Page 44 - Human anatomy COMPLETELY DONE1

HUMAN ENDOCRINE GLANDS (ENDOCRINE GLANDS)
The endocrine glands, or endocrine glands, produce hormones that flow directly
into the blood or lymph.
Hormones are compounds belonging to a group of biologically active substances.
Hormones act on "target" cells, as a result, biochemical processes change in these cells.
Hormones are able to have an effect, being in the blood in very small quantities, so the
endocrine glands are small organs.
The regulation of the body's work through hormones is called humoral
regulation. In addition, the work of the human body is regulated by the nervous system
(nervous regulation).
The work of the endocrine glands themselves is regulated by both the nervous
and humoral systems. In the latter case, some glands produce hormones that affect the
production of hormones by other endocrine glands.
The glands of internal secretion can be attributed to (figure 31):
 Hypothalamus

 Pituitary gland
 Epiphysis
 Thyroid gland
 Parathyroid glands
 Adrenal glands
 Thymus, or thymus gland
 Pancreas
 Ovaries (in women)

 Testicles, or testes (in men)
The last three of the above are glands of mixed secretion. In addition to
hormones, they secrete substances or cells that do not enter the blood and are not
hormones. This is how the pancreas secretes digestive enzymes into the duodenum.
And the sex glands produce eggs or spermatozoa.
The hypothalamus is part of the intermediate brain. In addition to neurons of the
usual type, it has neurosecretory cells that produce substances of a protein nature that
stimulate or inhibit the production of pituitary hormones.
Neurosecretory cells convert a nerve impulse into a neurohormonal one. These
cells respond to impulses coming to them like ordinary nerve cells, but when excited,
they also secrete substances that affect the pituitary gland, and it in turn changes the
state of other endocrine glands.
Thus, through the hypothalamic-pituitary system, the nervous system can
enhance or inhibit the secretory activity of the endocrine glands. Also, the
hypothalamus is able to "assess" the concentration of hormones in the blood and,
depending on this, transmit signals through the nervous system and stimulate the
production of its own hormones and the pituitary gland.

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