Endocrine system (Chapter 17) Flashcards
(198 cards)
1
Q
what is the endocrine system
A
on of the two major communication systems of the body
2
Q
how does the nervous system communicate
A
via transmitters realeased by neurons
3
Q
how does the endocrine system communicate
A
via hormones released by particular cells into the bloodstream
4
Q
what are the nervous and endocrine system both key components of?
A
homeostasis
5
Q
how does the nervous system respond to stimuli in the environment
A
through various receptors (such as those for pain, temperature, pH, pressure)
neurotransmitters target other neurons, muscle cells (skeletal, smooth, or cardiac), or glands (including adrenal and salivary glands)
6
Q
what is the nervous system response time from stimulus to target cells
A
extremely rapid and only lasts for a brief period of time
7
Q
what do the many glands that the endocrine system involves produce
A
hormones that can target any cell type in the body
8
Q
how is the hormone response in the endocrine system (speed)
A
its initiated more slowly than the nervous system response, but the effects last much longer.
9
Q
why is it essential that the endocrine system and the nervous system cooperate?
A
to ensure proper reactions to changes in the external environment
10
Q
what are the major endocrine glands of the body
A
- hypothalamus
- pituitary gland
- pineal gland
- thyroid and parathyroid glands
- thymus
- pancreas
- adrenal glands
- testes
- ovaries
11
Q
what do endocrine glands release
A
hormones directly into the bloodstream
12
Q
what do exocrine glands release
A
substances (enzymes, swear, oil, mucus) through a duct to an epithelial surface or cavity
13
Q
functions of hormones
A
depending on the cell type that they bond to theres different functions HOWEVER these are the general funtions
- homeostatic regulation of blood sugar levels, water balance, blood, calcium levels, blood pressure, thirst, hunger, blood cell production, regulating other hormones in the blood.
- growth, metabolism, energy production
- reproductive functions (lactation, childbirth, development of sperm and eggs)
- stress response
- regulation of digestion
- regulation of circadian rhythms such as sleep-wake cycles
14
Q
what regulates the pituitary gland
A
hypothalamus
15
Q
for hormones to exert and effect what must they do
A
bind to a specific receptor either on the cell membrane or inside the target cell
16
Q
what is insulin
A
a hormone that is secreted by the pancreas to lower blood sugar after a meal
17
Q
all hormones initaiate a signaling pathway that does what
A
either directly or indirectly affects transcription and translation of a gene or multiple genes
18
Q
where does insulin bind
A
to very specific receptors on all cells to initiate the transcription and translation of the glucose-transporter protein which the embeds into cell membranes so glucose can enter the cells
19
Q
two categories of hormones
A
water soluble and fat soluble
20
Q
water- soluble hormones
A
polar hormones that act by binding to a receptor on a cell membrane rather then inside the cell.
21
Q
what can water-soluble hormones not do
A
they cant diffuse across membranes, so the specific receptor is located on the extracellular side of the membrane: only on cells that the hormone is meant to target.
22
Q
how do water soluble hormones elicit their response
A
indirectly through a messenger system. A second messenger relays a signal from the membrane receptor to a target molecule inside the cell, and this alters the activity of the cell.
23
Q
fat soluble hormone
A
non-polar hormones that can move into a target cell and bind to a receptor that affects gene expression.
24
Q
how do fat soluble hormones bind to their receptor
A
they easily cross the cell membranes to bind to their receptor inside the cell, and usually the receptors directly affect transcription and function as transcription factors.
25
what are transcription factors (meaning)
factors that promote or inhibit the transcription of RNA in a eurkoratyic cell
26
what are water coluble hormones (chemical make up)
modified amino acids, small peptides, or proteins.
27
what are water soluble hormones (5)
* Catecholamines: dopamine, epinephrine, norepinephrine
* Pancreas: insulin, glucagon
* Pituitary hormones
* Hypothalamus hormones
* Parathyroid hormone
28
what are the fat soluble hormones (2 types)
* Thyroid hormones: (T3, T4).
