Bio #5 Flashcards
1
Q
hypothalamus communicates with the anterior pituitary via the ________ and with the posterior pituitary via _____
A
hypophyseal portal system
nerves in the posterior stalk
2
Q
hypothalamus releases
A
GnRH, GRH, TRH, GHRH, PIF
3
Q
anterior pituitary releases
A
FSH/LH, ACTH, TSH, GH, Prolactin
4
Q
posterior pituitary releases
A
oxytocin, ADH
5
Q
what are the tyrosine derivitive hormones
A
catecholamines
T3, T4
6
Q
what are the tyrosine derivative hormones
A
catecholamines (proteins)
T3, T4 (steroid)
7
Q
_____ are the messengers of the endocrine system
A
hormones
8
Q
glands
A
organs that secrete hormones
9
Q
hormones
A
signaling molecules that are secreted directly into the bloodstream to distant target tissues. At target tissues they bind to receptors and either change gene expression or cellular functioning.
10
Q
what are the different structures of hormones
A
peptide hormones
steroid hormones
amino acid derivative hormones
11
Q
peptide hormones
A
made up of amino acids, ranging in size from quite small (such as anti-diuretic hormone, ADH) to relatively large (such as insulin)
12
Q
naming of peptide hormones and steroid hormones
A
Most peptide and amino acid-derivative hormones end in “-in” or “-ine”. Most steroid hormones end in “-one”, “-ol” or “-oid”.
13
Q
how are peptide hormones processed in the cell
A
Many are cleaved during posttranslational modification and visit the Golgi to be modified before going to a certain place in the cell or being exocytosed.
14
Q
how do peptide hormones function at their targets?
A
Too large so they bind to extracellular receptor as first messenger and trigger transmission of second signal, second messenger.
Signaling cascade: the connection between the hormone at the surface and the effect brought about by second messengers within the cell.
• Each step has the possibility of amplification.
15
Q
signaling cascade
A
the connection between the hormone bound at the surface and the effect brought about by second messengers within the cell.
• Each step has the possibility of amplification.
16
Q
peptide hormones are considered _____
A
first messengers
17
Q
what are common second messengers
A
- Cyclic adenosine monophosphate (cAMP)
- Inositol triphosphate (IP3)
- Calcium
18
Q
explain the GPCR pathway
A
• Binding of peptide hormone either activates or inhibits enzyme adenylate cyclase, raising or lowering cAMP, cAMP can bind to intracellular targets such as protein kinase A, which phosphorylates txn factors like CREB which is the hormone’s ultimate affect. CREB changes gene expression in some way in the cell.
19
Q
peptide hormones are ____ soluble which means they can _____ in the blood but they need to be _____ to get passed the cell membrane.
A
water
flow freely
exocytosed
20
Q
peptide hormones have ______ effects
A
rapid but short lived
21
Q
steroid hormones
A
derived from cholesterol and are produced primarily by the gonads and adrenal cortex.
22
Q
what are peptide hormones and steroid hormones derived from
A
peptide: amino acids (or polypeptides)
steroid: cholesterol
23
Q
steroid hormones ______ the cell membrane and bind to receptors in the ______
A
cross
cytoplasm or nucleus
24
Q
steroid hormones have _______
A
slower, longer lives
25
describe steroid hormones in the bloodstream
they are non-polar, non-water soluble so they must be carried by proteins in the bloodstream
Ex: albumin: carries free fatty acids
hormones are generally inactive when bound
26
amino acids derivative hormones
(epinephrine, norepinephrine, triiodothyronine, and thyroxine) not as common but VERY important. Derived from one or two amino acids with a few modifications.
Chemistry is wacky so it may be best to just memorize.
Catecholamines (epinephrine and norepinephrine): bind to GPCR
Thyroid hormone: binds intracellularly
Thyroxine and triiodothyronine have slower onset but longer duration.
27
catecholamines
(epinephrine and norepinephrine): bind to GPCR
28
catecholamines are _____ hormones while thyroid hormones are ____ hormones
protein
| steroid
29
direct hormones
secreted and then act directly on the target tissue
| Ex: insulin released by pancreas causes increased uptake of glucose by muscles.
30
tropic hormones
require an intermediary to act. Cause secretion of another hormone by a gland that then travels to the target tissue and acts.
