hormonal communication Flashcards

Question

function of androgens

Answer 1

released and are converted to sex hormone which help secondary sexual characteristics develop and regulate production of gametes

Answer 2

adrenaline

Answer 3

polar molecule derived the amino acid tyrosine cannot pass directly across cell surface membrane so must be detected by specialised receptors in the target cell

Answer 4

many cells and tissues have specialised adrenaline receptors

Answer 5

adrenaline is hydrophilic so soluble in plasma binds to receptor on cell surface membrane (complementary binding) receptor changes shape, causing a G protein to be activated G protein binds to and activates adenyl cyclase enzyme this converts ATP into the 2nd messenger cyclic AMP this activates other enzymes (protein kinases) which activate other enzymes (cascade effect) this leads to a response (e.g. glycogenolysis and inhibition of glycogenesis)

Answer 6

muscles need glucose for respiration to release ATP to sustain muscle contraction to run away/ fight

Answer 7

adrenaline continues to be secreted form adrenal glands over a long period of time

Answer 8

islets of langerhans pancreatic duct acinar cells

Answer 9

carries pancreatic juice to small intestine

Answer 10

secrete pancreatic juice which drains into the duct

Answer 11

intarglobular ducts feed into interlobular ducts, which feed into pancreatic duct

Answer 12

more beta cells than alpha

Answer 13

insulin, to prevent hyperglycaemia

Answer 14

glucagon, to prevent hypoglaecemia

Answer 15

islets of langerhans (endocrine) are lightly staines, large spherical clusters which secrete and produce hormones pancreatic acini (exocrine) are darker stained, small berry-like clusters which produce and secrete digest enzymes

Answer 16

paler than surrounding more prominent nuclei cells more loosely packed bigger than surrounding acini

Answer 17

contain capillaries for hormone distribution large prominent nucleoli for secretory function

Answer 18

4-6 mol dm-3

Answer 19

consistently over 7mmol dm-3

Answer 20

diabetes hyperglycaemia so glucose loss in urine so lower BP bc water lost so less blood to brain, causing a coma

Answer 21

consistently less than 4 mol dm-3

Answer 22

hypoglycaemia cells run short on glucose ketoacidosis coma

Answer 23

detected by beta cells, which secrete insulin, leading to an increased uptake and respiration of glucose, increased glycogenesis, increased lipogenesis, decreased glycogenolysis and gluconeogenesis this lowers BGL

Answer 24

detected by alpha cells, which secrete glucagon increased glycogenolysis, gluconeogenesis, release of glucose and lipolysis increased BGL

Answer 25

the addition of glucose monomers to form glycogen

Answer 26

the synthesis of glucose from non sugar precursors

Answer 27

the breakdown of glycogen into glucose

Answer 28

the release of each other therefore control mechanism for blood glucose levels is an example of negative feedback as BGL fluctuates around a set point

Answer 29

cell membrane has K+ and Ca2+ ion channels, the K+ ones are normally open so K+ flow out when BGL is too high, the glucose moves into the beta cell by FD glucose is metabolised to produce ATP, which is used to close the K+ channels the accumulation of K+ ions alter the potential difference across the cell membrane: the inside becomes less -ve the change in PD opens the Ca2+ channels Ca2+ ions caused the vesicles of insulin to fuse with the cell membrane, releasing insulin by exocytosis

Answer 30

by opening K+ channels some diabetes drugs inhibits K+ channels, so trigger insulin release

Answer 31

insulin binds to complementary tyrosine kinase receptor tyrosine kinase enzyme is activated this activates other enzymes (2nd messengers) enzymes cause vesicles containing glut 4 transporters to move to and fuse with the membrane glucose transporter proteins inserted into the membrane extra glucose enters the cell by facilitated diffusion

Answer 32

cells carrying out secretion= beta cells in islets of langerhans and sensory/relay pre-synaptic neurone stimulus= high BGL and AP transmitted along axon membrane effect of stimulus on membrane= glucose enters cell->ATP closes K+ channels vs local current causes Na+ channels to open on synaptic knob vesicles contain insulin vs NT

Answer 33

common metabolic disease in humans BGL cannot be controlled effectively

Answer 34

10% have type 1 90% have type 2

Answer 35

insulin dependent diabetes begins in early life pancreas doesn't secrete insulin so liver cannot store excess glucose as glycogen due to loss of B cells (caused by immune attack (autoimmune diseases)/ viral attack/ deficiency in human insulin gene)

