chapter 18: endocrine sytem Flashcards

1
Q

why fo the nervous and endocrine system work together?

A

to coordinate the functions of all body systems

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2
Q

difference between how nervous system acts and how the endocrine system acts

A

Nervous system acts through the action of
neurons, and neurotransmitters they
secrete
◦ The endocrine system acts through hormones
produced by cells or endocrine glands

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3
Q

true or false some mediators can act as both neurotransmitters and hormones

A

true, ex: norepinephrine.

but each is controlled by different mechanisms

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4
Q

what are examples of hormones controlling different processes

A

Regulation of different processes:
◦ Composition and amount of interstitial fluid
◦ metabolism
◦ biological clock
◦ contraction of cardiac & smooth muscle
◦ glandular secretion
◦ some immune functions
◦ growth & development
◦ reproduction

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5
Q

exocrine glands bs endocrine glands. Give examples

A

Exocrine glands
◦ secrete products onto an epithelial surface (into body cavity, or body surface);
may or may not use a duct
◦ sweat, oil, salivary glands, pancreas…
Endocrine glands
◦ secrete hormones into interstitial fluid, and normally ends up in the bloodstream
◦ pituitary, thyroid, parathyroid, adrenal

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6
Q

which organs secrete hormones as secondary function?

A

◦ Some organs secrete hormones as a 2ndary function
◦ hypothalamus, thymus, pancreas, ovaries, testes, kidneys, stomach, liver, small
intestine, skin, heart & placenta

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7
Q

what are the 3 different forms of endocrine signalling

A
  1. endocrine cells sends hormones through blood to distant target cells, which then land on hormone receptor
  2. a paracrine cell sends paracrines (hormones) to a nearby target cell. the paracrines bind to paracrine receptors

an autocrine cell signals itself. The hormones attach to the autocrine receptor

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8
Q

What is a hormone?
a) a molecule found in the cytoplasm of a cell
b) a molecule found in the nucleus of a cell
c) a molecule released by a cell
d) a molecule released by a neuron specifically

A

c) a molecule released by the cell

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9
Q

How does a hormone reach its target cell?
a) It usually travels through blood
b) It usually travels through lymph vessels
c) It travels through the nervous system
d) All the above

A

A

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10
Q

How does a hormone “know” what cell to
influence?
a) It only uses blood vessels that get to the target organ
b) It binds to hormone receptors found on target cells
c) It binds to all cells, but only target cells respond to the binding
d) All mechanisms above are possible

A

b) it binds to hormone receptors found on target cells

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11
Q

what needs to happen for a cell to be activated by hormones

A

To activate a cell, a hormone needs to bind to its receptor noncovalently
(reversibly; non permanently)

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12
Q

what are 3 factors that determine the level of activation of a target cell?

A

◦ Blood levels of hormones
◦ Number of receptors on target cell (if don’t receive a lot of hormones will grow more receptors. The opposite is also true)
◦ Affinity of receptor for its hormone

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13
Q

how do target cells change the number of receptors present

A

Hormone receptors are continually being synthesized and destroyed
1. ◦ Down-regulation
◦ cell responds to excess hormone by decreasing number of receptors
◦ surface receptors undergo endocytosis and are degraded
◦ decreases sensitivity of target cell to hormone
◦2. Up-regulation
◦ cell responds to deficiency of hormone by increasing number of receptors
◦ target tissue more sensitive to the hormone

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14
Q

what is the general mechanism of action for hormones

A
  1. Hormone binds to receptor
    ◦ receptor located on plasma membrane or in cytoplasm depending on type of
    hormone
  2. Binding of hormone to receptor triggers a response in the target cell
    ◦ synthesize new molecules
    ◦ let substances in or out of cell
    ◦ alter metabolism (speed up or slow down reactions)
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15
Q

what are the 2 chemical classes of hormones

A
  1. Lipid soluble hormones
  2. water-soluble hormones
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16
Q

how would you administer lipid soluble hormones vs water soluble hormones?

A

lipid soluble you would take through pills and water soluble you would take intravenously

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17
Q

what are examples of lipid-soluble hormones?

A

Steroids (e.g., estrogens, testosterone, glucocorticoids)
◦ Derived from cholesterol
Thyroid hormones (T3, T4)
◦ Iodination of tyrosine
Nitric oxide – NO (gas)

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18
Q

what are examples of water-soluble hormones?

