AP - Connective Tissue Overview - Chapter 4

Connective Tissue Overview

• functions to support, bind, and protect tissues and organs

• defined by their extracellular matrix (fibrous proteins and ground substance)

• highly vascularized (except cartilage, tendons and ligaments)

Ground Substance/Fibers

• medium where nutrients can diffuse to blood vessels

Connective tissue is ______ exposed to outside.

never

What are some other types of connective tissue?

cartilage, bone, fat, blood

CT Functions

• structural framework for body

• transport fluids/materials

• protect organs

• support tissue

• store energy

• defend body (immune system)

What are the 3 categories for CT?

1. CT proper

2. Fluid CT

3. Supportive CT

What are the subtypes of CT proper?

• Loose

• Dense

What are the subtypes for loose CT?

• areolar

• adipose

• reticular

What are the subtypes of dense CT?

• regular

• irregular

• elastic

What are the subtypes of supportive CT?

• bone

• cartilage

Subtypes of bone?

• compact and spongy

Subtypes of cartilage?

• hyaline

• fibro

• elastic

CT is classified as proper, supportive or _______.

fluid

All CT develops from the embryonic ________. 1st CT to develop is the _________, which all CT are derived from. the 2nd type is ___________ and is no longer present after birth.

• mesoderm

• mesenchyme

• Wharton’s jelly (mucous CT)

Loose CT has _____ cells and _______ fibers

Dense CT has _______ cells and ______ fibers.

1. more, less

2. less, more

CT proper is characterized as CT with many types of cells and _____________ fibers in ground substance.

extracellular

Fluid CT are populations of cells suspended in a _____ matrix.

• watery

Supportive CT has a less diverse cell pop. and a matrix with dense __________. They help support the weight of the body.

• fibers

What are the components of the ground substance? (3)

1. glycosaminoglycans

2. proteoglycans

3. glycoproteins

What are the 3 types of CT fibers?

1. Collagen

2. Elastic

3. Reticular

Ground substance is part of the ECM that is the space between the _____ and the fibers.

• cells

Fibroblast Cells

• always present in CT proper

• most abundant resident cells of CT proper

• secretes hyaluronan to make ground substance viscous + secretes proteins to make collagen

Fibrocyte Cell

• 2nd most abundant fixed cell in CT proper

• differentiate from fibroblasts

• help maintain CT fibers

Adipocyte Cells

• fat cells

• droplet shaped

• nucleus and organelles are pushed to the side

Mesenchymal Cells

• stem cells in CT

• they respond to injury by differentiating into different types that are needed

Melanocytes

• help determine skin color through synthesizing and storing melanin

Macrophages

• fixed or free phagocytic cells that engulf damaged cells or pathogens

Mast cells

• cells that contain histamine and heparin for inflammatory response

Basophils

• blood cells that have histamine/heparin to enhance inflammation

Lymphocytes

• important in immune response and can develop antibodies

Collagen Fibers

• most common/abundant

• long and unbranched

• extremely strong tensile strength (tendons and ligaments)

Reticular Fibers

• thinner branching fibers

• form interwoven flexible network

• help to stabilize positions of structures

Elastic Fibers

• branched and wavy fibers

• contain elastin protein

• can return to original length after stretching

• found in lungs, vocal ligaments, vertebrae