Regulation of body temperature

Regulation of body temperature

Body temperature above normal ranges

1. Erector muscles are less stimulated

2. Vasodilation

3. Reduction of contraction and relaxation of skeletal muscles

4. Stimulation of sweat glands

5. Less stimulation of adrenal glands

6. No stimulation of thyroid glands

Erector muscles are less stimulated

1. Erector muscles do not constrict, causing fine hair to lower towards the skin

2. A thin layer of air is trapped between the fine hair (heat can be released quickly)

Vasodilation

1. Allows more blood flow to the skin

2. More heat is lost to the external environment through radiation

Reduction of contraction and relaxation of skeletal muscles

Body does not shiver.

Stimulation of sweat glands

1. Produce more sweat

2. Heat is absorbed to evaporate sweat, which cools the skin

Less stimulation of adrenal glands

1. Less adrenaline is secreted

2. Metabolic rate decreases

No stimulation of thyroid glands

1. Less thyroxine is secreted

2. Metabolic rate decreases

3. No excess heat is generated

Body temperature below normal ranges

1. Contraction of erector muscles

2. Vasoconstriction

3. Contraction and relaxation of skeletal muscles

4. No stimulation of sweat glands

5. Stimulation of adrenal glands

6. Stimulation of thyroid glands

Contraction of erector muscles

1. Fine hairs stand erect

2. A thick layer of air trapped between fine hairs acts as a heat insulator

Vasoconstriction

1. Less blood flow to the surface of the skin

2. Less heat is lost to the external environment through radiation

Contraction and relaxation of skeletal muscles

1. Body shivers

2. Generates heat because the constriction of muscles requires energy (raise body temp)

No stimulation of sweat glands

Sweating does not happen.

Stimulation of adrenal glands

1. Secrete more adrenaline

2. Speeds up conversion of glycogen to glucose

3. Metabolic rate increases

4. Oxidation of glucose releases heat

Stimulation of thyroid glands

1. Secrete more thyroxine which increases metabolic rate

2. More heat is generated