in the perichondrium interstitial-lacunae-bound chondrocytes inside the cartilage
What are the bone stem cells called? Where are they located? Which one type of bone cell do they give rise to?
bone stem cells are called osteogenic cells; located in periosteum and endosteum; give rise to osteoblasts
How does cartilage growth occur in interstitial growth?
chondrocytes located in lacunae in the cartilage divide and secrete new matrix, which expands the cartilage from within
Name the 4 bone markings that help to form joints.
condyle, head, ramus, facet
Which tissue surrounds skeletal cartilage and contains blood vessels to supply nutrients to it?
dense irregular connective tissue girdle of perichondrium
The process in which bone forms from hyaline cartilage is called
endochondral ossification
There are two types of tissues that undergo ossification. What are they?
fibrous membranes and hyaline cartilage
Sternum and skull bones are examples of this class of bones.
flat bones
Which ONE class of bone is membrane bones? Give two examples of membrane bones.
flat bones are the only class of bones that are membrane bones; sternum, clavicles and cranial bones are examples
Which type of stem cells do osteoclasts come from?
hematopoietic stem cells (which are the same stem cells that differentiate into macrophages); osteoclasts do not come from osteogenic cells (bone stem cells)
The epiphysieal plate and the articular cartilage are both which type of cartilage?
hyaline cartilage
Which two locations is red marrow found in in infants?
in infants-red marrow is found in the medullary cavity of long bones and in all areas of spongy bone
When cartilage grows in length, this is called ___________ growth.
interstitial growth
In bone development, what is the difference between interstitial growth and appositional growth?
interstitial growth-increases the length of long bones appositional growth-increases the thickness and is responsible for remodeling of all bones
Which class of bones are vertebrae and hip bones?
irregular bones
Which bones are long bones? Which bones are not long bones?
long bones-all limb bones except patella, tarsals, and carpals
Another name for the medullary cavity
marrow cavity
Name the four substances that are stored in bones.
minerals, growth factors, blood cells, triglycerides
Does skeletal cartilage contain blood vessels and nerves?
no
Two medical terms for bone development are
osteogenesis and ossification
What substance do cells secrete in both types of cartilage growth? So since what they secrete is the same, how are they two types of cartilage growth different (2 ways)?
same-they both secrete matrix different-cell type and location appositional-chondroblasts in perichondrium secrete matrix against external face of existing cartilage interstitial-chondrocytes inside the cartilage secrete matrix which expands the cartilage from within
Which class of bones are wrist and ankle bones?
short bones
Which bones form from hyaline cartilage?
the majority of the skeleton (except for flat bones)
What type of marrow does the medullary cavity contain in adults?
yellow marrow
