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Endocrine System Overview
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Endocrine System Overview
Endocrine System Overview
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1
Question
What does the Endocrine System refer to?
Answer
The Endocrine System refers to all the glands that produce and secrete hormones.
2
Question
What are hormones?
Answer
Hormones are chemical messengers that are carried by the blood from endocrine glands to the cells and tissues upon which they act.
3
Question
What are the three types of hormones mentioned in the text?
Answer
1. Amine hormones: catecholamines, thyroxine VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV 2. Peptide hormones: oxytocin, vasopressin VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV 3. Steroid hormones: precursor of cholesterol, adrenocorticosteroids, estrogens, testosterone.
4
Question
What functions do hormones regulate?
Answer
Hormones regulate growth and development, puberty, reproduction, tissue function, metabolism, and mood.
5
Question
How are hormones delivered to target organs and tissues?
Answer
Hormones are delivered to target organs and tissues primarily by the blood.
6
Question
Where do hormones bind in target tissues?
Answer
In target tissues, hormones bind to cell surface or intracellular protein receptors.
7
Question
What is the area of production for 17b-estradiol?
Answer
Granulosa cells of ovaries (females), fat cells, artery walls, and the brain (males and females)
8
Question
Where is testosterone produced?
Answer
Testis (males), ovaries (females), and adrenal glands.
9
Question
Where is cortisol produced?
Answer
Adrenal gland.
10
Question
Where is Triiodothyronine produced?
Answer
Thyroid gland.
11
Question
What are nuclear hormone receptors?
Answer
Nuclear hormone receptors are acted upon by steroid hormones. Steroid hormone receptors are ligand-activated transcription factors
12
Question
What do xenobiotics (drugs and toxicants) do in relation to hormone receptors?
Answer
Most xenobiotics act by specifically binding to receptors and mimicking endogenously produced biochemicals.
13
Question
What does endocrine disruption refer to?
Answer
Endocrine disruption refers to any exogenous chemical that disrupts hormone metabolism or signaling VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV either by mimicking an endogenous hormone (DIRECT) VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV or blocking hormone synthesis and affecting receptor function (INDIRECT).
14
Question
What are some health risks associated with endocrine disruption?
Answer
Exposure to endocrine disruptors is associated with increased cancer risk, diabetes, behavioral abnormalities, and sexual dysfunction.
15
Question
What are the mechanisms of AHR-mediated disruption of estrogen signaling?
Answer
Increased estrogen metabolism (increase CYP1B1 transcription) VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV Increased degradation of estrogen receptors VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV Competition for transcriptional co-activators VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV Direct protein-protein interactions (transrepression)
16
Question
What are the endocrine disrupting effects associated with exposure to dioxin and dioxin-like chemicals?
Answer
Increased incidence of breast/prostate cancer VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV Increased incidence of uro-genital tract defects VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV Decreased male:female birth ratios VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV Increased rates of obesity and diabetes
17
Question
PART TWO: THE HYPOTHALAMUS, ANTERIOR PITUITARY AND ADRENOCORTICOSTERIODS πππππ§
Answer
πππππ§
18
Question
π Describe the Hypothalamus
Answer
π The Hypothalamus is a specialized region at the base of the brain that contains neurons that produce and secrete vasopressin, oxytocin and various releasing hormones that control the output of the anterior pituitary.
19
Question
π Describe the neurons contains in the Hypothalamus
Answer
π They originate predominantly from discrete areas within the hypothalamus, often referred to as nuclei. Their axons project along an axis termed the pituitary stalk where they secrete their respective hormones. Secretion occurs at nerve terminals that form varicosities or synapses with specialized pituitary cells, or in or around microvascular beds within the pituitary.
20
Question
π What is the pituitary gland?
Answer
The pituitary gland is a specialized endocrine organ that can be subdivided into two important functional regions in humans
21
Question
What are the two functional regions of the pituitary gland?
Answer
Anterior pituitary (adenohypophysis) VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV Posterior pituitary (neurohypophysis)
22
Question
Describe the anterior pituitary (adenohypophysis) and what hormones it secretes.
Answer
Distinct from the hypothalamus contains and intricate network of blood vessels called the hypophyseal portal system. VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV Secretes adrenocorticotropic, thyroid stimulating, growth, prolactin, luteinizing and follicle-stimulating hormones. Generally, specific cell types in the anterior pituitary produce different hormones.
23
Question
Describe the posterior pituitary (neurohypophysis) and what hormones it secretes.
Answer
Can be considered an extension of the hypothalamus and consists mainly of the axon terminals of nerve cells that lie in the supraoptic and paraventricular nuclei. VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV Secretes oxytocin and anti-diuretic hormones.
24
Question
What does growth hormone-releasing factor (Somatorelin) do?
Answer
Induces somatotrophs in the anterior pituitary to release growth hormone (Somatotrophin)
25
Question
What does Gonadotrophin-releasing hormone (GnRH) do?
Answer
Induces gonadotrophs in the anterior pituitary to release follicle stimulating hormone (FSH) and luteinizing hormone (LH)
26
Question
What does corticotrophin-releasing factor (CRF) do?
Answer
Stimulates corticotrophs in the anterior pituitary gland to release adrenocorticotropic hormone (ACTH). CRF acts synergistically with vasopressin and both its action and release are inhibited by glucocorticoids
27
Question
What does Thyrotrophin-releasing hormone do?
Answer
Causes the release of thyroid stimulating hormone (TSH) from the thyrotrophs in the anterior pituitary
28
Question
What is the function of [SOMATOSTATIN]? (hypothalamic hormone)
Answer
Somatostatin inhibits the release of growth hormone and thyroid-stimulating hormone (TSH) from the anterior pituitary and insulin and glucagon from the pancreas.
29
Question
What is the synthetic drug of somatostatin? What are its clinical uses?
Answer
Octreotide : Treatment of carcinoid syndrome and acromegaly
30
Question
How and where are [GROWTH HORMONES] released?
Answer
They are released in a pulsatile fashion and controlled by GHRF (simulatory) and somatostatin (inhibitory) from the hypothalamus