A&P2 wk7 Endocrine pt2

winniesmith1's version from 2017-05-19 19:32

Section 1

Question Answer
What are the general features of the endocrine system1. Endocrine glands are ductless 2 .Endocrine glands have a rich supply of blood. 3. Hormones, produced by the endocrine glands are secreted into the bloodstream. 4. Hormones travel in the blood to target cells close by or far away from point of secretion. 5. Hormone receptors are specific binding sites on the target cell
What are endocrine glandsEndocrine glands are ductless glands comprised of endocrine cells. The fact that endocrine glands are ductless means that these glands secrete hormones directly into the blood stream.
What are hormonesorganic chemical messengers produced and secreted by endocrine cells into the bloodstream. Hormones regulate, integrate and control a wide range of physiologic functions
How do hormones workcoordinate cells on a sustained basis. They circulate in the blood and bind to specific receptors on or in target cells. They alter membrane permeability, activate or inactivate key enzymes, or change genetic activity. Constant and sustained compared to nerves (work 24/7)
What are target cellscells that contain specific receptors (binding sites) for a particular hormone. Once a hormone binds to receptors on a target cell, a series of cellular events unfold that eventually impact gene expression and protein synthesis.
What are hormone receptorsbinding sites on the target cell (either on the surface or in the cytoplasm or nucleus of the target cell) that are activated only when specific hormones bind to them.

Section 2

Question Answer
What are the 3 types of hormonesAmino acid derivatives, peptide hormones (not lipid soluble so effect cell from outside) and lipid derivatives (lipid based so can enter cell)
What are amino acid derivativesSmall molecules, structurally similar to amino acids
What are peptide hormonesConsist of chains of amino acids, largest class of hormones
What are lipid derivatives2 classes of lipid-based hormones: steroids and eicosanoids
Which hormones bind on cell membraneIncludes receptors for: epinephrine, norepinephrine, all peptide hormones and eicosanoids
Which hormones bind inside cellIncludes receptors for all steroid hormones and thyroid hormones

Section 3

Question Answer
How do hormones work that bind on the outer membrane of cellsfirst messengers, that trigger the appearance of second messengers in the cytoplasm Link between first and second messengers involves G protein Important second messenger is cyclic AMP (cAMP)
How is cAMP activated 1. Activated G protein activates enzyme adenylate cyclase 2. Adenylate cyclase converts ATP to cyclic-AMP 3. Cyclic-AMP activates kinase enzymes 4. Activated kinases affect target cell
What is the action of kinasekinases activated by cyclic AMP --> phosphorylation of enzymes or membrane proteins
What are other important secondary messengers Cyclic-GMP (cGMP) -derivative of guanosine triphosphate (GTP) Calcium ions

Section 4

Question Answer
Describe (steroid) hormonal action inside the cell Cross cell membrane. Bind to receptors in cytoplasm or nucleus, activating or inactivating specific genes. Alter rate of DNA transcription in nucleus, changing patterns of protein synthesis. Directly affect metabolic activity and structure of target cell e.g. testosterone.
Describe (thyroid) hormonal action inside the cellCross cell membrane by diffusion or transport mechanism. Bind to receptors within nucleus or on mitochondria. Activate specific genes in nucleus, or change the rate of mRNA transcription. Increases metabolic activity of the cell.
Describe steroid hormonesNot all steroids build muscle (oestrogen, progesterone, cortisol don’t). Anabolic-androgenic steroids – synthetic hormone similar to testosterone
What is the risk of anabolic steroids-Teenagers: early skeletal and sexual maturation –> stunted growth.
-Damage to liver, cardiovascular systems and increased cholesterol.
-Males: reduced sperm count, infertility, baldness, increase risk of prostate cancer.
-Females: facial hair, male pattern baldness, cessation of menstrual cycles.

Section 5

Question Answer
What are the types of hormonal interactionsAntagonisitc, synergistsic, permissive, integrative
What are antagonisitic effectsopposing effects (e.g. PTH and calcitonin) (or in pancreas- insulin and glucagon)
What are synergistic effectsadditive, build on each other (GH and glucocoritcoids).
What are permissive effects1 hormone is necessary for another to produce effect
What are integrative effectshormones produce different but complementary results

Section 6

Question Answer
What hormones are needed for normal growth-Growth Hormone -Thyroid Hormones -Insulin -Parathyroid Hormone -Calcitriol -Reproductive Hormones
What does growth hormone doprotein synthesis and cellular growth
What do thyroid hormones donervous system development
What do you need insulin forto supply energy and nutrients
What do Parathyroid Hormone & calcitriol doCalcium absorption /deposition in bones
What do reproductive hormones docell growth & differentiation / secondary sexual characteristics

Section 7

Question Answer
What is acromegalyExcess growth hormone secretion after fusion of bone epiphyses. Enlarged thick bone (girth not length)
What is giantismGrowing excessively tall - tallest (8ft 11)
What can thyroid hormone insufficiency causePhysical and mental impairment. lead to enlarged thyroid- goitre.
What causes short statureMalnutrition, genetic, (food) deficiency or hormonal influences.

Section 8

Question Answer
What is stressAny condition that threatens homeostasis
What are the phases of general adaptation syndrome to stress 1) Alarm phase (sympathetic ANS response) 2) Resistance phase (glucocorticoid response) 3) Exhaustion phase (organ system failure)
Alarm phase* (pp)(sympathetic stimulation) mobilization of glucose reserves, changes in circulation, increases HR and respiratory rates, increased energy use by all cells.
Resistance phase*(GH, GC, Glucagon) Mobilization of remaining energy reserves, conservation of glucose, elevation of blood glucose concentrations, conservation of salts and water. (Decrease in GC) causes weaker immune system.
Exhaustion phasecollapse of vital systems- may include: exhaustion of lipid reserves, inability to produce glucocorticoids, failure of electrolyte balance, cumulative structural or functional damage to vital organs.