Anatomy of Endocrine System

Question 1

Endocrine system

Answer 1

• coordinates various activities of body parts by releasing chemical messengers (hormones) into the bloodstream
• works with nervous system but has slower reaction time (takes time for hormone to travel to destination, cells only respond to their specific hormones

Question 2

Hormone

Answer 2

• organic chemical produced by one set of cells that influences the metabolism of a different set of cells
• all hormones have specific: organ/gland of origin; target organ/gland; action
• many = proteins
• packaged into vesicles via golgi apparatus, secreted via plasma membrane

Question 3

2 main categories of hormones

Answer 3

1) peptide hormones

2) steroid hormones

Question 4

peptide hormones

Answer 4

• derived from proteins, peptides, or catecholamines
• activate existing cell enzymes
• need cell surface receptors to enter cell membrane/nucleus
• act quickly for short amount of time

Question 5

steroid hormones

Answer 5

• derived from cholesterol via metabolic reactions
• act more slowly than peptides, more sustained impact
• stored in fat droplets in cytoplasm until released
• don’t need cell surface receptors to enter cell membrane/nucleus
• bind to receptors in nucleus of target cell, create hormone receptor complex

Question 6

hormone receptor complex

Answer 6

• occurs when steroid hormone binds to receptors in nucleus of target cell
• activates specific genes, which causes the synthesis of new proteins

Question 7

endocrine glands

Answer 7

• responsible for hormone secretion
• ductless
• secrete contents directly into bloodstream

Question 8

endocrine organs

Answer 8

• 2 types: primary and secondary
• primary: secrete hormones that chemically regulate body functions
• secondary: secrete hormones as a secondary function

Question 9

exocrine glands

Answer 9

• have ducts that secrete their contents into an epithelial surface (ex = salivary glands)
• not responsible for hormone secretion

Question 10

primary endocrine organs (7)

Answer 10

1. hypothalamus
2. pituitary gland
3. pineal gland
4. thyroid gland
5. parathyroid glands
6. adrenal glands
7. pancreas

Question 11

secondary endocrine organs (4)

Answer 11

1. heart
2. kidneys
3. gonads
4. thymus

Question 12

negative feedback system

Answer 12

• how most hormones controlled
• allows body to maintain homeostasis/set point (range in which body maintains function)
• hormone production turns “on” when what it controls shifts outside the range required for homeostasis, turns “off” when back inside homeostasis range
• ex: ADH (dilutes blood, once blood is sufficiently diluted, the hypothalamus shuts of release of ADH until it is needed for dilution again)

Question 13

positive feedback system

Answer 13

• cycle that increases amount of hormone that is regulated
• ex: oxytocin during childbirth (action = uterine contraction, which releases more oxytocin, which causes another contraction, etc. etc. until baby born)