A

epinephrine, serotonin, histamine, oxytocin, ADH, insulin, prostaglandins

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19
Q

how are lipid soluble proteins transported in the blood

A

◦ Lipid-soluble hormones are hydrophobic – cannot travel in blood easily (plasma = water)
◦ Lipid-soluble hormones are generally bound to a transport protein (e.g., albumin)
◦ Transport protein is amphipathic
◦ prevents clumping and increases molecule size, so less likely to be filtered out by kidneys
◦ Hormone dissociates from transport protein as it approaches tissues, and
diffuses into cells

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20
Q

describe the action of lipid-soluble hormones

once they get to the cell

A
  1. lipid-soluble hormones diffuses into cell
  2. hormones binds to receptor in cytoplasm or nucleus which alters gene expression
  3. newly formed mRNA direct synthesis of specific proteins on ribosomes. The cell’s activities change because of the new proteins
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21
Q

what are amine hormones and what are some examples? are they water soluble or lipids soluble?

A

Amine hormones = modified amino acids (small)
◦ e.g., epinephrine from tyrosine; histamine made from histidine; serotonin
from tryptophan

They are water soluble

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22
Q

peptide/ protein hormones examples? Are they water or lipid-soluble?

A

◦ Peptide (3-49aa): antidiuretic hormone (ADH), oxytocin
◦ Protein (50-200aa): human growth hormone (hGH), insulin

water-soluble

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23
Q

what are eicosanoid hormones and what are some examples? ARe they water or lipid soluble?

A

water soluble

Eicosanoid hormones = made from fatty acids (oxygenation makes it polar)
◦ e.g., prostaglandins

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24
Q

how are water-soluble hormones transported in the blood

A

since they are hydrophilic they travel freely in blood

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25
Q

what are the steps in the action of water-soluble hormones?

A
  1. binding of hormone (first messenger) to its receptor activates G protein which activates adenylate cyclase
  2. Activated adenylate cyclase
    converts ATP to cAMP, which
    serves as a second messenger
    to activate protein kinases
  3. Activated protein
    kinases phosphorylate
    cellular proteins
  4. Millions of phosphorylated
    proteins cause reactions that
    produce physiological responses
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26
Q

A major difference between lipid-soluble
hormones and water-soluble hormones is
a) Lipid-soluble hormones bind to receptors; water-soluble
hormones don’t
b) Water-soluble hormones bind to receptors; lipid-soluble
hormones don’t
c) Lipid-soluble hormones increase metabolism; water-soluble
hormones decrease metabolism
d) Lipid-soluble hormones enter the cell; water-soluble hormones
don’t

A

D

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27
Q

Which chemical class of hormones is NOT
matched correctly?
a) Nitric oxide – lipid soluble
b) Steroids – lipid soluble
c) T3 and T4 – water soluble
d) Catecholamines – water soluble

A

C

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28
Q

Which gland or organ is not strictly classified
as an endocrine gland?
a) Thyroid gland
b) Adrenal gland
c) Pancreas
d) Pineal gland

A

c) pancreas

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29
Q

what things can trigger the release of hormones from glands

A

(it’s usually other hormones)

  1. Humoral stimuli
    - Hormone is released in direct response to changing levels of certain chemicals
    in blood or body fluids
  2. Neural stimuli
    ◦ Nerve impulses can trigger the release of hormones from certain glands
  3. Hormonal stimuli
    ◦ Hormones can be released in response to other hormones
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30
Q

describe the regulation of hormones secretion? (feedback systems)

A

Most hormonal regulatory systems work
via negative feedback, but a few operate
via positive feedback

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31
Q

describe hormone secretion

how often released

A

Release of most hormones occurs in short bursts, with little/no secretion
between bursts.
When stimulated, an endocrine gland will release its hormone in more frequent
bursts, increasing its concentration in the blood

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32
Q

what happens in the absence of stimulation?

hormones

A

The blood level of the hormone decreases

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33
Q

Which of the following is NOT true?
a) Secretion of hormones occurs in short bursts
b) Signals from the nervous system regulate hormone secretion
c) Chemical changes in the blood may determine concentration of
hormone release
d) Most hormone systems function under a positive feedback
system

A

D)

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34
Q

hat does the hypothalamus regulate?

endocrine system

A

The hypothalamus is part of the brain
The hypothalamus regulates the autonomic nervous system, body temperature,
thirst, hunger, sexual behaviour, fear, anger

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35
Q

what does the hypothalamus link and what gland does it control?

