Pituitary gland
Produces many hormones that regulate body conditions
“Master gland” located in the brain
Hormones released act on other glands to release hormones to bring about change
Thyroid
Produces thyroxine
Regulates rate of metabolism, heart rate, temperature
Adrenal Gland
Produces adrenaline
Prepares body for “fight or flight” response
Pancreas
Produces insulin
Regulates blood glucose level
Ovaries
Produces oestrogen
Involved in menstraul cycle
Testes
Produces testosterone
Controls puberty and sperm production
Insulin
Lowers blood sugar levels
Glucose absorbed by cells
Glucagon
Increases blood sugar levels
Produces glucose as liver breaks down glucogen to glucose
Diabetes
Chronic disease in which body cant metabolise carbohydrates/glucose effectively
Type 1 diabetes
Pancreas fails to produce insulin, treated wth insulin injections
Type 2 diabetes
Body cells no longer respond to insulin, treated wth carbohydrate controlled diet (obesity is risk factor)
Hypoglycaemic
Blood glucose levels too low
O dear i need sugar
Hyperglycaemic
Blood sugar levels too high
Er i feel sick with sugar
Kidney
Responsible for controlling water and ion levels in body
Produce urine by filtration of blood
Selective reabsorption pf useful substances
Urea
Excess amino acids converted to fats and carbohydrates whoch can be stored (deamination)> ammonia waste product> toxic, so converted to urea in liver, transported to kidneys to be excreted by urine
Ions
Ions taken into body by food, absorbed into blood, right balance of ions is maintained by the kidneys> some reabsorbed and rest is removed by urine
Water
Balance water by kidneys
Kidney Process
1) blood enters and kidneys filter blood (proteins too large so remain in blood, water, ions etc absorbed)
2) glucose etc reabsorbed as its useful
3) Loop of Henie, some water reabsorbed and some ions reabsorbed
4) collecting duct- urea in urine, stored in bladder
ADH (Anti-Diuretic Hormone)
Controls amount of water reabsorbed by kidneys
Secreted frim pituitary gland
Makes membranes of collecting duct more permeable
Dialysis Process
1) blood removed from kidneys
2) mixed wth blood thinners to prevent clotting
3) seperated by partially permeable membrane, blood flows opposite to dialysis fluids to allow exchange
4) dialysis fluid contains glucose, ions but no urea so urea leaves
5) clean blood pumped back into body
FSH (Follicle Stimulating Hormone)
Secreted from pituitary gland
Causes egg in ovary to mature
Surrounded by cells called “follicles”
LH (Lutenising Hormone)
Stimulates release of egg at ovulation
Oestrogen and Progestrone
Stimulates build up and maintenance of uterus lining
Menstraul Cycle
1) uterus lining builds up, becomes thicker
2) egg is released, travels through fallopian tube
3) attaches itself to uterus lining
4) if fertilised, foetus develops, if not, lining sheds and falls out of vagina
Oral Contraceptives
Contains hormones to inhibit FSH and without FSH, no other hormones will be stimulated and egg will not mature
Slow release progestrone
Progesterone inhibits FSH which means egg wont mature
Diaphragm or cap
Prevent sperm from entering uterus
Condom
Prevent sperm entering uterus and prevent spread of STDs
Process of IVF
1) FSH and LH injected into mother to stimulate the maturing of multiple eggs
2) remove eggs from ovary
3) sperm and egg placed into test tube and sperm fertilises egg to form and embryo
4) embryo is inserted into uterus
Negative feedback
Return to norm, it is a correction mechanism that reverses a change
Piloerection
Hair stands up to warm
Pilorelaxation
Hair lies flat to cool
Auxins
Plant hormones controls growth in response to tropisms
Roots: growth occurs wth fewer auxins
Shoots: growth occurs when there are more auxins
Tropic responses
A directional growth reponse causing movement of part of an organism
Phototropism
Response to light
Hydrotropism
Response to water
Gravitropism (geotropism)
Response to gravity
Positive tropism
Growth towards stimuli
Negative tropism
Growth away from stimuli
Gibberellin
Stimulates plant stems to grow
Controls dormancy
Induces flowering
Grows larger fruit
Ethene
Stimulates enzymes that cause fruit to ripen