Endocrine System

Question 1

What does the Endocrine system do?

Answer 1

It regulates growth, reproduction, metabolism(long-term events)

Question 2

WHat do the galnds and the tissues of the endocrine system do?

Answer 2

they secrete hormones that travel in the blood which travel to target cells.

Question 3

what are target cells?

Answer 3

they are cells that have specific receptors for the hormones secreted.

Question 4

where are receptors (proteins) found?

Answer 4

on the cell membrane or intracellular (nuclear)

Question 5

what are two type of hormones found in the

Human body.

Answer 5

Water soluble Hormones and Lipid soluble Hormones.

Question 6

name a couple 1st messenger water solubule hormones.

Answer 6

peptides, proteins, catecholamines

Question 7

what steps does a water solubule hormone go through?

Answer 7

a) hormone binds to cell-surface receptors (do not enter cell for their action)
b) hormone-receptor complex activates membrane proteins (e.g. G-proteins)
c) G-proteins then activate the second messenger systems.

Question 8

Name a couple of 2nd messenger Hormones.

Answer 8

cAMP (cylic adenosine monophosphhate) , Ca++ (calcium)

Question 9

in the example using cAMP as a second messenger, what happens when the the hormone binds too the cell-surface?

Answer 9

It activates G-proteins.

Question 10

Once the G-proteins is activated in the example using cAMP as a second messenger, what happens?

Answer 10

the G-protein activates adenylate cyclase (membrane protein)

Question 11

once adenylate cyclase is activated in the example using cAMP as a second messenger, what does it do?

Answer 11

adenylate cyclase converts ATP to cAMP ( which meanns it turns it into a second messenger)

Question 12

What doe cAMP do in the example using cAMP as a second messenger?

Answer 12

activates protein kinases (in cytosol)

Question 13

what does the protein kinases do in the example using cAMP as a second messenger?

Answer 13

it acts on other proteins (usually phosphorylates) to alter their activity

Question 14

Why do we use a second messenger system to enter a cell?

Answer 14

a) nhormone can’t enter the cell because it is water soluble.
b) it rapid acting
c) one hormone activates many enzyme molecules which creates multiple signals.
d) it is limited

Question 15

what can be water soluble Hormones?

Answer 15

steroids, thyroid hormones

Question 16

what can trigger protein synsthesis?

Answer 16

Lipid Soluble hormones.

Question 17

what is the first steps for action for lipid soluble hormones?

Answer 17

enter the target cell and bind ti intracellular (nuclear) receptors in cytosol or nucleus

Question 18

in the steps for Lipid soluble hormones, the hormone has entered the target cell, now what happens?

Answer 18

hormone-receptor complex binds to a specific region on DNA (activates genes)

[ starts gene transcription and produces messenger RNA (mRNA) ]

Question 19

once genes start transcription and mRNA is produced in the steps for Lipid soluble hormones what happens with the mRNA?

Answer 19

it attaches to ribosomes to produce proteins (translation)

Question 20

In Regulation of hormone secretion into the blood, stimuli acting on endocrine gland may be what kind of stimulus:

Answer 20

Humoral Stimulus, Neural Stimulus or Hormonal Stimulus

Question 21

What is the stimulus in a Humoral Stimulus?

Answer 21

ions/ nutrients

Question 22

For Humoral Stimulus, what happens when you get an increase of blood glucose? (after eating carbs)

Answer 22

pancreatic beta cells (Islets of Langerhans) detect glucose and release insulin which decreases blood glucose.

Question 23

For Humoral Stimulus, what happens when you get a decrease in blood calcium?

Answer 23

parathyroid gland detects low Ca++ and releases parathyroid hormone (PTH) which then increases bone reabsorbtion (breakdown) by increase in osteoclas activity and decrease in osteoblast activity…. This increases blood clacium.

Question 24

what is stress

Answer 24

any external or internal stimulus e.g. surgury infections, strong emotions,

Question 25

What does stress do to the body?

Answer 25

triggers a set of body changes called the General Adapting Syndrome.

Question 26

what co-ordinates (indirectly or directly) the General Adapting syndrome?

Answer 26

Hypothalamus.

Question 27

what is Phase 1 of stress?