A

The hypothalamus links the
nervous and endocrine
systems
It controls the pituitary gland
through the production of 9 (or
more) different hormones

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36
Q

how does the hypothalamus know when to produce hormones?

A

Hypothalamus receives signals from different parts of brain
It then sends signals to the pituitary gland, which produces several hormones
that regulate many body functions

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37
Q

what is the function of the infundibulum?

A

The infundibulum
attaches the pituitary
gland to the
hypothalamus

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38
Q

describe the structure of the pituitary gland

A

The pituitary gland attaches to
the hypothalamus and has two
anatomically and functionally
separate lobes

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39
Q

what are the steps of activating the anterior pituitary gland

A
  1. The hypothalamus secretes
    hormones to activate the
    anterior pituitary gland
  2. The anterior pituitary gland (adenohypophysis) secretes
    hormones in response to hypothalamic hormones
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40
Q

how are hypothalamic hormones delivred to the pituitary gland?

what are the two steps?

A

Hypothalamic hormones are
delivered to the anterior
pituitary gland via the
hypophyseal portal system -
A portal system connects two
capillary beds together

  1. Neurosecretory cells
    release hormones into the
    primary plexus of the
    hypophyseal portal system
  2. Hormones go from the
    primary plexus to the
    secondary plexus of the
    hypophyseal portal system
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41
Q

describe the relation between human growth hormone and insulin-like growth factors

A
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42
Q

what happens when there is hypersecretion of hGH before closing of the epiphyseal plates (in childhood)

A

Hypersecretion of hGH before closing of epiphyseal plates
(in childhood) causes gigantism. Abnormally tall, but well
proportioned

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43
Q

what happens if there is hypersecretion of hGH after closing the epi[hyseal plates (in adults)

A

Hypersecretion of hGH after closing of epiphyseal plates
(in adults) causes acromegaly (enlarged extremities) -
bones of hands, feet and face are still responsive to hGH

44
Q

what happens when there is hyposecretion of hGH

A

Hyposecretion of hGH results in pituitary dwarfism. Short
but normal proportions. If detected before puberty, can
treat with exogenous hGH

45
Q

Which of the following do you think would
lead to the release of hGH?
a) High blood glucose levels
b) Low blood glucose levels

A

B because low levels would make hgiher blood glucose levels)

I think :)

46
Q

Which of the following would lead to the
release of hGH?
a) High levels of amino acids in blood
b) Low levels of amino acids in blood
Hint: think about what effect hGH has on amino acid levels in blood

A

A

47
Q

Which of the following would lead to the
release of hGH?
a) High levels of fatty acids in blood
b) Low levels of fatty acids in blood

A

B because you break the fatty acids when low levels of glucose we need to break down fats to have more fatty acids

48
Q

what does Thyrotropin-releasing hormone (TRH) tigger? explain the process

A

Thyrotropin-releasing hormone
(TRH) from the hypothalamus
triggers the release of thyroid
stimulating hormone (TSH)
from the anterior pituitary

In response to TSH, the
thyroid gland produces
and releases thyroid
hormones (T3 and T4)

Thyroid hormones are
involved in the regulation
of metabolism

49
Q

what does Gonadotropin-Releasing Hormone (GnRH) from the hypothalamus trigger?

A

Gonadotropin-Releasing Hormone (GnRH) from
hypothalamus triggers the release of follicle stimulating hormone (FSH) and Luteinizing
hormone (LH) from the anterior pituitary

The ovaries and the
testes respond to FSH and to LH
Leads to production of sex
hormones (estrogens,
progesterone, testosterone)

Leads to development of
gametes (oocytes and sperm)

50
Q

what does prolactin (PRL) do?

A

Prolactin-Releasing Hormone (PRH) and Prolactin-inhibiting Hormone (PIH) from the hypothalamus control the release of prolactin (PRL) from the anterior pituitary

The mammary glands respond by altering
milk production

Together with other hormones, PRL initiates and maintain milk production
and secretion

51
Q

what does Adrenocorticotropic Hormone (ACTH) do?

