The Body Tissues

© 2012 Pearson Education, Inc.

The Body Tissues


• A. Define cell differentiation and explain its importance.

• B. Describe stem cells and explain their importance.

• C. Review tissue types.

• D. Epithelial tissue• 1.Describe important characteristics of epithelial tissue.

• 2.Describe essential functions of epithelial tissue.

• 3. Describe structural specializations of epithelial tissue.

• 4. Glandular epithlelia

• a.Distinguish between merocrine, apocrine and holocrine secretion.

• b.Distinguish between serous and mucous secretions.

• 5. Define exfoliative cytology and provide examples.

• E.Connective tissue• 1.Define fascia and describe its location and functions.

• F.Membranes• 1.Describe the basic structure of membranes.

• 2.Describe the 4 types of membranes, their functions and locations.


4-1 Four Types of Tissue

• Tissue

• Are collections of cells and cell products that perform specific, limited functions

• Four types of tissue

1. Epithelial tissue

2. Connective tissue

3. Muscle tissue

4. Neural tissue


4-1 Four Types of Tissue

• Epithelial Tissue

• Covers exposed surfaces

• Lines internal passageways

• Forms glands

• Connective Tissue• Fills internal spaces

• Supports other tissues

• Transports materials

• Stores energy

• Muscle Tissue• Specialized for

contraction

• Skeletal muscle, heart muscle, and walls of hollow organs

• Neural Tissue• Carries electrical

signals from one part of the body to another


4-2 Epithelial Tissue

• Characteristics of Epithelia

• Cellularity (cell junctions)

• Polarity (apical and basal surfaces)

• Attachment (basement membrane or basal lamina)

• Avascularity

• Regeneration


Figure 4-1 The Polarity of Epithelial Cells

Cilia

MicrovilliApicalsurface

Golgiapparatus

Nucleus

MitochondriaBasement membraneBasolateralsurfaces



• Functions of Epithelial Tissue

1. Provide Physical Protection

2. Control Permeability

3. Provide Sensation

4. Produce Specialized Secretions (glandular epithelium)



• Specializations of Epithelial Cells1. Move fluids over the epithelium (protection)

2. Move fluids through the epithelium (permeability)

3. Produce secretions (protection and messengers)

• Polarity

1. Apical surfaces

• Microvilli increase absorption or secretion

• Cilia (ciliated epithelium) move fluid

2. Basolateral surfaces



• Maintaining the Integrity of Epithelia

1. Intercellular connections

2. Attachment to the basement membrane

3. Epithelial maintenance and repair



• Epithelial Maintenance and Repair

• Epithelia are replaced by division of germinative

cells (stem cells)

• Near basement membrane


4-3 Classification of Epithelia

• Singular = Epithelium; Plural = Epithelia

• Classes of Epithelia

1. Based on shape

• Squamous epithelia — thin and flat

• Cuboidal epithelia — square shaped

• Columnar epithelia — tall, slender rectangles

2. Based on layers

• Simple epithelium — single layer of cells

• Stratified epithelium — several layers of cells


4-3 Classification of Epithelia• Simple squamous epithelium

• Absorption and diffusion

• Mesothelium: Lines body cavities

• Endothelium: Lines heart and blood vessels



• Glandular Epithelia

• Endocrine glands

• Release hormones

• Into interstitial fluid

• No ducts

• Exocrine glands

• Produce secretions

• Onto epithelial surfaces

• Through ducts


4-3 Classification of Epithelia--Modes of Secretion

• Merocrine Secretion• Produced in Golgi apparatus

• Released by vesicles (exocytosis)

• For example, sweat glands

• Apocrine Secretion• Produced in Golgi apparatus

• Released by shedding cytoplasm

• For example, mammary glands



• Holocrine Secretion• Released by cells bursting, killing gland cells

• Gland cells replaced by stem cells

• For example, sebaceous glands


Figure 4-6 Modes of Glandular Secretion

Salivary gland

Mammary gland

Hair

Sebaceousgland

Hair follicle

Stem cell

Cell division replaceslost cells

Cells produce secretion,increasing in size

Cells burst, releasingcytoplasmic contents

Secretion Regrowth

Golgi apparatus

Breaksdown

SecretoryvesicleGolgiapparatus

Nucleus

TEM 3039



• Glandular Epithelia

• Types of Secretions

• Serous glands

• Watery secretions

• Mucous glands

• Secrete mucins

• Mixed exocrine glands

• Both serous and mucous


4-4 Connective Tissue

Characteristics of Connective Tissue

1. Specialized cells

2. Extracellular protein fibers

3. Fluid extracellular ground

substance

• The Extracellular Components of Connective Tissue (Fibers and Ground Substance)

