Endocrine System

Two main controlling systems in the body
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Terms in this set (62)
Two main controlling systems in the body
Endocrine and Nervous
How is the endocrine system different from the nervous system?
1. Transmits hormones through blood
2. Targets any cells in body with the correct receptors (more widespread)
3. Has longer reaction times
4. Has longer-lasting effects (minutes to days and weeks)
4 functions of endocrine system
1. Regulates development, growth, and metabolism
2. Maintains homeostasis of blood composition and volume
3. Controls digestive processes
4. Controls reproductive processes
Path of hormone transport to target cells
1. Hormones are released into interstitial fluid, then enter the blood stream
2. They are transported within blood
3. Randomly leave blood and enter interstitial fluid
4. Hormone binds to target cells' receptors
Exocrine Gland and two examples
A gland that secretes its products into ducts that lead to the target tissue.

Ex: sweat, salivary, sebaceous, mucous
Endocrine gland and two examples
A gland which secretes its products directly into the blood stream.

Ex: pituitary gland, thyroid gland, adrenal glands.
5 major endocrine glands
1. Pituitary
2. Pineal
3. Parathyroid
4. Adrenal
5. Thyroid
Hormonal Stimulation
The endocrine gland is "told" how much hormone to release by hormones produced from a different endocrine gland.
Humoral Stimulation
The endocrine gland has its "dip stick" in the blood stream so it can monitor levels of the ion or nutrient that its hormones regulate.
Nervous Stimulation
The nervous system turns on/off the release of hormones from an endocrine gland.
3 chemical classes of hormonesSteroids, Proteins, Biogenic Amines (modified amino acids)What are steroid hormones synthesized from? Can they dissolve in blood? Can they cross a cell membrane?Cholesterol; No, they are fat-soluble, not water-soluble; Yes.The majority of hormones are ____________________. Can they dissolve in blood? Can they cross a cell membrane?Proteins; Yes, they are water-soluble, not fat soluble; No.What are local hormones?Signaling molecules that don't circulate in the blood. They bind to the cells that release them (autocrine stimulation) or neighboring cells (paracrine stimulation).Examples of local hormonesProstaglandins: important in inflammation Cytokines: important in communication of immune defense (ex: IL-2 and IL-4 from helper T-cells)Which class of proteins must be bound to a carrier to travel through the blood? Why?Steroid-based; They are lipid-soluble.What does half-life measure?The amount of time needed to decrease concentration of a hormone in blood by half.__________________-based hormones tend to be quick on/quick off while __________________-based hormones tend to be slow on/slow off.Protein; Steroid5 different changes a hormone can cause in a specific target tissue.1.Permeability of plasma membrane and/or membrane potential 2. Synthesis of proteins/enzymes 3. Enzyme activation and deactivation 4. Induce secretory activity 5. Muscle contraction/relaxationThe magnitude of the effect of a hormone depends upon what 3 things?1. Blood concentration 2. Number of receptors 3. Strength of hormone receptor bondHormone interaction when one hormone accentuates the activity of a second hormoneSynergistHormone interaction when one hormone diminishes the activity of a second hormone, often because it has the opposite effect on the cell.AntagonisticHormone interaction when first hormone must be present to give "permission" for the second hormone to do its job.Permissive.5 hormones the hypothalamus produces and sends to anterior pituitary. What does each one tell the pituitary gland to release? (the cows go pick grain)Thyrotropin > Thyroid stimulating hormone Corticotropin (CRH) > Adrenocorticotropin Growth Hormone > Growth Hormone Prolactin > Prolactin Gonadotropin > Gonadotropins (Luteinizing Hormone and Follicle-Stimulating Hormone)What hormones does the thyroid produce?T3 (Tri-iodothyronine) - most active hormone in thyroid T4 (Thyroxin) -These play an important role in metabolism, development, and catachollamine release (neurotransmitters) Calcitonin - decreases amount of calcium in the blood stream.Adrenocorticotropic (ACTH)Released by anterior pituitary. Tells the adrenal cortex (outside) to release corticosteroid hormones. Cortisol and aldosterone