Microanatomy trivia
Microanatomy Mini Quiz
Test your knowledge with these top questions!
What helps human alveoli stay open after exhalation?
Pulmonary surfactant lowers surface tension in the alveolar lining, helping prevent the air sacs from collapsing.
What do reuptake transporters do at many synapses?
Transporter proteins move signaling chemicals from the cleft into neurons or glial cells, helping end their effects.
What do calcium ions trigger at a chemical synapse?
An arriving action potential opens calcium channels; the influx makes synaptic vesicles merge with the terminal membrane.
At a chemical synapse, what carries a signal across the synaptic cleft?
Chemical messengers diffuse across the cleft and bind receptors on the receiving cell.
What does the nephron loop help create for urine concentration?
The loop's opposing flows make the renal medulla increasingly concentrated, allowing antidiuretic hormone to promote water reabsorption downstream.
What do human alveoli exchange with nearby blood capillaries?
Oxygen crosses the alveolar wall into blood, while carbon dioxide crosses from blood into alveolar air for exhalation.
Which neuron region usually triggers an action potential after inputs are integrated?
The axon initial segment contains many voltage-gated sodium channels, making the region a common trigger zone for action potentials.
How do electrical synapses pass signals between neighboring neurons?
Gap-junction channels link nearby cell membranes, letting ions flow directly between neurons.
Which nephron segment reabsorbs nearly all filtered glucose?
Normal kidneys reclaim nearly all glucose early in the tubule through sodium-linked transporters.
What is the main advantage of myelin around an axon?
Myelin insulates axons, reducing current loss and enabling rapid saltatory conduction between exposed nodes.