Connective Tissue

3 Components

1. Specialized Cells

2. Protein Fibers (outside the specialized cells)

3. Fluid ground substance“semi-fluid matrix”

Examples: bone, fat, and blood

Types of Connective Tissue

A. Loose Connective Tissue (areolar)1. Structure-general

1. The least specialized tissue in the body2. Few specialized cells made up mostly of ground substance3. Contains elastin- therefore it can distort and return to its original

shape4. Also contains collagen fibers

2. Function-general1. Found underneath the skin2. Forms a layer that separates skin from deeper structures.3. Cushions shocks- provides padding4. Surrounds and supports blood vessels and nerves5. Stores lipids6. Contains tiny capillaries therefore it’s a good route for diffusion

(subcutaneous shots)

Loose Connective Tissue

Specialized Loose Connective Tissue

B. Adipose Tissue- “fat”Structure- Specialized cells called adipocytes plus a “matrix” of fluid and

protein fibers- Each adipocyte contains a fat vacuole with lipids stored in itFunction- Adipose tissues accounts for 15-30% of the normal adult

weight.- Its is an energy reserve- Padding cushions shock- Insulator- Supports tissues and organs

Adipose Tissue

Specialized Loose Connective Tissue

C. Reticular TissueStructure

- fibrous framework or “stroma”

Function

- supports the functional cells of organs

Location

- spleen, liver and lymph nodes

Reticular Connective Tissue

Dense Connective Tissue

- Is also called “collagenous tissue” or “fibrous connective tissue”

- Dominant protein fibers are collagen

- Specialized cells are called fibroblasts

- Ground substance is clear and colorless

Types Of Dense Connective Tissue

A. Dense Regular Connective Tissue- structure- collagen fibers are arranged

parallel to each other and are tightly packed fibers are aligned with forces placed on tissues.

Dense Regular Connective Tissue

• Examples:– i. Tendons-

• Structure: are similar to cords– Have large number of fibroblasts between collagen fibers

• Function: connect skeletal muscle to bone– Transfer pull of contracting muscle to bone

Tendons

Dense Regular Connective Tissue

ii. Aponeuroses and Muscle Fascia-• Structure- sheets or ribbons somewhat like

broad, flat tendons• Function- attach, stabilize, enclose and

separate muscles and other internal organs

Dense Regular Connective Tissue

iii) Elastic Tissue-• Structure- here the elastin fibers outnumber

the collagen fibers• Specialized cells are still fibroblasts

• Function- cushions shocks to body• Can stretch and rebound, expand and contract• Walls of blood vessels and respiratory passages,

stabilize position of spine.

Elastic TissueAorta

Dense Regular Connective Tissue

iv) Ligaments-• Structure- resemble tendons

• Contain elastin and collagen fibers

• Function- can tolerate a small amount of stretching

• Connect bone to bone

Types of Dense Connective Tissue

B. Dense Irregular Connective Tissue• Structure- fibers form an interwoven

meshwork that do not show a pattern• Function- provides strength to resist forces

applied to the body• Gives skin its strength• Prevents overexpansion of urinary bladder• Surrounds organs such as the kidneys and

spleen• Encloses cavities of joints

Irregular Connective Tissue

Types of Connective Tissue

C. Fluid Connective Tissue• Structure- watery ground substance or fluid matrix

called plasma• Specialized cells called “formed elements”

including:• Red Blood cells- Erythrocytes• White Blood cells- Leukocytes• Platelets

• Functions- transports oxygen and carbon dioxide• Protects against disease• Closes wounds• Transports nutrients to the cells of the body.

Types of Connective Tissue

D. Supporting Connective Tissue• Two Types:

i) Cartilage: Structure: specialized cells called Chondrocytes

fluid matrix is a firm gel

may or may not contain collagen or elastin

Types/ Funcitons:

HYALINE cartilage: covers bony surfaces and acts as “pads” between bones.

ELASTIC cartilage: connects the ribs, supports passageways, forms ears and nose.

FIBROCARTILAGE: makes up “framework” for the body of embryonic humans

Hyaline Cartilage

Types of Connective Tissue

ii) Bone- Osseous Tissue• Structure: specialized cells are called

osteocytes.• Matrix contains calcium phosphate and calcium

carbonate• Collagen fibers are predominant

• Function: is the framework for the body.• Provides support; the spinal Column, ribs, arm,

and leg bones• Provides protection; the skull, spinal column and

ribs

Osteocytes (Owl Eyes)