and androgens.What 5 classes of steroid hormones does the adrenal cortex produce? (Good morning, pick an egg)Glucocorticoids, mineralocorticoids, progestins, androgens, and estrogensWhat does cortisol do?Increase blood glucose, suppresses immune system, and stimulates fight of flight responeWhat does aldosterone do?Increases reabsorption of salt (goes to kidneys and tells them not to take sodium out of blood), increase blood pressure, increase blood volume, and maintain hydrationWhat two hormones does the adrenal medulla produce?Noradrenaline (Norepinephrine) Adrenaline (Epinephrine)What does prolactin do?Stimulates milk productionWhat do gonadotropins do?Luteinizing hormone - Female:Stimulates progesterone and ovulation in females Male: Stimulates leydig cells which produce testosterone Follicle-Stimulating Hormone - Female: Stimulates follicle maturation which leads to estrogen Male: Stimulates sertoli cells which produce androgen-binding protein In males, LH combines with FSH produces sperm. In females, it prepares the uterus.What two hormones does the posterior pituitary produce? (OA)Oxytocin and Anti-diuritic hormone (ADH or Vasopresin)What does oxytocin do?Uterine contractions, milk ejection, and building relationships (both positive and negative)What does ADH do?Stops release of water from the body (stops urination > maintains hydration)What does the parathyroid gland release? What does this hormone do?Parathyroid hormone. Opposes action of calcitonin (increases blood calcium).What hormones do the kidneys release? (RE)Renin - increase blood pressure and volume Erythropoeitin - increases red blood cell productionWhat hormones does the pancreas release? (IG)Insulin - drops blood glucose levels Glucagon - Increases blood glucose levelsChronic inflammation is often treated with a glucocorticoid called _____________________CorticosteroneThe ____________________ extends from the base of hypothalamus to the pituitary gland.InfundibulumElevated levels of glucagon result in what?Increased lipolysis, increased blood sugar levels, increased glycogenolysisWhich organ releases secretin and cholecystokinin?Small intestineIncreased cortisol levels result in what?Increased blood sugar levels, increased blood fatty acid levels, and decreased glucose uptake by most cells of the body.The ________________ cells are the source of the parathyroid hormone, PTH.chiefThe zona fasciculata synthesizes a group of hormones called _______________GlucocorticoidsToo much growth hormone in children causes what?Pituitary gigantismLayers of the adrenal cortex from superficial to deepZona glomerulosa, Zona Fasciculata, Zona ReticularisThe wall of each thyroid follicle is formed by simple cuboidal epithelial cells called ___________________ cells.follicularThe lumen of the thyroid follicle is made of a protein-rich fluid called ____________________.colloidTropic Hormoneshormones that stimulate other glands to release their hormonesExplain the cAMP method (2nd messenger)1. 1st messenger hormone binds to carrier and is transported through blood to the site of receptor. 2. It attaches to the plasma membrane, binds with the high energy GTP, and releases GDP, which activates the G protein. 3. The activated G protein then activates the Adenylate Cyclase (this is inside plasma membrane). 4. This transforms ATP into cyclic AMP (cAMP - 2nd messenger) in the cytoplasm. 5. Protein kinases are then activated, which triggers the cell's response.Cascade effectMany enzymes activate more enzymesProtein KinasesEnzymes that phosphorylate other proteins/enzymesWhat is another second messenger system?PIP2 messengerWhy do protein-based hormones use the cAMP method?They are water-soluble and therefore cannot pass through the cell membrane.Thyroid structureHas many hollow follicles, which are made of simple cuboidal epithelial cells. These produce thyroglobulin (produces colloid - inner fluid in lumen of follicles).Major hormone produced by thyroid folliclesT4 ( tetraiodothyronine)What happens if a child has too much growth hormone? Too little?Pituitary gigantism; pituitary dwarfismParathyroid location4 pea-sized glands on posterior of thyroidWhich part of the adrenal gland is sympathetic nerve tissue?Adrenal medullaWhich part of adrenal gland has a high cholesterol content?Adrenal cortexWhat activates the renin-angiotensin-aldosterone system?When a person's blood pressure and blood volume drops