cells and tissues - mrs. flieg's classroom - home · 2019-08-09 · cells at the apical...

PowerPoint® Lecture Slide Presentation

by Patty Bostwick-Taylor,

Florence-Darlington Technical College

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings

PART D3

Cells and

Tissues


Body Tissues

Tissues

Groups of cells with similar structure and

function

Four primary types

Epithelial tissue (epithelium)

Connective tissue

Muscle tissue

Nervous tissue


Epithelial Tissues

Locations

Body coverings

Body linings

Glandular tissue

Functions

Protection

Absorption

Filtration

Secretion


Epithelium Characteristics

Cells fit closely together and often form sheets

The apical surface is the free surface of the tissue

The lower surface of the epithelium rests on a

basement membrane

Avascular (no blood supply)

Regenerate easily (readily divide) if well

nourished


Epithelium Characteristics

Figure 3.17a


Classification of Epithelia

Number of cell layers

Simple—one layer

Stratified—more

than one layer

Pseudostratified

Columnar – appears

to have several

layers but only has 1

layer

Figure 3.17a


Classification of Epithelia

Shape of cells

Squamous

flattened

Cuboidal

cube-shaped

Columnar

column-like

Figure 3.17b


Simple Epithelia

Simple Squamous

Single layer of flat cells

Usually forms membranes

Basement membrane anchors

epithelium to underlying

connective tissue.

Location: Capillary walls,

blood vessels, air sacs in

lungs, inner surface of ear

drum, lymph vessels

Function: filtration, diffusion,

osmosis, protection


Simple Epithelia

Figure 3.18a


Simple Epithelia

Simple Cuboidal

Single layer of cube-like

cells

Closely packed

Basement Membrane with

free surface

Location: Common in

glands and their ducts,

walls of kidney tubules,

covers the ovaries

Function: protection,

secretion, and absorption


Simple Epithelia

Figure 3.18b


Simple Epithelia

Simple Columnar

Single layer of tall cells

Basement membrane

Location: Lines digestive

tract (stomach and intestine

wall), uterus

Function: Secretion (often

includes mucus-producing

goblet cells),absorbs

nutrients from digested food,

protection, moves eggs

Can be ciliated or

nonciliated


Simple Epithelia

Figure 3.18c


Simple Epithelia

Pseudostratified Columnar

Single layer, but some cells are shorter than others

Often looks like a double layer of cells

Commonly ciliated (Pseudostratified Ciliated Columnar

Epithelium)

Basement membrane

Location: Respiratory tract (trachea, nasal cavity,

bronchi, bronchioles, lungs)

Function: Secretion, Protection, Moves mucous

Goblet cells within tissue secrete mucous


Simple Epithelia

Figure 3.18d


Stratified Epithelia

Stratified Squamous

2 or more layers

Cells at the apical surface are flattened (in the

deeper layers, they may be cuboidal or columnar)

Tightly packed

Basement membrane

Function: Found as a protective covering where

friction is common, regeneration of cells,

keratinization (in epidermis)

Locations: Epidermis, lines oral cavity, esophagus,

vagina, anal canal



Figure 3.18e



Stratified cuboidal

Two or more layers of cube shaped cells

Basement Membrane

Location: Lines larger ducts of mammary glands, sweat

glands, salivary glands, and pancreas.

Function: protection, secretion, and absorption



Stratified Columnar—surface cells are columnar, cells

underneath vary in size and shape

Location: male urethra, ducted deferens, pharynx

Function: protection and secretion

Stratified cuboidal and columnar

Rare in human body

Found mainly in ducts of large glands



Transitional epithelium

Shape of cells depends upon the amount of

stretching

Function: Change in response to increased

tension – expandable lining

Location: Lines organs of the urinary system



Figure 3.18f


Glandular Epithelium

Glands

One or more cells responsible for secreting a

particular product

Exocrine Glands – glands that secrete

their products into ducts that open onto

surfaces (skin, digestive tract)

Endocrine Glands- glands that secrete

their products into tissue fluid or blood.


Glandular Epithelium

Two major gland types

Endocrine gland

Ductless since secretions diffuse into

blood vessels

All secretions are hormones

Exocrine gland

Secretions empty through ducts to the

epithelial surface

Include sweat and oil glands


Connective Tissue

Found everywhere in the body

Includes the most abundant and widely

distributed tissues

Functions

Binds body tissues together

Supports the body

Provides protection


Connective Tissue Characteristics

Variations in blood supply

Some tissue types are well vascularized

Some have a poor blood supply or are

avascular

Extracellular matrix

Non-living material that surrounds living cells


Extracellular Matrix

Two main elements

Ground substance—mostly water along with

adhesion proteins and polysaccharide

molecules

Fibers

Produced by the cells

Three types

Collagen (white) fibers

Elastic (yellow) fibers

Reticular fibers


Connective Tissue Types

Bone (osseous tissue)

Composed of

Osteon, central canal, lamella, osteocytes,

solid matrix of calcium salts, collagen

fibers

Location: In spongy and compact bone (femur,

humerus)

