chapter 50

Question 1

What is endocrine gland?

Answer 1

Specialized glands that function in hormone synthesis and secretion
-comprise the endocrine the system

Question 2

what are the classification of hormones?

Answer 2

-Amines - derived from tyrosine and tryptophane
-Polypeptides - most hormones
-Steroid hormones - cholesterol derivatives
Less soluble in water - require carriers

Question 3

what are examples of amines?

Answer 3

Melatonin
epinephrine
Norepinephrine

Question 4

what are examples of proteins/peptides?

Answer 4

Glucagon
Insulin
Leptin

Question 6

what are examples of steroids?

Answer 6

testosterone
cortisol
aldosterone

Question 7

what are water soluble hormones?

Answer 7

amine and polypeptide
-receptor located on plasma membrane
-initiates pathways that involve 2nd messengers since must use receptors

Question 8

what are lipid soluble hormones ?

Answer 8

Steroids
-located in cytosol or nucleus
-influence multiple genes within a cells
functions as transcriptional activator

Question 9

what links the nervous and endocrine systems?

Answer 9

hypothalamus and pituitary gland

Question 10

How are the hypothalamus and pituitary gland connected?

Answer 10

by a thin piece of tissue called the infundbular stalk and portal veins

Question 11

purpose of hormones?

Answer 11

Hormones modulate appetite, digestion, absorption of nutrients, and blood glucose concentration

Question 12

what is thyroid hormone?

Answer 12

-Thyroid gland lies in neck of vertebrates
-Consists of follicles containing the colloid, with large amounts of thyroglobulin

Question 13

what is Thyrotropin-releasing hormone (TRH)?

Answer 13

stimulates thyroid-stimulating hormone (TSH) which stimulates the thyroid to make thyroid hormones
Thyroxine (T4 ) – 4 iodine atoms
Triiodothyronine (T3 ) – 3 iodine atoms

Question 14

What is an example of a thyroid hormone?

Answer 14

Gluccorticoids

Question 15

what do gluccorticods do?

Answer 15

they promote tissue breakdown
-break down protein, lipids of bone, immune, muscle and adipose tissue to provide energy
-also promote gluconeogenesis in liver during stress to raise blood glucose

Question 16

what is oxytocin?

Answer 16

targets smooth muscle uterine contractions during birth and stimulates milk secretion

Question 17

what is Prolactin function ?

Answer 17

Stimulates milk formation in mammals; participates in mineral balance in other vertebrates

Question 18

what is type I diabetes ?

Answer 18

Immune system has mistakenly destroyed insulin-producing cells
-Glucose accumulates to high level in blood
-Treated by administration of insulin

Question 19

what is type II diabetes?

Answer 19

Cells of the body lose much of their ability to respond to insulin
-Associated with obesity

Question 20

what is Juvenile hormone?

Answer 20

-Determine the character of molt
-Prevents final step into adult
-Amount declines to 0, allowing metamorphosis into adult

Question 21

Regulation of Ca2+ balance

Answer 21

Among the most tightly regulated ions
1,25-dihydrocyvitamin D (a vitamin D derivative)
-facilitates calcium transport in small intestine
Bones lose Ca2+ if not present in blood

Question 22

what are gonads?

Answer 22

make gametes and secrete sex steroids

Question 23

What is found in males ?

Answer 23

testes secrete androgens (testosterone)

Question 24

what is found in females?

Answer 24

ovaries secrete estrogens (estradiol) and progesterone

Question 25

what are sex steroids responsible for ?

Answer 25

Sex-specific reproductive behaviors Development of sex-specific phenotype Maturation of gametes Transition of young animals to reproductive maturity Ability of females to produce offspring

Question 26

What is dietary Iodine?

Answer 26

-humans rely on iodine for the production of thyroid hormones -if lacks iodine, the thyroid enlarges.

Question 27

what is the function of igf-1?

Answer 27

It stimulates elongation of bones, especially during puberty.