Ex: GnRH release from hypothalamus causes release of LH and FSH. LH and FSH activate other hormones which target tissues.
Have major effects on other endocrine tissues.
31
what are all of the endocrine glands
hypothalamus, pituitary, thyroid, parathyroid glands, adrenal glands, pancreas, the gonads (tests and ovaries), and the pineal gland
while the kidneys, gastrointestinal glands, heart, and thymus are involved.
32
hypothalamus
the bridge between the nervous and endocrine systems
o Regulated pituitary gland through tropic hormones. Very close to each other and connected via a portal system.
o Receives a lot of signals from everywhere.
o The release of hormones by the hypothalamus is regulated by negative feedback: occurs when a hormone (or product) later in the pathway inhibits hormones (or enzymes) earlier in the pathway.
Saves energy and maintains homeostasis
33
interactions between the hypothalamus and pituitary gland
Hypophyseal portal system: blood vessel system that directly connects the hypothalamus with the anterior pituitary (hypothalamus secretes compounds into it)
The hormones from the hypothalamus bind to the receptors in the anterior pituitary and stimulate the release of other hormones.
Hypothalamus release and anterior pituitary release:
• Gonadotropin-releasing hormone (GnRH) follicle stimulating hormone (FHS) and luteinizing hormone (LH)
• Growth hormone-releasing hormone (GHRH) growth hormone (GH)
• Thyroid-releasing hormone (TRH) thyroid-stimulating hormone (TSH)
• Corticotropin releasing factor (CRF) adrenocorticotropic hormone (ACTH) release of cortisol by the adrenal cortex and then feedback loop (Example of an axes)
• Prolactin-inhibiting factor (PIF), dopamine decrease in prolactin secretion (if no PIF is released then prolactin can be secreted)
34
hypophyseal portal system
only connects the hypothalamus to the anterior pituitary
blood vessel system that directly connects the hypothalamus with the anterior pituitary (hypothalamus secretes compounds into it)
The hormones from the hypothalamus bind to the receptors in the anterior pituitary and stimulate the release of other hormones.
35
Hypothalamus release and anterior pituitary release:
* Gonadotropin-releasing hormone (GnRH) follicle stimulating hormone (FHS) and luteinizing hormone (LH)
* Growth hormone-releasing hormone (GHRH) growth hormone (GH)
* Thyroid-releasing hormone (TRH) thyroid-stimulating hormone (TSH)
* Corticotropin releasing factor (CRF) adrenocorticotropic hormone (ACTH) release of cortisol by the adrenal cortex and then feedback loop (Example of an axes)
* Prolactin-inhibiting factor (PIF), dopamine decrease in prolactin secretion (if no PIF is released then prolactin can be secreted)
36
Posterior pituitary receives signals from the hypothalamus via _____
axons
37
hormones released by posterior pituitary
Oxytocin: stimulates uterine contractions during labor. As well as milk letdown during lactation.
Antidiuretic hormone: (ADH, vasopressin): increases reabsorption of water in the collecting ducts of the kidneys.
• Secreted in response to increased plasma osmolarity (increased concentration of solutes in the blood)
38
oxytocin
released by posterior pituitary, stimulates uterine contractions during labor. As well as milk letdown during lactation.
39
antidiuretic hormone
increases reabsorption of water in the collecting ducts of the kidneys.
• Secreted in response to increased plasma osmolarity (increased concentration of solutes in the blood)
40
what are the tropic hormones secreted by the anterior pituitary
FLAT
FSH and LH act on gonads
ACTH acts on the adrenal cortex
TSH acts on the thyroid
41
what are the direct hormones secreted by the anterior pituitary
PEG
prolactin
endorphins
growth hormone
42
prolactin
more important in females, stimulates milk production in the mammary glands.
• High levels of estrogen and progesterone allow for the development of milk ducts in prep for lactation but milk does not come until prolactin and oxytocin (contraction of breast smooth muscle and ejection of milk through the nipple) are secreted.
43
endorphins
decrease the perception of pain
| • Morphine mimics the effects of these.
44
growth hormone
promotes the growth of bone and muscle.
• Prevents glucose uptake in certain tissues that are not growing so that bone and muscle can have it. It also triggers the breakdown of fatty acids.
• Gigantism: excess of GH released during puberty
• Dwarfism: lack of GH released during puberty
• Acromegaly: gigantism in adults in which their smaller bones such as their hands or feet grow larger.
