Endocrinology

Question 1

Factors effecting Effective Plasma Concentration

Answer 1

– Rate of secretion
– Metabolic activations or conversion
– Binding to plasma protein (lipophilic 
hormones)
– Rate of removal

Question 2

Hydrophilic Hormones

Answer 2

– Peptide hormones
– Catecholamines
– Indolamines

Question 3

Hydrophobic Hormones

Answer 3

– Steroid Hormones

– Thyroid hormones

Question 4

Production of Peptide Hormones

Answer 4

– Prohormones built in Rough ER
– Cleaved into active hormone in the Golgi
– Golgi concentrates and packages hormone
– Stored in secretory vesicles

Question 5

Production of Steroid Hormones

Answer 5

• Synthesis
– Cholesterol is the precursor
– Enzymatic modification of cholesterol
– Secreted upon production

Question 6

How Hydrophilic Hormones Travel

Answer 6

Hydrophilic hormones dissolve

Question 7

How Hydrophobic Hormones Travel

Answer 7

Hormones ride on carrier

proteins

Question 8

How Non-genomic (rapid) Hormones Work

Answer 8

Bind to ligand gated channels and Activate (or inhibit) second messenger systems

Question 9

How genomic (slow) Hormones Work

Answer 9

Activate protein synthesis

Question 10

Responsiveness of target Tissue

varies

Answer 10

Down Regulation
• Permissiveness
• Synergism
• Antagonism

Question 11

Control of Hormone Release

Answer 11

Negative Feedback
• Neuroendocrine Reflexes
• Circadian Rhythms
• Lunar Rhythms
– Semilunar
• Seasonal Rhythms

Question 12

The Glands

Answer 12

Starting With Central Endocrine Glands

Question 13

Pineal Gland: Circadian Rhythms

Answer 13

Entrainment, Suprachiasmatic Nuclei

Question 14

Pineal Gland: Melatonin

Answer 14

Secreted primarily at night
• Helps set circadian rhythm
• Induces Sleep
• Inhibits reproduction
• Anti-oxidant 
• Immune and aging?

Question 15

Neurohypophysis Secretions

Answer 15

remember these are made in the hypothalamus

Question 16

Neurohypophysis: Vasopressin

Answer 16

• Controlled by Hypothalamic osmoreceptors
• Reduce water loss in the kidney
• Contraction of arteriolar smooth muscle

Question 17

Neurohypophysis: Oxytocin

Answer 17

• Controlled by cervical pressure and suckling
• Uterine contractions
• Milk Let Down
• Maternal behavior

Question 18

Growth Hormone (somatotropin)

Answer 18

– Control: GHRH/GHIH (somatostatin)
– Promotes Growth of bone and muscle
– Inhibits nutrient storage
– Enhances nutrient mobilization

Question 19

Thyroid Stimulating Hormone (thyrotropin)

Answer 19

– Control: TRH/GHIH

– Induces the release of thyroid hormones

Question 20

Adrenocorticotropic hormone

Answer 20

– Control: CRH (corticotropin releasing hormone)

– Secretion of cortisol from adrenal cortex

Question 21

Adenohypophysis: Follicle Stimulating Hormone

Answer 21

– Sperm production
– Stimulates follicles
– Estrogen secretion (estradiol)

Question 22

The Thyroid Gland Anatomy

Answer 22

– Follicular Cells 
Surrounding 
Colloid
– C Cells in 
interstitial space

Question 23

Adrenal Glands

Answer 23

Anatomy
– Cortex
• Zona Glomerulosa
• Zona fasciculata
• Zona reticularis
– Medulla