Answer 27

Alarm reaction. (fight or flight)

Question 28

Describe Phase 1 (fight of flight response) of stress.

Answer 28

CNS (sensory input-detect change) -communicates with- Hypothalamus (where the RAS increases alertness) -communicates with- either the adrenal medulla (releases more epi and NE to prolong the fight or fight response) or the organs.

Question 29

what happens to glucose in Phase 1 of stress (fight or flight response)

Answer 29

blood glucose increases, - SNS inhibits insulin release - EPi, NE trigger conversion of glycogen to glucose in the liver.

Question 30

what happens to the Heart in phase 1 of stress?

Answer 30

HR increases and so does the force of contraction

Question 31

what effects does phase 1 of stress have on blood flow?

Answer 31

Blood becomes more availible to skeletal and cardiac muscles + the brain. Blood flow to the skin and abdominla viscera decreases.

Question 32

what happens to digestion and urine production during phase one of stress?

Answer 32

decreases.

Question 33

What is phase two of stress?

Answer 33

resistance reaction phase. (long term phase) (permits recovery from the first phase..OR response to longer term stress (like starvation) hypothalamic hormones initiate phase 2.

Question 34

what is the use of GH in Phase 2 of stress?

Answer 34

stimulates growth (protein production and cell reproduction)

Question 35

what does cortisol do in phase two of stress?

Answer 35

it is released within 30 seconds of the stress but the response DOESN'T HAPPEN FOR HOURS... it also inhibits insulin release.

Question 36

what kind of hormone is cortisol?

Answer 36

steroid hormone.

Question 37

what does the release of hormones in phase two of stress do to the blood?

Answer 37

- Raises blood glucose. - Inhibits immune system, bone formation, formation of CT(delays healing) - release of aldosterone+antidiuretic hormone.

Question 38

During Phase two of stress blood glucose increases, so what happens to the liver?

Answer 38

it is stimulated to produce new glucose from fats and later from proteins. And little insulin (because of inhibition).

Question 39

Who uses glucose go during phase 2 of stress?

Answer 39

Nervous system, not taken up well by skeletal muscles of adipose tissue.

Question 40

Since glucose is spare for use by the nervous system, non-nervous tissues use what for energy?

Answer 40

fats, (control= GH, cortisol) | -if stress continues, cortisol inhibits GH release and proteins are then also used.

Question 41

what does the release of aldosteron + antidiuretic hormone cause in phase 2 of stress?

Answer 41

reduces salt and water loss at kidney to maintain blood volume.

Question 42

what are the longterm effects of stress?

Answer 42

- loss in weight - increase in blood pressure - increase in HR - immune suppression - decrease in bone density - risk of type 2 diabetes(because of high blood glucose)

Question 43

explain phase 3 of stress.

Answer 43

this is the exhaustion phase. . their is a depletion of body resouses. loss of K+ (because of aldosterone) and dammage to organs (heart, liver, kidneys)

Question 44

what brain area releases GnRH staring at puberty?

Answer 44

hypothalamus.

Question 45

what releases "LH" and "FSH" in the reproductive system?

Answer 45

anterior pituitary

Question 46

what develops the organs of male reproductive tract and secondary sex characteristics

Answer 46

testosterone.

Question 47

Which hormone stimulates bone growth at the epiphyseal plate?

Answer 47

testosterone.

Question 48

Which hormone converts the epiphyseal plate into bone?

Answer 48

estrogen

Question 49

which hormone promotes protein anabolism?

Answer 49

testosterone.

Question 50

which hormone directly stimulates spermatogenesis?

Answer 50

testosterone.

Question 51

what stimulates the primary follicle to become the secondary follicle?

Answer 51

FSH

Question 52

FSH is _______ when their is an increase of Progesterone.

Answer 52

inhibited.

Question 53

which hormone stimulates estrogen production from theca + granulosa cell of follicle?

Answer 53

leutinizing hormone. (LH)

Question 54

what happens when their is a surge of LH in the female reproductive system?

Answer 54

ovulation and then formation of corpus luteum from the remenant of the follicle.

Question 55

in the follicular phase, what happens to start things off?

Answer 55

Estrogen from secondary follicle rises for a few days.