• Make up the matrix• Majority of tissue volume\Determines specialized

function


4-4 Connective Tissue

• Functions of Connective Tissue

• Establishing a structural framework for the body

• Transporting fluids and dissolved materials

• Protecting delicate organs

• Supporting, surrounding, and interconnecting other types of tissue

• Storing energy reserves, especially in the form of triglycerides

• Defending the body from invading microorganisms


4-6 Membranes

• Four Types of

Membranes

1. Mucous membranes

2. Serous membranes

3. Cutaneous membrane

4. Synovial membranes

• Membranes

• Physical barriers

• Line or cover

portions of the body

• Consist of:

• An epithelium

• Supported by

connective tissue


4-6 Membranes

• Mucous Membranes (Mucosae)• Line passageways that have external connections

• In digestive, respiratory, urinary, and reproductive tracts

• Epithelial surfaces must be moist

• To reduce friction

• To facilitate absorption and excretion

• Lamina propria

• Is areolar tissue


Figure 4-16a Membranes

Mucous secretion

Mucous membranes are coated with thesecretions of mucous glands. These membranes line the digestive, respiratory, urinary, and reproductive tracts.

Epithelium

Lamina propria(areolar tissue)


4-6 Membranes

• Serous Membranes

• Line cavities not open to the outside

• Are thin but strong

• Have fluid transudate to reduce friction

• Have a parietal portion covering the cavity

• Have a visceral portion (serosa) covering the organs


4-6 Membranes

• Three Serous Membranes1. Pleura

• Lines pleural cavities

• Covers lungs

2. Peritoneum• Lines peritoneal cavity

• Covers abdominal organs

3. Pericardium• Lines pericardial cavity

• Covers heart


Figure 4-16b Membranes

Serous membranes line the ventral body cavities (the peritoneal, pleural, and pericardial cavities).

TransudateMesothelium

Areolar tissue


4-6 Membranes

• Cutaneous Membrane

• Is skin, surface of the body

• Thick, waterproof, and dry

• Synovial Membranes

• Line moving, articulating joint cavities

• Produce synovial fluid (lubricant)

• Protect the ends of bones

• Lack a true epithelium


Figure 4-16c Membranes

The cutaneous membrane, or skin, covers the outer surface of the body.

Epithelium

Areolar tissue

Dense irregularconnective tissue


Figure 4-16d Membranes

Synovial membranes line joint cavities and produce the fluid within the joint.

Articular (hyaline) tissueSynovial fluidCapsuleCapillary

Adipocytes

AreolartissueEpithelium

Synovialmembrane

Bone


4-7 Internal Framework of the Body

• Connective Tissues

1. Provide strength and stability

2. Maintain positions of internal organs

3. Provide routes for blood vessels, lymphatic vessels, and nerves

• Fasciae• Singular form = fascia

• The body’s framework of connective tissue

• Layers and wrappings that support or surround organs


4-7 Internal Framework of the Body

• Three Types of Fasciae

1. Superficial fascia

2. Deep fascia

3. Subserous fascia


Figure 4-17 The Fasciae

Body wall

Body cavity

Skin

Connective Tissue Framework of Body

Superficial Fascia

Deep Fascia

Subserous Fascia

Rib

Serous membrane

Cutaneous membrane

• Forms a strong, fibrous

• Dense connective tissue• Bound to capsules,

• Between serous

• Areolar tissue

internal framework

tendons, and ligaments

membranes anddeep fascia

• Between skin and

adipose tissue• Also known as

underlying organs• Areolar tissue and

subcutaneous layeror hypodermis


4-10 Tissue Injuries and Repair

• Tissues Respond to Injuries

• To maintain homeostasis

• Cells restore homeostasis with two processes

1. Inflammation

2. Regeneration



• Inflammation = Inflammatory Response

• The tissue’s first response to injury

• Signs and symptoms of the inflammatory response include:

• Swelling

• Redness

• Heat

• Pain



• Inflammatory Response

• Can be triggered by:

• Trauma (physical injury)

• Infection (the presence of harmful pathogens)

The Body Tissues

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