* Steroids (from cholesterol): cortisol, aldosterone, androgens (testosterone,
DHEA, estrogen, progesterone, calcitriol (active form of Vit D3)
29
what are water soluble hormones are peptides/ proteins
* Pancreas: insulin, glucagon
* Pituitary hormones
* Hypothalamus hormones
* Parathyroid hormone
30
what hormones are modified from tyrosine (amines)
thyroid hormones (fat soluble) and catecholamines (water soluble)
31
how are water soluble hormones released into circulation
gland cells package them into vesicles then release them into circulation by exocytosis
32
how are steroids released
by diffusion into extracellular fluid as soon as they are made
33
how are steroids and thyroid hormones transported
through the blood on the plasma protein albumin
34
can you buy inactive D3 to use for your body when needed
yes
35
what is the conrtol center of the brain
hypothalamus
36
what system is the hypothalamus a part of
the nervous system
and the endocrine system
37
how are they hypothalamus and pituitary connected
by the infundibulum, containing neurons and blood vessels
38
what is behind the hypothalamus and what does it produce?
pineal gland is behind the hypothalamus and it produces the hormone melatonin
39
what does melatonin do
induces sleep
40
what does the posterior pituitary store
hormones made by the hypothalamus
41
what hormones are made by the hypothalamus
oxytocin and ADH
42
what does the anterior pituitary make
hormones when stimualted by hypothalamus hormones
43
what is the direct blood connection between the hypothalamus and anterior pituitary
portal veins
44
how are hormones made in the hypothalamus and where are they stored
made by axon bodies, stored in terminals of the posterior pituitary
45
Oxytocin
involved in uterine contractions (positive feedback loop), milk, erection ejection, emotional bonding, love, empathy, feelings of social connection
46
another name for Antidiuretic hormone (ADH)
vasopressin
47
what is Antidiuretic hormone (ADH)
causes kidneys to reabsorb water and causes vasoconstriction to increase blood pressure when blood volume is low
48
what increases water excretion from the kidneys
a diuretic
49
what is growth hormone also called
somatotropin
50
what is the growth hormone stimulated by
deep sleep, high intensity exercise, periods of increased androgen production (growth spirts during childhood and puberty)
51
where is the growth hormone released
from the anterior pituitary gland in response to GHRH (growth hormone releasing hormone) produced by the hypothalamus
52
how much growth hormone is made in kids uposed to adults
2x more but still important for adults to maintain cell devision and to replace old or damaged cells
53
functions of growth hormones
- Promoting bone growth (height) in children and adolescents. GH causes calcium to be incorporated into bones, and decreases osteoporosis in adults.
- Stimulating protein synthesis. This occurs particularly in skeletal muscle where protein is required to increase muscle strength.
- Aiding metabolism. GH causes the liver to break down glycogen and fat and thereby increases the level of blood sugar so fuel is available for cells.
- Stimulating the immune system. Stress hormones inhibit growth hormone and inhibit the immune system.
54
what is it called when to much GH is produced during childhood
gigantism
55
what is it called when too much GH is produced after puberty
acromegaly
56
what is it called when to little GH production occurs
dwarfism
57
what do insulin like factors (IGF) stimulate
like GH, IGF stimulates cell devision, promotes bone growth, promotes protein synthesis mostly in muscle, break dow fats or energy and decrease the effects of insulin
58
what is required for synthesis of growth hormone
thyroid hormones
59
what simulates nutrient uptake, and inhibits protein break down
insulin
60
what do sex hormone (estrogen and testosterone) stimulate
GH and IGH, and protein synthesis
61
what does cortisol inhibit
growth
62
what is a mitogen
a molecule that stimulates cell devision
63
what is the thyroid stimulating hormone (TSH) also known as
thyrotropin
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what is the thyroid stimulating hormone (TSH) released in response of
the secretion of thyrotropin- releasing hormone (TRH) from hypothalamus
65
what does TSH act on
the thyroid gland causing it to release T3 and T4 (thyroid hormones)
66
what is TSH regulated through
negative feedback
- low T3 and T4 in blood = TRH release = TSH release = T3 and T4 to increase
- high T3 and T4 in blood = inhibits TRH and inhibits TSH = T3 and T4 to decrease
67
what is refered to as the good mood molecule
serotonin
68
what is Adrenocorticotropic hormone (ACTH) released in response of
the secretion of corticotropin- releasing hormone (CRH) from the hypothalamus
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where does ACTH act
on the adrenal cortex (top of kidneys)
70
what does ACTH regulate
glucocorticoid production, mainly cortisol, in response to stress
71
where does ACTH cause cortisol production from cholesterol
by the zona fasciculata region of the adrenal cortex
72
what are FSH and LH released in response of
gonadotropin- releaseing hormone (GnRH)
73
FSH
the primary hormone that stimulates sperm development in the testes and oocyte development in the ovaries
74
LH
stimulates gonads to produce testosterone, estrogen, and progesterone (LH is a tropic hormone) stimulates ovulation
75
what do males and females secrete (sex hormones)
testosterone, estrogen, and progesterone.