45
gigantism
excess of GH released during puberty
46
dwarfism
lack of GH released during puberty
47
acromegaly
gigantism in adults (after their epiphyseal plates close after puberty) in which their smaller bones such as their hands or feet grow larger.
48
posterior pituitary
Does not synthesize any hormones itself and the ones it releases are actually synthesized in the hypothalamus.
contains the nerve terminals of neurons with cell bodies in the hypothalamus
o ADH secreted in response to low blood volume or increased blood osmolarity
Increases the permeability of the collecting duct to water from the filtrate in the nephron. higher blood pressure and volume
o Oxytocin: secreted during childbirth and allows for coordinated contraction of uterine smooth muscle. Also promotes milk ejection through contraction of smooth muscle in the breast.
May be involved in bonding behavior
Is actually a positive feedback loop.
49
ADH/vasopressin
o ADH secreted in response to low blood volume or increased blood osmolarity
Increases the permeability of the collecting duct to water from the filtrate in the nephron. higher blood pressure and volume
50
oxytocin
secreted during childbirth and allows for coordinated contraction of uterine smooth muscle. Also promotes milk ejection through contraction of smooth muscle in the breast.
May be involved in bonding behavior
Is actually a positive feedback loop.
51
thyroid
o Controlled by the thyroid-stimulating hormone (TSH) from the anterior pituitary
o Located on the front side of the trachea
o Two functions
1. Sets basal metabolic rate: releases triiodothyronine (T3) and thyroxine (T4)
2. Promotes calcium homeostasis through the release of calcitonin
52
Triiodothyronine (T3) and Thyroxine (T4) are _____ hormones
thyroid hormones
steroid
amino acid derivative hormones
Both produced by the iodination of the amino acid tyrosine in the follicular cells of the thyroid.
• 3 and 4 refer to the number of iodine atoms attached to tyrosine.
Can make energy production more or less efficient and alter the utilization of glucose and fatty acids.
Increased triiodothyronine (T3) and thyroxine (T4) lead to increased cellular respiration.
53
T3 and T4 hormones are very important for ____
energy regulation
| alter utilization of glucose and fatty acids increase them leads to increased cellular respiration
54
hyperthyroidism
excess thyroid hormone, tumor or overstimulation
| Heightened activity level, increased respiratory and heart rate (pretty much the opposite of hypothyroidism)
55
calcitonin
released from the thyroid gland
Decreases plasma calcium levels in 3 ways: increase excretion in kidneys, decrease calcium absorption in the gut, increase storage of calcium in the bone.
56
calcitonin does what to plasma calcium levels
decreases it
57
what is calcium important for
- bone structure and strength
- release of neurotransmitters from neurons
- regulation of muscle contraction
- clotting of blood (calcium is a cofactor)
- also plays a role on cell movement and exocytosis of cellular materials.
58
GnRH
gonadotropin releasing hormone
59
FSH
follicle stimulating hormone
60
LH
luteinizing hormone
61
GHRH
growth hormone releasing hormone (GNRH)
62
GH
growth hormone
63
FLAT PEG
FLAT: tropic
PEG: direct
64
TRH
thyroid releasing hormone
65
TSH
thyroid stimulating hormone
66
CRF
corticotropin releasing factor
67
ACTH
adrenocorticotropic hormone ACTH
68
PIF
prolactin inhibiting factor
69
prolactin
mother prepares to lactate
70
parathyroid glands
o Four pea-sized structures that sit on the posterior surface of the thyroid.
o Parathyroid hormone (PTH) released from them.
o Antagonistic to calcitonin and raises blood calcium levels
Opposites of calcitonin
Negative feedback
o Also plays a role in phosphorous homeostasis, getting rid of it, and also absorbing it.
o Activates vitamin D: required for absorption of calcium and phosphate from the gut.
71
parathyroid hormone
released from them.
o Antagonistic to calcitonin and raises blood calcium levels
Opposites of calcitonin
Negative feedback
72
what activates vitamin D
PTH: Activates vitamin D: required for absorption of calcium and phosphate from the gut.
73
adrenal gland
are located on top of the kidneys. Each adrenal gland has a cortex and a medulla.
