Chapter 4 – Tissue: The Living Fabric - PowerPoint Presentation

Slide1

Chapter 4 – Tissue: The Living Fabric

Section 1 – Epithelial Tissue

(pp. 115-121)

Slide2

Levels of Structural Organization

Tissue

- Billions of structurally-similar

cells working together to perform a

common function

-

Includes extracellular

components

produced by cells

Four major categories of Tissues

:

1)

Epithelial

2)

Connective

3)

Muscular

4)

Nervous

Slide3

Epithelial Tissue

Epithelial

Tissue

- Forms

membranes that…

1)

Cover

the body

2)

Line

cavities

3)

Form

sweat

&

oil

glands

- Create

barriers

that…

1)

Resist

movement of substances through them

- For example,

skin

2)

Allow

movement of substances through them

- For example, lining

of

small intestines

&

lungs

Slide4

Epithelial Tissue

Important properties of Epithelial Tissue

1)

Cells have

polarity

- means they have

apical

(

upper

, free) &

basal

(

lower

, attached) surfaces

-

apical

surface may be covered w/

microvilli

or

cilia

2) Composed of closely

packed

cells

- continuous

sheets

held together by

tight

junctions &

desmosomes

Slide5

Epithelial Tissue

Important properties of Epithelial Tissue

3)

Supported by

connective

tissue

- helps form a “

basement

membrane

” that resists

stretching

&

tearing

4) No direct

blood

supply

(

avascular

)

- relies on

diffusion

from capillaries below for

nutrients

5) High

regenerative

capacity

- surface tissues; therefore often exposed to high

friction

forces, damaging

chemicals

,

bacteria

, etc.

- cells continuously

lost

(wear & tear) &

replaced

Slide6

Epithelial Tissue

Types of Epithelial Tissue

*E.T. classified based on

number

of cell layers

Simple

= 1 layer

Stratified = more than 1 layer

Slide7

Epithelial Tissue

Types of Epithelial Tissue

*E.T. also classified based on

shape

of cells

Squamous

= flattened

Cuboidal = cube-shaped

Columnar

= columns

Slide8

Epithelial Tissue

Types of Epithelial Tissue

1)

Simple squamous

- single layer,

flat

cells

-

simplest

E.T.

- allows passage of materials

by

diffusion

&

filtration

- form

membranes - line body cavities - line lungs & capillaries

Slide9

Epithelial Tissue

Types of Epithelial Tissue

2)

Simple cuboidal

- Single layer,

cube

cells

-

Secretion

&

absorption - Common in

glands

/

ducts - Form walls of

kidneys

Slide10

Epithelial Tissue

Types of Epithelial Tissue

3)

Simple columnar

- Single layer,

tall

cells

- Often include

goblet

cells

that secrete

mucous

- Used for absorption;

secrete

mucous

,

enzymes & other substances - Line digestive tract

Slide11

Epithelial Tissue

Types of Epithelial Tissue

4)

Pseudostratified

- Single layer,

irregular

shape

- Appears

multi

-layered

- Sometimes

ciliated

- Usually secrete

mucous

- Mucous

traps particles; cilia propel mucous out of

respiratory

tract

Slide12

Epithelial Tissue

Types of Epithelial Tissue

5)

Stratified squamous

-

Thick

membrane, many layers,

flat cells

-

Protective

covering where

friction

is common

- Easily

sloughed

off & replaced quickly - Skin, mouth, esophagus

Slide13

Epithelial Tissue

Types of Epithelial Tissue

6)

Stratified cuboidal

7)

Stratified columnar

**Neither are very common in humans

Slide14

Epithelial Tissue

Types of Epithelial Tissue

8)

Transitional

epithelium

-

Tissue that can

stretch

- Cell

shape

depends on

amount of

stretching

- Lines organs of

urinary

system

Slide15

Epithelial Tissue

Glandular Epithelial Tissue

-

Gland

is one or more cells that

make

/

secrete

a fluid

- Formed when epithelial tissue

folds inward- Cells able to secrete

substances onto surface

Two major types of glands

:

1)

Endocrine

glands - Ductless - Secrete hormones that travel through bloodstream to target organs