76
what enzyme do females have much more of and why
aromatase enzyme becasue it converts testosterone into estrogen
77
what is prolactin released in response of
released in response to the secretion of prolactin-releasing hormone (PRH) from the hypothalamus, inhibited by prolactin-inhibiting hormone (PIH)1
78
what does prolactin stimulate
the growth of mammary glands during pregnancy, and the productions of milk (lactation) after birth
79
what does prolactin play a role in
fetal lung surfactant production production at the end of pregnancy, and helps the mothers immune system not reject the infant
80
is prolactin produced in men
yes but only at low levels
81
what is a tropic hormone
a hormone that affects another hormone
82
where is the thyroid gland located
below layrnx, secretes T3, T4, and calcitronin
83
the thyriod hormone is stimulated by TSH to produce what
T3 (triiodothyronine) and T4 (thyroxine) in follicular cells
84
thyroid hormone synthesis requires what
iodine
85
what is the main role of the thyroid hormones
to regulate metabolism: increases cells oxygen use, break down fats and glycogen (glucose) to make ATP.
86
how many iodine atom does T3 conatin
3
87
how many iodine atoms does T4 contain
4
88
what do most cells do to T4
convert it to T3 which is more active (requires selenium)
89
what is selenium
a very important micronutrient required for thyroid hormone synthesis, and selenium deficiency can cause severe thyroid malfunction
90
what are the main functions of the thyroid hormones
- Regulating oxygen use by all cells during cellular respiration
- Increasing basal metabolic rate (BMR) by increasing the production of ATP from glycogen and fats
- Increasing the synergistic effects of epinephrine and norepinephrine in the breakdown of glycogen and fat for energy production
- Stimulating the production of growth hormone, especially important during fetal development
- Increasing heart rate, breathing rate, and cardiac output so that more oxygen can be delivered to cells
91
High TSH increases what and stimulates what
increases thyroid hormone production and stimulates thyriod gland to grow (hypertrophy)
92
whats an enlarged thyroid gland called
goiter
93
what is Hashimontos disease
autoimmune disease where the immune system attacks the thyroid hormone- producing cells, causing T3 and T4 decrease (hypothyroidism), causes increases TSH and goiter because T3 and T4 will never increase
94
What is Graves disease
an autoimmune disease where antibodies bind to TSH receptors activating them, and constantly stimulate the thyroid and secretion of T3 and T4 results in hyperthyroidism and goiter because TSH receptor is always.
95
what is hypothyroidism
low thyroid hormones
96
what is hyperthyroidism
excessive thyriod hormones
97
what do hyperthyriodism and hypothydroism
goiters
98
the appearance of an individual with graves disease experiencing exophthalmos
(experiencing exophthalmos) protruding eyes and goiter (buldge in neck from enlarged thryroid)
99
hypothyroidism is a condition caused by what
insufficient production of thyroid hormones.
100
what are people with hypothyoidism are not able to utilize
nutrients to produce energy, and so they feel very tired, have low energy, often gain weight, feel cold (since body heat is produced when ATP is produced), often have dry skin and brittle nails, and sometimes experience depression.
101
what does a lack of seritonin lead to
depression
102
what is the most common cause of hymothyroidism
iodine deficiency, selenium deficiency, any malfunction of the hypothalamus or anterior pituitary gland, extreme stress, and anorexia.
103
what is hyperthyroidism
a condition caused by excessive production of thyroid hormones.
104
how do people with hyperthyroidism feel
nervous, irritable, hot; have increased heart rate and difficulty sleeping; usually have weight loss; and sometimes have protruding eyes
105
thyroid hormones increase the effect of what
catecholamines (dompamine, epinephrine, and norepinephrine)
106
caclitonin is secreted by
parafollicular cells of the thyroid gland
107
the main function of calcitonin
prevent calcium (Ca2+) blood levels from being too high; it balances the effects of parathyroid hormone, which increases blood calcium levels.
