Answer to Question 1
Answer: Pain signals are transmitted to the spinal cord and from there to the thalamus and to various cortical regions (anterior cingulate, primary and secondary somatosensory cortex). Pain reactivity can be diminished by interrupting the ascending pain pathways, by reducing the activity of the anterior cingulate cortex (reduced aversiveness), or by activating a descending neural circuit from the PAG to the spinal cord.
Answer to Question 2
Answer: Taste receptors code for five qualities (sweetness, bitterness, sourness, saltiness, and umami). Each receptor type involves a different transduction process. Hydrogen ions generate a sour taste, which controls a potassium channel. Bitter and sweet tastes are coded for by receptors containing gustducin and that reduce cyclic AMP. Sweet receptors also are coded by gustducin receptors but increase cyclic AMP. The umami signal involves a specific glutamate receptor (mGluR4). The pleasant taste of fat seems linked to receptors that detect free fatty acids in foods.
An example of sodium balance achieved by the coordinated actions of three hormones.
Areas of Referred Pain, Posterior View
The titration curve of phosphoric acid (H3PO4), a common buffer in biological sy
Selected Biological Response Modifiers
Major Muscles: Origins, Insertions, and Actions