Exam 2 Vocab

Question 1

Digestion Process (there are four steps):

Answer 1

1) Begins in the (pre-)oral cavity (buccal)
2) Saliva enters this cavity from salivary/labial glands
3) food then passes into the pharynx
4) then food passes into the esophagus

Question 2

Buccal Cavity

Answer 2

digestion begins here in the pre-oral cavity

Question 3

Pharynx

Answer 3

carries food to the esophagus using large and powerful muscles

Question 4

Esophagus

Answer 4

food passes through from the pharynx to the stomach.

Question 5

3 main regions of the insect gut

Answer 5

1) Foregut
2) Midgut
3) Hindgut

Question 6

Foregut

Answer 6

• primarily for the storage and release of food
• consists of crop and proventriculus
• connecting to the Midgut via the Stomodeal Valve
• its lining is sclerotized

Question 7

crop

Answer 7

enlargement of the digestive tract

Question 8

proventriculus

Answer 8

aka. “gizzard”; a thin-walled, glandular stomach

Question 9

stomodeal valve

Answer 9

• the valve present between the gizzard and midgut
• regulates the flow of food and prevents regurgitation

Question 10

Intima

Answer 10

sclerotized gut lining
- the innermost coat of an organ (as a blood vessel)
- consists of an endothelial layer backed by connective tissue and elastic tissue

Question 11

Midgut

Answer 11

• site of most digestion and absorption

Question 12

gastric caeca

Answer 12

a blind-ending lateral diverticula

Question 13

peritrophic membrane

Answer 13

a network of chitin filaments in a protein-glycoprotein matrix

Question 14

Hindgut

Answer 14

• The primary function is water and mineral reabsorption
• includes the anterior intestine (ileum/colon)
• is lined with sclerotized intima

Question 15

Fat Body

Answer 15

• a white or yellow tissue formed of loose sheets or lobes
• serves a wide variety of metabolic functions
• similar to the vertebrate liver

Question 16

Excretion

Answer 16

nitrogenous waste products excreted by insects, such as:
- ammonia
- uric acid
- urea

Question 17

Malpighian Tubules

Answer 17

• the main organs of nitrogenous waste excretion
• suspended in the hemocoel and processing hemolymph like the nephron of a vertebrate kidney

Question 18

Rectum

Answer 18

plays a major role in reabsorption of water and material

Question 20

Open Circulatory System

Answer 20

where the “Hemolymph” circulates within the “Hemocoel”

Question 21

Hemolymph

Answer 21

• the insect body fluid that circulates within the “Hemocoel”
• can be 20% or more of total body weight
• contains plasma, food, hormones, and cells

Question 22

Hemocoel

Answer 22

the general body cavity where “Hemolymph” circulates through

Question 23

Hemocytes

Answer 23

• are all nucleated
• serve 4 major functions:
  1) Phagocytosis
  2) Encapsulation of foreign bodies/microbes
  3) Hemolymph coagulation
  4) Storage & distribution of nutrients

Question 24

Dorsal Vessel

Answer 24

• a major vessel running from back to front just under the dorsal surface
• contracts in pulses to propel the Hemolymph forward

Question 25

Ostia

Answer 25

openings in the posterior part of the dorsal vessel where Hemolymph enters through

Question 26

Alary (“winglike”) muscles

Answer 26

Support the “heart” and attach it to the body wall, but do not contract to move the fluid

Question 27

Aorta

Answer 27

• the anterior part that runs through the thorax and into the head
• this region doesn’t contract or have ostia openings

Question 28

Two major diaphragms

Answer 28

1) Dorsal Diaphragm
2) Ventral Diaphragm

Question 29

Dorsal Diaphragm

Answer 29

• Flow of hemolymph is directed and compartmentalized
• located below the dorsal vessel

Question 30

Ventral Diaphragm

Answer 30

• Flow of hemolymph is directed and compartmentalized
• located above the ventral nerve cord

Question 31

Accessory Pulsatile Organs

Answer 31

• assist the flow of hemolymph into appendages (antennae, wings, legs)
• are present for pumping fluid in and through “detours”

Question 32

Respiration

Answer 32

In insects, oxygen is not carried by specialized circulatory cells; instead, it passes into and throughout the body via the Trachea

Question 33

Trachea

Answer 33

a network of tubes that carries oxygen into and throughout the body

Question 34

Spiracles

Answer 34

• when air enters the body filters/valves to prevent the entry of foreign particles in order to limit water loss
• about 10 pairs or less
• line the thorax and abdomen

Question 35

Intima

Answer 35

• similar to the gut lining
• consist of a lining, shed at molting, in the tracheal tubes

Question 36

Taenidia

Answer 36

• spiral ridges or thickenings, giving flexible
  strength (like the hose of a vacuum cleaner)
• also in tracheal tubes

Question 37

Tracheoles

Answer 37

• Tracheal tubes that branch into smaller and smaller tubes until coming to small, fluid-filled blind endings
• are in intimate contact with metabolizing tissues
• at this point, the gas exchange happens via diffusion

Question 38

Special respiratory adaptations of aquatic insects

Answer 38

• Many have “closed” systems involving gills
• Others have open spiracles at the end of “snorkels”
• Some trap air bubbles and carry them below to breathe from