A

Corticotropin-releasing hormone
(CRH) from the hypothalamus
stimulates the release of
adrenocorticotropic hormone
(ACTH) from the anterior pituitary

The cortex of the
adrenal glands
respond by releasing
glucocorticoids

Glucocorticoids provide resistance to stress and act as anti
inflammatory agents

52
Q

what does Melanocyte-Stimulating Hormone (MSH) do?

A

Corticotropin-releasing hormone
(CRH) from the hypothalamus
stimulates the release of
melanocyte-stimulating hormone
(MSH) from the anterior pituitary

The melanocytes and
parts of the brain
respond to MSH

Melanin is produced
May play a role in
certain brain
functions? (appetite
and sexual arousal)

53
Q

true of flase the posterior pituitary lobe synthesises hormones?

A

false

54
Q

what are the steps in hormone delivery to posterior pituitary gland

A
  1. Neurosecretory cells
    synthesize hormones in
    the hypothalamus
  2. Hormones are transported
    down the axons located in the
    infundibulum and the
    posterior pituitary lobe
  3. Hormones are stored in
    the posterior pituitary lobe,
    in the axon terminals of
    neurosecretory cells, until
    they need to be released
  4. Hormones - oxytocin and
    antidiuretic hormone (ADH)
    are released in the capillary
    plexus of the infundibular
    process
55
Q

s the capillary plexus of the infundibular
process part of a portal system?
a) Yes
b) No

A

A) yes

56
Q

what is the role of oxytocin when a female is going through delivery?

A

During delivery
◦ Oxytocin release enhances muscle contraction of uterus
(+ feedback)
◦ Synthetic oxytocin often used to induce labor

57
Q

what is the role of oxytocin after a female delivers the baby?

A

*After delivery–uterine contractions necessary for expulsion of placenta–stimulates ejection of milk from breast

58
Q

Oxytocin is made by the:
a) Posterior pituitary
b) Adenohypophysis
c) Anterior pituitary
d) Hypothalamus
e) Milk ducts

A

d) hypothalamus

59
Q

what are the function of antidiuretic hormone (ADH)?

A

Functions in increasing blood pressure by:
◦ decreasing urine production
◦ decreasing sweat production
◦ Increasing vasoconstriction
In other words, ADH helps keep water in

60
Q

Which of the following situations would lead to
the release of ADH?
a) Dehydration
b) Overhydrating
c) High blood pressure
d) a and c

A

a) dehydration

61
Q

negative feedback mechanism of ADH secretion

A
62
Q

what happens when there is hyposecretion of ADH

A

leads to a condition called Diabetes Insipidus
excretion of large amounts of dilute urine
◦ urine output rises from 1-2 L/day to ~ 20 L/day
subsequent dehydration and thirst results

63
Q

Which statement is correct regarding the
relationship between the hypothalamus and
pituitary gland?
a) Releasing hormones are secreted by the anterior pituitary
b) The hypothalamus is ‘controlled’ by the pituitary gland
c) The posterior lobe of the pituitary secretes inhibiting hormones
d) The hypothalamus secretes releasing and inhibiting hormones
that influence the pituitary gland

A

d) the hypothalamus secretes releasing and inhibiting hormones that influence the pituitary gland

64
Q

How does a hormone “know” what cell to
influence?
a) It only uses blood vessels that get to the target organ
b) It binds to hormone receptors found on target cells
c) It binds to all cells, but only target cells respond to the binding
d) All mechanisms above are possible

A

B

65
Q

A major difference between lipid-soluble
hormones and water-soluble hormones is
a) Lipid-soluble hormones bind to receptors; water-soluble
hormones don’t
b) Water-soluble hormones bind to receptors; lipid-soluble
hormones don’t
c) Lipid-soluble hormones increase metabolism; water-soluble
hormones decrease metabolism
d) Lipid-soluble hormones enter the cell; water-soluble hormones
don’t

A

D

66
Q

Which statement is correct regarding the
relationship between the hypothalamus and
pituitary gland?
a) Releasing hormones are secreted by the anterior pituitary
b) The hypothalamus is ‘controlled’ by the pituitary gland
c) The posterior lobe of the pituitary secretes inhibiting hormones
d) The hypothalamus secretes releasing and inhibiting hormones
that influence the pituitary gland

A

D

67
Q

Which of the following do you think would
lead to the release of hGH?
a) High blood glucose levels
b) Low blood glucose levels
Hint: think about what effect hGH has on blood glucose levels

A

B ; when low-blood glucose, the hGH will be released to stimulate the breakdown of glycogen

68
Q

what is the function of the thyroid gland

(what do their hormones do?)

