Copyright © 2010 Pearson Education, Inc. C h a p t e r 4 The Tissue Level of Organization PowerPoint® Lecture Slides prepared by Jason LaPres Lone Star

Copyright © 2010 Pearson Education, Inc.

C h a p t e r

4

The Tissue Level of

Organization

PowerPoint® Lecture Slides prepared by Jason LaPres

Lone Star College - North Harris



4-1 The four tissue types

are epithelial, connective,muscle, and neural


Four Types of Tissues

• Tissues are groups of cells and cell

products that perform specific, limited

functions


Tissues of the Body

Figure 4-1


4-2 Epithelial tissue covers

body surfaces, lines cavitiesand tubular structures, andserves essential functions


Epithelial Tissues

• Characteristics of Epithelia

– Cellularity (cell junctions)

– Polarity (apical and basal surfaces)

– Attachment

– Avascularity

– Regeneration


Epithelial Tissues

• Functions of Epithelial Tissue

– Provide physical protection

– Control permeability

– Provide sensation

– Produce specialized secretions (glandular

epithelium)


Intercellular Connections

• Support and Communication

– CAMs (cell adhesion molecules):

• Transmembrane proteins

– Intercellular cement:

• Proteoglycans

– Hyaluronan (hyaluronic acid):

• Glycosaminoglycans



• Cell junctions

– Form bonds with other cells or extracellular material:

• Tight junctions

• Gap junctions

• Desmosomes (macula adherens)




Figure 4-2



Figure 4-2



Figure 4-2



Figure 4-2


The Surface of Epithelial Cells

Figure 4-3


Epithelial Renewal and Repair

• Epithelia are replaced by division of

germinative cells (stem cells)

• Near basal lamina


4-3 Cell shape and number of

layers determine the classification of epithelia


Classification of Epithelia

• Singular epithelium

• Plural epithelia

• Classes of Epithelia

– Based on layers:

• Simple epithelium: single layer of cells

• Stratified epithelium: several layers of cells

– Based on shape:

• Squamous epithelia: thin and flat

• Cuboidal epithelia: square shaped

• Columnar epithelia: tall, slender rectangles




Figure 4-4



Figure 4-4



Figure 4-4



Figure 4-5



Figure 4-5



Figure 4-5


Glandular Epithelia

• Endocrine Glands– Release hormones:

• Into interstitial fluid

• No ducts

• Exocrine Glands– Produce secretions:

• Onto epithelial surfaces

• Through ducts

Mechanisms of Glandular Secretion


Glandular Epithelia

• Mechanism of Secretion – Merocrine secretion:

• Is produced in Golgi apparatus• Is released by vesicles (exocytosis) • For example, sweat glands

– Apocrine secretion:• Is produced in Golgi apparatus• Is released by shedding cytoplasm• For example, mammary gland

– Holocrine secretion:• Is released by cells bursting, killing gland cells• Gland cells replaced by stem cells• For example, sebaceous gland


Mechanisms of Secretion

Figure 4-6


Glandular Epithelia

• Types of Secretions

– Serous glands:

• Watery secretions

– Mucous glands:

• Secrete mucins

– Mixed exocrine glands:

• Both serous and mucous



4-4 Connective tissue provides a

protective structural framework for other tissue

types


Connective Tissues

• Characteristics of Connective Tissues– Specialized cells

– Solid extracellular protein fibers

– Fluid extracellular ground substance

• The extracellular components of connective tissues (fibers and ground substance) make up the matrix

– Majority of tissue volume

– Determines specialized function


Connective Tissues

• Functions of connective tissues

– Support and protection

– Transportation of materials

– Storage of energy reserves

– Defense of the body


Major Types of Connective Tissue

Figure 4-7


Connective Tissues

• Cell Types of Connective Tissue Proper– Fibroblasts

– Macrophages

– Adipocytes

– Mast cells


Connective Tissues

• Connective Tissue Fibers

– Collagen fibers

– Reticular fibers

– Elastic fibers


Connective Tissues

• Ground Substance

– Is clear, colorless, and viscous

– Fills spaces between cells and slows

pathogen movement


Types of Connective Tissue Proper

• Loose Connective Tissue

– More ground substance, less fibers

– For example, fat (adipose tissue)

• Dense Connective Tissue

– More fibers, less ground substance

– For example, tendons


Cells and Fibers of Connective Tissue Proper

Figure 4-8


Connective Tissue Proper

Figure 4-9



Figure 4-9



Figure 4–9


Connective Tissues

• Fluid Connective Tissues

– Blood and lymph

– Watery matrix of dissolved proteins

– Carry specific cell types (formed elements)

• Formed elements of blood

– red blood cells (erythrocytes)

– white blood cells (leukocytes)

