Sensory Organs Flashcards
What is a Sensilla?
A small hair like protrusion of the cuticle that allows for sensory perception, can be used for mechano-, chemo- and photo reception
What are the main mechanoreceptors?
Trichoid Sensilla, Hair plates, Stretch Receptors and Campaniform Sensilla
What cells make up a Trichoid Sensilla?
Trichogen Cell, Tormogen Cell, Sensory Neuron
What’s the function of hairs beds?
To detect movement and position of joints
Where are stretch receptors found?
Inside the Insects body associated with muscles
What’s the function of the Campaniform Sensilla?
Detect the strain and movement of the cuticle
Compared to humans how is insects ability to perceive sound?
It is superior with a range from 1-2 Hz up to 100 000 Hz
What is the purpose of Sound Perception in insects of the same species?
Courtship and Mating
What is the function of Sound perception in insects of different species?
Detection of predators
What two types of sound reception is there?
Non-tympanal, and tympanal
How does an insect conduct Non-tympanal Reception?
Sensitive elongated trichoid sensilla are able to detect vibrations of the air very close around them and the substrate that they are perched on
What is a chordotonal organ made of?
Many scolopidia and the Johnstons organ, able to receive vibration stimuli
What the function of the Johnstons Organ?
Within the pedicel of the antennae, senses movement of the antennae relative to the rest of the body
What is a Tympani?
Thin cuticular membrane able to receive sound
What Chordotonal Organs are associated with Tympani?
Subgenual organ, intermediate organ, crista acustica
What is the main body of a tympanum made of?
A trachea, separated into anterior and posterior halves
What are the functions of contact chemoreceptors?
Taste, Gustation, detection of aqueous chemicals
What are properties of Contact chemoreceptors?
Uniporous and thick walled
What are functions of airborne chemoreceptors?
Smell, olfaction, detection of low concentration volatile substances in the air.
Properties of Airborne chemoreceptors
Multiporous, thin walled
How do Airborne Chemoreceptors Perceive Chemicals?
Chemicals enter through pores, dissolve in fluid, bind to receptors on dendritic membrane
What part of the deutocerebrum integrates Antennae signlas?
The Macroglomerular Complex
What is Optomotor Anemotaxis?
Upwind flight, with visual progress tracking
What tool can we use to test the effects of semiochemicals?
Electroantennograms
What can Insects use pheromones for?
Kin reception, trail-marking, alarm, aggregation, courtship, etc.
What are Ocelli?
Simple eyes, made up of a transparent cuticular lens and retina made of retinular cells
What are Stemmata?
Simple eyes found in larvae of holometabolous insects located laterally, have a cuticular lens overlaying a crystalline lens focusing light onto a rhabdom made of retinula cells
What are compound eyes made of?
Aggregation of many many ommatidia, with high variety in number of ommatidia
What is the structure of the ommatidia?
Cuticular lens overlaying crystalline cone, focusing light onto 6-10 retinula cells making an aggregate rhabdom, encased by pigment cells
What makes a rhabdom?
Rhabdomeres of multiple retimula cells in close proximity, rhabdomeres are made of microvilli filled with visual pigment
What is a Fovea?
A high resolution area of the compound eyes caused by larger cuticular cone
What is an Apis Ommatidia?
Retinula cells rotate around one another with an additional ninth retinular cell at the base
What is a Lepisma Ommatidia?
Stacked Retinular cells contributing to different parts of the rhabdom
What is a Spodoptera Ommatidia?
Single domminating retinula cell decreases contribution to rhabdom closer to base, at the base an eighth retinula cell takes over major part of rhabdom.
What are some adaptations for nocturnal vision?
Clear zones, tapetum, reflective mirror surface made by a trachea at the base of the ommatidia
What are appositional eyes adapted for?
Diurnal vision, high resolution
What are superpostion eyes adapted for?
Nocturnal vision, low resolution, clear zone
What the difference between apposition and superposition eyes?
Superposition eyes have reduced pigment cells and clear zones allowing light to shine on all rhabdoms
What are Migrating pigment cells?
Pigment cells that are able to change their position in the eye to either create or eliminate a clear zone, changing form dark adapted to light adapted vision
How do moths navigate while flying?
maintain a constant angle realtive to the source of light they sense
What type of spectral vision do insects have?
Trichomatic vision, UV B G
What are nectar guides?
Co-evolution with flowers that display themselves in UV light to the insects they wish to use to pollinate
Who proved that bees can see colour?
Karl von Frisch
What types of patterns were bees better at distinguishing?
Vertical Patterns
What types of horizontal patterns can bees not distinguish?
solid shapes
What allows insects to distinguish polarity of light?
Microvillar organization of ommatidia
How do insects use Polarized light perception?
Homing behaviour in bees, Orientation in Odonata and Dipteran, Detection of water surface in aquatic insects
What is Polarotaxis?
Orientation and movement based on polarization of light
Which insects use binocular vision best?
Mantids
Do some insects have extraocular photoperception?
Yes
