Basic Principles - Connective Tissue Flashcards
What is the function of connective tissue (CT) ?
Protects and supports
Connects and binds
Transportation
Immunity
Repairs
What is a plasma cell?
Wandering cell
Function is to produce antibodies
Activated B-lymphocyte
Off centre (eccentric) nucleus and extensive RER
What is the structure of CT?
Cells - fixed or wandering
Gels - “ground substance”, highly hydrated gels
Fibres - collagen, reticular or elastic.
What is the structure of a fibroblast?
Fixed cell, produces the ECM
Irregulary branched cytoplasm with extensive R.E.R and golgi apparatus
What are the 3 types of fibres found in CT?
Collagen:
Provides high tensile strength and is stretch resistant
Type III reticulin is the first collagen secreted in wound healing
Reticular:
Collagen type III
Stain with silver salts
Provides a network of supporting mesh to lymphatic tissues
Elastic
Main component is elastin
Found in dermis
Elastin core covered with glycoprotein fibrillin
Provides elasticity to tissues
What are chondrocytes?
Cells of cartilage.
Develop from chondroblasts
Produce the extracellular matrix
Exists within lacunae.
What is hyaline cartilage?
Contains chondrocytes - produce and maintain the cartilage matrix
The ECM consists of a gel-like substance primarily composed of water, collagen fibers (mostly type II collagen), and proteoglycans, makes cartilage hard
Territorial matrix surrounds chondrocytes and interterritorial matrix fills spaces between chondrocytes
Functions;
Shock absoprtion - acts as a cushion between bones
Support
Flexibility
What is elastic cartilage?
Like hyaline cartilage but …
Contains abundant elastic fibres
Flexible and able to spring back into position.
What is fibrocartilage?
No perichondrium
Chondrocytes arranged in straight rows separated by type I collagen fibres
Tensile strength and shock absorption, resists compression.
What are some functions of bones?
Protects internal organs
Supports the body
Facilitates movement
Produces blood cells
Stores and releases fat
Stores and releases minerals
What are osteoblasts?
Found on the surface of bone tissue, periosteum and endosteum
Function is to produce the extracellular matrix
Gradually surrounded by matrix and become osteocytes
What are osteocytes?
Located in the lacunae
Function - maintain the bone matrix
Canaliculi - small channels that connect lacunae to each other and allow flow of nutrients + oxygen through the matrix
Mechanosensitive cells, meaning they can detect mechanical forces and respond to them by signaling changes in bone remodeling activity
What are osteoclasts?
Located in depressions on bone surface
Function - resorption of bone
Structure - multinucleate, large, cell surface facing bone is highly folded.
Describe compact bone
Structure;
* Osteons - consists of concentric layers of mineralized matrix called lamellae, which surround a central canal called the Haversian canal
* Lacunae - house osteocytes
* Interstitial lamellae
functions;
support and protection
mineral storage
blood cell production
mechanical strength
Describe spongy bone.
Bone organised into trabeculae
Lamellae arranged concentrically but no central canal
No osteons
Osteocytes sit in lacunae between lamellae
