Homeostasis

Question 1

What are the homeostatic conditions?

Answer 1

pH= 7.365; Temp=37C, blood glucose= 5mmol/L

Question 2

What links the nervous system to the endocrine system?

Answer 2

The hypothalamus

Question 3

What are the functions of the hypothalamus?

Answer 3

Release of 8 major hormones by the pituitary gland; controls temperature, food and water intake, sexual behaviour and reproduction, daily cycles in physiological state and behaviour, and emotional responses

Question 4

What are the three main regions of the hypothalamus?

Answer 4

Supraoptic or anterior region; middle or tuberal region; mammilliary or posterior region

Question 5

What nuclei does the supraoptic region contain?

Answer 5

Supraoptic and paraventricular nuclei

Question 6

Why is it important to maintain glucose homeostasis?

Answer 6

o Prevents short term hypoglymecia and long-term hyperglycemia
• Hypoglycemia is lack of glucose in the brain
• Hyperglycemia is excessive amounts of glucose in the blood
• Prevents complications with diabetes
 Frequent urination and frequent thirst (because of cell dehydration), and excessive hunger

Question 7

What does insulin regulate in our blood?

Answer 7

o Insulin is absolutely essential for survival;
• It regulatesnormal blood conc of fatty acids, glucose, and amino acids almost exclusively
 Secretion of insulin is due to high levels of blood glucose after a meal

Question 8

What are hypo and hyperglycemia?

Answer 8

Hypo–lack of glucose to the brain

Hyper–excessive blood glucose levels; glucose can alter protein conformation via glycation

Question 9

What is IGF-1?

Answer 9

An endocrine/paracrine/autocrine hormone wit stimulating growth effects on:
• Osteoblast and chondrocyte activity to promote bone growth
○ Stimulates elongation of bones during puberty
○ Keeps elongating until a signal is sent to stop elongation

Question 10

What are the metabolic effects of GH?

Answer 10

o Metabolic effects of growth hormones:
• Increases calcium retention
 Strengthens bones by stimulating mineralization
• Helps organs grow
 Except the brain
• Increases muscle mass
 Stimulates sarcomeres hyperplasia and protein synthesis
• Regulate glucose and fatty acid levels in the blood by promoting gluconeogenesis and lipolysis