Insect Anatomy, Physiology, And Development

Front 1

metameres

Back 1

series of segments

Front 2

tagmata (sing. tagma)

Back 2

regions

Front 3

3 regions of insect body:

Back 3

thorax: locomotion; has legs and wings
abdomen: houses viceral organs; digestive, excretory, reproductive system components
head: sensory perception, neural integration, food gathering

Front 4

sclerites

Back 4

hardened plates developed in arthropods in skeletal system; make up the exoskeleton

Front 5

Structure of body wall

Back 5

epidermis: cellular layer
basement membrane (basal lamina): thin acellular layer below the epidermis
cuticle: secreted by cells of the epidermis

Front 6

endoskeleton

Back 6

supports, braces, ridges for muscle attachment

Front 7

cuticle

Back 7

secreted by cells of the epidermis; made up of chains of polysaccharide, chitin embedded in a protein matrix; cuticle hardness is from modifications of the protein matrix

Front 8

chitin chains

Back 8

they intertwine to form microfibrils -> laid down in a layer called a lamina

Front 9

procuticle

Back 9

soft, pliant, expandable; but the formation of sclerites in this cuticle makes it hard and dark through a process called sclerotization

Front 10

exocuticle

Back 10

a sclerotized cuticle

Front 11

endocuticle

Back 11

below exocuticle; forms the membranes that connect sclerites and can be reabsorbed into the body before molting

Front 12

epicuticle

Back 12

atop both endo and exo; thin acellular layer; no chitin layers-cuticulin (wax) and cement layer

Front 13

wax layer of the epicuticle:

Back 13

important to terrestrial insects to limit water loss across the body wall

Front 14

sulcus

Back 14

external grooves marking an infolding of cuticle of the outer body wall (subdivides sclerites)

Front 15

costae

Back 15

internal ridges usually corresponded to lines of inflection seen externally (sites of muscle attachment)

Front 16

abdomen

Back 16

max. 11 metameres; dorsal sclerite of each metamere = tergum; ventral sclerite = sternum; membranous lateral region = pleuron; genitalia located on or about abd. segment 8-9

Front 17

spiracles

Back 17

openings to respiratory system (located on pleuron)

Front 18

cerci

Back 18

sensory organs, sometimes modified as defense organs or specialized as accessory copulatory organs

Front 19

thorax

Back 19

3 segments: pro, meta, meso; terga on the thorax -> nota (notum); meta and mesothorax = pterothorax (several modifications associated with flight

Front 20

cervix

Back 20

membranous necklike region connects prothorax to head

Front 21

legs

Back 21

sclerotized and segmented (typ. 6); coxa (basal seg), trochanter, femur, tibia, tarsus, pretarsus

Front 22

joints may be:

Back 22

dicondylic (two points of articulation)
monocondylic (single point of articulation) like ball and socket

Front 23

wings

Back 23

outgrowths of bodywall (between nota and pleura) strengthened by sclerotized veins; muscles that move them attached to sclerites not to wings; movements produced indirectly by change in shape of thorax

Front 24

veins

Back 24

hollow structures may contain veins, tracheae, and hemolymph

Front 25

6 major veins

Back 25

costa (not branched, at leading edge of wing) - subcosta (can be branched once) - radius - media - cubitus - anal veins

Front 26

wings attach to thorax at three points

Back 26

notum at anterior and posterior notal wing processes and ventrally at the pleural wing process

Front 27

axillary sclerites

Back 27

at base of wing, are imp. in translating movements of thoracic sclerites into wing movements (most insects have 3)

Front 28

flight

Back 28

insects can steer accurately and quickly, hover, and go sideways, backward; forces: lift, thrust, altitude control

Front 29

flight is caused by:

Back 29

direct flight mechanism: thoracic muscles pulling on base
indirect flight mechanism: causing changes in the shape of the thorax-translated by axillary sclerites into wing movements (primary flight for most insects

Front 30

head

Back 30

metameric body segment; eyes antenna, mouthparts; connected to thorax by membranous cervix

Front 31

Head appendages of hexapods from back to front:

Back 31

labium, maxillae, mandibles, labrum, antennae

Front 32

hypognathous

Back 32

(ancestral condition) mouth parts directed downward

Front 33

prognathous

Back 33

directed anteriorly (predatory, burrowing)

Front 34

antennae

Back 34

paired segmented appendages between or