Chapter 5Tissues

5 - 2

Cell ReviewA. 75 trillion cells, various shapes & sizesB. Differences in shape make different

functions possible

A. includes many different cell structuresB. three main parts

-nucleus, cytoplasm, cell membraneC. specialized organelles w/ specific functions

5 - 3

5 - 4

Cell Differentiation1. Process by which

cells develop into different types of cells w/ specialized functions

2. Reflects genetic control of the nucleus as certain genes are turned on & others are turned off

5 - 5

Tissues: A. Cells w/ common structures are arranged

in tissues that serve specific functions B. four major types

• Epithelial tissue• Connective tissue• Nervous tissue• Muscle tissue

C. Arise from 3 embryonic germ layers• Endoderm• Mesoderm• Ectoderm

5 - 6

5 - 7

5 - 8

A tissue may be held together by a sticky extra cellular matrix that coats the cells or weaves them together in a fabric of fibers

5 - 9

Epithelial Tissues: 9 types

1. covers organs, line body surfaces, cavities & hollow organs

2. anchored to a basement membrane3. tightly packed cells w/ prominent

nuclei4. generally lack blood vessels5. replaced frequently6. functions: protection, secretion,

absorption, excretion, sensory reception

5 - 10

• Simple• 1 layer

• Stratified• more than

1 layer

5 - 11

Simple Squamous Epithelium 1. 1 layer of thin, flattened scale like cells2. suited for diffusion: found in the lungs, lines blood & lymph vessels & body cavities

5 - 12

Stratified Squamous Epithelium 1. layers of flattened cells designed to

protect underlying layers 2. outer layer of skin, lines the

mouth, throat, vagina, & anal canal 3. cells undergo keratinization;

except for where tissues remain moist: throat, vagina, anal canal

5 - 13

5 - 14

Simple Cuboidal Epithelium 1. 1 layer of cube-shaped cells w/ centrally located nuclei2. functions: secretion & absorption in the kidneys, & secretion in glands

5 - 15

5 - 16

Stratified Cuboidal Epithelium1. 2 or 3 layers of cuboidal cells lining a lumen of the mammary glands, sweat glands, salivary glands, & pancreas2. Several layers provide greater protection

5 - 17

Simple Columnar Epithelium1. row of elongated cells, nuclei located near basement membrane, may be ciliated (move substances)2. lines the uterus, stomach, & intestines, protects underlying tissues, secretes digestive fluids, & absorbs nutrients

5 - 18

3. In the intestine, these cells possess microvilli to increase surface area for absorption4. can contain mucus-secreting goblet cells

5 - 19

Stratified Columnar Epithelium 1. several layers of cells found in

the vas deferens, part of the male urethra, & parts of the pharynx.

5 - 20

5 - 21

Pseudostratified Columnar Epithelium1. appear layered due to the varying positions of their nuclei, but are not layered2. may have cilia & globlet cells, line & sweep debris from respiratory tubes

5 - 22

5 - 23

Transitional Epithelium

1. designed to distend & return to normal size, ex. the lining of the bladder2. provides distensibility & keeps urine from diffusing back into the internal cavity

5 - 24

5 - 25

Glandular Epithelium1. designed to produce & secrete substances into ducts or into body fluids

2. Glands that secrete products into ducts (inside & outside) are exocrine; those that secrete into body fluids (i.e. blood) are endocrine

3. Glands are classified by the ways the glands secrete their products

5 - 26

a. Merocrine release products by exocytosis (pancreas) & are grouped as serous which produce a watery fluid or mucus which produce a thicker, protective substance.

b. Apocrine glands lose portions of their cell bodies during secretion (mammary glands)

c. Holocrine glands release entire cells (sebaceous glands)

5 - 27

5 - 28

5 - 29

5 - 30

Connective Tissues:1. bind, support, protect, serve as

frameworks, fill spaces, store fat, produce blood cells, protect against infection, and repair tissue damage

2. have abundant matrix, or intercellular material throughout, & have good blood supplies (except cartilage)

5 - 31

Connective Tissue Fibers

1. Strong collagenous fibers (white) made of the protein collagen, add strength for holding body parts together

2. Elastic fibers (yellow), made of the protein elastin, are stretchy & add flexibility

3. Reticular fibers are thin collagenous fibers that form supportive networks in a variety of tissues

5 - 32

3 Major Cell Types 1. Fibroblast most common, a fixed star-shaped cell, large in size & secretes fibers2. Wandering macrophages function as scavenger cells & defend against infection3. Mast cells are large, located near blood vessels where they release heparin (anticoagulant) & histamine (promotes inflammation)