108
what are osteoclasts
Osteoclasts are the bone cells that break down the mineral matrix and release stored calcium and phosphate into the blood
109
the two major hormones increase plasma calcium concentration
- - parathyroid hormone
- vitamine D (active form) causes small intestine to increase calcium uptake
110
what is the parathyroid hormone (PTH) secreted by
the parathyroid glands (4 posterior of thyroid)
111
PTH is the bodies main regulation of what
calcium, and works to increase bloos calcium
112
functions of the PTH (parathyroid hormone)
- Stimulating osteoclasts to release calcium and phosphate into the bloodstream
- Stimulating kidney cells to increase reabsorption of Ca2+ and Mg2+
- Increasing the excretion of PO43– by the kidneys
- Increasing the production of active vitamin D (calcitriol) by the kidneys, which then increases the absorption of calcium in the small intestines
113
what is the PTH release stimulated by
low blood calcium concentrations and inhibited by high concentrations
114
chronic Ca2+ deficiency can lead to what
hypersecretion of PTH, bone demineralization and osteoporosis
115
what is rickets (in children) and osteomalacia (in adults)
bone matrix mineralization is defiecient, causing sofe and easily fractured bones
116
what a major casue of rickets and osteomalacia
vitamin D deficiency
117
what is osteoporosis
results from an imbalance between bone resorption and formation; causes decreased bone mass and strength, increase of fractures
118
treatment for osteoporosis
focuses mainly on prevention and maintinance: dietary calcium, vitamin D, exrsice, bisphophonates (inhibit bone resorption)
119
who get osteroporosis
immobolized people, elderly, particularily females during menopause because decreased estrogen
120
adrenal glands are located where
one above each kidney
121
what do adrenal glands consist of
outer adrenal cortex and inner adrenal medulla
122
how many zones are in the adrenal cortex
- outer zona glomerulosa (mineralocorticoids, eg. aldosterone)
- middle zona fasciculata (glucocorticoids, e.g cortisol)
- inner zona reticularis (androgens eg DHEA)
123
all adrenal cortex hormones are what
steroids
124
what is the adrenal medulla controlled by
autonomic nervous system and stimulation from sympathetic preganglionic neurons causes the medulla to secrete epinephrine and a small amount of norepinephrine
125
does the adrenal medulla make more epinephrine or norepinephrine
a lot more epinephrine
126
when epinephrine is released from neurons they are called
neurotransmitters
127
do neurons release more epinephrine or norepinephrine
norepinephrine
128
aldosterone
main mineralocorticoid made by the cortex
129
aldosterone is made from
cholesterol in the zona glomerulosa
130
when is aldosterone produced
when blood pressure is low
131
main function of aldosterone
signaling kidney to reabsorb sodium in distal tubule and collecting ducts
132
aldosterone signals what
nephrons to secrete potassium ions
133
cortisol
main glucocorticoid produced in the cortex in response to ACTH from pituitary
134
crotisol is made from what
cholesterol in the zona fasciculata
135
cortisol has a daily what
cycle and increases during short or long term stress
136
potentiates action of epinephrine and norepinephrine causes what
vasoconstriction
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cortisol helps break down what
nutrients to increase blood sugar
138
higher concentrations of cortisol decrease
inflammatory response
139
cortisol is used as an ...
anti-inflammatory medication (in higher doses). At normal levels, helps to limit too much inflammation
140
synthetic versions of cortisol are important what
important drugs for limiting inflammatory damage
141
cortisol secretion is highly linked to
carcadian rhythm
142
cortisol levels rise when
a couple hours before waking (increases blood sugar until breakfast)
143
cortisol levels decrease when
through the day and is the lowest at night while sleeping
144
cortisol cycle is dependant on what
regular sleep schedule
145
cushings syndrome results from
excess cortisol secretion
146
symptoms of cushings syndrome
* Depression, moodyness
* Osteoporosis
* Muscles weakness
* hyperglycemia (may lead to type 2 diabetes)
* Immunosuppression
* Redistribution of fat from limbs to trunk (buffalo
hump and moon face)
* Hypertension (high blood pressure) – cortisol potentiates the effects of epinephrine and increases vasoconstriction
147
DHEA (dehydroepiandrosterone) is the mane androgen produced where
in the zona reticularis of the adrenal cortex
148
when is DHEA produced
during exercise
149
what does DHEA have similar effects to
testosterone though it plays a more significant role in adult females then males
150
in females adrenal androgens are converted to what
estrogen by aromatases. after menopause, this is the only source of estrogen
151
what can overstimulating the adrenal glands do
rarely it can lead to masculinization in females because of increased androgen production
152
the endocrine system responds to stresses by releasing ...
