Chapter 46-The Endocrine System and Chemical Regulation

Question 1

Paracrine regulators

Answer 1

-many types, nearly all cells in body secrete one type or another, act only at short distances on neighboring cels with complementary receptors

Question 2

Neurotransmitters

Answer 2

• most secreted by neurons into synapses, transmits nerve impulse across chemical sunapse
• some neurontransmitters distributed by blood and act as a hormone (norepinephrine)

Question 3

neurohormones

Answer 3

hormones made by neurons that are transmitted by blood (ex. antidiuretic hormone)

Question 4

Endocrine Hormones

Answer 4

Regulatory chemicals that are secreted by special glands into extracellular fluid and carried by the blood to target tissues/organs

Question 5

3 Classes of Endocrine Hormones

Answer 5

1. Peptide and Proteins (hydrophilic)
   - glycoproteins
2. Amino acid derivatives (hydrophilic)
   - thyroid hormones
   - meltonin
3. Steroids (hydrophobic)
   - sex steroids
   - corticosteroids

Question 6

Lipophilic Hormones

Answer 6

• non polar, fat soluble
• steroid and thyroid hormones
• travel in blood, attached to transport proteins
• bind to intracellular receptors
• act over brief time period

Question 7

Hydrophilic Hormones

Answer 7

polar, water soluble

• all hormones except steroids and thyroids
• freely soluble in blood
• bind to extracellular receptors, activate kinase cascades
• longer active period

Question 8

Hypothalamus

Answer 8

• Releasing Hormones, Inhibiting Hormones
• Target tissue=adenhoypophysis
• Principle action=acitvate/inhibit release of adenohypophyseal hormones

Question 9

Posterior Pituitary Gland

Answer 9

• Secretes hormones produced by hypothalamus neuron bodies
• Antidiuretic Hormone, Oxytocin
• Target Tissue=kidneys, uterus, mammary glands
• Actions=conserves water (ADH), stimulates contraction, stimulates milk ejection (in that order for hormones/tissues)

Question 10

Anterior Pituitary gland

Answer 10

• Produces 7 essential hormones, act on and regulate other endocrine glands
• controlled by hypothalamus
• -negative feedback inhibition
• Peptide hormones
  1. ACTH-Adrenal Cortex-Stimulates secretion of adrenal hormones
  2. MSH-SKin-stimulates color change in reptiles
• Protein hormones
  3. Growth Hormone-many organs-stimulates bone growth, protein synthesis
• Glycoprotein Hormones
  4. Thyroid Stimulating Hormone-Thyroid gland-stimulates thyroxine secretion
  5. Luteinizing hormone-gonads-stimulates ovulation
  6. Prolactin-mammary glands- milk production
  7. Follicle stimulating hormone-gonads-stimulates spermatogensis in males, development of ovarian follicles in females

Question 11

Thyroid Gland

Answer 11

1. Thryroid Hormones-most cells-stimulates metabolic rate

2. calcitonin-bone-inhibits loss of calcium from bone

Question 12

Parathyroid Gland

Answer 12

1. Parathyroid Hormone-bone, kidneys, digestive tract-raises blood calcium level, stimulates calcium reabsorption in kidneys
   - 4 small glands attached to thyroid

Question 13

Adrenal Medulla

Answer 13

• inner portion of Adrenal Glands

- Epinephrine and Norepinephrine-muscle-initiates stress response

Question 14

Adrenal Cortex

Answer 14

Stimulated by anterior pituitary hormone

• Glucocorticoids-many organs-raises blood glucose level
• Mineralocorticoids-kidney tubules-maintains proper balance of NA+ and k+ in blood

Question 15

Pancreas

Answer 15

Exocrine and Endocrine Gland

• secretes insulin-liver-lowers blood glucose levels
• glucagon-liver-raises blood glucose levels

Question 16

Pineal Gland

Answer 16

• located in roof of third ventricle of brain

- melatonin-gonads, brain, pigment-regulates biological rhythms

Question 17

Testis

Answer 17

-testosterone-stimulates development of sex organs, stimulates secondary sex characteristics in males

Question 18

Ovaries

Answer 18

Progesterone-uterus-completes preparation for pregnancy, stimulates development

Question 19

Pituitary gland

Answer 19

-Master gland-consists of anterior pituitary, posterior pituitary

Question 20

Anterior Pituitary Disorders

Answer 20

• growth hormone
• Hypersecretion=gigantism
• hyposecretion-pituitary dwarfism

Question 21

Diabetes Mellitus

Answer 21

• Diabetics cannot take up glucose from blood
• type 1=individuals lack insulin secreting beta cells, treated by daily injections of insulin
• type 2=very low number of insulin receptors, treated by diet and exercise

Question 22

What are the 5 steroid hormones

Answer 22

• minerocorticoids (aldosterone)
• glucocorticoids (cortisol)
• estradiol
• progesterone
• testosterone