A

Secretes hormones that affect metabolic rate and
calcium levels in body fluids.

69
Q

describe the histology of thyroid gland

A

Each thyroid follicle is formed
of follicular cells (simple
cuboidal epithelium)

Large amounts of proteins
(Thyroglobulin) are stored in
the follicles
Each thyroid follicle is formed
of follicular cells (simple
cuboidal epithelium)
Follicular cells use thyroglobulin to
make thyroid hormones (T3 and T4)

Parafollicular cells (in between the
follicles) produce the hormone
calcitonin
◦ It lowers the blood calcium levels

70
Q

what do thyroid hormones T3 and T4 do? which one is more abundant and which one is more potent?

A

T3 & T4 influence almost all body cells–increase metabolic rate–increase body temp –stimulate protein synthesis–increase ATP generation–stimulate breakdown of fats (for ATP) –stimulate Na+/K+ pump synthesis–regulate bone and nervous tissue growth

T4 more abundant than T3
T3 more potent than T4
T4 converted to T3 in body cells

71
Q

steps in the formation, storage and release of thyroid hormones

A
  1. Iodide trapping
  2. Synthesis of thyroglobulin (TGB)
  3. Oxidation of iodide
    Required for iodine to bind to tyrosine
  4. Iodination of tyrosine
    ◦ Tyr + 1 Io = T1; Tyr + 2 Io = T2
  5. Coupling of T1 and T2 to form colloid
    ◦ T1 + T2 = T3; T2 + T2 = T4
  6. Pinocytosis and digestion of colloid
  7. Secretion of thyroid hormones
  8. Transport in the blood
72
Q

what are the different types of thyroid gland disorders

A

Grave’s disease – most common cause of
hyperthyroidism

◦ Autoimmune disease that causes production of
antibodies that mimic TSH
◦ Weight loss, nervousness, tremor, exophthalmos
(edema behind eyes)

Goiter = enlarged thyroid (can be
due to dietary iodine deficiency)
Can lead to hyper-, hypo-, or
normal thyroidism

73
Q

what are the steps in the control of T3 and T4 secretion?

A
  1. When T3/T4 levels drop, hypothalamus
    secretes thyrotropin-releasing hormone (TRH)
  2. anterior pituitary secretes thyroid-stimulating
    hormone (TSH)
  3. Thyroid follicular cells in thyroid produce T3
    and T4
  4. elevated levels of T3 inhibit the production of
    TRH and TSH (negative feedback
74
Q

Which of the following is an effect of the thyroid hormones?
a) Increases blood cholesterol
b) Increases carbohydrate synthesis
c) Increases oxygen consumption
d) Helps slow down body growth

A

C

75
Q

Which of the following hormones would
increase in a laboratory animal after a thyroidectomy?
a) Thyroid stimulating hormone (TSH)
b) Thyrotropin-releasing hormone (TRH)
c) Triiodothyronine (T3)
d) Thyroxine (T4)
e) a and b

A

E

76
Q

what do parathyroid glands do?

A

Parathyroid glands (behind thyroid gland) release parathyroid hormone (PTH)

77
Q

what is the function of parathyroid hormone?

