Types of Connective Tissues Prof. Dr. Malak A. Al-yawer

Department of Anatomy/ Histology Section

Objective

At the end of this lecture, the 1st medical student will be able to

Define the different types of connective tissue

Distinguish between the different types of connective tissues

Describe the components of adipose tissue and compare between its two types

Draw a diagram illustrating the types of connective tissue

State few related disorders

Connective Tissue Proper

Two classes

1. loose

2. dense

Loose connective tissue

No predominant

element

papillary layer of the

dermis,

hypodermis ,

linings of peritoneal

and pleural cavities,

glands

mucous membranes

Dense connective tissue

offer resistance and

protection.

fewer cells

clear predominance

of collagen fibers

Dense connective

tissue 1.1. Dense irregular connective tissue

dermis.

2. Dense regular connective tissue

Tendons, ligaments

Elastic Tissue

yellow color and

great elasticity.

yellow ligaments of

the vertebral column,

suspensory ligament

of the penis.

Reticular Tissue

hematopoietic

organs and lymphoid

organs

Mucous Tissue

abundance of

ground substance

few fibers.

umbilical cord, pulp

of young teeth.

Adipose Tissue

Adipose cells can be found

isolated or in small groups

in large aggregatesadipose tissues.

Adipose tissue represents

15-20% of the body weight in men of

normal weight

20-25% of body weight in women of

normal weight

Two types of adipose tissue

Multilocular (brown)

adipose tissue

composed of cells that

contain numerous lipid

droplets and abundant

brown mitochondria.

have a rich blood supply.

Unilocular (common,

yellow) adipose tissue

composed of cells that

contain one large central

droplet of yellow fat in

their cytoplasm.

have a rich blood supply

Unilocular adipose cells

spherical (isolated),

polyhedral (closely packed)

(the signet ring cell).

have eccentric and

flattened nuclei.

Photomicrograph of unilocular adipose

tissue of a young mammal.

Arrowheads show

nuclei of adipocytes

(fat cells)

compressed against

the cell membrane.

Multilocular Adipose Tissue

(Brown adipose tissue)

brown color

In humans,

important in the first

months of postnatal lifer

greatly reduced in

adulthood.

Distribution of adipose tissue. In a human newborn, multilocular adipose tissue

constitutes 2-5% of the body weight and is distributed as shown. The black areas indicate

multilocular adipose tissue; shaded areas are a mixture of multilocular and unilocular

adipose tissue.

Multilocular tissue cells

cytoplasm contains

a great number of

lipid droplets of

various sizes

spherical and central

nucleus,

numerous

mitochondria with

abundant long

cristae.

Development of fat cells

Undifferentiated

mesenchymal cells

are transformed into

lipoblasts

mature fat cells may

return to the

lipoblast stage.

Lipomas & liposarcomas

Unilocular adipocytes can generate very common benign tumors called lipomas.

Malignant adipocyte-derived tumors (liposarcomas) are not frequent in humans.

Types of Connective Tissue

Summary

Connective tissue consists of CT proper, CT with special

properties and supporting CT

Two types of CT proper can be recognized Loose & dense

Cartilage and bones are supporting CT

Mucous Tissue, elastic tissue, hematopoietic tissue and

adipose tissue are CT with special properties

Two kinds of adipose tissue can be recognized: Unilocular

& multilocular adipose tissues

Thank you