I had the same problem: I plug in headphones, and sound comes out of the headphones and my laptop speakers. Here's how I fixed this problem: Go to Sound Preferences [click on the Sound icon in the top-right, on the bottom of the menu, you'll see sound preferences ].Next, go to the Output tab.Here, look at the bottom, where it says  Connector: . I think mine was on Analog Speakers [or possibly Analog Headphones]. had the same problem: I plug in headphones, and sound comes out of the headphones and my laptop speakers. Here's how I fixed this problem: Go to Sound Preferences [click on the Sound icon in the top-right, on the bottom of the menu, you'll see sound preferences ].
Amino acidâbased hormones (amines and peptide or protein hormones) are water-soluble and act on the surface of target cells via second messengers; steroid hormones, being lipid-soluble, move through the plasma membranes of target cells (both cytoplasmic and nuclear) to act within their nuclei. Hormone secretion may occur in many tissues.
(These may respectively be called alkylamines and arylamines; amines in which both types of substituent are attached to one nitrogen atom may be called alkylarylamines.) Important amines include amino acids, biogenic amines, trimethylamine, and aniline; see Category:Amines for a list of amines.n aliphatic amine has no aromatic ring attached directly to the nitrogen atom. Aromatic amines have the nitrogen atom connected to an aromatic ring as in the various anilines.