Circulation and Gas Exchange Flashcards
What is Hemocoeal?
It is the insect body cavity with sinuses
What is the dorsal sinus called?
The pericardial Sinus
What is the structure that seperates the pericardial sinus?
The dorsal diaphragm
What is the ventral sinus called?
The perineural sinus
What separates the perineural sinus?
The ventral diaphragm
What allows for single direction circulation in appendages?
Septa
What is Hemolymph?
The fluid of the hemocoel carries nutrients, waste, hormones, chemical defense
What makes up hemoplymph?
Plasma and Hemocytes
What pumps the hemolymph?
The dorsal Vessel
What are the 2 sections of the dorsal vessel?
Aorta anterior, Heart posterior
What makes up the plasma of the Hemolymph?
Ions, Waste, Organic acids, Sugars (trehalose or glycerol-rarely), lipids, amino acids, proteins (Hexamerins, lipophorin)
What are the functions of hemocytes?
Phagocytosis, encapsulation of parasites and large foreign material, coagulation, storage and distribution of nutrients
What is the dorsal diaphragm made of?
Connective tissue and alary muscles
What are Ostia?
Arranged openings into the dorsal vessel with one way valves.
In what direction does hemolymph circulate?
postero-venterally, towards the venter and posterior
How does the ventral diaphragm aid circulation?
Pushes hemolymph back and to the sides from the venter
What are accessory pulsatile organs?
Additional pumps throughout the body that help move hemolymph, found at the base of appendages, antennae, legs, cerci and wings
What organ allows air to enter the gas exchange system?
Spiracles
How many spiracles are typical?
8, up to 10
What triggers the opening of spiracles?
Lack of oxygen and a build up of Carbon Dioxide
What are the three types of Spiracles?
Simple, Atriate, Filter
What are trachea?
paired invaginations of the epidermis, that aid in the transport of air through the body and shed at molting
What are Tracheoles?
Fine tubules that branch off of trachea, come into contact with cells to facilitate gas exchange
What are the four different Trachea?
Visceral, Dorsal, Ventral, and lateral trunk
What are the three phases of gas exchange?
Closed Spiracular, Flutter, Open spiracular
How is gas moved throughout the system?
Simple Diffusion and Ventilation
What are air sacs?
Dilated sections of trachea to serve as oxygen reserves
What are Ventilation Movements?
Body compression and expansion of trachea with coordinated opening and closing of spiracles
What do air sacs do?
Assist in flight, serve as an oxygen reservoir, decrease mass, give space for molting, have tympanic structures
What is characteristic of a Closed Tracheal System?
No spiracles, aquatic insects
Challenges of Aquatic insects with gas exchange?
Breaking the waters surface, keeping water out of spiracles, current, much lower concentration of oxygen in water
Whats a terminal spiracle?
Suspended from the water meniscus, water repellent hairs at the tip
What are piercing siphons?
Terminal spiracle with the capability of piercing the aerenchyma of plants
What are Hydrofuge Hairs?
Hairs with hydrophobic properties that let siphons get gas without letting water into the spiracles
What are Compressible Gills?
Air bubble on insects dorsal or ventral side that has relatively the same pressure as the atmosphere, allowing more oxygen to go in
What are Plastrons?
Made up of dense hydrofuge hairs on the surface of the bugs that trap air in a layer around the spiracles
What are Tracheal Gills?
Thin Cuticular layer that allows for O2 uptake across the membrane
