Parathyroid Hormone (PTH) and Calcium Homeostasis Quiz

Hormone Binding and Signaling

• Steroid hormones bind to and activate receptors within cells
• Cyclic adenosine monophosphate (cAMP) is the second messenger released inside the cell when a water-soluble hormone binds to a membrane receptor

Hormone Regulation

• Hormone secretion is controlled by negative feedback, stimulatory hormonal signals, and neural signals
• Negative feedback is the most common type of feedback system that regulates hormonal secretions

Glands and Hormones

• The hypothalamus is the major integrating link between the nervous system and endocrine system
• Exocrine glands secrete their products into ducts
• Steroid hormones are made from cholesterol
• Down-regulation is the process by which a hormone is present in excess and there is a decrease in the number of receptors
• Water-soluble hormones include peptides and proteins

Endocrine System Functions

• The main function of the endocrine system is to regulate various bodily functions, including growth and development, metabolism, and reproductive processes
• Insulin decreases blood glucose levels, while glucagon increases blood glucose levels
• The adrenal cortex is responsible for secreting mineralocorticoids
• Aldosterone is responsible for increasing sodium and water reabsorption and decreasing potassium reabsorption

Reproductive System

• The ovaries produce gametes in females

Stress and Glucocorticoids

• High concentrations of glucocorticoids during stress can cause physiological effects such as glucose release, fat mobilization, and suppression of the immune system
• Chronic stress is associated with diseases such as hypertension, diabetes, and ulcers
• Exhaustion occurs during stress due to depletion of energy stores
• Stress is not related to gigantism
• Interleukin-1 (IL-1) links stress and immunity by stimulating the immune response

Glands and Hormones (continued)

• The pineal gland is attached to the roof of the third ventricle inside the brain
• The testes produce sex hormones related to the development and maintenance of male sexual characteristics
• The thymus secretes hormones related to immunity, promoting the proliferation and maturation of T cells
• Adipose tissue, the pancreas, and the heart also secrete hormones, acting as paracrines and autocrines in most body tissues
• Extreme, unusual, or long-lasting stress can trigger bodily changes such as hypertension, atherosclerosis, and suppressed immunity

Pituitary Hormones

• The most plentiful anterior pituitary hormone is prolactin
• Thyroid-stimulating hormone (TSH) stimulates the thyroid gland to produce thyroxine
• Luteinizing hormone (LH) stimulates ovulation in females
• Prolactin (PRL) stimulates milk production in lactating females
• Calcitonin, produced by the parafollicular cells of the thyroid gland, lowers the blood level of calcium