Skeletal System (KT) Flashcards
What are the 2 divisions of the skeletal system?
- Axial
2. Appendicular
What components make up the axial skeleton?
Head, center of body, skull, ribs, vertebral column
What components make up the appendicular skeleton?
Movements, limbs, pelvis
2 types of bone tissue
- Compact
2. Spongy
How much percent of total body mass are the bones?
20%
Components of the skeletal system? (4)
- Cartilage
- Bone
- Tendons
- Ligaments
Functions of skeletal system? (5)
- Protection
- Support (rigid support)
- Movement (bones act as levers)
- Storage (Ca, P, and fat)
- Blood cell production
Cartilage cells are called…
Chondrocytes
Where are chondrocytes found…?
Chondrocytes are found in compartments called lacunae
What is the extracellular matrix of cartilage?
- Collagen and elastic fibers
- Ground substance of chondroitin sulfates
Does cartilage have arteries, veins, or lymphocytes?
No.
- That’s why it heals slowly- because not a lot of nutrients getting in
What types of cartilage are there…? (3)
- Hyaline
- Elastic
- Fibrocartilage
Cartilage that…
- is the most common
- weakest concerning tensile strength
- found in places that can be compressed
- lack fibers
Hyaline Cartilage
Hyaline Cartilage Structure (3)
- Chondrocytes
- Chondroitin
- Some collagen
Location of Hyaline Cartilage (5)
- Embryonic Skeleton
- Articular surfaces
- Respiratory passages
- Nasal Septum
- Between ribs and sternum
Cartilage that…
- is elastic yet still needs compression
- flexible, maintains shape but recoils and pushes back
- Ex. nose, ear, epiglottis
Elastic Cartilage
Elastic Cartilage Structure (3)
- Chondrocytes
- Chondroitin Sulfate
- Densely packed elastic fibers
Locations of Elastic Cartilage
- nose,
- ear
- epiglottis
Cartilage that…
- is very strong
- need tensile resistance AND compression resistance
Fibrocartilage
Structure of Fibrocartilage (3)
- Chondrocytes
- Chondrotin Sulfate
- Densely packed collagen fibers
Location of Fibrocartilage (3)
- Intervertebral Disc
- Pubic Symphysis
- Articular Cartilage in Knee
Fibrous connective tissue that surrounds cartilage
Perichondrium
What does perichondrium provide…? (2)
- Support & Protection
2. New Chondrocytes
Locations of Perichondrium (2)
- Hyaline Cartilage
2. Elastic Cartilage
Where is perichondrium absent from…? (2)
- Articular surfaces
2. Fibrocartilage
How many layers does the perichondrium have?
2
What are the layers of the perichondrium?
- Outer
2. Inner
Binds cartilage to adjacent tissues; provides support and protection
Outer layer of perichondrium
Layer for growth and maintenance
Inner layer
- Have cartilage, it expands outward by growing from its own ledge
- this is facilitated by the perichondrium
Appositional Growth
Appositional Growth Steps (6)
- Starts in the Perichondrium
- Mesenchymal (stem) cells at periphery form in inner layer of perichondrium
- Mesenchyme move toward the matrix to become chondrogenic cells
- Chondrogenic cells aggregate and become chondroblasts
- Chondroblasts secrete ,matrix and force cells apart
- Chondroblasts become enclosed in matrix and become chondrocytes
Is Appositional Growth a Fast or a Slow Process?
Slow- because there is no blood supply, oxygen, and glucose
- Internal cartilage growth
- Chondrocytes are enclosed in matrix and divide
- As they move apart, the matrix forms between them
Interstitial Growth
Characteristics of Osseous Tissue (3)
- Supportive CT
- Contains specialized cells
- Solid extracellular matrix
Solid Extracellular Matrix
fibrous
-Osteoid
What components make up the osteoid? (2)
- Organic Portion
2. Protein fibers
Ground Substance of Osseous Tissue
- Ca salts (forms mineralized salts
- water
- Mesenchyme bone cell
- Predecessor to osteoblasts
- Play a role in initial bone growth and fracture repair
Osteoprogenitor
Bone cell that…
- Is derived from osteogenic cells
- secrete osteoid
- common in growing bone
- predecessor to osteocytes
- Increased osteoblast activity=stronger bone
Osteoblasts
Bone cells that... -Are mature cells -Exist within matrix -Maintain Ca and PO4 homeostasis -
Osteocytes
Bone cells that…
- involved in the breakdown of bone
- very large
- increased osteoclast activity –> weaker bone
Osteoclast
How are osteoclasts formed?
Formed by the fusion of many white blood stem cells
Inorganic Materials of Bone Matrix
- 65%
- Brittle Salts
- Na, K, Mg
Organic Materials of Bone Matrix
- Osteoid
- 35%
- Flexible Fibers aka collagen, glycoproteins, and proteoglycans
How are compact bones arranged?
Osteons