Topic 7 Flashcards Preview

GCSE Edexcel Biology grade 9-1 course, topics 6-9 > Topic 7 > Flashcards

Flashcards in Topic 7 Deck (200)
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181

how does thermoregulation work when you are too cold?

•the erector muscles contract and the hairs stand upright on the skin to form an insulating layer of air
•little sweat is produced
•blood vessels near the surface of the skin constrict, resulting in less blood flow near the skin surface so less energy is transferred to the surroundings. this is vasoconstriction
•shivering is your muscles contracting automatically, increasing the rate of respiration, this transfers energy to warm the body.

182

what structures in the skin used for thermoregulation are in the epidermis?

the sweat pore and hair

183

what structures in the skin used for thermoregulation are in the dermis?

sweat gland, blood vessels, fat layer, temperature receptors, oil gland and hair erector muscle

184

how can the body gain heat apart from processes involved in thermoregulation?

exercise generates heat because muscles need to respire to contract more and wearing more clothes insulates the body

185

how can the body lose heat apart from by processes involved in thermoregulation?

wearing fewer clothes allows heat loss

186

why is osmoregulation important?

to keep cells functioning properly, containing the correct amounts of water

187

what happens to cells if the blood contains too much water?

if the concentration of water in the blood is too high then water will move into the body's cells by osmosis (from an area of higher water potential to an area of lower water potential). if too much water moves into the cells the cells will undergo lysis (burst), animal cells burst when they contain too much water because they don't have a rigid cell wall (unlike plant cells)

188

what happens to cells if the blood contains too little water?

if the concentration of water in the blood is too low then water will move out of the cells into the blood by osmosis (from an area of higher water potential to an area of lower water potential), when the water starts move from the cells the cells will shrink.

189

what are the three main roles of the kidneys in the urinary system?

•removal of urea from the blood
•adjustment of ion levels in the blood
•adjustment of water content of the blood

190

how are the structures of the nephron in animals living in drought conditions different to that of humans?

they have a longer Loop of Henle to absorb more water

191

what concentration of salts and glucose does dialysis fluid have?

the same concentration of salts and glucose as blood plasma so glucose and salts are removed from the patient's blood in dialysis

192

if the thyroid is overactive what physically happens to it?

becomes enlarged and increases in size to form a goiter (like a large lump in the neck where the thyroid is)

193

if the thyroid gland is underactive what physically happens to it?

it decreases in size

194

what are some issues to be considered with surrogacy as an infertility treatment?

•difficultly making mother and baby bond
•baby is not genetically linked to one or both of the parents
•it is difficult to find a surrogate mother
•the surrogate mother may not wish to give up the baby
•health issues / genetic disorders

195

what is one of testosterone's target organs?

the bones

196

what are the target organs for insulin?

the liver and muscles

197

why would using some sort of blood glucose monitor help someone with type 1 diabetes?

•it would help them determine the exact dose of insulin needed
•the monitor would track the long-term effects of diabetes
•the data would allow patients to understand their condition better
•the data would be useful to health professionals

198

approximately how long do kidney transplant patients have to wait for a kidney for the transplant?

approximately 2 to 3 years

199

what does the patient need to do after a kidney transplant?

they must take immunosuppressants for the rest of their life to stop the immune system from attacking the kidney and rejecting it.

also lifestyle changes: no smoking, regular exercise, reducing alcohol intake, not taking drugs, having a healthy diet (avoiding foods with a high level of salt which could increase blood pressure) and avoiding foods with a high risk of food poisoning because the immune system will be weaker due to the immunosuppressants

200

how long does a transplanted kidney last for?

on average:
95% last 1 year
85%-90% last 5 years
75% last 10 years