Lect 6.

Types of Connective Tissue

Loose CT

consists of a number of cell types embedded in a matrix

a large amount of ground substance in which fibers are arranged in a loose irregular manner.

found in all parts of the body responsible for binding various structures

together muscle fibers to muscle fibers skin to underlying tissues. Various membranes and mesenteries

Mesentery – Loose / areolar CT

Mesenteries in the small intestine of cat.

Loose CT

comprises all the main components of CT proper. comprises all the main components of CT proper. With no predominant cellWith no predominant cell fibroblasts and macrophages - most numerous fibroblasts and macrophages - most numerous

cells, but all the other types of CTcells are also cells, but all the other types of CTcells are also presentpresent

With moderate amount of collagen, elastic, and With moderate amount of collagen, elastic, and reticular fibers reticular fibers

has a delicate consistencyhas a delicate consistency it is flexible, it is flexible, well vascularizedwell vascularized not very resistant to stress.not very resistant to stress.

Loose CT

fills spaces between groups of muscle cells

supports epithelial tissue

forms a layer that sheathes the lymphatic and blood vessels

Found in: papillary layer of the

dermis Hypodermis serosal linings of

peritoneal and pleural cavities, and in glands

mucous membranes (wet membranes that line the hollow organs) supporting the epithelial cells.

Papillary layer of the dermis – Loose CT

Dense connective tissue

adapted to offer resistance and protection

fewer cells and a clear predominance of collagen fibers

Dense CT is less flexible far more resistant to stress than is

loose CT.

Dense irregular CT

when the collagen fibers are arranged in bundles without a definite orientation.

collagen fibers form a 3-dimensional network

provide resistance to stress from all directions. dermis.

Reticular dermis: Dense irreg. CT

Blue arrow indicates the reticular dermis

Dense regular CT

The collagen bundles are arranged according to a definite pattern aligned with the linear orientation of

fibroblasts in response to prolonged stresses exerted in the same direction;

offer great resistance to traction forces. tendons (attach muscle to bone) most ligaments (attach bone to bone) aponeuroses (sheetlike tendons that attach

muscle to muscle or muscle to bone.

Tendons – Dense regular CT

elongated cylindrical structures attach striated muscle to bone

rich in collagen fibers white and inextensible have parallel, closely packed

bundles of collagen separated by a small quantity of intercellular ground substance.

fibrocytes contain elongated nuclei parallel to the fibers and sparse cytoplasmic folds that envelop portions of the collagen bundles.

Asignment: Determine the Connective Tissues types found in the following structures.

Fats in newborn Fats in the belly of

adults Tunica intima of

large artery Dermis of the skin Ear auricle Wharton’s jelly

(umbilicus) Mesentery

Splenic capsule Stem cell tissue Tendons Glisson’s capsule of

the liver Hypodermis of the

skin Precursor cells in

primitive supporting tissue

Ligaments Muscle fascia