Endocrine system Flashcards
Circadian rhythm
Sleep / wake cycle. Biological processes that follow a 24-hour cycle
Colostrum
Firstly produced breast fluid containing water, lacto-sugar & antibodies. Acts as a laxative to encourage BM which removes bilirubin build up
Corpus luteum
A hormone secreting structure that develops in an ovary following ovulation
Glands
There are two type of glands: Exocrine and Endocrine.
Glands; Endocrine
Ductless, secreting hormones directly into the blood. Inc. Hypothalamus (neuroendocrine gland), pituitary (glandular and neuroendocrine), pineal, thyroid, parathyroid, adrenal, pancreatic: islets of Langerhans, Thymus, Ovaries, Testes
Glands; Exocrine
Excrete products into ducts leading to body cavities / organ / skin e.g. salivary glands (saliva), gastric glands (digestive enzymes), mammary glands (milk)
Homeostasis system controls (x 2)
Two control systems control homeostasis;
Endocrine and Autonomic Nervous System:
Endocrine system;
Slower change, More precise
Longer duration, Hormones,
Control centre = hypothalamus
Autonomic nervous system;
Rapid change, less precise
Shorter duration, neurotransmitters,
Control centre - central nervous system
Hormones
Chemical messengers released into blood from glands which produce them. The endocrine system coordinates the activity of organs through hormones. Have specific target cells, can be Peptides, Steroids, Amino acid derivatives
Hormone derivatives; peptides
Proteins (water soluble) i.e. insulin
Hormone derivatives; steroids
Sex hormones; e.g. oestrogen
Hormone derivatives; Amino acid
Adrenaline, thyroxine
Hormones: Releasing hormones
Releasing hormones (5). Hypothalamus signals the anterior pituitary to stimulate particular glands & cause them to release secretions. Inc:
* Thyrotropin releasing hormone (TRL),
* Growth hormone releasing hormone (GHRH),
* Corticotropin releasing hormone (CRH),
* Prolactin releasing hormone (PRH),
* Gonadotropin releasing hormone (GnRH)
Hormones: Inhibiting hormones
Inhibiting hormones (2);. Sent from the hypothalamus to the anterior pituitary. Stop the signals to the pituitary. Inc:
* Growth hormone inhibiting hormone (GHIH)
* Prolactin inhibiting hormone - Dopamine (PIH)
Hormone (Releasing); Gonadotropin releasing hormone (GnRH)
Releasing hormone. Released by the hypothalamus to signal the pituitary to secrete follicle stimulating hormone (FSH) and luteinising hormone (LH)
Target tissue - ovaries & testes
Hormone (Releasing); Growth hormone releasing hormone (GHRH)
Releasing hormone; Released by the hypothalamus to signal the pituitary to secrete growth hormone (GH)
Target tissue = most body tissues