Chapter 4 Tissues and Membranes

Introduction Multicellular organisms are composed of many different types of cells. Each of these cells performs a special function. These millions of cells are grouped according to their similarity in shape, size, structure, intercellular materials and function. Cells so grouped are called tissues.

Tissues Tissues are groups of cells Tissue types Epithelial tissue Connective tissue Muscle tissue Nervous tissue

Epithelial Tissue Classification of Epithelia Squamous epithelial cells Cuboidal epithelial cells Columnar epithelial cells Endocrine gland cells Exocrine gland cells

Epithelial Tissue Functions Covering and lining tissue Squamous Cuboidal Columnar Glandular or secretory tissue Endocrine Exocrine

Connective Tissue Classification of connective tissue Adipose tissue Areolar (loose) tissue Dense fibrous tissue Supportive tissue Vascular (liquid blood tissue)

Connective Tissue Functions Adipose tissue Stores lipid Acts as filler tissue Cushions, supports, and insulates the body

Adipose Tissue

Areolar Tissue Areolar (loose) tissue Surrounds various organs and supports both nerve cells and blood vessels which transport nutrient materials (to cells) and waste (away from cells) Fibers embedded in areolar tissue include Elastin tissue Collagen

Connective Tissue Functions Dense fibrous tissue Types include: Ligaments Tendons Aponeuroses Fasciae

Supportive Tissue Supportive tissue Osseous (bone) tissue Cartilage Hyaline Fibrocartilage Elastic cartilage

Connective Tissue Functions Vascular (liquid blood tissue) Blood Lymph

Muscle Tissue Cardiac Skeletal (striated voluntary) Smooth (non-striated involuntary)

Nervous Tissue Neurons (Nerve Cells) Irritability Conductivity

Membranes Two thin layers of tissue together form a membrane Membrane classification Epithelial membranes Connective membranes

Epithelial Membranes Mucous membranes Respiratory mucosa Gastric mucosa Intestinal mucosa Serous membranes (parietal and visceral) Pleural membrane Pericardial membrane Peritoneal membrane

Connective Membranes Synovial membrane Lines joint cavities Secrete synovial fluid which prevents friction inside the joint cavity

Organs An organ is tissues grouped together to form a specific function Organs coordinate their activities to form a complete functional organism Organ system Group of organs that act together to perform a specific, related function

Organ Systems Skeletal Muscular Digestive Respiratory Circulatory Endocrine Lymphatic Nervous Endocrine Reproductive Integumentary

Tissue Repair Primary repair Secondary repair Takes place in “clean” wounds Repair over a large skin area usually results in a typical scab to help in wound healing Repair of deep tissues the edges of the wound must be brought or sewn together with sutures Secondary repair Repair of large open wounds with small or large tissue loss occurs through a process called granulation Granulation - forms new blood vessels surrounded by young connective tissue and wandering cells of different types; fibroblasts will produce new collagenous fibers; bactericidal fluid is secreted to help reduce risk of infection