Neuro-6 Flashcards
What is the key difference between different mechanoreceptors?
The outer filter which determines what energy is able to access the mechanoreceptor
What are the components of the hearing sensory system?
The filter is mechanical or colcear
The transduction is mechano/electrical through the actions of a hair cell
Transmission occurs through an afferent neuron
Intergration and analysis occurs in speech spatial maps
How does signal reach the ear?
This is through pressure waves which are amplified through the actions of ear drum and the bones in the middle ear which insert the pressure fluctuations in to the fluid compartments of the inner ear in the cochlear where the receptors are located
The pressure wave is converted to a movement which can be detected by cilia through the basilar membrane which oscillates gently up and down, the hair cells are attached to this membrane and therefore will also move, this causes the cells to come into contact with the tectorial membrane which pushes backwards and forwards against the cilia
This causes the hair cells to change their membrane potential and release neurotransmitter to signal the afferent neuron
How are different frequencies detected in hearing?
The basilar membrane is different thicknesses which changes which regions will vibrate at different frequencies allowing the cochlear to act almost like a spectrum analyser with different afferent nerve fibres being activated
How can directional hearing be obtained?
Sound will arrive at one ear before the other allowing detection of the direction of the sound
Sound will also appear louder at one ear due to our head casting a “shadow” on the sound waves
How do the barn owls have such good sound localization?
It has developed facial features which allow for better channelling of the sound
How do hair cells acts as balance organs?
There are three semi circle canals which allow determination of angular movements or velocity as they are typically at right angles to plains of space
These canals are filled with fluid that will tend to stay still during movement as a result of its inertia
Sitting inside the ampullae here is a patch of hair cells which get pushed on by the fluid activating the mechanosensory hair cells to give information about the rotation of the head
What are otoliths?
Organs which allow determination of linear acceleration, one of these developed into the cochlea
What is the lateral line system of fish?
This contains mechanoreceptors that function similarly to the mammalian inner ear and provide fish with information concerning its movement through water or the direction and velocity of water flowing over its body allowing the fish to orientate itself appropriately
What are the two key components if the fish lateral line?
There are superficial neuromasts which tell the fish about water currents
There are canal organs which detect water vibrations telling the fish whats happening in the water around it
Where is insects sense of taste located?
In the sensillae on the feet and mouthparts
Where is mammals sense of taste located?
On the tongue with olfaction playing a large role
What are the two methods of sharks used to track blood?
Chemotaxis where it will swim in circles spiralling to the source through use of the olfactory system using the relative strength of the signal provided to each nostril to orientate itself
Rheotaxis where it will swim up the current unless it loses the scent where it will swim back and forth at right angles to the current
