BIOH111 - ENDOCRINE SYSTEM EXAM QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS

BIOH111 - ENDOCRINE SYSTEM EXAM QUESTIONS AND

ANSWERS WITH COMPLETE SOLUTIONS


Lipid-soluble hormone transport & entry to cell

- Travel through blood bound to transport proteins

- Molecule diffuses from blood through plasma membrane into cell (passive)

Water-soluble hormone transport & entry to cell

- Circulate free in blood stream

- Bind to receptors on cell

Lipid-soluble hormone examples

- Steroid hormones

- Thyroid hormones (T3 T4)

- Nitric oxide

Water-soluble hormone examples

- Amines (NE, E, melatonin, histamine, serotonin)

- Peptides & protiens (TSH, FSH, prolactin, insulin)

- Eicosanoids (prostaglandins)

Synergistic effect of two hormones.

Two hormones acting together for greater effect

Permissive effect of two hormones (some hormones on target cells require a

simultaneous or recent exposure to a second hormone)

Second hormone, strengthens the effects of the first

, Antagonistic effect of two hormones

Two hormones with opposite effects

RECEPTOR UP-REGULATION

- Occurs when hormone is deficient and makes target cell more sensitive to a hormone

- The deficiency of the hormones leads to an increase in the number of receptors

RECEPTOR DOWN-REGULATION

- Occurs when hormone is in excess and makes target cell less sensitive to a hormone

- Excess hormones lead to a decrease in the number of receptors by endocytosis and

degradation

Hypothalamus

Master gland on HOMEOSTASIS

Hormones the act in ANTERIOR PITUITARY

- Gonadotropin releasing hormone [GnRH]

- Thyrotropin releasing hormone [TRH]

- Growth hormone releasing hormone [GHRH]

- Growth hormone inhibiting hormone [GHIH] - somatostatin

- Corticotropin releasing hormone [CRH]

- Prolactin inhibiting hormone [PIH] - dopamine

- Prolactin releasing hormone [PRH]

(PRODUCED IN HYPOTHALAMUS)

Hormones the act in POSTERIOR PITUITARY

- Oxytocin [OT]

- Anti-diuretic hormone [ADH]