Exam 2 Flashcards
What happens to these receptors when the tympanum vibrates?
They become deformed
How do these receptors respond to energy contained in selected stimuli?
they change the permeability of the cell membrane to positively charged neurons
What is a tenant of modern ethology?
Observing and efficiently describing behavior
How does one use behavioral quantification to build a better understanding of an animals umwelt
action patterns
moths can detect ____ of bats
High frequency sounds
What is the echolocation hypothesis
The suggestion that bats use high frequency sounds to listen to echos reflected back
- can estimate distance by measuring time delay
- can determine shape and size
What do moth ears consist of?
A thin flexible sheet of cuticle that lies over a chamber on the side of the thorax called a tympanum
The effected stimuli for the auditory receptor is provided by the…
tympanum which mechanically stimulates the receptor cell, opening stretch-sensitive channels in the cell membrane
A1 and A2 receptors are linked to relay cells called…
interneurons
How does the inflow of positively charged ions change the cell?
It changes the charge inside the cell which is normally more negative and causes the nerve to fire, sending a signal down the axon
- called an action potential
Does the A1 receptor have poor or great sensitivity?
great sensitivity
What does the A1 receptors great sensitivity allow for?
It allows it to generate action potentials in response to the cries of little brown bats up to 30m away (this is BEFORE bats can detect a moth)
Rate of firing with an A1 receptor is proportional to the loudness of the sound. This provides information about what?
the direction the bat is moving and the bats location in space
- also allows moths to know if the bat is above or below it due to the oscillations when the moth beat their wings up and down
When the bat is close to the moth, which receptors fires in the moth?
the A2 receptors
what are the special features of moth ears?
1) the A1 receptors are sensitive to the ultrasounds of low to moderate intensity whereas the A2 receptors begin to produce action potentials only when the ultrasound is loud
2) A1 receptor fires much more frequently in pulses of sound rather than long sounds
3) sound increases = A1 receptor fires more often and with a shorter delay
4)receptor cells don’t respond at all to low frequency sounds
A1 receptors fire rapidly but…
slows after a bit of a constant buzz
A1 receptors fires ONLY…
on high intensity calls
A1 receptors are sensitive to both…
high and low intensity bat feeding buzzes
which receptor is the main bat detector?
the A1 receptor
Which receptor is the emergency system?
the A2 receptor
What is stimulus filtering?
The ability of neurons and neural circuits to filter out large amounts of info in order to focus on biologically relevant elements
Explain the nose appendages of the star nosed mole
Appendage 2 is the most sensitive but does not contain more emmers’ organs than the other appendages, instead it uses more neurons. It’s named the tactile fovea
- moles also dedicates more brain function to the nose so that info from the nose travels through nerves to the somatosensory cortex
What is the somatosensory cortex?
It decodes sensory signals from tough receptors
How much of the somatosensory cortex is dedicated to the 22 nose appendages?
25%