– platelets


Supportive Connective Tissues

• Cartilage

– Gel-type ground substance

– For shock absorption and protection

• Bone

– Calcified (made rigid by calcium salts, minerals)

– For weight support



• Cartilage Matrix

– Proteoglycans derived from chondroitin sulfates

– Ground substance proteins

• Chondrocytes (cartilage cells) surrounded by

lacunae (chambers)



• Cartilage Structure

– No blood vessels:

• Chondrocytes produce antiangiogenesis factor

– Perichondrium:

• Outer, fibrous layer (for strength)

• Inner, cellular layer (for growth and maintenance)



• Types of Cartilage – Hyaline cartilage:

• Stiff, flexible support• Reduces friction between bones• Found in synovial joints, rib tips, sternum, and trachea

– Elastic cartilage:• Supportive but bends easily• Found in external ear and epiglottis

– Fibrous cartilage (fibrocartilage): • Limits movement• Prevents bone-to-bone contact• Pads knee joints• Found between pubic bones and intervertebral discs


Types of Cartilage

Figure 4-10


Types of Cartilage

Figure 4-10


Types of Cartilage

Figure 4-10



• Bone or osseous tissue– Strong (calcified: calcium salt deposits)– Resists shattering (flexible collagen fibers)

• Bone cells or osteocytes– Arranged around central canals within matrix– Small channels through matrix (canaliculi) access

blood supply

• Periosteum – Covers bone surfaces– Fibrous layer– Cellular layer


Bone

Figure 4-11



4-5 Membranes are physical

barriers of four types: mucous,serous, cutaneous, and

synovial


Membranes

• Membranes

– Are physical barriers

– That line or cover portions of the body

– Consist of:

• An epithelium

• Supported by connective tissues


Membranes

• Four Types of Membranes

– Mucous membranes

– Serous membranes

– Cutaneous membrane

– Synovial membranes


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


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


Membranes

• Three Serous Membranes– Pleura:

• Lines pleural cavities

• Covers lungs

– Peritoneum:• Lines peritoneal cavity

• Covers abdominal organs

– Pericardium:• Lines pericardial cavity

• Covers heart


Membranes

Figure 4-12


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


Membranes

Figure 4-12


4-6 The three types of muscle

tissue are skeletal, cardiac,and smooth


Muscle Tissue

• Specialized for contraction

• Produces all body movement

• Three types of muscle tissue– Skeletal muscle:

• Large body muscles responsible for movement

– Cardiac muscle:• Found only in the heart

– Smooth muscle:• Found in walls of hollow, contracting organs (blood vessels;

urinary bladder; respiratory, digestive, and reproductive tracts)


Muscle Tissue

Figure 4-13


Muscle Tissue

Figure 4-13


Muscle Tissue

Figure 4-13


4-7 Neural tissue responds to

stimuli and conducts electricalimpulses throughout the body


Neural Tissue

• Also called nervous or nerve tissue

– Specialized for conducting electrical impulses

– Rapidly senses internal or external

environment

– Processes information and controls

responses


Neural Tissue

• Neural tissue is concentrated in the

central nervous system

– Brain

– Spinal cord


Neural Tissue

• Two Kinds of Neural Cells

– Neurons:

• Nerve cells

• Perform electrical communication

– Neuroglia:

• Supporting cells

• Repair and supply nutrients to neurons


Neural Tissue

• Cell Parts of a Neuron

– Cell body:

• Contains the nucleus and nucleolus

– Dendrites:

• Short branches extending from the cell body

• Receive incoming signals

– Axon (nerve fiber):

• Long, thin extension of the cell body

• Carries outgoing electrical signals to their destination


Neural Tissue

Figure 4-14


4-8 The response to tissue

injury involves inflammationand regeneration


Tissue Injuries and Repair

• Tissues respond to injuries to maintain

homeostasis

– Cells restore homeostasis with two

processes:

• Inflammation

• 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)


4-9 With advancing age,

tissue repair declines andcancer rates increase


Aging and Tissue Structure

• Speed and efficiency of tissue repair

decrease with age due to

– Slower rate of energy consumption

(metabolism)

– Hormonal alterations

– Reduced physical activity


Aging and Cancer Incidence

• Cancer rates increase with age

– 1 in 4 people in the United States develops cancer

– Cancer is the #2 cause of death in the United States

– Environmental chemicals and cigarette smoke cause

cancer


Aging and Cancer Incidence

• Three most common types of skin cancer

– Basal cell carcinoma

– Squamous cell carcinoma

– Malignant melanoma

Documents

Copyright © 2010 Pearson Education, Inc. C h a p t e r 4 The Tissue Level of Organization PowerPoint® Lecture Slides prepared by Jason LaPres Lone Star