5 - 33

5 - 34

Loose Connective (areolar) Tissue 1. forms thin membranes throughout the body that bind body parts together such as skin & underlying organs2. mostly fibroblasts separated by a gel-like ground substance containing loosely packed collagenous & elastic fibers

5 - 35

5 - 36

Adipose Tissue 1. loose connective tissue stores

fat2. beneath the skin, around

joints, padding the kidneys & other internal organs, in certain abdominal membranes

5 - 37

Dense Connective Tissue 1. densely packed collagenous

fibers, very strong but lacks good blood supply2. part of tendons & ligaments

5 - 38

Elastic connective tissue• abundant in elastic fibers• some collagenous fibers• fibroblasts•walls of large arteries, airways, heart

5 - 39

5 - 40

Reticular connective tissue• composed of reticular fibers• supports• walls of liver, spleen, lymphatic organs

5 - 41

5 - 42

Cartilage1. rigid connective tissue, provides a supportive framework for various structures lacks a vascular system (heals slowly)2. Cartilage cells (chondrocytes) lie

within lacunae in the gel-like fluid matrix3. enclosed within a connective tissue perichondrium

5 - 43

4. Hyaline cartilage, most common, white with abundant fine collagen fibers, found at the ends of bones, supports respiratory passages

5 - 44

5. Elastic cartilage, with elastic fibers, provides a flexible framework for the external ears & parts of the larynx

5 - 45

6. Fibrocartilage, with many collagenous fibers, tough tissue that provides a shock-absorbing function in intervertebral disks, knees & pelvic girdle

5 - 46

5 - 47

Bone 1. rigid connective tissue, w/ deposits

of mineral salts & collagen within the matrix

2. supports the body, protects, forms muscle attachments, site for blood cell formation

3. has a good blood supply, enabling rapid recovery after injury

4. Osteocytes arranged in concentric circles around a central canal

5 - 48

5 - 49

5 - 50

Blood 1. cells suspended in liquid matrix, plasma2. transports substances thru the body

3. 2 types of cell : Red & White

5 - 51

Muscle Tissues:Muscle cells, fibers, can contract 3 major types: skeletal, cardiac & smooth

5 - 52

Skeletal Muscle Tissue 1. attached to bone, can be

controlled by conscious effort (voluntary)

2. long & cylindrical, striated, have many nuclei, contract from nervous impulse

5 - 53

Smooth Muscle Tissue1. lacks striations, 1 nuclei,

spindle- shaped cells (tapered)2. involuntary, found in the

walls of internal organs, digestive tract, blood vessels, & urinary bladder

5 - 54

Cardiac Muscle Tissue 1. in the heart, branching fibers connected via intercalated

disks2. involuntary, single nucleus,

striated

5 - 55

Nervous Tissues: 1. in the brain, spinal cord, nerves2. Neurons conduct impulses 3. helper cells, neuroglia, support & nourish neurons

6 - 56

Types of Membranes Serous Mucous Synovial Cutaneous/ Integumentary

6 - 57

A. Serous membranes line body cavities that lack openings to the outside

1. line the thorax & abdomen and cover the organs within these cavities

2. epithelial & connective tissue

3. secrete serous fluid that acts as a lubricant

6 - 58

B. Mucous membranes line the cavities & openings that lead to the outside of the body including the oral and nasal cavities, and openings of the digestive, reproductive, respiratory, and urinary systems

1. epithelium & connective tissue

2. w/ specialized cells that secrete mucus

6 - 59

C. Synovial membranes line joint cavities

1. only connective tissues

2. lubricating synovial fluid

D. Cutaneous membrane consists of the skin

1. epithelial & connective tissues

Practice Tissue ID

5 - 60

5 - 61

Simple Squamous Epithelium Stratified Epithelium

Pseudostratified Epithelium

Simple Cuboidal Epithelium

5 - 62

Bone

Dense Fibrous, Collagenous

Areolar Connective Tissue

Reticular

5 - 63

Adipose Tissue

Blood

Nervous Tissue

Hyaline Cartliage

5 - 64

Skeletal Muscle Smooth Muscle Cardiac Muscle

Clinical ApplicationCollagen Disorders

Chondrodysplasia• collagen chains too wide• stunted growth• deformed joints

Dystrophic epidermolysis bullosa• breakdown of collagen that attaches skin layers• stretchy skin• lax joints

Hereditary osteoarthritis• change in amino acid in collagen• painful joints

5-25

5 - 66

5 - 67

5 - 68

5 - 69