The number of cycles per second (Hertz) (abbreviated as, hz) of anything that oscillates is called the frequency. The electricity of an AC wall outlet is said to have a frequency of 60 Hertz as it cycles negative then positive 60 times each second. Sound is an oscillating wave, but it has a broad range of frequencies. A low frequency sound (say, 50 hz) might sound like a low rumble, while a high frequency sound (say 12,000 hz), might sound more like a sizzle. A person with normal hearing can hear all the way up to about 20,000 hz.
The noun SECRETORY PHASE has 1 sense: 1. the second half of the menstrual cycle after ovulation; the corpus luteum secretes progesterone which prepares the endometrium for the implantation of an embryo; if fertilization does not occur then menstrual flow begins Familiarity information: SECRETORY PHASE used as a noun is very rare.
Secretory Vesicle: Cell secretions-e.g. hormones, neurotransmitters-are packaged in secretory vesicles at the Golgi apparatus. The secretory vesicles are then transported to the cell surface for release. Cell Membrane: Every cell is enclosed in a membrane, a double layer of phospholipids (lipid bilayer).