1. Tissues: An Overview

2. Overview of Tissue Science Tissues are groups of cells and extracellular material that perform a specific group of functions. The four tissue types, in different combinations, form all of the structures of the human body. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

3. Overview of Tissue Science Histology The study of tissues Four Basic Tissue Types ◦ Epithelial ◦ Connective ◦ Muscular ◦ Neural We use these to build organs* Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

4. Overview of Tissue Science An Orientation to the Tissues of the Body

5. Epithelial Tissue Functions of Epithelia ◦ Physical protection ◦ Permeability control ◦ Sensation trigger ◦ Specialized secretions Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

6. Epithelial Tissue Characteristics of Epithelia ◦ Cells closely packed ◦ Has a “top and bottom”  Apical cells exposed to external or internal surface (“checkers”)  Cells attached to basement membrane ◦ Lack blood vessels (avascular) ◦ Cells continually replaced Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

7. Epithelial Tissue Epithelium An avascular layer of cells that forms a barrier that covers internal or external surfaces Glands Secretory structures derived from epithelia Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

8. Epithelial Tissue Two Classes of Glandular Secretion ◦ Exocrine secretion—Secretion onto a body surface ◦ Endocrine secretion—Secretion (of hormones) into neighboring tissues and blood Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

9. Connective Tissues Functions ◦ Structural framework ◦ Fluid and solute transport ◦ Physical protection ◦ Tissue interconnection ◦ Fat storage ◦ Microorganism defense Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

10. Connective Tissues Major Types of Connective Tissue Figure 4-7

11. Connective Tissues Connective Tissue Proper ◦ Protein fibers  Collagen fibers  Provides toughness  Reticular fibers  Supports cells  Elastic fibers  Provides resilience Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

12. Connective Tissues Supporting Connective Tissue ◦ Cartilage  Avascular  Covered by a fibrous perichondrium  Three types of cartilage  Hyaline cartilage  Elastic cartilage  Fibrocartilage Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

13. Connective Tissues Bone (Osseous Tissue) ◦ Matrix provides unique properties  Collagen fibers resist bending  Calcium salts resist compression ◦ Diffusion through canaliculi nourishes osteocytes ◦ Covered by periosteum Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

14. Membranes Properties of Membranes ◦ Barrier or interface ◦ Cover and protect ◦ An epithelium plus connective tissue ◦ Four types of membranes Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

15. Membranes Types of Membranes ◦ Mucous  Lines cavities that connect to exterior  Mucus moistens surface  Examples: oral cavity, airways Serous  Line internal cavities  Watery fluid moistens surface  Example: peritoneal membrane Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

16. Membranes Types of Membranes (continued) ◦ Cutaneous  Covers body surface  Dry surface waterproofs the body  Example: the skin ◦ Synovial  Lines joints  Secretes slippery synovial fluid  Lubricates joints  Examples: knee, elbow Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

17. Membranes Membranes

18. Muscle Tissue Properties of Muscle Tissue ◦ Capable of contraction ◦ Three types of muscle tissue  Skeletal muscle  Cardiac muscle  Smooth muscle Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

19. Muscle Tissue Skeletal Muscle Tissue ◦ Contains elongated cells (fibers)  Fibers tied together by loose connective tissue  Possesses microscopic striations  Contains many nuclei  Controlled by voluntary nervous system  Moves and stabilizes the skeleton Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

20. Muscle Tissue Cardiac Muscle Tissue ◦ Only in heart ◦ Short, branched fibers ◦ Single nucleus ◦ Striated ◦ Involuntary contraction ◦ Blood circulation ◦ Blood pressure Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

21. Muscle Tissue Smooth Muscle Tissue ◦ Short, tapering cells ◦ No striations ◦ Involuntary contraction  Blood vessels  Urinary bladder  Digestive organs  Uterus Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

22. Neural Tissue Properties of Neural Tissue ◦ Conduct electrical impulses ◦ Transfer, process, and store information ◦ Comprises neurons and neuroglia Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

23. Neural Tissue Neurons- conduct nerve impulses Neuroglia-provides support, protection and nutients. Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

24. Tissue Injuries and Repair An injury harms multiple tissues simultaneously Tissues make coordinated response Responses restore homeostasis Two response types ◦ Inflammation ◦ Restoration Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

25. Tissue Injuries and Repair Inflammation ◦ Isolation of injured area ◦ Cleanup of damaged tissue ◦ Four signs of inflammation  Warmth  Redness  Swelling  Pain Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

26. Tissue Injuries and Repair Regeneration ◦ Repair/replacement of damaged tissue ◦ Restoration of tissue function ◦ Scar tissue from fibroblast activity ◦ Complete, partial, or no regeneration ◦ Tissue fibrosis common outcome (scar tissue) Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

27. Tissues and Aging ◦ Healing slows ◦ Epithelia become thinner ◦ Connective tissues become more fragile ◦ Bones weaken, become brittle ◦ Neuron and muscle fiber losses accumulate ◦ Lifestyle interventions slow decline Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

28. Aging and Tissues Tissue heals faster in young adults Surgery of a fetus normally leaves no scars Young tissues have a better nutritional state, blood supply, and higher metabolic rate Extracellular components also change with age Changes in the body’s use of glucose, collagen, and elastic fibers contribute to the aging process