Week 2 Study Guide
ANAT 260 OL
Blezinski
Chapters 5, 6, 7 & 8
Chapter 5:
● Function(s) of the skeletal system:
o support
o protection
o movement
o storage
o blood cell production
● Bone is categorized as what tissue type?
o Osseous Connective Tissue
● Composition of bone:
o Organic collagen fibers and inorganic calcium phosphate
Bone cells and their function
● Osteocytes: maintains bone tissue
● Osteoblasts: builds bone tissue
● Osteoclasts: breaks down bone tissue
● Osteoprogenitor cells: stem cells for bone repair
Type of bone
● Compact bone:
o Function: support and resist stress
o Structure:dense, contains osteons
o Anatomy of the osteon:
▪ Central canal - a big tunnel in the middle with blood and
nerves to keep the bone alive
▪ Lamellae - rings around the central canal that make the bone
hard and strong
▪ lacunae - tiny for bone cells(osteocytes) sitting between the
rings
, ▪ canaliculi - tiny roads that let the bone cells talk to each
other and get food from the blood
▪ perforating canal - side tunnel that connects different osteon
so blood and nerves can travel everywhere
● Spongy bone:
o Function: reduce weight, allows space for marrow
o Structure: trabeculae with open spaces filled with bone marrow
● Periosteum:
o Location: outer surface of bones
o Function: Protects and nourishes bone, attachment for tendons/
ligaments
o Tissue Type: Dense Irregular connective tissue
o What are Sharpey’s Fibers aka Perforating Fibers? Anchor
periosteum to bone
● Endosteum:
o Location: Lines medullary cavity
o Function: Bone growth and remodeling
o Tissue Type: Thin connective tissue membrane
Bone structures:
● Epiphysis: End of long bone, contains red marrow
● Diaphysis: Shaft of long bone
● Metaphysis: Region between epiphysis and diaphysis
● Epiphyseal plate - Growth plate of cartilage
● Medullary Cavity: Central cavity in diaphysis, contains marrow
, ● Red Bone Marrow:
o Function: Blood cell production
o Components: Hematopoietic tissue
o Location: Spongy bone, sternum, pelvis
● Yellow Bone Marrow:
o Components: Fat storage
o Location: Medullary cavity of long bones
● Anatomy of Compact Bone
o Osteon: Structural unit of compact bone
▪ Lacunae - Small spaces housing osteocytes
▪ Canaliculi - tiny channels for nutrient/ waste exchange
o Concentric lamellae - layers of bone matrix around canal
o Interstitial lamellae - fills spaces between osteons
o Central canal - contains blood vessels and nerve
o Perforating canal - connects central canals transversely
● Ossification:
o Ossification center: site where bone formation begins
o Intramembranous ossification: Bone develops from mesenchymal
tissue
o Endochondral ossification: Bone replaces hyaline cartilage
● Describe how hormones regulate the bony tissue.
o Parathyroid hormone: Increases blood calcium levels by stimulating
osteoclasts
o Calcitonin: lowers blood calcium levels by inhibiting osteoclasts
o Growth Hormone: stimulates bone growth, especially at growth
plates
o Thyroxine (T4): regulates metabolism and bone growth
● How much of the human skeleton is broken down and rebuilt each year?
o Approximately 20% of the adult skeleton is replaced each year
o purpose: maintains bone strength, adapts to stress, and recycle
minerals
ANAT 260 OL
Blezinski
Chapters 5, 6, 7 & 8
Chapter 5:
● Function(s) of the skeletal system:
o support
o protection
o movement
o storage
o blood cell production
● Bone is categorized as what tissue type?
o Osseous Connective Tissue
● Composition of bone:
o Organic collagen fibers and inorganic calcium phosphate
Bone cells and their function
● Osteocytes: maintains bone tissue
● Osteoblasts: builds bone tissue
● Osteoclasts: breaks down bone tissue
● Osteoprogenitor cells: stem cells for bone repair
Type of bone
● Compact bone:
o Function: support and resist stress
o Structure:dense, contains osteons
o Anatomy of the osteon:
▪ Central canal - a big tunnel in the middle with blood and
nerves to keep the bone alive
▪ Lamellae - rings around the central canal that make the bone
hard and strong
▪ lacunae - tiny for bone cells(osteocytes) sitting between the
rings
, ▪ canaliculi - tiny roads that let the bone cells talk to each
other and get food from the blood
▪ perforating canal - side tunnel that connects different osteon
so blood and nerves can travel everywhere
● Spongy bone:
o Function: reduce weight, allows space for marrow
o Structure: trabeculae with open spaces filled with bone marrow
● Periosteum:
o Location: outer surface of bones
o Function: Protects and nourishes bone, attachment for tendons/
ligaments
o Tissue Type: Dense Irregular connective tissue
o What are Sharpey’s Fibers aka Perforating Fibers? Anchor
periosteum to bone
● Endosteum:
o Location: Lines medullary cavity
o Function: Bone growth and remodeling
o Tissue Type: Thin connective tissue membrane
Bone structures:
● Epiphysis: End of long bone, contains red marrow
● Diaphysis: Shaft of long bone
● Metaphysis: Region between epiphysis and diaphysis
● Epiphyseal plate - Growth plate of cartilage
● Medullary Cavity: Central cavity in diaphysis, contains marrow
, ● Red Bone Marrow:
o Function: Blood cell production
o Components: Hematopoietic tissue
o Location: Spongy bone, sternum, pelvis
● Yellow Bone Marrow:
o Components: Fat storage
o Location: Medullary cavity of long bones
● Anatomy of Compact Bone
o Osteon: Structural unit of compact bone
▪ Lacunae - Small spaces housing osteocytes
▪ Canaliculi - tiny channels for nutrient/ waste exchange
o Concentric lamellae - layers of bone matrix around canal
o Interstitial lamellae - fills spaces between osteons
o Central canal - contains blood vessels and nerve
o Perforating canal - connects central canals transversely
● Ossification:
o Ossification center: site where bone formation begins
o Intramembranous ossification: Bone develops from mesenchymal
tissue
o Endochondral ossification: Bone replaces hyaline cartilage
● Describe how hormones regulate the bony tissue.
o Parathyroid hormone: Increases blood calcium levels by stimulating
osteoclasts
o Calcitonin: lowers blood calcium levels by inhibiting osteoclasts
o Growth Hormone: stimulates bone growth, especially at growth
plates
o Thyroxine (T4): regulates metabolism and bone growth
● How much of the human skeleton is broken down and rebuilt each year?
o Approximately 20% of the adult skeleton is replaced each year
o purpose: maintains bone strength, adapts to stress, and recycle
minerals
