Animal Organization

8/8/2019 Animal Organization

1/75


2/75

are a major group of mostlymulticellular,eukaryotic organismsof the kingdom

Animalia or Metazoa. Most are motile, meaning they can move

spontaneously and independently.

are also heterotrophs, meaning they

must ingest other organisms forsustenance.

comes from the Latin word animal

(meaning with soul, from anima, soul).


3/75

multicellular with well-developed tissues

usually motile; heterotrophic by

ingestion; diplontic life cycle classified based on the type of

symmetry, number of tissue layers, typeof coelom, and presence of segmentation


4/75

As to the presence of backbone

As to symmetry

As to type of Body Coelom


5/75

1. Invertebrates

o an animal without a skeletal structure.The group includes 95% of all animal

species all animals except those inthe Chordate subphylum Vertebrata(fish,reptiles,amphibians,birds, andmammals).


6/75

2. Vertebrates

o are members of the subphylumVertebrata,chordates with backbones

or spinal columns.


7/75


8/75

There are three types of symmetry.

Spherical

Radial

Bilateral


9/75

Spherical symmetry occurs mainlyamong protozoans.

Radial symmetry occurs among the

Cnidarians (jellyfish) and Echinoderms(starfish, sea urchins).

Bilateral symmetry commonest form ofsymmetry. When cut at the center of the

body, it will produce two identical halveswith definite right and left halves.Worms, mollusks, arthropods,echinoderms, and chordates.


10/75

A variety of descriptive terms are used toA variety of descriptive terms are used todescribe orientation in bilateral animals.describe orientation in bilateral animals.


11/75

An animals body results from division ofcells during embryonic development.

Differences in developmental patternshave been used to classify more complexanimals so an understanding of basicembryology is necessary to follow this.


12/75

Once an egg is fertilized it becomes azygote. This cell divides into a largenumber of cells called blastomeres.

Cleavage of cells proceeds until a fluid-filled hollow ball of cells is formed. Thisis a blastula.

In multicellular animals other thansponges the blastula invaginates to beginforming the future gut. At this stage theembryo is a gastrula.


13/75


14/75

The invaginating layer of cells, which willgive rise to the gut, form a germ layercalled the endoderm. The endoderm

surrounds and defines a body cavitycalled the gastrocoel.

The cells not involved in forming the

invagination constitute another germlayer the ectoderm. The ectodermsurrounds a cavity called the blastocoel.


15/75

gastrocoel


16/75

When the invaginating gastrocoel forms acomplete tube by forming a secondopening to the outside it is then called

the gut.

In the cnidarians (jellyfish, seaanemones) no second opening develops.


17/75

In most animals (but not cnidarians,which are two-layered or diploblastic) athird germ layer of cells called themesoderm develops.

The mesoderm gives rise to manyinternal organs. Organisms withmesoderm are called triploblastic

having three germ layers.


18/75


19/75

Endoderm: innermost germ layer of anembryo. Forms the gut, liver, pancreas.

Ectoderm: Outer layer of cells in early

embryo. Surrounds the blastocoel.Forms outer epithelium of body andnervous system.

Mesoderm: Third germ layer formed in

gastrula between ectoderm andendoderm. Gives rise to connectivetissue, muscle, urogenital and vascularsystems and peritoneum.


20/75


21/75

The way in which the mesoderm forms,and whether or not a cavity (called acoelom) develops within it, are

important characters in deciphering therelatedness of animal groups.


22/75

The coelom is a cavity entirelysurrounded by mesoderm.

A coelom provides a tube-within-a-tubearrangement which has manyadvantages: Allows flexibility in arranging visceral organs

permits greater size and complexity byexposing more cells to surface exchange

fluid-filled ceolom can act as a hydrostaticskeleton


23/75


24/75

Triploblastic organisms (organisms withthree germ layers including mesodermfall into one of three different coelomicstates: Acoelomate: mesoderm fills the blastoceol,

no cavity occurs in the mesoderm. Flatwormsand nemerteans.

Pseudocoelomate: mesoderm lines onlyouter edge of blastocoel. No peritoneal lining

develops. Nematodes and rotifers. Eucoelomate: Have a true coelom derived

from mesoderm and lined with peritoneum.Arthropods, annelids, mollusks, echinoderms,vertebrates.


