Must
remember these 3 (very important) :
- Blood osmotic pressure (involves water)
- Blood glucose level
- Body temperature
Regulation of blood osmotic pressure :
Situation A
Drink too much water
Blood osmotic pressure …………………………….
Osmoreceptor in hy………………………. less
stimulated
P…………………………… less stimulated
Less …………….. is secreted into blood
Lower ……………….., d……………………………, c……………………………are less permeable to water
Less water is re…………………………………
Urine contains more …………………. means
more d…………………….
Blood osmotic pressure increases back to
normal
Situation
B
Drink too little water
Blood osmotic pressure ………………………….
Os………………………………. in h………………………….. detect
and is s…………………..
Stimulate p………………………………….
More ……………………….. is secreted into blood
Higher level of ……………………….. causes
d…………………………….. & ………………………………. more permeable to water
M…………….. water is re…………………………
Urine contains less ……………………., more
con………………………….
Blood osmotic pressure decreases back to
normal
Regulation
of blood glucose level
Pancreas secretes hormones i…………………….
and g………………………..
Situation
A
Blood glucose level increases (Eg. After
meal), pancreas secretes hormone ………………………..
I…………………….. transported by bloodstream
to liver, muscle cells, adipose tissue
I…………………….. stimulates liver to : use
glucose for respiration, convert excess glucose to
glycogen & stores excess
glucose as glycogen
I…………………….. stimulates muscle cells to :
use glucose for respiration, converts glucose to
glycogen & stores glycogen to
build proteins
I…………………….. stimulates adipose tissue to
: use glucose for respiration, use glucose to form fat
Situation
B
Blood glucose level decreases (Eg.
Fasting), pancreas secretes hormone ……………………
G…………………… transported by bloodstream to
liver cells, adipose tissues
G…………………… stimulates liver to break down
g…………………. into g……………….
G…………………… stimulates adipose tissue to
break down l…………… which release fatty acids
that can be metabolised to generate
energy
Regulation
of body temperature
Normal body temperature 370C
(optimum temperature for metabolic reactions & enzyme
activities)
Situation A
Surrounding temperature is hot
Change in normal body temperature
T………………………………. in hypo…………………… detects
blood temperature;
t…………………………. in s……………… detects external temperature
Both t………………………………. send nerve impulses
to hypothalamus
Action? V…………………………………… (arterioles
dilate), smooth muscles around arterioles relax,
more blood flows through skin,
increase amount of heat radiated & loss via blood
Increase s…………………………., heat lost through
surrounding when sweat evaporates, cools body down
Hair e………………………………… in the skin relax,
warm air is not trapped & free to escape
Adrenal gland & thyroid gland are
less stimulated to secrete a…………………………….. and
t……………………………, thus metabolic rate
is low & no excess heat generated
No shivering
Decrease body temperature
Situation
B
Surrounding temperature is cold.
Change in normal body temperature.
T…………………………………. in hypo…………………… detects
blood temperature; t………………………….. in s………………….. detects external
temperature
Both ………………………………….. send nerve impulses
to hypothalamus
Action? V………………………………… ( arterioles
constrict), smooth muscles around arterioles
c…………………., d…………………… amount of
blood flows through skin, d…………………….
amount of heat loss
Sweating does not occur
Hair e……………………………………… in the skin
c…………….., trapping & insulating air;
preventing air from e……………………
A……………………………….. & T…………………………. are
stimulated to secrete more
a…………………………. & t………………, thus increases
m………………………………. & generates more h…………….
Skeletal muscles are stimulated;
s……………………. occurs; heat is generated