A

Main regulator of calcium, magnesium & phosphate levels in blood
◦ increases activity of osteoclasts, which perform bone resorption, leading to
the release of Ca2+ & phosphate from bone into the blood
◦ increases reabsorption of Ca2+ and Mg2+ by kidneys
◦ promotes formation of calcitriol (vitamin D) by kidneys which enhances
absorption of Ca2+ and Mg2+ by intestinal cells

78
Q

what are the steps in the control of the parathyroid hormone

A
79
Q

The release of calcitonin by the thyroid gland is
triggered by the release of hormones from the
anterior pituitary gland
a) True
b) False

A

b) False

80
Q

Which statement is NOT true of the interplay
between PTH and calcitriol?
a) Calcitriol increases calcium absorption from foods
b) PTH increases resorption of bone
c) High blood calcium levels increases calcitonin release
d) PTH decreases calcitriol levels

A

B) false

81
Q

what are the two different kinds of parathyroid gland disorders

A

Hypoparathyroidism
◦ Low levels of calcium, phosphate, magnesium (cations)
◦ Results in muscle twitches, spasms and tetany (maintained contraction)

Hyperparathyroidism
◦ High levels of calcium, phosphate, magnesium
◦ Excessive bone resorption so that bones become soft and easily fractured

82
Q

acini of pancreas vs iselts of langerhans in pancreas

A

Acini
◦ exocrine function of pancreas
◦ 99% of pancreas
◦ produce pancreatic juice and produce digestive enzymes

  • Islets of Langerhans
  • endocrine function of pancreas
  • produce hormones
  • 1% of pancreas
83
Q

describe the control of the pancreas

hypoglycemia / hyperglycemia

A
84
Q

Low blood glucose triggers:
a) Alpha cells to secrete insulin
b) Alpha cells to secrete glucagon
c) Beta cells to secrete insulin
d) Beta cells to secrete glucagon

A

B)

85
Q

what is diabetes mellitus?

A

◦ A group of disorders caused by an inability to produce or use insulin

◦ Type I diabetes (juvenile diabetes or insulin-dependent diabetes) mellitus is
caused by an absolute deficiency of insulin.
◦ Often due to autoimmune attack of beta cells

◦ Type II diabetes (insulin-independent diabetes; associated with obesity) is
caused by decreased sensitivity to insulin
◦ E.g., Downregulation of insulin receptor on target cells

86
Q

what happens when you have diabetes mellitus

symptoms

A

excessive urine production (polyuria); excessive thirst (polydipsia)
◦ kidneys can’t reabsorb enough water
◦ excessive eating (polyphagia)
◦ because no glucose available to cells
◦ fatty acids broken down for energy
◦ ketone bodies in blood make blood acidic (can lead to “diabetic coma”)
◦ excess glucose damages blood vessels, leading to tissue death and kidney
pathologies
◦ excess lipids in blood leads to atherosclerosis and cardiovascular problems

87
Q

what are the 3 different hormones secreted by the suprarenal cortex?

A

The suprarenal cortex secretes three different hormones

  • glucocorticoids– Include cortisol (aka hydrocortisone - 95% of glucocorticoid
    activity), corticosterone and cortisone– role in stress response
  • mineralocorticoids – role in maintaining blood volume and electrolytes levels
  • androgens– role in male features
88
Q

how to glucocorticoids provide resistance to stress?

A

◦ promoting protein and fat breakdown for ATP – (keep glucose for brain)
◦ gluconeogenesis - conversion of amino acids and fats to glucose (for ATP)
◦ enhancing vasoconstriction (increase BP)

89
Q

Glucocorticoids have anti-inflammatory and immune suppression effects. explain

A

Glucocorticoids have anti-inflammatory and immune suppression effects
◦ due to anti-inflammatory effects, glucocorticoids delay tissue repair/wound healing
◦ but they can be used to treat acute and chronic inflammatory diseases
◦ due to immuno-suppressive effects, glucocorticoids are used in organ transplant
and some autoimmune diseases

90
Q

what is Cushing’s syndrome?

A

Hypersecretion of glucocorticoids
Due to tumor or to use of immunosuppresive drugs
muscle wasting resulting in spindly arms and legs
Redistribution of fat resulting in rounded face, hump on back, hanging abdomen
Wound healing is poor, bruise easily
Elevated cortisol levels cause hyperglycemia, osteoporosis, weakness,
hypertension, susceptibility of infections, decreased resistance to stress, mood
swings

91
Q

describe the steos in regulation of glucocorticoid levels

A
92
Q

describe mineralocorticoids

A

Steroid hormones that regulate the homeostasis of sodium, potassium and
water
◦ the main mineralocorticoid is aldosterone
Aldosterone promotes sodium reabsorption, thereby promoting water
reabsorption
◦ regulates blood volume and blood pressure