Question 56

in the follicular phase, what happens after a few days when estrogen from the secondary follicle has risen?

Answer 56

stimulation of LH release via GnRH

Question 57

in the follicular phase, once the LH is release via GnRH whats the next step?

Answer 57

stimulation of the follicle to increase Estrogen secretion (+ve feedback)

Question 58

in the follicular phase, what is the end result?

Answer 58

their is a surge in LH

Question 59

what is the luteal phase?

Answer 59

Where progesterone inhibits LH

Question 60

what develops the secondary sex characteristics for women?

Answer 60

estrogen

Question 61

in women, what is required for ovulation and stimulates growth of and maintains endometrium?

Answer 61

estrogen

Question 62

what hormone, in women, increases bone growth and closes the epiphyses?

Answer 62

estrogen

Question 63

what hormone forms the corpus luteum?

Answer 63

progesterone.

Question 64

what hormone prepares the uterus for pregnancy?

Answer 64

progesterone.

Question 65

early on in this phase, Progesterone is low, and FSH secreted some primary follicles which turned into secondary follicles. This then raised the Estrogen. What phase is this? Later on the secondary follicle turns into a vesicular follicle.

Answer 65

It is the preovulatory phase during the first 14 days of the uterine cycle.

Question 66

what happens in the first five days of ovarian/ uterine cycle?

Answer 66

it is the the menstrual phase. In the phase the stratum functionalis sheds, and this causes bleeding.

Question 67

what happens in days 6-14 of the ovarian/ uterine cycle?

Answer 67

Estrogen --> repair + proliferation of stratum functionalis (due to mitosis in stratum basalis)

Question 68

what happens on day 14 of the uterine? ovarian cycle?

Answer 68

Ovulation: due to the surge in LH, LH triggers: A) completion of meiosis (creating the secondary oocyte) B) rupture of vesicular follicle with the release of secondary oocyte.

Question 69

Which two phhases happen in days 15-28 of the ovarian cycle?

Answer 69

ovary: luteal phase Uterus: Secretory phase

Question 70

in days 15-28, what happen in the Luteal phase?

Answer 70

high Progesterone from corpus luteum inhibits GnRH (LH and FSH) and no follicles develop

Question 71

What happens in the Secretory phase in days 15-28?

Answer 71

Progesterone from corpus luteum: - prepars endometrium for implantation - becomes vascular, thick + stores glycogen - inhibits uterine conractions

Question 72

if fertilization occurs, what secretes chorionic gonadotropin (hCG)

Answer 72

the placenta.

Question 73

what maintains the corpus luteum if fertilization occurs?

Answer 73

chorionic gonadotropin

Question 74

what is the corpus luteum mainly made of for about 6 weeks if fertilization occurs? and after this period, what takes over?

Answer 74

P and E, then the placenta takes over

Question 75

what causes no new follicles to develop when fertilization occurs?

Answer 75

the progesterone inhibits FSH and LH

Question 76

what happens if no fertilization occurs?

Answer 76

corpus luteum degenerates to corpus albicans and Progesterone and estrogen decreases and no longer inhibit LH and FSH. This restarts the baby maker and can't maintain the endometrium which causes menstruation.

Question 77

How do oral contraceotives work?

Answer 77

the high level of P and E which inhibits the GnRH secretion ( mimics the luteal phase) -no follicle maturation... no ovulation

Question 78

what does implanted contraceptives contain?

Answer 78

progestin

Question 79

What does the morning after pilll do to prevent a baby being made?

Answer 79

prevents implantation, ovulation or fertilization due to high levels of E and progestin

Question 80

What is the placenta formed by?

Answer 80

formed by the chorion and endometrium

Question 81

what what the two different functions of the placenta?

Answer 81

it is an exchage site and it secretes hormones.

Question 82

Since the Placenta is an exchange site, what does it exchange?

Answer 82

- gases, nutrients/ wastes, hormones, antibodies - drugs like alcohol, morphine, nicotine - viruses- measles, polio

Question 83

What hormones does the placenta secrete

Answer 83

E+P and hCG

Question 84

What does hCG do in the placenta?

Answer 84

maintains corpus luteum for about 6 weeks post-fertilization this is detected by pregnancy tests