Anatomy and Physiology I

1. Anatomy and Physiology I Tissue Types

2. Key Terms • Histology: • the study of tissues. • Tissues: • groups of cells which are similar in structure and which perform common or related functions.

3. Four Basic Kinds of Tissues • Epithelial Tissue • Connective Tissue • Muscle Tissue • Nervous Tissue

4. Epithelial Tissue • Epithelial Tissue Locations: • Covers the body • Lines the cavities, tubes, ducts and blood vessels inside the body • Covers the organs inside body cavities • Epithelial Tissue Functions: • Protection from physical & chemical injury, • Protection against microbial invasion, • Contains receptors which respond to stimuli, • Filters, secretes & reabsorbs materials and • Secretes serous fluids to lubricate structures.

5. Examples of Epithelium Tissue • Lines the respiratory tract • Lines the digestive system • Skin • Surrounding internal organs • Characteristics of Epithelium Tissue • Cells are tightly packed • Regenerate easily • Avascular – lack blood vessels • apical surface – exposed surface • Basement membrane – anchors down cells

6. Connective Tissue • Connective Tissue: • Most abundant & widely distributed tissue • Connective Tissue Functions: • Connects, binds and supports structures, • Tendons, ligaments, etc. • Protects & cushions organs and tissues, • Insulates (fat) and • Transports substances (blood).

7. Examples of Connective Tissue • Bones • Cartilage • Tendons • Blood • Fat • Characteristics of Connective Tissue • Most are well vascularized – have a good blood supply • Some have very poor blood supply being avascular. • Extracellular matrix – nonliving substance found outside the cells

8. Extracellular Matrix explained • Nonliving material between cells • Produced by the cells and then extruded • Responsible for the strength • Two components • Ground substance • Of fluid, adhesion proteins, proteoglycans • Liquid, semisolid, gel-like or very hard • Fibers: collagen, elastic or reticular

9. Epithelial Tissue in Detail

10. Classification of epithelia • According to thickness • “simple” - one cell layer • “stratified” – more than one layer of cells (which are named according to the shape of the cells in the apical(base) layer) • According to shape • “squamous” – wider than tall • “cuboidal” – as tall as wide • “columnar” - taller than wide

11. Simple: just one layer or cell shape Stratified: multiple layers and cell shapes Classes of Epithelia Human Anatomy, Larry M. Frolich, Ph.D.

12. Simple Epithelia Human Anatomy, Larry M. Frolich, Ph.D.

13. to protect

14. where diffusion is important where tissues are involved in secretion and absorption: larger cells because of the machinery of production, packaging, and energy requirements

16. Simple Squamous Epithelium • Descriptions: • Single layer, flattened cells, simplest of epithelia • Function: • Allows passage of materials by diffusion and filtration • Secretes lubricating substances • Location: • Air sacs of lungs, lining of heart, blood vessels, lining of ventral body cavity

18. Simple Cuboidal epithelium • Descriptions: • Single layered, cube like, large spherical central nuclei • Function: • Secretion and absorption • Location: • Kidney tubules, ovary surfaces

19. “ciliated” literally = eyelashes (see next page)

20. Simple Columnar Epithelium • Descriptions: • Single layer, tall, round or oval nuclei, some bear cilia, • may contain mucus-secreting glands(goblet cells) • Function: • Absorption, secretion of mucus and enzymes, cilia propels mucus • Location: • Nonciliated lines the digestive tract • Ciliated lines small bronchi, uterine tubes, parts of uterus.

22. Pseudostratified Columnar Epithelium • Descriptions: • Single layer w/ differing heights, nuclei at different levels, may have goblet cells or cilia • Function: • Secretion(especially mucus), propulsion of mucus by ciliary action • Location: • Nonciliated in sperm carrying ducts • Ciliated lines the trachea and upper respiratory tract.

23. Stratified: regenerate from below

24. Stratified Squamous Epithelium • Descriptions: (most common stratified) • Several layers, surface cells are squamous, basal cells are cuboidal or columnar • Function: • Protects underlying tissues in areas of abrasion • Location: • Esophagus, the mouth, outer portion of skin

25. Rare…

26. Stratified Cuboidal Epithelium • Descriptions: (rare) • Usually two layers of cube-like cells • Function: • Protection • Location: • Rare • Largest ducts of sweat glands, mammary glands, and salivary glands.

27. Rare…

28. Stratified Columnar Epithelium • Descriptions: (rare) • Several layers thick, columnar with varying in size and shape • Function: • Protection, secretion • Location: • Rare • Large ducts of glands

30. Transitional Epithelium • Descriptions: • Highly modified, several layers of cuboidal or columnar cells • Function: • Stretches readily, allowing distention of urinary organs • Location: • Lines the ureters, bladder, parts of urethra

31. Human Anatomy, Larry M. Frolich, Ph.D.

32. Quiz!! E Can You Identify the Classes of Epithelium? D A B C Human Anatomy, Larry M. Frolich, Ph.D.

33. Specific Connective Tissue In Detail

35. Bone • Descriptions: Aka: osseous tissue • Hard calcified matrix, surrounded by layers of calcium salts in additions to lots of collagen fibers • Cells sit in cavities called “lacunae” • Function: • Protection and support • Location: • Skeletal system

37. Hyaline Cartilage • Descriptions: (hyalin=glass) • Most common and widespread type • Collagen fibers with a rubbery matrix • Function: • Supports/reinforces, resilient cushioning • Location: • Covers ends of bones in joints, nose, trachea, larynx, embryonic skeleton

39. Elastic Cartilage • Descriptions: • Collagen fibers with a rubbery matrix • Very elastic • Function: • Maintains shape of structure • gives flexibility • Location: • External ear • epiglottis

41. Fibrocartilage • Descriptions: • Similar to hyaline but less firm • Much like a cushion • Function: • Absorbs compressive shock • Location: • Intervertebral discs, discs of knee joint

44. Dense Connective Tissue • Descriptions: • Collagen fibers, fibroblasts fill gaps between collagen • Strong ropelike structures like tendons and ligaments • Function: • Connect muscles to bones, connect bones at joints, lots of tensile strength • Location: • joints

45. Vocab • Fibroblasts – cells that make collagen fibers • Tendons – attach skeletal muscles to bones • Ligaments - connect bones to bones at joints. More stretchy and contain more elastic fibers than tendon

47. Loose CT: Areolar Tissue • Descriptions: • Gel-like matrix w/ all three fiber types • Very loose network w/ lots of open space • Function: • Wraps and cushions organs, a reservoir of water and salts for surrounding tissues, important for swelling • Location: • Under epithelia, around organs, surrounds capillaries

49. Loose CT: Adipose Tissue • Descriptions: (fat) • Very similar to areolar tissue • Fat cells predominate • Function: • Insulates against heat loss, supports and protects organs, reserve food fuel • Location: • Under skin, around kidneys and eyeballs, abdomen and breast