Chapter 6
Organic material consists of
Collagen and proteoglycans
-Dense solid outer layer surrounding bone -More matrix
Compact bone
The functional unit of this type of bone is an osteon (harvesian system)
Compact bone
Double layered outer layer of dense irregular connective tissue containing fibroblasts. Inner delicate layer has fewer fibers and contains chondroblasts
Perichondrium
Double layers connective tissue sheath surrounding cartilage
Perichondrium
What mineral are stored in the skeletal system?
Phosphorus, calcium, adipose tissue
Lacunae
Small space of cavity
What covers the ends of bones within some joints allowing for free movement
Smooth Cartilage
Vitamin ____ is necessary for osteoblasts to synthesize collage
Vitamin C
Entire skeleton renews every ____ years
10
Body support of the skeletal system
-Cartilage is firm and flexible in certain structures (Nose, external ear, thoracic cage, trachea) -Ligaments-holds bones together with strong bands of fibrous connective tissue
Cartilage growth where chondrocytes in perichondrium add new cartilage to the outside edge of existing cartilage
Appositional
How do bones increase in size?
Appositional growth
Two type of cartilage growth
Appositional, interstitial
Hyaline cartilage that covers ends of bone. Does not have perichondrium or blood vessels
Articular cartilage
The lamellae found in osteons are A.Circumferential Lamellae B.Concentric Lamellae C.Interstitial Lamellae
B.Concentric Lamellae
Some mesenchymal cells become A.Osteocytes B.Chondrocytes C.Stem cells D.your mom
C.Stem Cells
Each osteocyte is associated with others through __________. They receive nutrients through this because no blood vessels can penetrate the trabeculae
Canaliculi
What disease is caused by a vitamin D deficiency in children and adults?
Children-Ricketts Adults-Osteomalacia
-Form the outer surfaces of compact bone, which are thin plates that extend around the bone
Circumferential lamellae
Defect where maxillae doesn't form and is more common in males
Cleft lip
Defect where the embryonic plate fails to fuse and results in an opening in the roof of the mouth. Is more common in females
Cleft palette
How do nutrients transfer within perichondrium
Diffuse through cartilage matrix to reach chondrocytes
Ossification that starts as a hyaline cartilage model and is surrounded by perichondrium. forms the bones of the base of the skull, part of mandible
Endochondral ossification
3 types are carilage
Fibrous, hyaline, elastic
Bone with an interior framework of spongy bone between two layers of compact bone
Flat bones
Most bones in the body start out as a
Hyaline cartilage model
Inorganic Material consists of a calcium phosphate material called
Hydroxyapatite
Cartilage growth where chondrocytes in center of tissue divide and add more matrix between existing cells
Interstitial
What is formed where 2+bones come together
Joints
Chondroblasts form chondrocytes, rounded cells that occupy _______ within matrix
Lacunae
-Mature bone -has thin concentric sheets of lamellae
Lamellar bone
-Bone-building -extensive endoplasmic reticulum and numerous ribosomes
Osteoblasts
These bone cells secrete matrix vesicles, and contain high concentrations of CA2+ and PO43- which forms hydroxyapatite crystals
Osteoblasts
What bone cells produces collagen and proteoglycans which are packed into vessicles by the golgi apparatus and secreted by exocytosis
Osteoblasts
Cells that can become osteoblasts or chondroblasts that are located in the inner layer of the perichondrium and in layers of connective tissue that cover bone
Osteochondral progenitor cells
-Bone destroying -large multinucleated cells -These mature cells carry out bone reabsorption by accessing bone matrix. ---When they come in contact with bone surface they form attachment structure via interaction with the protein integrin, after structures called podosomes develop and forms a ruffled border
Osteoclasts
What cells are derived from stem cells in red bone marrow
Osteoclasts
Bone cell that is connected to others through cell extension and housed within the bone matrix in lacuna. Also have cell extensions housed in canaliculi
Osteocytes
Brittle bone disorder and have mutations that yield reduced or defective type one collagen
Osteogenesis imperfecta
____ delivers blood to the central canals of osteons and run perpendicular to central canals
Perforating canals
_____ contains blood vessels from periosteum and medullary cavity
Perforating canals
What disease is caused by a Vitamin C deficiency
Scurvy
Bone with a compact bone surface surrounding a spongy bone center with small spaces filled with marrow. -not elongated and do not have a diaphysis
Short and irregular bones
-Porous bone with less bone matrix -has interconnecting rods/plates called trabeculae and between that is spaces filled with bone marrow and blood vessels
Spongy bone
Thin and consist of several lamella with osteocytes located in lacunae between lamellae
Trabeculae
2 bones formed during ossification
Woven and lamellar bone
-First type of bone osteoblasts form during ossification -Fairly weak and collagen fibers are randomly oriented
Woven bone
Nutrition and hormones are factors that
affect bone growth
If amount of collagen is reduced and mineral is the primary constituent the bone will be
brittle
The flexible strength of bone occurs because of
collagen fibers
Hormones that affect bone growth
growth hormone, thyroid hormone, sex hormones
at the 5th week of development, embryonic mesenchyme condenses around the brain to form a membrane of connective tissue with randomly oriented collagen fibers (will eventually become cranial bones). Stops at age two
intramembranous ossification
If mineral in bone is reduced, collagen is the primary constituent and the bone will be
overly flexible
Air filled spaces lined with mucous membranes
sinuses
Functions of the skeletal system
support, protection, movement, storage, blood cell production