ANAT 150 Chapter 6 Lecture Notes Flashcards
Support
Bone is hard and rigid; Cartilage is flexible yet strong
Protection
Skull around brain; ribs, sternum, vertebrae
Protect thoracic cavity organs
Movement
Produced by muscles attached to bones by tendons (ex: nervous system)
Storage
Calcium & phosphate stored and released.
Adipose tissue is stored in marrow cavities.
Blood Cell Production
Bone marrow that gives rise to blood cells and platelets
What is responsible for blood cell production
Red bone marrow
What are the types of cartilage?
Hyaline cartilage (main type)
Fibrocartilage
Elastic cartilage
The fetal skeleton is made up of ______ cartilage at one point.
Hyaline
Matrix
Collagen fibers for strength
Proteoglycans for resiliency
Perichondrium
Double-layered C.T. sheath
Covers cartilage
(Outer edge surrounding layer)
Articular cartilage
Covers bones at joints; no perichondrium growth
Appositional
Growth in width or diameter
Interstitial
Growth in height
Osteoblasts
Immature bone cells forming bones through ossification or osteogenesis
Osteocytes
Mature bone cells surrounded by matrix, but can make small amounts of matrix to maintain it
Osteocytes are surrounded by a cavity or pit called a ______
Lacuna
Canaliculi
Many tiny canals are that radiate from each lacuna that has osteocyte processes
Osteoclasts
Destructive bone cells; cause bone resorption
Woven bone
Crude type bone tissue with collagen fibers randomly oriented
First bone type to form by osteoblasts during ossification
During fetal development, growth, and fracture repair
Lamellar bone
Mature type bone tissue; in sheets called lamellae
Fibers are oriented in one direction in each layer, but in different directions in different layers for strength
Bone remodeling
Osteoclasts remove old bone, osteoblasts add new
Woven bone is remodeled into lamellar bone
What bone cells are involved in bone remodeling
Osteoclasts, osteoblasts
Histological classification
(Based on tissue type)
- Trabecular (spongy/cancellous) bone
- looks cancerous but isn’t - Compact bone
Structural classification
(Based on physical appearance)
Long bone: length > width (ex: arm)
Short bone: length = width (ex: wrist)
Flat bone: width > length (ex: cranium bone)
Irregular bone: (ex: sphenoid bone)
____________ is a long bone
(2nd digit)
Finger bone
Trabecular bone
Trabeculae: Interconnecting rods or plates of bone
Like scaffolding
Compact bone
Solid, outer layer surrounding each bone; has more matrix and is denser than spongy bone
What is the functional unit of a compact bone?
Osteon/Haversian system
Central (Haversian) canal
Contains blood vessels and nerves
__________ in a lacuna with canaliculi radiating from the lacuna
Osteocytes
Perforating/volkmann’s canal
Perpendicular to long axis and contain blood vessels that run from one canal to the next
Lamellae
Calcium & phosphate
Concentric lamellae
Located within osteon
Circumferential lamellae
Located on peripheral (outer edge)
Interstitial lamellae
Located in between osteons
Sesamoid bone
Small bone embedded in a tendon/ligament or muscle near a joint (ex: knee cap)
Epiphysis
End of a bone
Epiphyseal plate
Growth plate/region
(Becomes epiphyseal line when closed off)
Diaphysis
Shaft of bone
Yellow bone marrow
Fatty tissues
Endosteum
Lining of medullary
Intramembranous ossification
Takes place in embryonic connective tissue membrane
(ex: “soft spots” of newborn skull closing)
Endochondral ossification
Takes place in cartilage
(ex: growth of long bone)
Growth in length occurs at the _________ plate
Epiphyseal/epiphysis
Between what ages is the epiphyseal plate ossified becoming the epiphyseal line?
12 & 25
Osteoblasts in bone growth in width
Osteoblasts from the periosteum lay down bone under the periosteum
Osteoclasts in bone growth and width
Osteoclasts resorb bone surrounding the medullary cavity
What causes bones to be small?
Lack of calcium, protein, and other nutrients
What is needed for the absorption of calcium?
Vitamin D
Rickets
Lack of vitamin D during childhood
Osteomalacia
Lack of vitamin D in adulthood
________ is necessary for collagen synthesis by osteoblasts
Vitamin C
Scurvy
Vitamin C deficiency
Growth hormone (GH)
From anterior pituitary
Stimulates interstitial cartilage growth and appositional bone growth
____________ (T3 & T4) are required for growth of all tissues
Thyroid hormones
Gigantism
Excessive growth hormone secretion during growing years (childhood)
Acromegaly
Excessive growth hormone-like secretion in adulthood
Dwarfism
Insufficient growth hormone during growing years (childhood)
What are the 4 stages of bone repair/healing?
- Hematoma formation
- Callus formation (fibroblasts, chondroblasts)
- Callus ossification (osteoblasts)
- Bone remodeling (osteoclasts)
Calcitonin inhibits osteoclasts, slowing bone resporption during
Hypercalcemia
PTH and calcitriol stimulate formation of osteoclasts during ___________
Hypocalcemia
Osteoporosis
Porous bones, loss of bone matrix
(Prone to fracture)