Chapter 2

1. Chapter 2 Histology

2. Objectives • Name the four basic tissues, and cite one example of each • Describe the general characteristics and functions of epithelial tissues • Name the major types of epithelium and identify an organ in which each is found • Describe the general characteristics and functions of connective tissues • List the major types of connective tissues that occur within the body • Distinguish between the three types of muscle tissue • Describe the general characteristics and functions of nerve tissue • Distinguish all types of tissues and their characteristics from a slide • State the meanings of the prefixes, suffixes, and root words of this unit

3. Body Tissues • Groups of cells that are similar in __________ and __________ • Most organs contain several tissue types • Arrangement determines each organs structure - Four Types • Epithelium • ____________ • Nervous • _________

4. Epithelial Tissue Locations cover _____ ________ line ______ _________ Functions _________ osmosis absorption secretion filtration ___________ • Characteristics • packed very closely together, forming continuous sheets that contain no blood supply • regenerated easily • exhibit polarity: top (apical) bottom (basal) • one free surface or edge, called apical, exposed to body’s exterior or cavity of an organ • basal surface rests on the basement membrane • have a basement membrane which is a semi-permeable filter

5. Structure of Epithelia

6. Classifications of Epithelium based on shape • _________ Types or shapes: • ___________: • shield-like or flattened cells • ___________: • same __________ as __________, cube-shaped cells • nucleus is __________ and found in the ________ of the cell

7. Classifications of Epithelium based on shape Cont. • ___________: _____________ cells (taller than wide) • nucleus is _______ and tends to be found near • the ___________ • often presence of microvilli or cilia on • apical surface • ______________: • __________ shapes, able to stretch with distention of urinary organ they line

8. Classifications of Epithelium based on cell arrangement (layers) • Two Types: • ___________: • __________ layer of cells of the same shape • _____________: • many layers of cells; named for the shape of cells in the outer layer • Pseudostratified: • __________ layer of tall cells that wedge together to ___________ as if there are two or more layers • Columnar that appear stratified due to crowding of cells

9. Simple Squamous • very thin ________ layer of ________, shield-like, _________ shaped cells • nuclei are usually broad and thin • substance can pass through easily • easily damaged • Function: - diffusion ex. - filtration - transportation - ex. • Location: - walls of the ____________, air sacs of lungs

13. Simple Cuboidal • _________ layer of cube-shaped cells • ___________ located, _____________ nuclei • Function: - secretion, ______________ • Location: - ___________, Kidneys tubules, pancreas and liver

17. Simple Columnar • single layered, ____________ cells (higher than they are wide) • nuclei located near _________ of each cell, also elongated - open spaces “___________ _______” produce mucus • Function: - ___________, secretion, _____________, and absorption • Location: ___________, lining of _____________

20. Pseudostratified Epithelial - appear to have __________ layers (how it gets it’s name pseudo meaning false) - “looks” as if more than one layer because _________ are at two different levels • commonly have ____________ • Function: - protection, _____________, secretion -ex: • Location: - lines the passage ways of the _____________ ________

23. Stratified Squamous - most common stratified • several _____________, closely packed • new cells push older ones farther outward, where they flatten • appearance of top layer is used in naming • Function: - ________________ - ex. • Location: - __________, esophagus, outer ____________

27. Stratified Cubodial • 2-3 ___________ of cubodial cells • Function: _______________ • Location: - lines the larger ducts of the ___________, sweat, and _________ glands, pancreas

29. Stratified Columunar • consists of several ___________ of cells • __________ layer of ___________ cells overlying several layers of cubodial cells • Functions - • Locations - male ___________, ductus deferens and parts of the ___________

31. Transitional Epithelial - specialized to change in response to increased tension - capable of ____________ - ________ layers of varying ________ • Function: protection • Location: - all parts of the urinary system -lining of ___________, _____________, part of the urethra

34. Connective Tissue Locations (everywhere) - _______ - membranes - __________ - nerves - all internal organs • Functions - _____________, surround and connect other tissues - establish structural framework - _____________ - store energy - transportation - _____________

35. Connective Tissue Cont. • Characteristics - most abundant, and widely distributed - bind structures, provide ___________ and ___________ - serve as frameworks, fill spaces, store _____, produce blood cells, protect against ____________, help repair tissue damage - varying degrees of ____________, most are well nourished (exception tendons, ligaments, cartilage) - _____________ (except cartilage) - made up pf many different types of cells - most cells can ________ - varying amounts ______________ ______ between each - composed of protein fibers, and ground substance - mesenchyme is their common tissue of origin

36. Components of Connects Tissue __________: ex. __________: ex. ________________: - background material within which all other connective tissue elements are embedded - mainly ________ whose major role is to provide a route for communication and transport (by diffusion) between tissues  - colorless, homogeneous in appearance, and transparent or translucent as long as its not calcified - glycosaminoglycans (GAGs), proteoglycans, and glycoproteins, (small fraction of the weight of the ground substance)  

37. Types of Connective Tissue • Connective tissue ____________ - __________ - dense • Supportive - ___________ - ___________ • _________ - ___________ - lymph

38. Mesenchyme • ____________ connective tissue • gel-like ground substance with fibers and star-shaped mesenchymal cells • gives rise to all other connective tissue • found in the embryo

40. Connective Tissue Fibers • Collagenous: - most common - _________ threads of the protein ___________ - grouped in long, _________ __________, flexible, but only slightly elastic (like a rope) - great tensile strength (stronger than steel when pulled from end) • Elastic: - contain the protein _______________ - ________ _______, branched fibers forming complex networks - weaker than collagenous - stretch easily and resume shape and length

41. Connective Tissue Fibers Cont. • Reticular: - very _________, _________ collagenous fibers that form delicate networks, called a ____________ - resist forces applied in many direction, tough but flexible

42. Connective Tissue Proper • a generalized form of connective • contains all of the basic components of connective tissue in reasonable proportions, including cells (of several types), extracellular fibers, and extracellular ground substance • Cells - __________ - melanocytes - mesenchymal - __________ - mast cells - mircophages - macrophages - lymphocytes - adipocytes *Fibroblasts: one of the most abundant permanent cells, secrete proteins the aid in the ___________ of long fibers, ____________ that lock epithelium together, and make ground substance viscous *Fibrocytes: second most abundant cells, _____________ the fibers

43. Subunits of Connective Tissue Proper • Loose - _________ - _________ - _________ • ___________ - _________ - irregular - _________

44. Loose Connective Tissue • Areolar (little space) - least specialized CT in adults - form delicate, thin membranes throughout body - contains cells (mainly fibroblasts) located some distance apart - extracellular matrix containing many collagenous and elastic fibers, account for most of its volume - bind _________ to underlying organs and filling spaces between ___________ - lies beneath epithelial, highly _____________ (common injection site for drugs)

46. Loose Connective Tissue Cont. • Adipose - ________ - white fat, pale yellow-white (most abundant) - brown fat highly vascularized, containing mitochondria - located between __________, around ________, heart, certain joints, __________ of eyes - provides padding, absorbs shock, acts as an ___________, as stores _________ * Average adult has between 40 50 billion fat cells

49. Loose Connective Tissue Cont. • Reticular - fibers create a ____ storma - Functions: provide ____________ framework - Locations: liver,__________, spleen, lymph nodes and ________ __________

50. Dense Connective Tissue • Regular - fibers are __________ to each other - packed tightly, aligned with the forces applied to the tissue - contain _________ fibers - Functions: provide firm attachments, conducts pull of muscles, reduces ___________ between muscles, _________ relative positions of bones - Locations: between ___________ and ___________ between bones of stabilizing positions of internal organs