Endocrine System

Question 1

Explain second messenger mechanism for water soluble hormones

Answer 1

1. Hormone birds to corresponding receptors
2. Receptor activates G protein
3. G protein activates enzyme, adenylate cyclase,
4. Adenylale cyclase converts ATP TO cAMP 2nd messenger
5. Camp activates protein kinase wich triggers response of target cell

Question 2

Explain direct gene activation mechanism of lipid soluble hormones

Answer 2

1. The steroid hormone diffuse through plasma membrane and binds with intracellular receptor
2. The receptor hormone complex enters the nucleus
3. The receptor hormone complex binds A specific DNA region
4. Binding initiates transcription of g protein
5. The mRNA directs protein synthesis

Question 3

List and explain 3 types of endocrine gland stimuli

Answer 3

1) humoral stimulus ( hormone release caused by altered levels of certain critical ions or nutrients ) ex. Low Ca in blood = parathyroid gland release PTH to bring those levels back up.
2. Neural stimulus, hormone release caused by mural input(ex. Spinal cord response tofear is to realease adrenaline from adrenal medulla )
3. Hormonal stimulus, release of hormones causes other hormones to be secreted

Question 4

Explain hypothalamus interactions with pituitary gland (2 answers)

Answer 4

1. Posterior pituitary: AP’s pertrude down axon of hypothalamus down to posterior pituitary and releases ADH and oxytocin
2. Anterior pituitary: hypothalamic release inhibitory or release hormones which travel through special blood vessels where anterior pituitary secretes the hormones example: growth hormone

Question 5

Where is oxytocin produced and what stimulates it?

Answer 5

Produced in hypothalamus and secreted by posterior pituitary gland and is stimulated during birth and breast feeding mainly

Question 6

ADH

Answer 6

ADH is secreted by posterior pituitary and is stimulated by dehydration (makes you thirstly)