Lecture 8 Flashcards
What two things overcome to fly?
Gravity and Air resistance
How to water strider walk on water?
Water is sticky so if an insects small enough and does not break through surface tension, they’ll walk. Their legs have little hair, microsity, that repel water. Entire body covered in them.
Indirect Flight
Conserve energy by using different muscles. Move muscles to get lifting motion and move different angles/speeds
Ex. Bees, flies, beetles, wasps, butterfly
Direct Flight
The wings are attached to the muscle. Wing is flapped after muscle pulled. Thorax is actually moving
ex. Dragon Fly (Odonata), and Mayfly (Ephemeroptera)
Haemocoel
This is a body cavity containing hemolymph
Haemocoel
This is a body cavity containing hemolymph
Nervous System
Carries input signals from sensors to CNS and action signals from CNS to
Functional unit= neuron
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Neuron
Node of ravier- uninsulated and allowed electric signal to jump nodes
Schwann cell- helps axon regrow in case of damage
How many exons brank out from nucleus?
Just one? Monopolar
2? Bipolar
more than 2? Multipolar
Synapse?
The area where two neurons meet or the connection between neurons. Neurotransmitters are released and swim until receptors pick it up.
Ex of neurotransmitters: Acetylcoline and Catecholoamines
Insect Neurobiology
Nervous system composed of interconnected cells called neurons where electrical charges (impulses) travel.
Impulses are carried across synapse by neurotransmitters
-NT are ACh and GABA and glutamate, released from pre-synapse, move across and received by post-synapse.
When NT bind successfully at receptor site, the cycle continues
Types of Neurons
1) Sensory neurons
2) Interneurons
3) Motory Neurons
4) Neurosecretory cells
Sensory neurons and Motor neurons and interneurons
carry messages from sensory receptors , and motor neurons regular the contraction of muscles. Interneurons usually mediate these actions
*the aggregated soma of motor neurons and interneurons make up ganglia of insect CNS
CNS
Theres the brain, then esophogus. Now from the beginning from esophogus, you have the thoracic ganglia(3) then abdominal ganglia(6).
* Numbers vary and may combine to one big ganglia
Hormones
1) Neurohormones released by corpus cardiacum
2) Juvenile Hormones released by corpus allatum
3) Ecdysteroid released by prothroric gland
4) Pre- ecdysis and ecysis triggering hormones by inka cells
Haemolymph
Insect blood
Haemolymph
Insect blood
Circulatory System
Transport Hormones, Nutrients, waste,
Ventilation for pressure, thermoregulation, water reserve, protect from injury/infection
RARELY TRANSPORT O2/CO2
Protection from injury/infection
Haemocytes-blood cells do a lot of work:
1) Phagocytosis- eat invading cell
2) Encapsulation- trap invading cell
3) Clotting-
4) Storage/distribute nutrients
Insect Heart
Dorsal vessel (aorta) Dorsal vessel (heart) Dorsal diaphram Ostia Ventral diaphram organ of antenna
Physiology and Gas Exchange
ANIMAL CELLS NEED ENERGY
get this from food
sugar+oxygen—>carbon dioxide and water
(also get ATP)
Spiracles
10 max, 2 thoracic, 8 abdomenal
-connected to trachea then to tracheoles then to cells, OXYGEN transported directly to cell
FOR OXYGEN TO GET INTO INSECT
Taenidia and Trachea
Trachea lined with Taenidia. Trachea is part of exoskeleton so it can be molted
Open system and Closed system
Cockroach system is very simple.
Bees have consistent air to keep flying
5-50% of body volume
Mosquito Larvae
They have anal breathing tubes, not spiracles
Caudal Gills and Internal Rectal Gills
Gills on terminal of abdomen
Ex. Damselfly naiad
Gills inside rectum
Ex. Dragonfly Naiad
How does gas exchange happen?
Diffusion and Ventilation, just works by moving, air moving in and air moves out.
