what I need to learn

chemicals in a synapse set off a new electrical signal in the next neuron.

cerebral cortex- consciousness,intelligence,memory,language

cerebellum- muscle contraction

medulla- unconsciuos activities like breathing and heart beat

electrically stimulate the brain by pushing an electrode into it. add a tiny zap of electricity and see what the effect is

bright light- circular muscles contract and radial muscles relax

close object- ciliary muscles contract (curved lense) suspensory ligaments relax (increases the amount light is refracted)

hyperopia- short eye, convex lense (fat)

myopia- long eye, concave lense (hourglass)

Soft lenses are more comfy but have a higher risk of infection.

Thermoregulatory centre is sensative to the temperature of blood.

Hormones are chemical molecules released directly into the blood.They affect target organs. They control things in organs and cells that need constant adjustment.

A normal metabolism removes glucose from the blood.

Urea is made by the body needing to get rid of excess proteins or amino acids. They're taken to the liver where amino groups are converted into fats and carbohydrates andremoved as ammonia through the process of deamination. ammonia is toxic so is converted to urea. This is stored in the bladder and sent out as urine.

The kidneys produce urine by filtering the blood and reabsorbing all the sugar, ions and water needed by the body. it then releases excess ions, water and urea as urine.

adh controls the concentration of urine.

dialysis- blood flows through pp membrane surrounded by dialysis fluid that is p to ions and waste substances .

dialysis fluid has the same concentration of dissolved ions and glucose as healthy blood

oestrogen- ovaries. causes the lining of the uterus wall to grow. stimulates the release of LH and inhibits the release of FSH.

FSH- pituitary gland. causes eggs to mature in follicle and stimulates ovaries to produce oestrogen

LH- pituitary gland. stimulates release of an egg (ovulation)

progesterone- in ovaries by the remains of follicle after ovulation. maintains lining of uterus during 2nd half. inhibits release of LH+FSH.

plastic iud release progesterone and copper iud prevent sperm from surviving. ( kills sperm and prevents implantationof a fertilised egg)

thyroxine is released in response to TSH.

auxin is used for killing weeds, growing from cuttings using rooting powder and growing cells in a tissue culture.

giberellins are used to control dormancy, induce flowering and grow larger fruits.

ethene is producedby the aging parts of a plant. it controls cell division and stimulates enzymes that speed up the ripening of fruit