Chapter 6 and 7: Bones And Skeletal Tissue Flashcards
What 3 things do the skeletal system contain?
- Bones
- Cartilage
- Joints
What are the 3 types of cartilage in the bone?
- Hyaline
- Elastic
- Fiberocartilage
What are the functions of the bone?
- Support
- Protection
- Movement
- Mineral and growth factor storage
- Blood cell formation
- Triglyceride (fat) storage
- Hormone production
Support
For body and soft organs
Protection
Protect brain, spinal cord, and vital organs
Movement
Levers for muscle action
Mineral and growth factor storage
Calcium and phosphorus, and growth factors reservoir
Blood cell formation
Hematopoiesis occurs in red marrow cavities of certain bones
Triglyceride (fat) storage
Fat, used for an energy source, is stored in bone cavities
Hormone production
Osteocalcin secreted by bones helps to regulate insulin secretion, glucose levels, and metabolism
What are the 4 major cells of the bone tissue?
- Osteogenic cells
- Osteoblasts
- Osteocytes
- Osteoclasts
Osteogenic cells
- Active stem cells
- Differentiate into osteoblasts or other bone cells (stimulated)
- Some stay the same
Osteoblasts
Function: Bone-forming cells that secrete osteoid
- Actively mitotic
Osteoid
Unmineralized bone matrix
Osteocytes
- Mature bone cells that don’t divide (in lacunae)
- Maintain bone matrix and stress/ strain sensors
- Communicate info to osteoblasts and osteoclasts for bone remodeling
Osteoclasts
- Giant, multinucleate
- Function: breaking down of bone
- Increase surface area for enzyme degradation of bone (from ruffled borders of cells)
Compact Bone
Dense outer layer on every bone that appears smooth and solid
Spongy Bone
Made up of a honeycomb of small, needle-like or flat pieces of bone
- Appears poorly organized but is organized along lines of stress to help with bone resistance to stress
- Trabeculae
Trabeculae
Needle-like or flat pieces of bone
- like cables on a suspension bridge, confer strength to bone
(No osteons are present)
What does compact bone consist of?
- Osteon (Haversian system)
- Canals and canaliculi
- Interstitial and circumferential lamellae
Osteon (Haversian system)
- the structural unit of compact bone
- consists of an elongated cylinder that runs parallel to long axis of bone
- Osteon cylinder consists of several rings of bone matrix
Lamellae
Rings of bone matrix
Canals and canaliculi
- Central (Haversian) canal runs through ore of osteon (blood vessels and nerve fibers)
- Lacunae
- Canaliculi
(Both allow communication)
Lacunae
Small cavities that contain osteocytes
Canaliculi
Hairlike canals that connect lacunae to each other and to central canal
Interstitial and circumferential lamellae
Lamellae that are not part of osteon
- Some fill gaps others are remnants of osteon scut by bone remodeling
Suture
A seamlike immovable junction between 2 bones
Meatus
Tubelike opening or channel
Foramen
Round hole for vessels and nerves
Condyle
Rounded bump; usually fits into a depression on another bone to form a joint
Spine
Sharp, pointed process
Body
The main or central portion of a bone
Epicondyle
Bump near a condyle; often gives the appearance of a “bump” on a bump
Head
Distinct epiphysis on a long bone, separated from the shaft by a narrowed portion (or neck)
Neck
A narrowed portion, usually at the base of a head
Tuberosity
Oblong, raised bump
