Question

Explain how reflexes play a critical role in maintaining homeostasis .

Answer 1

When you detect a change in enviornment (a stimulus) and react to change (a response) in a way to maintain homeostasis, when you do this without thinking it is reflex, reflexes maintain homeostasis.

Homeostasis is the activity of the cells throughout the body to maintain physiological state within a narrow range that is compatible with lilfe, homeostasis is regulated by negative feedback loop and positive feedback loop.

for eg, Baroreceptors are specalised receptors located within blood vessels and heart chambers that respond to degree of stretch caused by the presence of blood, they send impulse to cardiovascular system to regulate blood pressure, when the cardiovascular center in the medulla oblongata receives the input it triggers a reflex that maintains homeostasis. When blood pressure increases the baroreceptors fires at higher rate and triggers a parasympathetic stimulation of the heart as a result cardiac output falls, sympathetic stimulation of peripheral arterioles will also decrease resulting in vasodilation, combined these activites cause blood pressure to fall. When the blood pressure falls baroreceptors fire at lower rate this will trigger sympathetic stimulation of the heart causing cardiac output to increase, it will also trigger sympathetic stimulation of the peripheral vessel resulting in vasoconstriction, combined, these activity raise the blood pressure.

In additon to baroreceptor there are chemoreceptor reflex that maintain levels of oxygen, carbon di oxide and hydrogen ion concentration thereby contribute to vascular homeostasis.simlarily body temperature is maintaines within narrow range by the negative feed back loop.