Module 12: Endocrine System

Question 1

Gap Junctions

Answer 1

a. Chemical mediator used:
b. Distribution of effects:

Question 2

Paracrines

Answer 2

a. Method of signal transmission:
b. Distribution of effects:

Question 3

Hormones

Answer 3

a. Method of signal transmission:
b. Distribution of effects:

Question 4

Neurotransmitters

Answer 4

a. Method of signal transmission:
b. Distribution of effects:

Question 5

Endocrinology

Answer 5

involves the diagnosis and treatment of endocrine system disorders

Question 6

Endocrine glands

Answer 6

pituary, thyroid, adrenal glands and pancreas: multicellular glands producing hormone

Question 7

There are other organs and tissues that produce hormones

Answer 7

adipose tissue produces leptin hormone; looking more globally

Question 8

Target organs and target cells

Answer 8

whose functions are altered in response to a hormone

Question 9

Nervous System

Answer 9

a. Communicate using neurotransmitters and action potentials
b. Act at synapses on target cells
c. Local, specific effects
d. Act within milliseconds
e. Stops quickly when stimulus stops
f. Adapts quickly
g. Short term stresses
h. Targets are muscles, glands, adipose tissue, neurons

Question 10

Endocrine System

Answer 10

a. Communicate using hormones released into blood
b. Act on targets far from site of release
c. General, widespread effects
d. Act within seconds to days
e. Continues to respond long after stimulus stops
f. Adapts relatively slowly
g. Long term stresses
h. Targets are body cells

Question 11

Monoamines (biogenic amines)

Answer 11

a. Produced from amino acids
i. Tyrosine
ii. Tryptophan

Question 12

Peptide hormones

Answer 12

a. Chains of amino acids
i. Oligopeptides
ii. Polypeptides
iii. Glycoproteins

Question 13

Steriod hormones

Answer 13

a. Made from cholesterol

Question 14

Hydrophilic hormones freely circulate in blood

Answer 14

a. Effects are short-lived because
i. Diffuses out of blood and binds to receptors
ii. Filtered out at the kidney
iii. Broken down by enzymes in IF, plasma, liver, & kidney

Question 15

Hydrophobic hormones must bind to transport proteins (albumins and globulins)

Answer 15

a. Bound hormone
b. Unbound hormone
c. Transport protein binding allows for longer hormone half-life
i. Provide protection from enzymes in plasma, liver, & kidney
ii. Prevent filtration at kidney
d. Bound hormone acts as hormone reserve
i. Replenishes free fraction

Question 16

Hormone receptors

Answer 16

a. Cells have receptors for many hormones
i. Specificity
ii. Saturation
b. Cells have different combinations of receptors
c. Cells must have the correct receptor to be affected by a hormone

Question 17

Plasma membrane receptors

Answer 17

a. Used by:
b. Mechanism of action:
i. Formation of a First Messenger
ii. Formation of a Second Messenger
c. Effects on the cell:
i. Phosphorylation of existing enzymes or increasing calcium concentrations
d. Signal amplification allows one hormone molecule to trigger the synthesis of an
enormous number of enzymes
e. Receptor number can change to adjust target cell sensitivity
i. Down-regulation
ii. Up-regulation

Question 18

Intercellular Receptors

Answer 18

a. Diffusion of hormones across plasma membrane
b. Bind to receptors in cytoplasm or nucleus
c. Effect on the cell:
i. Activate or deactivate specific genes
ii. Increase rates of mitochondrial activity
d. It takes hours to days to show an effect