Endocrine System Flashcards
Structure and function of endocrine system
- S = network of glands and organs located throughout the body, hormones throughout blood
- F = regulate a range of bodily functions & maintain homeostasis by secreting hormones
What is a gland
Organ that secretes substances (often hormones)
Endocrine vs exocrine gland
- Endocrine: ductless gland that secretes hormones directly into the blood
- Exocrine: releases substances onto an external surface via a duct
Function of a hormone
Chemical messenger that controls and coordinates bodily functions by affecting the activity of target cells
What is C and what is its function in the endocrine system?
Hypothalamus
- Produces hormones which stimulate other glands to secrete hormones for homeostasis as a link between the nervous and endocrine systems
What is D and what is its function?
Pituitary gland
- Regulates growth and reproduction
What is E and what is its structure and function?
Parathyroid gland
- S = 4 small circular glands embedded in the posterior surface of the thyroid gland
- F = regulate calcium levels in blood and bones by secreting PTH
What is J and what is its function?
Testis
- Secretes testosterone to regulate sex drive, bone mass, fat, muscle mass, RBC, sperm etc
What is B and what is its function?
Pineal gland
- Secretes the hormone melatonin to regulate sleep/wake cycles
What is F and what is its structure and function?
Thyroid gland
- S = butterfly-shaped gland with 2 lobes
- F = regulate metabolism by secreting hormones (thyroxine, calcitonin, triiodothyronine)
What is A and what is its endocrine function?
Thymus
- Mature T lymphocytes by secreting the hormone thymosin
What is G and what is its structure and function?
Adrenal gland
- S = small glands with an outer cortex and inner medulla, located superior to each kidney
- F = regulate BP, HR, fight/flight by secreting adrenaline, noradrenaline, cortisol, aldosterone
What is H and what is its structure and endocrine function?
Pancreas
- S = feather shaped organ located inferior to the stomach
- F = secrete insulin and glucagon to regulate BGL
What is I and what is its function?
Ovary
- Secrete oestrogen and progesterone to regulate female sexual development, menstruation and pregnancy, secrete testosterone
What is the role of the stomach in the endocrine system?
Secretes hormones (ghrelin, leptin) which regulate hunger
2 examples of hormones secreted by the hypothalamus
- Corticotropin-releasing hormone (CRH): stimulates adrenal glands to release corticosteroids
- Growth hormone-releasing hormone (GHRH): stimulates pituitary gland to release growth hormone (HGH)
What is growth hormone (HGH) & where is it secreted?
Regulates growth and physical development (pituitary gland)
What is ACTH and where is it secreted?
Stimulates adrenal glands to secrete steroid hormones, mainly cortisol (pituitary gland)
What is prolactin and where is it secreted?
Stimulates milk production (pituitary gland)
What is TSH and where is it secreted?
Stimulates thyroid gland to secrete thyroid hormones (pituitary gland)
What is oxytocin and where is it secreted?
Regulates of lactation and childbirth (pituitary gland)
What is ADH and where is it secreted?
Regulates water absorption in kidneys (secreted in pituitary gland)
Role of LH in males and females and where is it secreted?
- Male: causes testicles to produce testosterone
- Female: triggers oestrogen production and ovulation
(Pituitary gland)
Role of FSH in males and females and where is it secreted?
- Male: controls production of sperm
- Female: controls production of eggs
(Pituitary gland)
What is melatonin and where is it secreted?
Controls sleep/wake cycle (secreted by pineal gland)
What is the importance of sleep?
- Repairs body and mind, consolidate neural pathways, conserve energy
- Decreased risk of obesity, depression, anxiety
- Decreased blood pressure
How does melatonin regulate sleep/wake cycles (circadian rhythm)
- Suprachiasmatic nucleus in brain receives signals about light from eyes and sends messages to pineal gland to secrete melatonin
- Low light = more melatonin = more drowsy = better sleep
What is PTH and where is it secreted?
- Parathyroid hormone
- Regulates Ca levels in blood and bones (out of bones into blood)
- Secreted by parathyroid gland
How can hyperparathyroidism contribute to osteoporosis?
Because hyperparathyroidism is the condition of an overactive thyroid gland, then too much PTH will be secreted into the blood which means too much Ca will be released out of the bones into the blood. Therefore they will become brittle, weak and porous (osteoporosis)
What is triiodothyronine (T3) and where is it secreted?
Regulates body temp, metabolism, heart rate (thyroid gland)
What is thyroxine (T4) and where is it secreted?
Regulates body temp, metabolism, heart rate (thyroid gland)
What is calcitonin and where is it secreted?
- Regulates Ca storage and concentration (decreased Ca in blood)
- Secreted by thyroid gland
Functions of calcium in the body
Strong bones, immune response, nerve impulses, blood clotting
What is thymosin and where is it secreted?
Regulates maturation of T lymphocytes (thymus gland)
What are adrenaline and noradrenaline and where are they secreted?
- Regulates fight/flight (sympathetic NS) e.g. increased HR, metabolism, dilation of pupils etc
- Secreted by medulla of adrenal gland
What is cortisol and where is it secreted?
- Regulate metabolism, BGL, anti-inflammatory
- Secreted by cortex of adrenal gland
What is aldosterone and where is it secreted?
- Regulate salt and hence water balance to regulate BV > BP
- Secreted by adrenal gland
What is insulin and where is it secreted?
- Responds to high BGL by converting glucose into glycogen in liver and muscle cells, decreasing BGL back to WNL
- Secreted by beta cells of the pancreas
What is glucagon and where is it secreted?
- Responds to low BGL by converting glycogen into glucose in liver and muscle cells, increasing BGL back to WNL
- Secreted by alpha cells of the pancreas
What is oestrogen and where is it secreted?
- Regulates female sexual development and menstrual cycle
- Secreted by ovaries
What is progesterone and where is it secreted?
- Regulates menstrual cycle and pregnancy
- Secreted by ovaries and uterus
What is testosterone and where is it secreted?
- Regulates sex drive, bone mass, fat distribution, RBC, sperm, muscle mass, male secondary sex characteristics
- Secreted by testes AND OVARIES
What are ghrelin and leptin and where are they secreted?
- Ghrelin promotes hunger to encourage eating
- Leptin suppresses hunger to prompt you to stop eating
- Secreted by stomach
Thyroaden/o
Thyroid/o
Thyroid gland
Orchid/o
Orch/o
Testes
Pituitar/y,o
Hypophys/e,o
Pituitary gland
Endocrin/o
Adren/o
Endocrine
Adrenal gland
Parathyroid/o
Adrenal/o
Parathyroid gland
Adrenal gland
Oophor/o
Ovari/o
Ovaries
-pexy
Surgical fixation
What is the breakdown of the medical term hypophyseal?
- Root: hypophys (pituitary gland)
- Combining vowel: /e
- Suffix: -al (pertaining to)
What is enlargement of the thyroid gland called?
Goitre