25/75

Both eucolomate


26/75


27/75


28/75

Within the eucolomates there are twomajor evolutionary lineages that splitearly in the history of animals and followquite different developmental pathways.

These are the protostomes mouth firstand deuterostomes mouth second .


29/75

The differences in development thatdistinguish the protostomes anddeuterostomes include:

Whether cleavage of cells in the early zygoteis spiral or radial.

Whether or not, if the early blastomere isseparated, each cell can develop into a normallarva or not.

Whether the blastopore ultimately forms themouth or anus of the organism.

Whether or not the organism possesses acoelom and how that coelom is formed.


30/75


31/75


32/75

Protostomes include the annelids,mollusks, and arthropods.

Deuterostomes include the echinodermsand vertebrates.


33/75


34/75


35/75

Ectoderm, mesoderm, and endoderm areembryonic tissues that give rise to all ofthe tissues, organs, and organ systemsin the body.


36/75

Ectoderm forms the outer layer of skinand nervous system.

Mesoderm forms the muscles,

connective tissues, skeleton, kidneys,and circulatory and reproductive organs.

Endoderm forms the lining of the gut,respiratory tract, and urinary bladder. Italso forms the glands associated with thegut and respiratory tract.


37/75


38/75

Epithelium

ConnectiveMuscle

Nervous


39/75

Lines, covers, and protects externalsurfaces and internal cavities andorgans.

Forms continuous layer of compactly

arranged cells Cells have two ends, one end free or

exposed to external or internalenvironment, the other end attachedor supported by a basement

membrane


40/75

1. Simple epithelial tissue

composed of one layer of cells

Linings of blood vessels, ducts, digestivetracts

Squamous Epithelium - Frog Skin Flat Mount


41/75

2. Stratified epithelial tissue

Composed of two or more layers ofcells

Located in sites subjected to friction orpressures such as skin (keratinized), vagina,esophagus (non-keratinized)

Stratified Squamous Epithelium, Human sec. X 100


42/75

3. Pseudostratified epithelial tissue

All cells are in contact with thebasement membrane but not reach

the surface Lining of the respiratory tract, urethra of

males

Pseudostratified Ciliated Columnar Epithelium


43/75

1. glandular epithelial tissue- for secretion of chemicals

a. Unicellular glandular epithelial tissue

- goblet cells in intestines

b. Multicellular glandular epithelial tissue could be with ducts (exocrine glands)such as sweat glands and oil glands, or

without ducts (endocrine glands) suchas the thyroid and adrenals


44/75

2. Sensory epithelial tissue

- for reception of stimuli andtransmission of impulses; located in the

sense organs, skin, retina, tongue

3. Germinal epithelial tissue

- for reproduction; located in the sex

organs, ovary and testis.


45/75

1. Squamous epithelium flat cells, liningof mouth, esophagus

2. Cuboidal epithelium- cube-shaped cells,

lining of kidney tubules3. Columnar epithelium pillar-shaped

cells with the nuclei usually located nearthe bottom of each cell; lining oftrachea, small intestines


46/75


47/75


48/75

Cells cube shaped- secretionand absorption. Kidney tubules

Duct and small glands

Surface of ovary


49/75


50/75

Binds structures together, connects manybody parts

Provides support and protection

Fills spaces, stores fat, and forms bloodcells

With abundant intercellular materials(matrix) composed of collagenous

and/or elastic fibers


51/75

1. Loose connective tissue

loose arrangements of fibers in the matrix

cells (fibroblasts) are farther apart andseparated by jelly-like matrix with white

collagen fibers (for flexibility and strength)and yellow elastic fibers (for elasticity)

Lies beneath the epithelium of the skin andmost of the internal organs.


52/75

a. Mesenchyme

- during embryonic development;disappears in the adult; composed of finefibers in fluid matrix.

b. Mucous connective tissue

- composed of large and stellatefibroblasts in soft and jelly-like matrix withfine collagenous fibers; umbilical cord.

c. Reticular connective tissue

- composed of stellate cells in matrix withreticular fibers; lymphoid organs, bonemarrow, liver.


53/75

d. Areolar connective tissue

- composed of round/oval cells in matrixwith collagen and elastic fibers;mesenteries, omentum of alimentary

canal, subcutaneous tissue, submucosa ofdigestive tract.

e. Adipose connective tissue

- no formationof matrix; storage of fats;composed f globular with nucleicompressed in the peripheral rim ofcytoplasm.