93
Q

describe steps Regulation of Aldosterone:
renin-angiotensin-aldosterone pathway

A

The RAAS is stimulated by a decrease in blood volume and/or blood pressure
◦ Low BP stimulates juxtaglomerular cells in the kidney to secrete the enzyme
renin
◦ Renin converts the plasma protein angiotensinogen (produced in the liver)
into angiotensin I.
◦ As angiotensin I circulates to the lungs, an enzyme called angiotensin-converting enzyme (ACE) converts angiotensin I to angiotensin II
◦ Angiotensin II stimulates the adrenal cortex to secrete aldosterone (salt and H20 resorption indirectly increases BP), and it is a potent vasoconstrictor
(which directly increases BP

94
Q

Which of the following situations would lead to the
release of aldosterone?
a) Dehydration
b) High levels of sodium
c) Low blood pressure
d) a and c

A

D

95
Q

Aldosterone:
a) is synthesized by the kidneys in response to a drop in blood
pressure.
b) helps regulate blood pH.
c) production is inhibited by high blood K+ levels
d) would be helpful to restore Na+ levels after eating a bag of
potato chips.
e) promotes relaxation of vascular smooth muscle.

A

B; by regulating sodium and potassium

96
Q

what are androgens?

A

Androgens are masculinizing hormones produced by the adrenal cortex
◦ insignificant effect in males (because of testosterone produced by testes)
◦ in female, promote libido and are converted to estrogens
◦ after menopause, all estrogens come from conversion of adrenal androgens

97
Q

what does the suprarenal medulla do and what are the steps?

A

Produces epinephrine (80%) and norepinephrine (20%)

  1. Neurotransmitters from the
    hypothalamus trigger cells of
    the adrenal medulla to release
    the hormones epinephrine and
    norepinephrine
  2. epinephrine and
    norepinephrine cause the
    fight-or-flight response
98
Q

what does the release of epinephrine and norepinephrine lead to?

A

Increased heart rate and force of contraction
Constriction of blood vessels of most viscera and skin
Decrease in digestive activities
Dilation of blood vessels of heart, lungs, brain, and skeletal muscles
Conversion of glycogen into glucose in liver
Dilation of airways
Decrease in blood flow to kidneys, leading to decrease in urine output, water
retention and elevated blood pressure

99
Q

what are the types of stress responses

A
  1. Fight-or-flight response is short-lived and is initiated by nerve impulses from
    the hypothalamus
  2. The resistance reaction is longer-lasting; it helps the body continue fighting
    a stressor long after the fight-or-flight response dissipates. It is initiated
    mostly by hormones released from the hypothalamus
  3. Eventually, the body runs out of resources and cannot sustain the resistance
    phase: exhaustion results
100
Q

Which of the following does NOT happen
after prolonged stress response:
a) Muscle wasting
b) Gluconeogenesis
c) Protein synthesis
d) Lipolysis
e) Immune suppression

A

C

101
Q

what hormones are produces in the ovaries and what does each one of them do?

A

◦ Estrogen and Progesterone
◦ regulate the reproductive cycle, maintain pregnancy & prepare mammary glands
for lactation
◦ Also help maintain female secondary sex characteristics (enlargement of the
breasts, widening of the hips at puberty)
◦ Relaxin
◦ helps dilate the uterine cervix during labour and delivery
◦ Inhibin
◦ a protein hormone that inhibits the secretion of FSH

102
Q

what hormones do the testes produce?

A

◦ produce testosterone
◦ regulates descent of testes, sperm
production & 2nd sexual characteristics
◦ Also produce inhibin

103
Q

what does the pineal gland do?

A

Releases melatonin – involved in circadian rhythm

104
Q

what does the thymus do?

A

Secretes several factors involved in T lymphocyte
development and activation, and in various
responses of the immune system

105
Q

what does the heart release

A

Releases atrial natriuretic peptide (ANP) in response to high blood pressure

106
Q

what hormones do the kidneys release?

A

Release erythropoietin in response to hypoxia

107
Q

Which of the following is NOT part of the
endocrine system?
a) Kidney
b) Ovaries
c) Hypothalamus
d) Heart
e) All the above have endocrine function

A

E