Chapter 18: Endocrine System

Question 1

a molecule that is released in one part of
the body but regulates the activity of the cells in
other parts of the body.

Answer 1

HORMONE

Question 2

comprises all endocrine glands and hormone-secreting cells

Answer 2

Endocrine System

Question 3

• secretetheir products into
  ducts that carry the secretion into cavities, into
  the lumen of an organ, or to the outer surface of
  the body.

Answer 3

EXOCRINE GLANDS

Question 4

secrete their product
(hormones) into the interstitial surrounding the
secretory cells rather than into ducts

Answer 4

ENDOCRINE GLANDS

Question 5

include steroid hormones, thyroid hormones ,and nitric oxide

Answer 5

LIPID SOLUBLE HORMONES

Question 6

derived from cholesterol

Answer 6

Steroid Hormones

Question 7

(T3 and T4)are synthesized by attaching iodine to the amino acid tyrosine.

Answer 7

2 Thyroid Hormones

Question 8

• the gas, is both a hormone and a
  neurotransmitter. It synthesis is catalyzed by the
  enzymes nitric oxide synthase

Answer 8

Nitric Oxide

Question 9

include amine
hormone, peptide and protein hormones, and
eicosanoid hormone.

Answer 9

Water Soluble Hormones

Question 10

they are called amines because
they retain an amino group(-NH3+)

Answer 10

AMIMNE HORMONES

Question 11

• they are amino
  acid polymers. The smaller peptides hormones
  consist of chains of 3 to49 amino acids ; the larger
  protein hormones include 50 to200 amino acids.

Answer 11

PEPTIDEAND PROTEIN HORMONES

Question 12

• it is important local
  hormones, and they may act as circulating hormones
  as well

Answer 12

ECOSANOID HORMONES

Question 13

What are the functions of transport proteins:

Answer 13

1. They make lipid-soluble hormones temporarily
   water-soluble, thus increasing their solubility in
   blood
2. They retard passage of small hormones molecules
   through the filtering mechanism in the kidneys, thus
   slowing the rate of hormone loss in the urine. 3. They provide a ready reserve of hormone, already
   present in the bloodstream

Question 14

What are the factors that affect the responsiveness of a target
cell to a hormone:

Answer 14

1. The hormone’s concentration in blood
2. The abundance of the target cell’s hormone
   receptors
3. Influence exerted by other hormone

Question 15

increases the number of receptors for the other
hormone, and sometimes it promotes the synthesis
of an enzymes required for the expression of the
other hormone’s effect.

Answer 15

PERMISSIVE EFFECT

Question 16

when the effect of the two hormones acting
together is greater or more extensive than the effect of each hormone acting alone, the two hormone are said to have a ______________

Answer 16

SYNERGISTIC EFFECT

Question 17

where one hormone opposes the action of other hormone, the two hormones are said to have ____________

Answer 17

ANTAGONISTIC EFFECT

Question 18

-synthesized by hypothalamic neurosecretory cells are transported within axons and released at axon terminals. The hormones diffuse to capillaries are carried by the hypophyseal portal veins to plexus for distribution to target cells in the anterior pituitary.

Answer 18

HYPPTHALAMUS AND PITUITARY GLANDS

Question 19

Secretes human growth hormone

Answer 19

Sometotrophs

Question 20

Secrete thyroid stimulating- hormones

Answer 20

Thyrotroph

Question 21

• Secrete2 gonadotropins :
  Follicle-stimulating hormone sand Luteinizing
  Hormone

Answer 21

Gonadotrophs

Question 22

Secrete Prolactin

Answer 22

Lactrotrophs

Question 23

• Secrete adrenocorticotropic
  Hormones

Answer 23

Corticotrophs

Question 24

-contains axon terminals of neuro secretory cells whose bodies are in the hypothalamus.

Answer 24

POSTERIOR PITUITARY

Question 25

it is located inferior to the larynx
-composed of follicular cells, which secrete the thyroid hormone thyroxine and triiodothyronine, and particular cells which secrete calcitonin

Answer 25

THYROID GLANDS

Question 26

• embedded in the posterior surfaces of the lateral
  lobes of the thyriod glands
• regulates homeostasis of calcium, magnesium, and phosphate ions by increasing blood calcium and magnesium levels and decreasing blood phosphate

Answer 26

PARATHYRIOD GLANDS

Question 27

-productive stress is termed eustress, and harmful
stress is termed distress. -the resistance reaction is initiated by nerve impulses from the hypothalamus to the symphatic division of autonomic nervous system and adrenal
medulla. - this response rapidly increases circulation, that
promotes ATP production..

Answer 27

THE STRESS REPONSE

Question 28

What is the mechanism of action of the lipid-soluble steroid hormones and thyroid hormones

Answer 28

1. Lipid Soluble Hormone diffuses onto cell
2. Activated Receptor-hormone complex alters gene expression
3. Newly formed mRNA directs synthesis of specific proteins on ribosomes

Question 29

What is the mechanism of action of the water-soluble hormone(amines, peptides, proelcosanoids)

Answer 29

1. Binding of hormone (first messenger) to its receptor activates (3 protein which activates adenylate cyclase, Adenylate Cyclase
2. Activated adenylate cyclase converts ATPto cAMP
3. cAMP serves as a second messenger to activate protein kinases
4. Activated protein kinases phosphorylate cellular proteins