54/75


55/75

2. Dense (fibrous) connective tissue Contains many collagen fibers that are packed

closely together

More specific functions in vertebrates than loose

connective tissues With less amorphous ground substance

a. Irregular arranged dense connective tissue

- occurs in sheets; with coarse, tough networkof fibers; dermis of skin, cartilage, fascia

b. Regular arranged dense connective tissue

- with densely packed fibers parallel to eachother, tendon, ligaments, aponueroses


56/75


57/75

3. Specialized connective tissuea. Cartilages

Skeleton during embryonic stage composed of dells(chondrocytes) located in small spaces called lacunaewith collagenous or elastic fibers.

b. Bones or osseous tissues Rigid form of connective tissue; comprises most of

the skeleton in higher vertebrates; composed of cells(osteocytes) located in small cavities (lacunae) ofcalcified matrix; radiating from each lacuna arenarrow channels (canaliculi) which penetrate adjacent

canaliculi of neighboring lacunae forming lamallarstructure.


58/75

c. Hemopoietic tissue

formation and maturation of blood cells;lymphoid tissue- located in the lymphnodes, liver ands spleen; forms

lymphocytes and monocytes; myeloidtissue- located in bone marrow; formserythrocytes and granulocytes.

d. Blood

Composed of blood cells (erythrocytes,

leukocytes and thrombocytes) and a fluidintercelluler substance (plasma).


59/75

White Fibrous Connective Tissue X 200Hyaline Cartilage X 200

Bone, dry ground human c.s. X 100 Human Blood, Wright Stain X 1000


60/75

For contraction to produce movement

Cell (muscle fiber) is enclosed bysarcolemma and contains sarcoplasm

where the contractile elements(myofibrils) are located


61/75

1. Smooth involuntary muscle tissue also called visceral muscle

Composed of elongated cells within taperedends (fusiform)

Contains homogenous or clear sarcoplasm andcentrally located nucleus

Found in internal organs which bring aboutinvoluntary movement in these organs


62/75

2. Striated voluntary muscle tissue Also called skeletal muscle

Composed of long, cylindrical cells(filamentous)

Contains thin and transparent sarcolemma Sarcoplasm contains parallel rows of myofibrils

with alternating light (l band) and dark bands(A-band) forming striations

Multinucleated

Found attached to the skeleton responsible forthe voluntary movement of the body


63/75

3. Striated involuntary muscle tissue Also called cardiac muscle

Composed of linear branching bundles offibers joined end to end by the intercalateddisc

With elongated nucleus centrally locatedbetween diverging cells

Found in the walls of the heart bring about

the involuntary contraction of the organ


64/75


65/75


66/75


67/75

For reception of stimuli and transmissionof impulses

Consists of neuroglia and neurons

Motor Neuron X 200


68/75

Nueroglia

Supporting cells for the nourishment,protection and insulation of the neurons

Undergo cell division, thus may cause brain

tumor


69/75

Astrocytes

Star-shaped neuroglia located betweenneurons and capillaries

Microglia

Phagocytes, dispose dead cells of the system

Ependymal cells

Line the fluid filled cavities of the centralnervous system

OligodendrocytesForm the myelin sheath aroung the fibers

Schwann cells and satellite cells


70/75

Made up of cell body (perikaryon) andone or more protoplasmic processses

( axon and dendrites)

Do not undergo cell division Responsible for reception of stimuli and

transmission of impulses


71/75


72/75

1. Unipolar neuron With only one protoplasmic process, found in

dorsal root ganglion of the spinal cord.

2. Bipolar neuron With two protoplasmic processes (axon and

dendrites); found in the retina of the eye.

3. Multipolar neuron With several dendrites and one axon; found in

ventral horns of the gray matter of the spinalcord.


73/75

Sensory neuron

Transmit impulses from sensory receptors ofthe sense organ to nerve center (CNS)

Motor neuron

Transmit impulses from the nerve to theeffectors (muscle or glands)

Adjustor or associative neuron (interneuron)

Connects sensory and motor neurons; located

in the nerve center.


74/75


75/75

Animal Organization

Documents

Transcript of Animal Organization