BOICHEMICAL PROCESS

STIMULANT RECEPTOR INTEGRATING CENTRE

EFFECTOR RESPONE RESULT

BREATHINGRATE

↑ CO2 Central chemoreceptor

Respiratory centre in the MO

Intercostal muscleDiaphragm

Contract and relax faster More CO2 is removed.∴ CO2 ↓ and back to normal

↓ O2 Peripheral chemoreceptor in carotid,aortic arch

Heart Heart beat increase More O2 is inhaled.∴ O2 ↑ and return to normalIntercostal muscle

DiaphragmContract and relax faster

BLOOD PRESSURE

BP ↑ Baroreceptor in carotid, aortic arch

Cardiovascular centre in the MO

Cardiac muscle Weaker contraction and relaxation Blood flow slower.Blood pressure ↓, return to normal.Artery Smooth Relax and vasodilation occur

BP ↓ Muscle (ASM) Stronger contraction and relaxation Blood flow faster.Blood pressure ↑, return to normal.Contract and vasodilation occur

BLOOD OSMOTIC PRESSURE

Drink too more water

BOP ↓

Osmoreceptor in the hypothalamus

Pituitary gland is less stimulated

Less ADH is secreted to blood

DCT, CD is less permeable to water. Less water is reabsorbed.Water content of urine decease.Urine becomes darker and more concentrated.∴ BOP ↑, return to normal.

Adrenal is stimulated to secrete aldosterone.

More salt is reabsorbed.

Drink too little water

BOP ↑

Pituitary gland is more stimulated

More ADH is secreted to blood

DCT, CD is more permeable to water.

More water is reabsorbed.Water content of urine decease.Urine becomes darker and more concentrated.∴ BOP ↓, return to normal.

Adrenal is not stimulated

Less salt is reabsorbed

℃ ℃ ↑(internal/external)

Thermoreceptor in the hypothalamus/ skin

Thermoregulatory centre in hypothalamus

(ASM) Contract and vasodilation occur More heat lost to the skinHeat is removed through sweatLess heat is generated

℃ ↓, return to normal

Sweat gland SweatingAdrenal/Thyroid g. Less stimulated, low metabolismSkeletal muscle No shiveringErector muscle-skin Relax, lower skin hair to no trap H

℃ ↓(internal/external)

Relax and vasodilation Less heat lost to the skinHeat is conservedMore heat is generated

℃ ↑, return to normal

No sweatingMore stimulated high metabolismShiveringContact, raising skin hair to trap H

BLOOD GLUCOSE LEVEL

BGL ↑ Pancreas β cell secrete insulin Faster cellular respirationConvert glucose to glycogenBuild protein, form fatInhibit vice versa∴ BGL ↓, return to normal.Stimulate liver cell

BGL ↓ α cell secrete glucagon

Stimulate muscle cell Slower cellular respirationConvert glycogen to glucoseBreak down lipids produce energyInhibit vice versa∴ BGL ↑, return to normal.

Stimulate adipose tissue

Is detected byGenerate and send impulse Send impulse Carry out