Endocrine System
This hormone helps regulate long-term stress by increasing glucose levels and suppressing the immune system.
What is cortisol?
The sodium-potassium pump moves these two ions in opposite directions to maintain resting membrane potential.
What are sodium (Na⁺) and potassium (K⁺)?
This ion triggers neurotransmitter release at the synaptic terminal.
What is calcium (Ca²⁺)?
The sliding filament model explains that myosin pulls on this filament during muscle contraction.
What is actin?
Why did the sarcomere file a complaint?
Because it was being stretched too thin!
High levels of juvenile hormone (JH) in insects prevent this major developmental transition.
What is metamorphosis?
These channels open in response to depolarization and allow Na⁺ to rush into the neuron, initiating an action potential.
What are voltage-gated sodium channels?
These sensory receptors detect physical stimuli like touch, pressure, and vibration.
What are mechanoreceptors?
ATP binds to this protein in the sarcomere, allowing for detachment and resetting of the cross-bridge cycle.
What is myosin?
Why don't myosin and actin ever fight?
Because they always slide past their differences!
This hormone is released by the hypothalamus and stimulates the anterior pituitary to secrete FSH and LH.
What is gonadotropin-releasing hormone (GnRH)?
This type of neuron has long dendrites to collect sensory input and transmits signals toward the central nervous system.
What is a sensory neuron?
The cochlea is tonotopically organized, meaning its base detects these types of frequencies, while its apex detects the opposite
What are high frequencies (base) and low frequencies (apex)?
This protein stores and releases calcium ions in muscle fibers to trigger contraction.
What is the sarcoplasmic reticulum?
Why did the photoreceptor refuse to go out at night?
Because it didn't want to be left in the dark!
A tumor in the adrenal cortex that secretes excess aldosterone would cause these two physiological effects.
What are increased sodium retention and high blood pressure?
This mechanism prevents action potentials from traveling backward along an axon.
What is the refractory period?
In vision, light activates rhodopsin, which causes this molecule to change from a cis to a trans conformation.
What is retinal?
During muscle contraction, these two sarcomere regions shorten, while the A band remains the same length.
What are the I band and H band?
Why are neurons bad at relationships?
Because they have too many connections but no real commitments!
In negative feedback, this happens to ADH secretion after hydration is restored.
What is inhibition (or a decrease in ADH secretion)?
Myelinated neurons use this type of conduction, which allows action potentials to "jump" between nodes of Ranvier.
What is saltatory conduction?
Otoliths in the vestibular system respond to these two types of motion.
What are gravitational pull and linear acceleration?
This neurotransmitter is released at the neuromuscular junction to initiate muscle contraction.
What is acetylcholine (ACh)?
Why don't caterpillars trust their hormones?