Endocrine 1

Question 1

what are the components of the endocrine system?

Answer 1

• hormones, organs, metabolites/metabolic products

Question 2

hormone

Answer 2

• produced in one area
• transported by blood
• affect cells in another area
• act in low concentration

Question 3

paracrine

Answer 3

• produced in one cell
• transported in extracellular fluid to affect adjacent cells
• may overlap some with hormones: prostaglandins, cytokines, somatomedins

Question 4

neurotransmitters

Answer 4

• could be considered paracrine

Question 5

autocrine

Answer 5

• produced by and affect the same cell

Question 6

types of hormones

Answer 6

• steroids and proteins

Question 7

what differentiates hormones?

Answer 7

• modes of: synthesis, secretion, and transport
• receptor location and function

Question 8

protein synthesis

Answer 8

• made in ribosomes as a pre pro hormone
• pre part attaches to rough ER (removed), leaving pro hormone
• put into cytoplasmic vesicles which come together and lose the pro
• hormone stored in granules until released
• secretion mediated by ATP and Ca (requires energy)
• pre and pro help to guide protein (essential)

Question 9

steroid synthesis

Answer 9

• formed as needed, NOT stored (besides cholesterol)
• mostly made from cholesterol from liver
• can also be built anew from acetate
• formed in mitochondria and other cell compartments

Question 10

protein transport

Answer 10

• hydrophilic, simply dissolve and float along

Question 11

steroid transport

Answer 11

• lipophilic, must get to blood on own and associated with binding proteins
• nonspecific binding to albumin or specific binding proteins (high affinity and specificity)
• bound and unbound exist in equilibrium with unbound at about 1%

Question 12

protein hormone receptors

Answer 12

• protein hormone receptors are on cell surface
• trigger a cascade of activations of enzymes
• eventually signal to the nucleus - effecting metabolism

Question 13

steroid hormone receptors

Answer 13

• in cytosol or nucleus
• shorter pathway to up-regulate nucleus

Question 14

protein hormone degradation

Answer 14

• cleaved by peptidases

Question 15

steroid hormone degradation

Answer 15

• reduced, conjugated with sulfate or glucuronides. they are then water soluble and can be excrete in urine

Question 16

what do hormones do?

Answer 16

• regulate metabolism: mineral balance, water balance, energy production and maintenance, reproductive control
• most hormones target only one of these functions