Lecture 2 Connective Tissue (general) (fibers)

What are the four types of connective tissue?

Connective Tissue Proper (fat/fibrous)

Skeletal (bone)

Cartilage

Blood

Components of connective tissue.

Cells

Matrix

Ground Substance

Characteristics of Connective Tissue

Small number of cells

Large amount of Matrix

Ground substance

Originates from mesenchymes

Connective Tissue cells contain

Fibroblast (Fibrous tissue)

Chondroblast (Cartilage)

Osteoblast (Bone)

Fat (Adipose)

WBC (White blood cells)

Macrophage (kills stuff and worker)

Mast Cell (contains chemicals which trigger inflammation and allergic responses against Pathogens)

Connective Tissue Matrix is made out of three fibers…

Collagen

Elestin

Reticular

Difference between fibers and cartilage

(in minecraft terms)

Cartilage is like a a wood house

Fiber is like a wooden plank

Cartilage is it’s own structure

While fiber is just a building material for something else in this case (matrix)

Collagen Fiber Function

Structural support (holds stuff together and in place)

Tensile Strength (resist stretch)

Connective Tissue Component (main tissue)

Bone Health (main structural framework, giving it strength and withstanding stress)

Skin elasticity (collagen helps maintain firm skin, look younger)

Regeneration (tissue repair, scar formation boo… attracts cells needed for healing and provides scaffold for new tissue growth)

Major component for many things

Joint health

Organ support

Immune system support (amino acids in collagen are essential for immune system) (Also blocks stuff)

Collagen fibers location!

• Bone: Provides scaffolding and durability. 

• Tendons & Ligaments: Arranged in parallel to provide high tensile strength. 

• Skin: Found in the dermis, providing strength and structure. 

• Cartilage: Contributes to the structure of cartilage, such as in the nose and ears. 

• Blood Vessels: Forms a supportive network within arteries and other vessels. 

• Organs: Supports the structure of many internal organs. 

• Cornea: Type I collagen provides strength to the transparent outer layer of the eye. 

What are collagen fibers the building blocks of?

• Tendons & ligaments (strength)

• Dermis of skin (support, durability)

• Cartilage (flexibility + support)

• Bone (strength + framework for minerals)

• Areolar & reticular tissues (soft support)

• Scars & basement membranes (repair + anchoring)

Elestin Fiber function is to

provide elasticity and recoil (useful in lungs too)

support tissue structures

allows organs to withstand blood flow (like blood vessels like arteries)

It’s what allows things to stretch, like doing yoga or smth

Where tf is it found?

Skin dermis

Lungs

Blood Arteries

Ligaments, particular in the spine

Cartilage

Tissue

Reticular fiber function (had no idea what this was for a while)

• Structure: Unlike the thick, straight bundles of collagen fibers, reticular fibers are thin, delicate, and highly branched, forming a net-like pattern.

• basically just structure

Where? 🤔🤔

Stroma of the spleen,

lymph nodes, (kidney bean tissue)

red bone marrow,

liver,

kidneys.

What the hell is the Extracellular Matrix (ECM)?

The ECM is what makes connective tissue connective.

It’s a gel-like substance

It’s a non-living framework that provides mechanical and structural support. It’s non-living because the protein structures, and the ground substance isn’t living, also thus why it is avascular.

Is made out of the three fibers, collagen, elastin (or elastic?), and reticular, which give it its strength, stretch, and cushioning.

It also determines the tissue properties, such as whether it is rigid or soft.

It uses a “ground substance” which fills up the “empty space” often visualized. as a blank space.

It’s found ANYWHERE IN CONNECTIVE TISSUE. bone, blood, cartilage, etc

So what are the three things the ground substance is made of?

It’s made of three things,

proteoglycan (attract water, resist compression, hydrate cells)

glycosaminoglycan (bind water to provide firmness to cells)

glycoprotein (helps cells attach to the ECM)

and the ground substance’s function?

It cushions and supports cells

Fills space

Allows exchange of nutrient and waste diffusion between cells and blood

Regulates cell behavior, growth, migration, and differentiation

Remember the animated videos of blood cells moving through the tubes or veins? the empty space is the ground substance/matrix