Exam 2 Flashcards
Which of the following evolutionary adaptations result in increasing the speed of conduction of AP’s by decreasing the longitudinal resistance of the axon?
Increasing the diameter of the axon
Which of the following events is associated with depolarization of a neuronal membrane
Flow of cations into the cell
During the depolarization phase, the voltage hated Na+-channel is in what conformation?
Open, activated
Sensory adaptation refers to
The ability of receptors to become less responsive to a stimulus of a given intensity
The part of a visual photoreceptor in which the detection of light (signal transduction) is initiated is the
Outer segment
Statocysts are sensory organs used to perceive
An organisms orientation in space
A receptor neuron
Converts stimulus energy into AP’s, is specialized to respond to a particular sensory modality, can be found in a sense organ grouped with other cells (ALL OF THE ABOVE)
In sensory cells, amplification can be accomplished by
Signal transduction pathways
What is it called when a receptors potential reaches the spike initiating zone causing AP’s?
Generator potential
Which of the following tastes detects the presence of essential ions
Salty
Which of the following tastes does not use g-protein mediated pathways?
Sour
How can we smell so many different oderant molecules?
There are over a thousand different sequences of receptor proteins
Which of the following receptors detects deep pressure
Pacinian corpuscles
What is a part of an organ of equilibrium that a crustacean must pick up from the environment every time it sheds it’s exoskeleton?
Statolith
The steriocillia of hair cells in the organ of Corti are embedded in the
Tectorial membrane
The scalla media of the cochlea….
Is filled with endolymph
When rhodopsin is hit by photons, it…
Splits into opsin and all-trans-retinal
The functional subunit of the arthropod compound eye is…
The ommatidium
Which of the following in skeletal muscle shortens during the normal physiological muscle contraction?
I-band
Which of the following characteristics do skeletal muscle and smooth muscle have in common?
Sliding of thick and thin filaments relative to each other depends on a rise in cytosolic calcium
Depolarization of the t-tubule membrane causes mechanically-gated, calcium channels on the sarcoplasmic reticulum to
Open, leading to an elevation of cytosolic calcium levels
Stimulus intensity, or strength is encoded by
Frequency of AP’s with stronger stimuli eliciting higher frequencies