Slide16

Epithelial Tissue

Glandular Epithelial Tissue

- Gland is one or more cells that makes/secretes a fluid

- Formed when epithelial tissue folds inward

- Cells able to secrete substances onto surface

Two major types of glands

:

2)

Exocrine

glands

- More

numerous

than endocrine glands

- Secrete product into ducts

- Empty secretions

onto

body surfaces or into body cavities - Include mucous, sweat, oil, & salivary glands

Slide17

Epithelial Tissue

Types of exocrine glands

:

Merocrine

glands

- secrete their products by

way of

exocytosis

-

sweat

& salivary glands

Slide18

Epithelial Tissue

Types of exocrine glands

:

Holocrine

glands

- entire

secretory

cell

ruptures

- releases

secretions & dead cell

fragments

-

Oil glands of the skin

Slide19

Chapter 4 – Tissue: The Living Fabric

Section 2 – Connective Tissue

(pp. 124-134)

Slide20

Connective Tissue

Connective

Tissue

- Most

abundant

&

widely

distributed

tissue types

-

Serves mainly to…

1)

Bind

body tissues together 2) Support the body 3) Provide protection & insulation 4) Provide

transportation

(blood)

Slide21

Connective Tissue

Structural C

haracteristics

of Connective Tissue

:

- All C.T.’s are composed of

ground

substance,

fibers

, &

cells

Ground substance - Medium through which solutes

diffuse

between

capillaries & connective tissue cells

- Contains

fibers

& adhesion proteins (“glue”) - Holds varying amounts of water affecting overall viscosity

Slide22

Connective Tissue

Structural C

haracteristics

of Connective Tissue

:

- All C.T.’s are composed of ground substance, fibers, & cells

Fibers

(3 different types)

a)

Collagen

-

strongest & most abundant

type

- provides high tensile strength

b)

Elastic

- long, thin; allow for stretch c) Reticular - short, fine; highly branched; provide cushioning

Slide23

Connective Tissue

Structural C

haracteristics

of Connective Tissue

:

- All C.T.’s are composed of ground substance, fibers, & cells

Cells

- each type of C.T. has its own specialized

cell

- chondrocytes in

cartilage

- osteocytes in

bone

- hematopoietic stem cells in

bone marrow

-

fat cells (adipocytes), white blood cells, mast cells, & macrophages

Slide24

Connective Tissue

Types of Connective Tissue

Areolar connective tissue

-

wraps

& cushions organs

-

binds

body parts together & allows them to move freely over each other

- helps to defend against

infection

- stores nutrients such as

fat - found all over the body lying under epithelial tissue - most widely distributed C.T.

Slide25

Connective Tissue

Types of Connective Tissue

2) Reticular connective tissue

- mostly found in

lymph

nodes

,

spleen

& bone marrow

Slide26

Connective TissueTypes of Connective Tissue

3) Dense regular connective tissue

- Densely

packed

w/ collagen fibers that run

same

direction

- Very

flexible

& incredibly strong if force is in

1 direction - Compose tendons & ligaments

Slide27

Connective TissueTypes of Connective Tissue

4) Dense irregular

connective tissue

- Densely

packed

w/ collagen fibers that run

many

directions

- Forms flexible sheets & very strong in all directions

- Compose

joint capsules & leathery dermis

Slide28

Connective TissueTypes of Connective Tissue

5)

Elastic Connective Tissue

- Dense C.T. w/ large numbers of

elastic

fibers

- Able to

recoil

after stretching - Keeps blood vessels from bursting under pressure

- Causes lungs to

recoil

during exhale

Slide29

Specialized Connective TissueTypes of Connective Tissue

6) Hyaline Cartilage

- Flexible & very

resilient

- Provides support framework

for

respiratory

tract

- Supports bridge of nose - Component of rib

cage

- Covers ends of

long bones

-

Fetal

skeleton

Slide30

Specialized Connective TissueTypes of Connective Tissue

7) Fibrocartilage

- High

tensile

strength

- Holds up to

compression

-

Intervertebral

discs - Pubic symphysis - Discs of knee joint

Slide31

Specialized Connective TissueTypes of Connective Tissue

8) Elastic cartilage

- Like hyaline; more

elastic

fibers

- Maintains

shape

- Great

flexibility

- Supports

outer ear - Forms epiglottis

All

cartilage types

LACK

nerve

fibers

& blood vessels!