cortisol from the adrenal cortex and epinephrine from the adrenal medulla (fight or flight )
153
epinephrine breaks down what
stored fat for gluconeogenesis (increases effects of glucagon and thyroid hormones)
154
epinephrine increases blood sugar for what
Atp production
155
Epinephrine helps cells use O2 to promote what
ATP production
156
Epinephrine increases what
heart rate
157
cortisol breaks down
fat and glycogen to increase blood sugar
158
long term stress is
detrimental
159
pancreas location
behind the stomach
160
the pancreas is what kind of gland
both endocrine and exocrine
161
(pancreas) exocrine:
secretes enzymes and bicarbonate into small intestine during digestion
162
(pancreas) Endocroine:
secretes insulin and glucagen to regulate blood glucose
163
panceratic islets of Langerhand for endocrine funtion:
alpha cells- glucagon,
beta cells- insulin
164
eating stimulates what
insulin production (sugars and starch most); signals all cells to take up blood stream nutrients store anything not needed immediately. decreases blood glucose (stimulated GLUT production)
165
excess nutrients are taken up by what
the liver, muscles (glycogen) and fat cells (triglycerides)
166
fasting stimulates
glucagon
167
glucagon signals
cells to break down stored energy so glucose is available for ATP production, maintains blood sugar in a narrow range even during exercise
168
low blood sugar is called
hypoglycemia
169
hypoglycemia stimulates
some epinephrine release, also causing cells to break down stored nutrients
170
thyroid hormone, epinephrine, cortisol, growth hormone, and glucagon all stimualte
breakdown of stored nutrients to increase blood glucose and give cells a constant supply for ATP
171
Type 1 diabetes
* Autoimmune disease: immune cells attack the pancreatic islet beta cells that produce
insulin, so no insulin can be produced.
* Insulin-dependent diabetes or juvenile diabetes: insulin injections required to signal
cells to take up blood glucose, and patients must monitor blood glucose
172
Typer 2 diabetes
* Long-term, a diet rich in sugars leads to constant high insulin secretion from pancreas.
* Fewer insulin receptors on cells and they do not respond well to insulin, called insulin
resistance.
* So your body reacts as if there is insufficient or no insulin.
* Eventually pancreas may stop producing insulin as beta cells die from constantly
making insulin.
173
glucose stays in the bloodstream and doesn't enter cells (hyperglycemia) in what type of diabetes
both type one and type two
174
how is glucose excreted (diabetes)
in urine causeing thirst
175
symptoms of diabetes
increased hunger, high blood sugar, weakness, fatigue,
dizziness/fainting
176
what happens to cells (diabetes)
theyy starve because nutrients stay in blood bot going into cells
177
being overweight increses the risk of what
type two diabetes BUT type 2 often causes an increase in body weight because of excessive hunger since cells call for more energy.
178
Gonad hormones (testosterone, estrogen, progesterone) are stimulated by
LH from the anterior pituitary
179
testes mostly produce
testosterone
180
ovaries produce
estrogen and progesterone
181
Follicle stimulating hormone (FSH) from the anterior pituitary signals
spermatogenesis (testes) and oogenesis (ovaries).
182
testosterone is the
primary androgen in males
183
testosterone is made by what
leydig cells
184
Anabolic (tissue growth):
increases protein synthesis (muscle), increased bone density and maturation, and sex organ
development and secondary sex
characteristics (facial and armpit hair,
deepening voice).
185
FSH stimulates Sertoli cells to produce
sperm
186
The theca cells surrounding the developing oocyte
produce
estrogen in response to LH
187
FSH acts on granulosa cells, promoting
egg development
188
As the follicle grows, the theca cells surrounding granulosa
cells produce
more estrogen because they have more LH receptors stimulated by granulosa cells.
189
The corpus luteum (empty follicle) then secretes progesterone to increase
growth of uterine lining.
190
progesterone functions
*Increase uterine lining before fertilization
*Support pregnancy and fetal development
191
estrogen functions
*Estrogen functions:
*Secondary sex characteristic development during puberty
*LH surge due to estrogen increase in menstrual cycle
*Increases bone formation (osteoporosis is a consequence of menopause)
*Increases blood clotting (increased stroke risk from birth control)
192
aging causes a decrease in
hormone and hormone receptor production
193
theres no what in menopause
estrogen in ovaries
194
when aging testosterone decrease but what stimulates it
exercise
195
elderly people sleep ledd so what has decreased
melatonin
196
GH decreases (aging)
muscle and bone density loss; exercise can
stimulate some production.
197
TH production decreases (aging)
slower basal metabolism and so
weight gain and lower body heat.
198
Parathyroid hormone increases to help
calcium absorption in intestine, but
also causes bone resorption; exercise can help maintain bone density.
