Chapter 19: Endocrine System Flashcards Preview

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Flashcards in Chapter 19: Endocrine System Deck (40):
1

What are the general characteristics of the endocrine system? (3)

1.) Chronic regulation of homeostasis
-slow & prolonged responses
-acute = nervous system
2.) Interrelated with nervous system
(hypothalamus & posterior pituitary)
3.) Ductless system
-hormones produced by specialized cells
carried in blood stream

2

What are hormones?

-Substance synthesized by a specific organ or tissue & secreted
-Act on target cells
(have specific receptors for specific hormones)

3

if a hormone is secreted into extracellular spaces this called what signaling?

paracrine signaling

4

if the blood carries the hormone to other sites this is known as what?

endocrine signaling

5

for the chemistry of hormones, what are the four different categories? briefly describe each category

1.) Steroids
-made from cholesterol, non-polar
2.) Peptides
-polar
3.) Amines
-derived from amino acids
-polar & non-polar
4.) Eicosanoids
-most are non-polar
-paracrine signals (prostaglandins)

6

describe steroid hormones and give examples

Lipid soluble therefore can cross cell membrane
transduction --> regulation of DNA transcription

Examples:
estrogens like estradiol
androgens like testosterone
aldosterone
cortisol

7

describe amine hormones
what are the most important ones made by?

Derived from either tyrosine or tryptophan
Some are membrane soluble (thyroxine)
Some are not (epinephrine)
Most important ones are made by:
-thyroid
-adrenal medulla

8

describe peptide hormones

short chains of amino acids
cannot cross cell membrane
all pituitary hormones

9

describe Eicosanoid hormones

derived from fatty acids
most cross cell membranes
coordinate functions in extracellular fluid
e.g. prostaglandins

10

describe negative feedback (4)

-gland is sensitive to concentration of substance
-concentration exceeds limits --> prevents gland from secreting hormone
-concentration decreases --> secretion increases
-results in relatively stable concentration of both substance & hormone

11

the hypothalamus sends signals to the.....

pituitary gland

12

true or false: the pituitary is the MOST important endocrine gland for regulation.

true

13

describe the two lobes of the pituitary gland

Posterior Lobe:
-does not make any hormones
-mostly hypothalamic axons

Anterior Lobe:
-5 types of endocrine cells
-controlled by hypothalamic regulatory hormones
(releasing hormones/inhibiting hormones)

14

what are two posterior pituitary hormones?

oxytocin and antidiuretic hormone (ADH)

15

who three things does oxytocin cause and what is it significant in?

-causes contraction of muscles in uterine walls
-causes muscles associated with milk ejection to contract
-cause contraction of prostate gland
-Significant in emotional bonding
Familial
Romantic

16

what does ADH do?

causes kidney to decrease water excretion
increases blood volume --> rise in BP

17

what are the 7 anterior pituitary hormones?

1.) Melanocyte stimulating hormone (MSH)
2.) Follicle stimulating hormone (FSH)
3.) Luteinizing hormone (LH)
4.) Growth Hormone (GH)
5.) Thyroid stimulating hormone (TSH)
6.) Prolactin (PRL)
7.) Adrenocorticotropic hormone (ACTH)

18

the thyroid gland consists of what 2 things and lies inferior to what?

2 lobes + isthmus
inferior to larynx

19

the thyroid gland has two types of cells. What are they and describe them

Follicular cells
-line follicle cavities
-filled with thyroglogulin colloid
-remove Iodine from blood
-secrete T3 and T4

Parafollicular cells
-produce calcitonin

20

Follicular cells secrete 2 hormones. What are they? describe them

-Thyroxine (T4)
↑ glycogenolysis
↑ protein synthesis
↑ growth
-Triiodothyronine (T3)
same as T4 but 5x’s more potent

21

Parafollicular cells secrete 1 hormone. What is it? describe it

Calcitonin
↓ blood Ca+2 & PO4
↑ renal excretion
↑ osteoblast activity

22

describe the parathyroid glands

Posterior surface of thyroid
many tightly packed secretory cells
oxyphil & transitional cells = immature
chief cells = produce parathyroid hormone

23

what does the parathyroid hormone do?

↑ blood Ca+2
↓ renal Ca+2 & PO4 excretion
↑ osteoclast activity
↑ calcitriol = intestinal Ca+2 absorption

24

slide 21

fun stuff

25

Where is the thymus located?

Thoracic cavity, posterior to sternum

26

What does the Thymus produce? describe it

produces thymosin
-enhances lymphocyte production & competence
-most active in infancy & childhood

27

what two parts are associated with the adrenal glands?

adrenal cortex and adrenal medulla

28

what are the three zones in the adrenal cortex? what do they produce?

1.) Glomerulosa
aldosterone --> Na+ retention
Fasciculata
cortisol --> glycogen formation
3.) Reticularis
androgens --> secondary sexual characters

29

what is located in the adrenal medulla? what are they and what do they produce?

-chromaffin cells which are modified postganglionic cells of the SNS
-epinephrine & norepinephrine

30

what are the three hormones in the kidneys? describe them

Renin
-start cascade to increase blood pressure
Erythropoietin (EPO)
-erythrocyte production
Calcitriol
-increases absorption of digested Ca+2

31

What is the hormone in the heart? describe it

Atrial natriuretic peptide (ANP)
-suppresses aldosterone & ADH
-decrease blood volume & blood pressure

32

where is the pancreas located?

posterior to stomach and attached to the duodenum of stomach

33

the group of pancreatic cells that secrete hormones (have the endocrine function in the pancreas) are called what?

Islets of Langerhans

34

What are the three different Islets of Langerhan cells? what hormone does each produce?

1.) Alpha cells
-glucagon- increases blood sugar
2.) Beta cells
-insulin- decreases blood sugar
3.) Delta cells
-somatostatin- inhibits glucagon and insulin secretion
-antagonizes GH

35

the male gonads are made up of what two cells?

interstitial cells and Nurse (sertoli) cells

36

what do interstitial cells secrete?

-androgens
-testosterone
Stimulate nurse cells
secondary sex characteristics

37

what do nurse cells secrete?

secrete inhibin
-↓ FSH from anterior pituitary
-Stimulate spermatogenesis

38

slide 28

weird wording with stuff just look at it

39

in the pineal gland there are _______ in _________ that produce _________ which is responsible for what?

pineacytes; epithalamus;
Melatonin
-circadian rhythms
-puberty (?)

40

slide 30

last slide ayyy