SPM bio.帮帮我.要考SPM了

白羊座aries

稍微解释下 vasodilation和vasocontricion.

为什么heart beat increase 就会有vasodilation?warm condition 又vasodilation ?

另外,如果可以请帮我解释oestrogen/progesterone/LH/FSH. oestrogen是 repair/thickening endometrium 和 stimulateFSH,progesterone 是 inhibitovulation,LH promote ovulation,FSH 是stimulate follicle cell develop.
我想知道graph of hormone against day 而已.这些hormone如何relate去graph?

floating plant.
有几种?可以告诉我有什么tissue support them to float 吗?要reason 哦.谢谢

解释respiration 那里的 鱼,青蛙的 repiratory system
''  ''  locomotion 里的earthworm ,鸟, 鱼和grasshoper. 希望可以仔细的为我解释谢谢.

p/s:用form 5 level的英文解释.不要翻译去华语

@res

既然是楼主的要求来用英文解释，请版主原谅
First thing you need to know what are vasoconstriction and vasodilation.
Vaso is from the word "vessel", that means blood vessel
constriction can be said as spasm, or in Malay "mengecut",收缩in chinese
dilation is something like relaxation (of muscles).
So when they combine, they mean something like narrowing of the vessel lumen and widening of vessel lumen respectively.
Both are a "technique" used by the human body to maintain the homostasis of blood pressure and body temperature.

When heart beat increase (pulse rate increase), the blood pressure in the body will increase. This increment can be detected by baroreceptor in various part of the body., impulse will be sent up to the brain. The brain will activate a conteract mechanism (parasympathetic nervous system or PSNS) to lower the blood pressure. These machanism will cause decrease of heart beat rate and widening of vessel lumen (vasodilation).
Imagine in a vessel with a narrow lumen and a wide lumen, same amount of water is flowing at the same velocity, which pressure is higher?

In a warm environment/feverish condition, vasodilation will help the body to release heat to the surrounding. Why? The body temperature is because of the temperature of the blood. When vasodilation occur, blood vessels will come nearer to the surface ofthe skin, ease the heat removing process.. This explains why some people will kind of like blushing/having very red cheeks in a stuffy room.
The opposite thing happens when a person is in a air-con room. Vasoconstriction occurs, blood vessels "sink" to a deeper layer of skin, blood from the upper and lower extremities are drawn back to internal organs, and this explains why people look pale and very cold hands and legs in a very cold environment.

白羊座aries

原帖由 @res 于 15-10-2008 10:42 PM 发表
既然是楼主的要求来用英文解释，请版主原谅
First thing you need to know what are vasoconstriction and vasodilation.
Vaso is from the word "vessel", that means blood vessel
constriction can be said ...

很仔细,我喜欢,谢谢.我知道vasodilation和vasocontriction了.
还有hormone的能否解释下.拜托

@res

Erm...menstrual cycle我其实已经忘了。不过，hormone的secretion其实可以解释的。不难，只是很多东西要背。After all, this is a girls thingy，我也不是很清楚
我做完我的revision过后，再解释吧。。。

白羊座aries

原帖由 @res 于 16-10-2008 03:03 AM 发表
Erm...menstrual cycle我其实已经忘了。不过，hormone的secretion其实可以解释的。不难，只是很多东西要背。After all, this is a girls thingy，我也不是很清楚
我做完我的revision过后，再解释吧。。。

hormone secretion ?那一个gland secret hormone 和他们的function吗?这个我没问题.只是我不明白 那个graph of hormone against time ...有时高,但是有时底,我完全不明白.还有其他的哦.拿不拿到A就靠你了

p/s:我没有补习的

白羊座aries

对了,忘记问什么是corpus lutuem .degenerate 又什么?

海仙子

原帖由 白羊座aries 于 16-10-2008 08:32 AM 发表


hormone secretion ?那一个gland secret hormone 和他们的function吗?这个我没问题.只是我不明白 那个graph of hormone against time ...有时高,但是有时底,我完全不明白.还有其他的哦.拿不拿到A就靠你了

p ...

你首先要明白hormone 之间的interaction,
（我不大会用华语解释， 你将就将就点看英文）

graph of hormone against time.
understand the interaction among the hormones, then you will know why  the hormone level are sometimes high and
sometimes low.

at the begining of menstrual cycle, the FSH is secreted,(FSH concentration increase)
then follicle stimulated by FSH to delvelop and secrete Oestrogen,
high level of oestrogen then stimulate the secretion of LH（LH concentration increase）
on day 14 ,
ovulation occurs and fromation of corpus luteum,
(follicle -->corpus luteum), thus progesterone is secreted by the corpus luteum , while the oestrogen concentration become lower,
low oestrogen ----> low LH
at the same time FSH concentartion also gone low.
就醤

原帖由 白羊座aries 于 16-10-2008 10:18 PM 发表
对了,忘记问什么是corpus lutuem .degenerate 又什么?

其实， bio 可以去看pelangi focus 的参考书， 不错下的。
我都是用这本。


加油哦！！

lipterstar

哈哈，男生的确比较难懂。。。
像当年很多男同学也是找我来解释。。。。
班上的女同学不大要帮他们，可能害羞呱。。。
讲真太久没有复习还真的是忘记了。。。。

lipterstar

Corpus lutuem 其实是graafian follicle演变成的。。。。
它会secrete estrogen(increase uterus lining)和progesteron(inhibit LH and FSH so that no other follicle will be develop)...

如果没有受精，corpus lutuem就会degrade。。。
一没有progrestrone，另一个follicle就会因为FSH和LH的增加而开始为下一个cycle成熟。。。。
相反如果受精，它就会remain。。。。
继续提供estrogen和progrestrone,持续3-4个月直到placenta形成。。。
placenta会代替corpus lutuem继续释放estrogen和progrestrone。。。

白羊座aries

谢谢啊!明天我SPM了.你们真是我的救星

lipterstar

加油咯！