Function: Protection, support, framework,

mineral storage



Figure 3.19a



Hyaline cartilage

Most common type of cartilage, glassy

appearance

Composed of:

Chondrocytes, collagen fibers, rubbery

matrix

Locations: ends of bones, end of nose, ribs,

larynx

Function: Support, framework, smooth

surface, bone growth/development



Figure 3.19b



Elastic cartilage

Location: Supports the external ear

Function: Provides elasticity, more flexible than hyaline

Fibrocartilage

Highly compressible, tough, collagenous fibers

Location: Forms cushion-like discs between vertebrae, knee, pelvic girdle

Function: Shock absorption



Figure 3.19c



Dense Regular Connective Tissue (dense fibrous tissue)

Main matrix element is collagen fiber (tightly packed)

Fibroblasts are cells that make fibers

Locations:

Tendons—attach skeletal muscle to bone

Ligaments—attach bone to bone at joints

Dermis—lower layers of the skin

Function: strength, support, bind organs, connects

bones to bone, and muscles to bones.



Figure 3.19d



Loose connective tissue types

Loose Areolar Tissue

Most widely distributed connective tissue

Soft, loosely intertwined, pliable tissue like

“cobwebs”

Contains all fiber types (elastic and collagen), in a

gel-like matrix

Location: below epithelial tissues, between muscles, in

wall of stomach and intestines, dermis, blood vessels

Function: flexibility, support, connects epithelium to

muscle, “packing tissue”, can soak up excess fluid

(edema)



Figure 3.19e




Loose Adipose tissue

Matrix is an areolar tissue in which fat globules

predominate

Adipocytes store fat (lipid deposits) in droplets in

cytoplasm

Nucleus is pushed to the side, against plasma

membrane

Location: Under skin, around joints, around organs,

behind eye ball

Functions: Insulation, protection, support, energy

storage



Figure 3.19f




Reticular connective tissue – NOT ON TEST

Delicate network of interwoven fibers

Forms stroma (internal supporting

network) of lymphoid organs

Lymph nodes

Spleen

Bone marrow



Figure 3.19g



Blood Connective Tissue (vascular tissue)

Blood cells surrounded by fluid matrix called

blood plasma

Formed Elements: Red blood cells, white

blood cells, platelets

Fibers are visible during clotting

Location: In blood vessels (veins, arteries,

capillaries), heart chambers

Function: Transport vehicle for materials

(oxygen, nutrients, wastes, hormones),

immunity



Figure 3.19h


Muscle Tissue

Function is to produce movement

Three types

Skeletal muscle

Cardiac muscle

Smooth muscle


Muscle Tissue Types

Skeletal muscle

Characteristics of skeletal muscle cells:

Striated

Multinucleate (more than one nucleus)

Long, cylindrical

Function: Voluntary movement of bones,

produces heat, facial expression

Location: attached to bones of the skeleton

(biceps, quadriceps)


Muscle Tissue Types

Figure 3.20a


Muscle Tissue Types

Cardiac muscle

Characteristics of cardiac muscle cells

Cells are attached to other cardiac muscle

cells at intercalated disks

Striated

One nucleus per cell

Branching cells

Location: Heart Wall

Function: Contraction of heart wall (pump

blood), involuntary, produces heat


Muscle Tissue Types

Figure 3.20b


Muscle Tissue Types

Smooth muscle

Characteristics of smooth muscle cells

No visible striations

One nucleus per cell

Spindle-shaped cells

Location: Wall of hollow organs (stomach,

intestines, colon, bladder, uterus, blood

vessels)

Function: Involuntary movement of organs

(digestion), produce heat


Muscle Tissue Types

Figure 3.20c


Nervous Tissue

Composed of:

Neuron – Axon, dendrite, cell body

Neuroglia (support cells)

Location: Brain, spinal cord, nerves

Function: Send impulses to other areas of the

body

Irritability

Conduction of sensory information and motor

impulses


Nervous Tissue

Figure 3.21


Tissue Repair (Wound Healing)

Regeneration

Replacement of destroyed tissue by the same

kind of cells

Fibrosis

Repair by dense (fibrous) connective tissue

(scar tissue)

Determination of method

Type of tissue damaged

Severity of the injury


Events in Tissue Repair

Capillaries become very permeable

Introduce clotting proteins

A clot walls off the injured area

Formation of granulation tissue

Growth of new capillaries

Rebuild collagen fibers

Regeneration of surface epithelium

Scab detaches


Regeneration of Tissues

Tissues that regenerate easily

Epithelial tissue (skin and mucous

membranes)

Fibrous connective tissues and bone

Tissues that regenerate poorly

Skeletal muscle

Tissues that are replaced largely with scar tissue

Cardiac muscle

Nervous tissue within the brain and spinal

cord


Developmental Aspects of Tissue

Epithelial tissue arises from all three primary

germ layers

Muscle and connective tissue arise from the

mesoderm

Nervous tissue arises from the ectoderm

With old age, there is a decrease in mass and

viability in most tissues

cells and tissues - mrs. flieg's classroom - home · 2019-08-09 · cells at the apical...

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