Animal Tissues Animal Tissues and and

Organ Organ SystemsSystems

HomeostasisHomeostasis

Stable operating conditions in the internal Stable operating conditions in the internal environment environment

Brought about by coordinated activities of Brought about by coordinated activities of cells, tissues, organs, and organ systemscells, tissues, organs, and organ systems

TissueTissue

A group of cells and intercellular A group of cells and intercellular

substances that interact in one or more substances that interact in one or more

taskstasks

Four typesFour types

Epithelial tissueEpithelial tissue Muscle tissueMuscle tissue

Connective tissueConnective tissue Nervous tissueNervous tissue

OrgansOrgans

Group of tissues organized to perform a Group of tissues organized to perform a task or taskstask or tasks

Heart is an organ that pumps blood Heart is an organ that pumps blood through bodythrough body

Heart consists of muscle tissue, nervous Heart consists of muscle tissue, nervous tissue, connective tissue, and epithelial tissue, connective tissue, and epithelial tissuetissue

Organ SystemsOrgan Systems

Organs interact physically, chemically, or Organs interact physically, chemically, or

both to perform a common task both to perform a common task

Circulatory system includes the heart, the Circulatory system includes the heart, the

arteries, and other vessels that transport arteries, and other vessels that transport

blood through the bodyblood through the body

Epithelial TissueEpithelial Tissue

Lines the body’s surface, cavities, ducts, and tubesLines the body’s surface, cavities, ducts, and tubes

One free surface faces a body fluid or the One free surface faces a body fluid or the

environmentenvironment

simplesquamousepithelium

basementmembrane

connective tissue

Figure 33.3b, page 560

Simple EpitheliumSimple Epithelium

Consists of a single layer of cellsConsists of a single layer of cells

Lines body ducts, cavities, and tubesLines body ducts, cavities, and tubes

Cell shapes:Cell shapes:

Squamous Cuboidal Columnar

Figure 33.3c, page 560

Stratified EpitheliumStratified Epithelium

Two or more layers thickTwo or more layers thick

Functions in protection, as in skinFunctions in protection, as in skin

Cells in the layers may be squamous, Cells in the layers may be squamous,

columnar, or cuboidalcolumnar, or cuboidal

GlandsGlands

Secretory organs derived from epitheliumSecretory organs derived from epithelium

Exocrine glands have ducts or tubesExocrine glands have ducts or tubes

Endocrine glands are ductless Endocrine glands are ductless

Cell JunctionsCell Junctions

Tight junctions Tight junctions

prevent leaks prevent leaks

Gap junctions Gap junctions

connect abutting connect abutting

cytoplasms cytoplasms

Adhering junctions Adhering junctions

cement cells togethercement cells together

Figure 33.5, page 561

Connective TissueConnective Tissue

Most abundant tissue in the bodyMost abundant tissue in the body

Cells are scattered in an extracellular Cells are scattered in an extracellular

matrixmatrix

Matrix is collagen and/or elastin fibers in a Matrix is collagen and/or elastin fibers in a

polysaccharide ground substancepolysaccharide ground substance

Soft Connective TissuesSoft Connective Tissues

Loose connective

tissue

Dense, regular connective

tissue

Dense, irregular connective

tissue

Figure 33.6a-c, page 562

Specialized Specialized Connective TissuesConnective Tissues

Cartilage Bone Adipose tissue

Figure 33.6d-e, page 562-563

BloodBlood

Classified as a connective tissue because Classified as a connective tissue because

blood cells arise in boneblood cells arise in bone

Serves as the body’s transport mediumServes as the body’s transport medium

Red cells, white cells, and platelets are Red cells, white cells, and platelets are

dispersed in a fluid medium called plasmadispersed in a fluid medium called plasma

red blood cell

white blood cell platelet

Fig. 33-8, p.563

Muscle TissueMuscle Tissue

Composed of cells that contract when Composed of cells that contract when

stimulatedstimulated

Helps move the body and specific body Helps move the body and specific body

partsparts

Skeletal, cardiac, smoothSkeletal, cardiac, smooth

Skeletal MuscleSkeletal Muscle

Located in muscles that attach Located in muscles that attach

to bonesto bones

Long, cylindrical cells are Long, cylindrical cells are

striated striated

Cells are bundled closely Cells are bundled closely

together in parallel arraystogether in parallel arrays

Figure 33.9a, page 564

Smooth MuscleSmooth Muscle

In walls of many internal In walls of many internal

organs and some blood organs and some blood

vessels vessels

Cells are not striped and Cells are not striped and

taper at the endstaper at the ends

Figure 33.9c, page 564

Cardiac MuscleCardiac Muscle

Present only in the heartPresent only in the heart

Cells are striated and Cells are striated and

branchingbranching

Ends of cells are joined by Ends of cells are joined by

communication junctions communication junctions

Figure 33.9b, page 564

Nervous TissueNervous Tissue

Detects stimuli, integrates information, Detects stimuli, integrates information,

and relays commands for responseand relays commands for response

Consists of excitable neurons and Consists of excitable neurons and

supporting neuroglial cellssupporting neuroglial cells

NeuronsNeurons

Excitable cellsExcitable cells

When stimulated, an electrical impulse When stimulated, an electrical impulse

travels along the plasma membranetravels along the plasma membrane

Arrival of the impulse at the neuron Arrival of the impulse at the neuron

endings triggers events that stimulate or endings triggers events that stimulate or

inhibit adjacent neurons or other cellsinhibit adjacent neurons or other cells

NeurogliaNeuroglia

Constitute more than half of the nervous Constitute more than half of the nervous

tissuetissue

Protect and support the neurons, both Protect and support the neurons, both

structurally and metabolicallystructurally and metabolically

Primary TissuesPrimary Tissues

In vertebrate embryos, cells become In vertebrate embryos, cells become

arranged to form three primary tissuesarranged to form three primary tissues

EctodermEctoderm

MesodermMesoderm

EndodermEndoderm

These give rise to all adult tissuesThese give rise to all adult tissues

Major Organ SystemsMajor Organ Systems

IntegumentaryIntegumentary

MuscularMuscular

SkeletalSkeletal

NervousNervous

Endocrine Endocrine

LymphaticLymphatic

RespiratoryRespiratory

UrinaryUrinary

CirculatoryCirculatory

ReproductiveReproductive

Integumentary SystemIntegumentary System

An animal’s outer coveringAn animal’s outer covering

ExamplesExamples Chitin-hardened cuticle of many Chitin-hardened cuticle of many

invertebratesinvertebrates

Vertebrate skin and its derivatives Vertebrate skin and its derivatives

Vertebrate SkinVertebrate Skin

Two layersTwo layers Upper epidermisUpper epidermis

Lower dermisLower dermis

Lies atop a layer Lies atop a layer

of hypodermisof hypodermis

Figure 37.14Page 668

Functions of Human SkinFunctions of Human Skin

Protects the body from injury, Protects the body from injury,

dehydration, UV radiation, and some dehydration, UV radiation, and some

pathogens pathogens

Helps control temperatureHelps control temperature

Receives some external stimuliReceives some external stimuli

Produces vitamin DProduces vitamin D