19 - Organization of Hypothalamus and Pituitary Gland

Question 1

how are hormones classified?

Answer 1

as protein and polypeptide, amine, steroid

Question 2

what are the peptide hormones?

Answer 2

consist of specific amino acids

synthesized as large precursor proteins

stored in membrane enclosed compartments

hydrophilic

Question 3

what is the relationship between the protein and polypeptide hormone receptor?

Answer 3

• Surface receptor
• Hormone binds
• Transduction
• Enzyme activation
• Open channels
• Second messenger systems
• Synthesis

Question 4

what aa are amine hormones derived from?what do these include?what happens to them after they are synthesized?

Answer 4

tyrosine; thyroid and catecholamines; stored until secreted

Question 5

what are the receptors for amine hormones?

Answer 5

surface and intracellular

Question 6

describe the amine hormone? examples?

Answer 6

Small size, OH group
Benzene ring

examples being thyroxin and epinephrine

Question 7

what is the precursor for steroid hormones?

Answer 7

cholesterol

Question 8

T/F, steroid hormones are lipophilic?

Answer 8

T

Question 9

what happens to steroid hormones after they are synthesized?

Answer 9

Immediately released from the cell following synthesis

Question 10

where are the receptors for steroid hormones located?

Answer 10

cytoplasmic or nuclear receptors

Question 11

describe the steroid hormones? examples?

Answer 11

• Activate DNA for protein synthesis
• Slower acting, longer half-life

cortisol, estrogen, testosterone

Question 12

what is the function of the hypothalamus?

Answer 12

Integrates functions that maintain chemical and temperature homeostasis

Functions with the limbic system

Controls the release of hormones from the anterior and posterior pituitary

Question 13

what are the hypophysiotropic hormones synthesized and released by the hypothalamus?

Answer 13

• Thyrotropin-releasing hormone (TRH)
• Corticotropin-releasing hormone (CRH)
• Gonadotropin-releasing hormone (GnRH)
• Growth hormone-releasing hormone (GHRH)
• Growth hormone-inhibiting hormone (GHIH)
• Prolactin-releasing factor (PRF)
• Prolactin-inhibiting hormone (PIH)

Question 14

T/F, hypothalamus is influenced by emotions?

Answer 14

T

Question 15

T/F, Can be influenced by the metabolic state of the individual

Answer 15

T

Question 16

T/F, Delivered to the anterior pituitary via the hypothalamic-hypophyseal portal system

Answer 16

T

Question 17

T/F, Usually initiates a three-hormone sequence

Answer 17

T

Question 18

what are the three levels of integration in endocrine control?

Answer 18

Hypothalamic stimulation–from CNS

Pituitary stimulation–from hypothalamic trophic hormones

Endocrine gland stimulation–from pituitary trophic hormones

Question 19

posterior pituitary is comprised of ending of axons from cell bodies in the _____?

Answer 19

the hypothalamus (supraoptic and paraventricular)

Question 20

axons pass from the hypothalamus to the posterior pituitary via the _____?

Answer 20

the hypothalamohypophysial tract

Question 21

posterior pituitary hormones are synthesized where?

Answer 21

in the cell bodies of neurons in the supraoptic and paraventricular nuclei

Question 22

what are the principal hormones of the posterior pituitary gland?

Answer 22

Vasopressin & Oxytocin

Question 23

describe oxytocin?

Answer 23

Smooth muscle contraction of uterus and vas deferens and “let’s milk down”

Question 24

describe vasopressin?

Answer 24

Regulates plasma osmolality
o Decreases water excretion by kidneys (V2 receptors)
o Constricts blood vessels (V1 receptors)
o Increases adrenocorticortropin Hormone (V1B receptors)

Question 25

vasopressin secretion is stimulated by?

Answer 25

Large decreases in blood volume

Decreases in blood pressure