Chapter 6: Tissues and Membranes

Copyright © 2007 by Saunders, an imprint of Elsevier Inc. Lesson 6.1 Objectives List the four basic types of tissues. Describe the functions of epithelial tissue. Explain how epithelial tissue is classified. Differentiate between endocrine and exocrine glands. Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Copyright © 2007 by Saunders, an imprint of Elsevier Inc. Types of Tissues Tissues: groups of cells that are similar to one another in structure and function Histology: study of tissues Four major types of tissues: Epithelial Connective Nervous Muscular Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Epithelial Tissue Functions Protection Absorption Filtration Secretion Transportation Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Epithelial Tissue Traits Forms continuous sheets, like floor tiles Outer surface is unattached Undersurface is attached to basement membrane Avascular: no independent blood supply Well-nourished and regenerates quickly Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Types of Epithelial Tissue Classification according to shape: Squamous Cuboidal Columnar Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Types of Epithelial Tissue (cont’d.) Classification according to number of layers: Simple epithelium Stratified epithelium Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Types of Epithelial Tissue (cont’d.) Simple epithelia: Simple squamous epithelium Simple cuboidal epithelium Simple columnar epithelium Pseudostratified columnar epithelium Stratified epithelia: Stratified epithelia Transitional epithelia Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Types of Epithelial Tissue (cont’d.) Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Types of Epithelial Tissue (cont’d.) Glandular epithelia: Exocrine glands Endocrine glands Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Copyright © 2007 by Saunders, an imprint of Elsevier Inc. Lesson 6.2 Objectives Describe the functions of connective, muscle, and nervous tissue. List the types of epithelial and connective tissue membranes. Differentiate between mucous and serous membranes. Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Connective Tissue Functions Connection Support Protection Fat storage Transportation Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Connective Tissue Traits Most connective tissues are well-vascularized Exception: tendons and ligaments have poor blood supply, and cartilage has no blood supply These heal slowly Type of intercellular matrix varies Presence and amount of protein fibers varies Collagen Elastin Reticular fibers (fine collagen) Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Types of Connective Tissue Loose connective tissue Areolar tissue: surrounds, protects, and cushions many organs Adipose tissue: stores fat, helps regulate body temperature, deposited around certain organs Reticular connective tissue: framework for lymphoid tissue such as spleen, lymph nodes, and bone marrow Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Types of Connective Tissue (cont’d.) Dense fibrous connective tissue Tendons: attach muscles to bone Ligaments: attach bones to one another Capsules: enclose some organs such as kidney and liver Fascia: sheets that cover muscles, blood vessels, and nerves, and cover, support, and anchor organs Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Types of Connective Tissue (cont’d.) Cartilage Chondrocytes: cartilage cells Most cartilage is covered by perichondrium Types of cartilage: hyaline, elastic, and fibrocartilage Bone Also known as osseous tissue Protects organs, supports weight, stores minerals Blood: blood cells surrounded by plasma Lymph: fluid in lymphatic vessels Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Copyright © 2007 by Saunders, an imprint of Elsevier Inc. Connective Tissue Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Copyright © 2007 by Saunders, an imprint of Elsevier Inc. Nervous Tissue Nervous tissue: makes up the brain, spinal cord, and nerves Two types of cells: Neurons Neuroglia Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Copyright © 2007 by Saunders, an imprint of Elsevier Inc. Muscle Tissue Muscle tissue: composed of cells (fibers) that shorten or contract to cause movement of a body part Three types of muscle: Skeletal muscle Smooth muscle Cardiac muscle Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Muscle Tissue (cont’d.) Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Copyright © 2007 by Saunders, an imprint of Elsevier Inc. Tissue Repair Two types of tissue repair: Regeneration: replacement of tissue via mitosis by cells identical to original cells Fibrosis: replacement of injured tissue with fibrous connective tissue Keloid scarring: excessive fibrosis Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Tissue Repair (cont’d.) Steps in tissue repair: Wound Clot and scab Tissue repair begins Scar tissue forms Epithelial cells multiply Scab detaches; regenerated layer is over scar tissue Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Copyright © 2007 by Saunders, an imprint of Elsevier Inc. Membranes Membranes: thin sheets of tissue that cover surfaces, line body cavities, and surround organs Classification of membranes: Epithelial Connective tissue Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Copyright © 2007 by Saunders, an imprint of Elsevier Inc. Cutaneous Membranes Outer layer: epidermis, formed of stratified squamous epithelium Inner layer: dermis, formed of fibrous connective tissue Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Copyright © 2007 by Saunders, an imprint of Elsevier Inc. Mucous Membranes Line all body cavities that open to the exterior of the body Adapted to enable absorption and secretion Mucus is secreted to lubricate and moisturize Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Copyright © 2007 by Saunders, an imprint of Elsevier Inc. Serous Membranes Pleura Parietal pleura line wall of thoracic cavity Visceral pleura cover each lung Pericardium: around heart Peritoneum Parietal peritoneum lines abdominal cavity walls Visceral peritoneum covers organs Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.