Slide32

Specialized Connective TissueTypes of Connective Tissue

9)

Bone

- Like cartilage, but hardened w/

calcium phosphate

-

Protects

& supports the body

- Provides

levers

for movement - Stores calcium

& fat

- Red blood cell formation

Slide33

Specialized Connective TissueTypes of Connective Tissue

10)

Adipose

tissue

(

fat

)

- Long-term

energy

storage - Insulation for animals in cold - Cushioning

for organs

- Found in many places in body

- Layer between

skin & muscle

Slide34

Specialized Connective TissueTypes of Connective Tissue

11)

Blood

-

Transport

of respiratory

gases

,

nutrients, wastes - Fibers only visible during clotting

Slide35

Chapter 4 – Tissue: The Living Fabric

Section 3 – Nervous Tissue

(pp. 134-136)

Slide36

Nervous Tissue

Nervous

Tissue

- Specialized

to

generate

&

conduct electrical impulses

-

Regulate/control body functions

- Brain,

spinal cord, & nerves

Slide37

Chapter 4 – Tissue: The Living Fabric

Section 4 – Muscle Tissue

(pp. 136-137)

Slide38

Muscle Tissue

Muscle

Tissue

- Has the ability to

contract

when stimulated

Three

main types

:

1)

Skeletal

muscle

- attaches to

bones

to cause movement 2) Cardiac muscle - only found in the heart

3)

Smooth

muscle

-

squeezes

substances through

all

hollow

organs

Slide39

Chapter 4 – Tissue: The Living Fabric

Section 5 – Covering & Lining Membranes (pp. 138-139)

Slide40

Epithelial Membranes

Epithelial

membranes

:

- Composed of an

epithelium

bound to an

underlying

connective tissue layer3 major categories: 1) Cutaneous

Membranes

- membrane exposed to

air

;

dry membrane - skin

Slide41

Epithelial Membranes

Epithelial

membranes

:

- Composed of an epithelium bound to an underlying connective tissue layer

3 major categories

:

2)

Mucous

Membranes - lines

body

cavities

that

open to the exterior - “wet” membrane - digestive, respiratory, urogenital tracts - adapted for absorption & excretion

(usually mucous)

Slide42

Epithelial Membranes

Epithelial

membranes

:

- Composed of an epithelium bound to an underlying connective tissue layer

3 major categories

:

3)

Serous

Membranes - moist membrane found in

closed ventral

cavity

Parietal serosae = lines

internal body

walls

Visceral serosae = covers internal organs*Serous fluid lubricates parietal & visceral layers; allows internal organs to slide across each other easily…

Slide43

Chapter 4 – Tissue: The Living Fabric

Section 6 – Tissue Repair

(pp. 139-141)

Slide44

Tissue Repair

Tissue repair occurs in two major ways

:

- depends on

type

of

tissue

damaged

- depends on severity of injuryRegeneration

-

replacement of destroyed tissue

Fibrosis

- growth of fibrous C.T. to close wound; scar tissue

Slide45

Tissue Repair

Steps in Tissue Repair

:

Inflammation

- release of

inflammatory

chemicals

- blood vessels

dilate & become more permeable - allows WBCs, clotting proteins, & antibodies to seep into injured area

-

clotting

occurs; scab formation

Slide46

Tissue Repair

Steps in Tissue Repair

:

Organization of restored

blood

supply

-

clot

replaced w/ granulation tissue (highly vascularized) - epithelium begins to regenerate - collagen

fibers are built to

bridge gap of wound - debris

is phagocytized (“

eaten” & disposed of)

Slide47

Tissue Repair

Steps in Tissue Repair

:

Regeneration

&/or

fibrosis

- scab

detaches

- fibrous tissue matures; epithelium thickens & begins to resemble adjacent tissue - depending on severity

of injury,

scar

may remain