BODY TISSUESThe four main types of body tissues are:

1) Epithelium – Sheets of tissue that line and cover, provide protection specialized for absorption/secretion

2) Connective – Provide support and framework.3) Muscle – Provide movement4) Nervous – Provide communication

CONNECTIVE TISSUES• These tissues are the most

abundant tissues in the body and they show the most variation in their functions.

• May act to build structures, connect one tissue to another, anchor structures, support, defense, transportation and protection.

With That Much Diversity – What Do They Have In Common?

• Connective tissues differ from epithelial tissues in both their arrangement and in the amount and type of intercellular material -MATRIX (material found between cells)

Connective Tissue Composition

1. Tend to have few cells in comparison to the amount of space the tissue occupies.

2. Extracellular matrix (non-living material secreted by cells) is found between the living cells.

• The matrix and fibers found between the cells is ultimately what determines the qualitative characteristics of that connective tissue.

Common Types of Connective Tissues

1.Areolar – Adhesive connective tissue.

2.Adipose – Fatty tissue consisting of adipocytes.

3.Fibrous Connective Tissue – Forms tendons to attach muscle to bones.

4.Bone – Living cells that secrete calcium deposits.

5.Cartilage – Chondrocytes lay out gristle-like gel matrix.

6.Blood – Erythrocytes (red), leukocytes (white) and thrombocytes (platelets) in a fluid matrix (plasma).

7.Hemopoietic – Found in red bone marrow cavities, produces new blood cells.

AREOLAR

-STRUCTURE and FUNCTION:

-This connective tissue forms the “GLUE” for other tissues. Has gel-like matrix with several different types of fibers in gel for reinforcement.

-Wraps and cushions organs, holds tissues together.

ADIPOSE

-STRUCTURE and FUNCTION:

-Small amounts of gel-like matrix in between closely packed adipocytes (fat cells)

-Provides reserve food fuel, insulates body against heat loss, and provides padding.

LIPOSUCTION – The removal of adipose tissue

FIBROUS CONNECTIVE TISSUE

-STRUCTURE and FUNCTION:

- Cells synthesize and secrete collagen protein fibers that run parallel to each other.

-Attach muscles to bones (TENDONS), attach bones to bones (LIGAMENTS). Strong and flexible but no ability to stretch.

Collagen :stronger than wire

BONE

-STRUCTURE and FUNCTION:

- Osteocytes (bone cells) secrete calcified matrix, which has many channels for vascularization.

-Bones support and protect, provides levers for muscle contraction to work on, stores calcium and other minerals, stores marrow for blood cell formation.

CARTILAGE

-STRUCTURE and FUNCTION:

- Chondrocytes (cartilage cells) produce and secrete a gristle-like matrix surrounding themselves.

-Cartilage acts to support and reinforce joints, acts to cover and cushion bones at the joints.

BLOOD

-STRUCTURE and FUNCTION:

- Red and white blood cells along with cell fragments (platelets) in a fluid matrix called plasma.

- Erythrocytes and plasma transport respiratory gases (O2 and CO2), nutrients, wastes and other substances (hormones)

-Leukocytes = Fight infection Thrombocytes = Clotting

HEMOPOIETIC

-STRUCTURE and FUNCTION:

- Blood stem cells found in spleen, tonsils, red bone marrow, lymph nodes. Stem cells found closely packed together in a liquid matrix

-Blood cell formation