Internal Insect Morphology 1

Question 1

What are 4 characteristics of the internal insect structure?

Answer 1

Invertebrate- lacking a vertebrae
Ventral nerve cord
Dorsal vessel- not blood vessel
Open circulatory system

Question 2

What are the 8 major internal organ systems, and their roles?

Answer 2

Digestive
Obtain and assimilate food, remove waste products

Excretory
Remove nitrogenous waste products, involved in internal chemical and water balance

Respiratory
Obtain oxygen and remove carbon dioxide

Muscular
Movement, internally and through the environment

Circulatory
Transportation of items throughout the body, wound healing, storage

Nervous
A system of communication between stimuli and the organism

Reproductive
procreation

Endocrine
Growth, reproduction, change, internal communication

Question 3

What does the digestive tract do? (4)

Answer 3

Ingestion

digestion

absorption

egestion

Question 4

What is absorption?

Answer 4

passage of digested food molecules from the digestive tract to the hemolymph and body cavity

Question 5

What is egestion?

Answer 5

elimination of undigested food waste

Question 6

What makes up the digestive tract of an insect? (11)

Answer 6

labium
labrum
pharynx
esophagus
crop
stomodeal valve
ventriculus
malpighian tubules
pyloric valve
rectum
anus

Question 7

What is the labium? (2)

Answer 7

the bottom portion of the mouth, controls/ grabs the food

Possesses labial gland that produces saliva that breaks down food

Question 8

What is the labrum?

Answer 8

the roof of the mouth

Question 9

what does the crop do?

Answer 9

stores food

Question 10

what does the stomodeal valve do, and where is it?

Answer 10

Controls what the insect takes in for digestion

Between the foregut and the midgut

Question 11

What does the ventriculus do? (2)

Answer 11

Where digestion occurs, similar to the stomach
Epithelial cells produce enzymes to breakdown food

Question 12

What makes up the foregut?

Answer 12

intima
epithelial cells
basement membrane
longtiudinal muscles
circular muscles

Question 13

What is the intima?

Answer 13

in plant-feeding insects, to protect the insect from the plant’s defense mechanism
Most inner layer

Question 14

Where is the epithelial cells in the foregut?

Answer 14

layer unter the intima

Question 15

Where is the basement membrane, and what does it do?

Answer 15

under the epithelial cells
Prevents permeation

Question 16

Where is the longitudinal muscles, and what does it do?

Answer 16

layer under the membranous layer
Helps move food from the mouth to the crop

Question 17

What makes up the midgut?

Answer 17

stomodeal valve, ventriculus, and the malpighian tubule

Question 18

What is the malpighian tubule, and what does it do? (6)

Answer 18

slender tubes that run along the ventriculus

Where water and ionic balance occurs

The waste product is removed

assist in passive movement of sugars and ions

Actively transports larger molecules like potassium using water

Osmoregulates

Question 19

What does the pyloric valve do>

Answer 19

regulates food that goes from the midgut to the hindgut

Question 20

what are the three sections of the gut?

Answer 20

Foregut
midgut
hindgut

Question 21

what does the excretory system do?

Answer 21

Eliminates nitrogenous waste
Regulates water and ionic balance

Question 22

What is in the waste product?

Answer 22

amine group and hydrogen from water

Question 23

What is ammonia secreted by? (2)

Answer 23

excreted by small insects in moist environments
Easy to produce, but toxic

Question 24

what is urea secreted by?

Answer 24

excreted by most vertebrates
It is not as easy to produce, not as toxic

Question 25

what is uric acid secreted by?

Answer 25

secreted by most terrestrial insects Difficult to produce, not toxic

Question 26

What does the respiratory tract do?

Answer 26

Need oxygen, removed as CO2 Do not transport oxygen through the circulatory system

Question 27

What is cuticular diffusion used by?

Answer 27

used by small insects in moist environments

Question 28

What are spiracles?

Answer 28

openings in the exocuticle that are located laterally along the thorax and abdomen of most insects opens into the trachea, which opens into the tracheole

Question 29

what is the tracheole?

Answer 29

tubes that begin large and branch into successive smaller tubes as it penetrates deeper into the tissues

Question 30

what are air sacs? (4)

Answer 30

used by flying insects Increases the volume of air in the body for gas exchange Lowers specific gravity for flight Provides room for the growth of internal organs

Question 31

how do aquatic insects breathe?

Answer 31

gills

Question 32

what are spiracular tubes, where is it found, and an example?

Answer 32

used by aquatic insects Spiracles at the posterior end Ex- mosquito larvae

Question 33

what are plastrons? (4)

Answer 33

used by aquatic insects A thin layer of air around the body's surface Held by hydrophobic hair Spiracles open directly into this thin layer

Question 34

What does the circulatory system do?

Answer 34

Not significantly involved in the movement of oxygen and CO2 Movement of information

Question 35

what is the ostia?

Answer 35

small openings entering the dorsal vessel of the heart

Question 36

What is hemolymph, and what does it not contain?

Answer 36

insect blood does not contain hemoglobin- cannot transport oxygen

Question 37

What are the functions of hemolymphs? (8)

Answer 37

Lubricant for movement of internal structures Hydraulic medium for molting- Internal pressure Transports substances in the body from one tissue to the other- Waste products, hormones, amino acids, metabolites Contains specialized cells that encapsulate foreign particles Storage- Water and ions Phagocytosis Coagulation Wound healing

Question 38

What are hemocytes, and their 4 functions?

Answer 38

Hemolymph cells Phagocytosis Removes dead cells Migrates to wounds and forms a plug Congregate around foreign bodies

Question 39

What are the three neuron types?

Answer 39

Sensory Associated with sensory structures Motor Associated with muscles and glands Central nervous system