Flashcards
Anatomy - Endocrine System
Cards in this deck (24)
- 1The endocrine system?A group of ductless glands and endocrine tissues within other organs
-Secrete chemical signals (hormones) into the blood which are then transported to target cells (with receptors) that initiate a response - 2Classes of the endocrine system?1) Steroids - derived from cholesterol and are lipid soluble
-e.g. testosterone, estrogen, vitamin D
2) Derived from amino acids
-e.g. thyroxine (T4) and catecholamines are formed from tyrosine
3) Peptides and proteins - chains of amino acids
-e.g. oxytocin, antidiuretic hormone, growth hormone, insulin - 3Endocrine gland?Gland with no other function
- 4Pituitary gland?Sits in sella turcica of the sphenoid bone; suspended from the hypothalamus
- 5Two parts of pituitary?Anterior pituitary and posterior pituitary
- 6Anterior pituitary?Glandular epithelium tissue
- 7Secretions regulated by hormones secreted by hypothalamus?i) growth hormone (GH) - affects growth, metabolism
ii) thyroid-stimulating hormone (TSH) - stimulates secretions by thyroid gland
iii) adrenocorticotropic hormone (ACTH) - stimulates secretions by thyroid gland
iv) gonadotropins - reproductive hormones
-Luteinizing hormone (LH) and follicle stimulating hormone (FSH)
v) prolactin (PRL) - stimulates milk production - 8Posterior pituitary?Nervous tissue (extension of hypothalamus)
-Stores and secretes hormones synthesized in hypothalamus - 9Secretions of posterior pituitary?i) oxytocin - stimulates uterine contractions, milk letdown
ii) antidiuretic hormone (vasopressin) - enhances water absorption by collecting ducts of nephrons - 10Thyroid gland?Butterfly shaped
-Inferior to larynx on anterior surface of trachea - 11Histology of thyroid gland?a) follicles - secrete thyroxine
-Walls = follicular (epithelial) cells
-Thyroxine (T4) converted to active form (T3) in other tissues; affects metabolism, tissue growth, and development
b) parafollicular cells - between follicles
-Secrete calcitonin; lowers blood Ca2+ by increasing its uptake by bone - 12Parathyroid glands?Four glands imbedded in posterior thyroid
Secretes parathyroid hormone (PTH) - 13PTH increases blood Ca2+ by increasing what?i) its release by bone (activates osteoclasts)
ii) its reabsorption by kidneys
iii) vitamin D activation (increases Ca2+ absorption by intestine) - 14Adrenal glands?Superior surface of each kidney
Each composed of two functionally distinct glands - 15Two functionally distinct glands that compose an adrenal gland?Adrenal cortex and adrenal medulla
- 16Adrenal cortex?Secretes only steroids
- 17Each layer of the adrenal cortex secretes a single class of hormones, what are they?i) zone glomerulosa - mineralocorticoids
-Mainly aldosterone (salt balance)
ii) zone fasciculata - glucocorticoids
-Mainly cortisol (stress; CHO metabolism)
iii) zone reticular - androgens (male sex hormones)
-Mainly converted to testosterone and estrogen - 18Adrenal medulla?Modified sympathetic nervous system neurons
Synthesizes catecholamines, which play an important role in the "fight or flight" response:
i) epinephrine (80%)
ii) norepinephrine (20%) - 19Endocrine tissues?Endocrine secretions by organs with additional functions
- 20Endocrine tissues?Endocrine secretions by organs with additional functions
- 21Pancreatic islets of Langerhans?a) alpha cells - secrete glucagon, increases blood [glucose]
b) beta cells - secrete insulin; decreases blood [glucose] - 22Hypothalamus produces what?a) produces hormones that stimulate or inhibit release of hormones from anterior pituitary:
i) growth hormone-releasing hormone (GHIH) or somatostatin
ii) growth hormone-inhibiting hormone (GHIH or somatostatin)
iii) gonadotropin-releasing hormone (for LH, FSH)
b) produces posterior pituitary hormones
c) major coordinator of autonomic nervous system
-e.g. homeostatic control area for temperature regulation, thirst, hunger, daily rhythms - 23Gonads?a) testis
-Leydig cells - secrete testosterone
b) ovaries
-2^o follicles - secrete estrogen
-Corpus luteum - secretes estrogen and progesterone - 24Other tissues/organisms that secrete things?a) duodenum - e.g. CCK, secretin
b) heart - atrial natriuretic peptide (ANP)
c) kidney - renin, erythropoietin (EPO)
d) skin - vitamin D
e) adipose - leptin (Ob)
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- Anatomy Flashcards on Anatomy - Endocrine System, created by Emma Granger on 02/01/2017.
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- Emma Granger
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