Hormones and Homeostasis: Part of Topic 6.6

Question 1

Describe how the body responds to hyperthermia to restore a homeostatic temperature.

Answer 1

During hyperthermia, the thermoreceptors in the skin send signals to the hypothalamus and it releases chemical signals that trigger vasodilation where arterioles get bigger and fill with blood to transfer heat to skin and out of the body as well as increasing sweat gland activity to cool the body

Question 2

Outline the role of thyroxin in maintaining metabolic rate and body temperature.

Answer 2

Thyroxin is a hormone secreted by the thyroid gland of the endocrine system in response to signals derived from the hypothalamus. Thyroxin acts on the body and causes an increase in the body’s metabolic rate, it causes an increase in carbohydrate and lipid metabolism, and it causes increased oxygen consumption and the hydrolysis of ATP causing an increase in body temp

Question 3

Outline the causes and consequences of hypothyroidism.

Answer 3

Occurs when there is an insufficient amount of thyroxin in the body
Symptoms: weight gain, loss of energy, feeling cold all the time, forgetfulness, and depression

Question 4

Describe the role of melatonin in the control of circadian rhythms.

Answer 4

Produced in the pineal gland as a response to light, controls 24hr circadian rhythm, production of melatonin is controlled by the amount of light detected by the retina, higher production at night then during the day (why screens keep you up), amount of melatonin is proportional to the lengths of nights, promotes sleep in diurnal animals and activity in nocturnal animals