How does thyroxin work? | increases metabolic rate by oxidation of carbohydrate + fatty acids
produces heat = controls body temp |
How does thyroxin work? | increases metabolic rate by oxidation of carbohydrate + fatty acids
produces heat = controls body temp |
What is homeostasis? | maintaining a constant internal environment for optimal functioning. This involves body temp and fluids |
Where is melatonin made? use? response to? | pineal gland - controls biological clock
responds to light = signal to hypothalamus |
Where is ADH made? use? | pituitary gland - osmoregulation |
Where is thyroxin made? use? signalled by? | thyroid gland bec of signal from hypothalamus - metabolic rate |
Where is adrenaline made? use? | adrenal gland - fight/flight |
where is insulin and glucagon made? use? where in the body does it act on? | pancreatic pits (islets of Langerhans) pancreas - sugar levels act on the liver |
Where is leptin made? use? binds to? | adipose tissue - inhibits appetite
binds to receptors in hypothalamus |
Where is testosterone and estrogen made? use? | leydig cells and ovaries - sex characteristics |
When is insulin released? where is it released from? what happens? (3) | when glucose levels are high (after eating)
released from beta cells
causes glycogen synthesis in liver = glucose uptake by liver + adipose tissue |
When is glucagon released? where? what happens? (3) | alpha cells of pancreas
when glucose levels are low ( after exercise)
breakdown glycogen = releases glucose |
Difference bw type 1 + type 2 diabetes? treated by? | t1 = no producing insulin = insulin injections
destruction of b cells
t2 = no response to insulin = diet
down regulation of insulin receptors |
How does thyroxin work? | increases metabolic rate by oxidation of carbohydrate + fatty acids
produces heat = controls body temp |
What increases/ decreases leptin production? | overeating = more adipose cells = more leptin
starvation = less adipose = hunger |
Who has leptin resistance? why? side effects? | obese = desensitized bec of high levels of leptin = feel more hungry = overeat
older = weight gain
skin irritations |
What were the results in the mice experiments? (2) | leptin gene mutation + healthy = leptin transferred to obese = lost weight
defective leptin receptor + healthy = leptin to healthy mouse bec obese mouse overproduced = obese mouse remained the same but healthy bec thin bec of too much leptin |
what happens during jet lag? symptoms? (2) | change in circadian rhythms from travelling and diff time zones
fatigue, headaches but only lasts a few days |
soil and seed theory? William Harvey? | male = seed mixes with menstrual blood (soil) = fetus develops from info from the seed (Aristotle)
william harvey = investigated 7 week pregnant deer and couldn't detect the embryo before that - debunks theory |
What is the SRY gene? what does it do? what does it code for? | sec determining region Y from the Y chromosome
causes male characteristics
codes for TDF (testis determining factor) = forms testes |
What is the role of testosterone? (2) | develops male genitals
sperm production
secondary characteristics (body hair, muscle, deeper voice) |
What is the role of estrogen and progesterone? | female organs
secondary characteristics
menstrual cycle |
label a pp + use of each part (6) | van deferens: moves sperm from testes to prostate gland
urethra: semen to outside
seminal vesicle: fructose for sperm, mucus to protect sperm, prostaglandin to cause uterine contractions
prostate gland: alkaline fluid to neutralise vaginal acids
testis: produce sperm + testosterone
epididymis: sperm matures and is stored here
(scrotum, penis, erectile tissue, ureter, bladder) |
label a vg + use (5) | ovaries: oocytes mature before release + secretes estrogen + progesterone
fimbriae: move oocyte into oviduct
fallopian tube: oocyte to uterus (fertilisation occurs here)
uterus: fertilised egg implants and develops
endometrium: thickens to prepare for implantation |
What do FSH, LH, Estrogen and progesterone do? | FSH: follicular growth = estrogen secretion from developing follicles
LH: ovulation = forms corpus luteum
= anterior pituitary
Estrogen: thickens edometrium lining, inhibits fsh and lh + stimulates before ovulation
progesterone: thickens endometrium + inhibits fsh and lh |
describe the menstrual cycle? (all steps nd hormones involved in order) (5) | 1. FSH grows follicles = produces estrogen = inhibits FSH (-) = prevents other follicles to grow = thickens endometrium lining
2. before ovulation estrogen causes pituitary to secrete LH and FSH again. LH causes follicle to rupture and release 2nd oocyte = ovulation
3. ruptured follicle = corpus luteum = secretes a lot of progesterone + little estrogen = thickens endo wall. P and E inhibit FSH and LH
4. corpus luteum degenerates (corpus albicans) = E + P levels drop = endo wall removed
cycle repeats bec e+p are too low to inhibit FSH and LH |
What happens with ivf? STOP SUPEREGG FARTING PROTEIN IMPLANTS (5) | 1) STOP hormones (FSH and LH) = no cycle with drugs
2) SUPEROVULATION =(FSH = many follicles + HCG produce by embryo = follicle matures
3) EGG collected before it ruptures
4) FERTILISATION with sperm
4) PROGESTERONE DRUGS treatment 2 weeks prior = develops endometrium
5) IMPLANTED |