Answer 36

non-insulin dependent diabetes pancreas secretes insulin but receptors on liver and muscle cells don't respond (insulin resistance) OR less insulin secreted due to fatty pancreas (stops B cells functioning properly)

Answer 37

obesity high sugar/fat diet genetics lack of exercise Asian and Afrocaribbean people have higher incidence

Answer 38

BGL remains high after high-carb meal glucose lost in urine, so excessive urination, so dehydration, hunger and thirst fat & proteins used as respiratory substrates, leading to ketoacidosis and low blood pH no glycogen stores so low BGL between meals, causing hypoglycaemia bc blood sugar plummets

Answer 39

damage to blood vessels eye and gum problems higher risk of heart attack/ stroke. kidney failure

Answer 40

insulin treatments e.g. animal insulin (pig), GM bacteria Transplants e.g. pancreas, islets of langerhans, stem-cell derived islets

Answer 41

A: tried and tested method early treatment kept people alive D: needs to be purified risk of allergic reaction high production lost religious/ethical issues of animal products

Answer 42

high purity less risk of allergic reaction lower production cost, can make large quantities to meet demand overcomes religious/ethical issues of animal products allows use of smart pumps/pens pumps can be monitored by app

Answer 43

people had to be persuaded to change form previous regime e.g. animal insulin some may not understand the technology eg. injection routine (risk of hypoglycaemia if inject too much) side effects of pumps e.g. hard lumps under skin

Answer 44

patient can now produce insulin so more physiological control of BGL less risk of hypos and decreases longtime risk of mortality form severe hypos (hypos common if too much insulin injected) increased QoL 80% success rate (most of the time, no need to inject)

Answer 45

not enough pancreases available due to donor shortage patients require immunosuppressants for life (can lead to side effects) use of immunosuppressant drugs leaves patients vulnerable to infections

Answer 46

doctors use enzymes to remove islets from pancreas of organ donor purified and counted (around 400,000 islets transplanted in each procedure) doctors insert the cells into hepatic portal vein towards the Liver

Answer 47

proven curative measure patient can now produce insulin so more physiological control of BGL less risk of hypos and decreases longtime risk of mortality form severe hypos (hypos common if too much insulin injected) increased QoL slows development of diabetes complications e.g. heart diseases, kidney disease and nerve eye damage

Answer 48

limited donor supply risk of rejection need lifelong immunosuppressants still classed as an experimental treatment- only performed in certain clinical trials not all people are good candidates for transplantation. doctors must weigh up risk of taking immunosuppressants risks to treatment e.g. bleeding and blood clots low success rate so chance that transplanted cells may not work well/ stop working

Answer 49

reprogrammed from somatic cells e.g. skin fibroblasts from diabetic patient, have similar ability to differentiate and proliferate like ESCs ESC-derived B cells can be successfully generated by stepwise application of specific factors

Answer 50

transplant of pancreatic stem cell-derived pancreatic islet cells immunotherapy gene therapy developmental biology

Answer 51

pluripotent stem cells could differentiate into B cells and increase the mass of the islets and increase the secretion of insulin

Answer 52

pluripotent stem cells can protect B cells from autoimmune attack by inhibiting T cell proliferation and reduce the inflammatory response

Answer 53

opportunities to use genetic modification to provide enhanced endocrine function and survival and modulate the immune response

Answer 54

opportunities to study function and longevity of human islet cells with varied genotypes and develop nw drugs for treatment

Answer 55

no longer need to inject insulin so money saved functioning B cells in pancreas improved QoL no hypoglycaemia or need for immunosuppressants could reprogram immune system to prevent B cell damage

Answer 56

still in early stages so need more clinical trials ethical issues with use of stem cells risk of cancer might still need low dose insulin initially high cost not suitable for all people

Answer 57

lifestyle changes medication insulin therapy

Answer 58

losing weight regular exercise low sugar diet

Answer 59

metformin acts on liver cells to decrease glucose released and increase glucose uptake sulfonylureas stimulate pancreas ti produce more insulin

Answer 60

gestational diabetes affects pregnant women: high levels of glucose in blood even though normal levels of insulin produced. caused by hormones released by placenta, which prevent body using insulin effectively TREATMENT: diet, exercise, medicines e.g. metformin, or insulin if not working