74
adrenal cortex
secretes corticosteroids, can be divided into 3 classes:
| salt-sugar-sex
75
glucocorticoids
adrenal cortex
steroid hormones that regulated glucose levels and affect protein metabolism
o Cortisol: released in times of stress
o Cortisone and cortisol raise blood glucose by increasing gluconeogenesis and decreasing protein synthesis. Can also decrease inflammation and immunological responses.
o CRF from hypothalamus ACTH from anterior pituitary glucocorticoids
76
mineralocorticoids
adrenal cortex
used in salt and water homeostasis, with their most profound affects on the kidneys.
o Aldosterone: increases sodium reabsorption in the distal convoluted tubule and collecting duct of the nephron. Water follows the sodium ions into the bloodstream which increases blood volume and pressure.
No change in osmolarity
Decreases reabsorption of potassium and hydrogen ions in the same segments of the nephron.
Under control of angiotensin-aldosterone system: decreased blood pressure causes the juxtaglomerular cells of the kidney to secrete renin, which cleaves an inactive plasma protein, angiotensinogen, to its active form angiotensin I. Angiotensin I is then converted to angiotensin II by angiotensin-converting enzyme (ACE) in the lungs. Angiotensin II stimulates the adrenal cortex to secrete aldosterone.
77
cortical sex hormones
adrenal cortex
78
cortisol
released in times of stress.
along with cortisone, increases blood glucose level
79
angiotensin-aldosterone system (explain and draw)
decreased blood pressure causes the juxtaglomerular cells of the kidney to secrete renin, which cleaves an inactive plasma protein, angiotensinogen, to its active form angiotensin I. Angiotensin I is then converted to angiotensin II by angiotensin-converting enzyme (ACE) in the lungs. Angiotensin II stimulates the adrenal cortex to secrete aldosterone.
80
hypothyroidism
Hypothyroidism: a deficiency of iodine or inflammation of the thyroid thyroid hormones are secreted in insufficient amounts or not at all.
• Lethargy, slow heart rate and respiratory rate
• Cretinism: intellectual and developmental delay caused by thyroid deficiency.
81
cortical sex hormones
androgens and estrogens
o Play a larger role in females because the male tests already secrete large amounts of hormones.
o Excess cortical hormones can lead to genotypic male or female having phenotypic problems
82
adrenal medula
o Nestled inside the adrenal cortex
o Derivative of the Nervous system
o Produces epinephrine and norepinephrine. Both are part of larger class called catecholamines.
Can be secreted directly into the blood stream.
o System wide effects all centered on the fight or flight response.
Increase breakdown of glycogen to glucose in liver and muscle and increase metabolic rate.
Dilate bronchi, increase heart rate.
Fast stress response
Vasodilation of blood vessels and shunts blood flow to systems used in the sympathetic response.
83
epinephrine and norepinephrine
Increase breakdown of glycogen to glucose in liver and muscle and increase metabolic rate.
Dilate bronchi, increase heart rate.
Fast stress response
Vasodilation of blood vessels and shunts blood flow to systems used in the sympathetic response.
84
pancreas
o Has both endocrine and exocrine (secrete substances directly into ducts) functions
endocrine: islets of langerhans cells secrete hormones into blood vessels.
exocrine: acinar cells secrete digestive enzymes into the pancreatic duct
alpha cells: glucagon
beta cells: insulin
delta cells: somatostatin
85
exocrine function
secrete substances directly into a duct
86
acinar cells
pancreas
| secrete digestive enzymes into the pancreatic duct
87
islets of langerhans cells
secrete hormones into blood vessels.
small clusters of hormone-producing cells grouped together in the pancreas
• Islets contain 3 distinct types of cells: alpha (glucagon), beta (insulin), and delta (somatostatin) cells
88
glucagon
secreting during times of fasting, when glucose levels are low. Triggers glycogenolysis, gluconeogenesis, and degradation of protein and fat
89
insulin
antagonistic to glucagon and secreted when blood glucose levels are high. Induces muscle and liver cells to take up glucose and store it as glycogen for later. Triggers fat and protein synthesis.
90
hypoglycemia
when insulin is in excess, low blood glucose concentration
91
hyperglycemia
: excess glucose in the blood, when insulin is underproduced or not secreted or insensitivity to insulin.
92
diabetes mellitus type I vs. type II
Hyperglycemia: excess glucose in the blood, when insulin is underproduced or not secreted or insensitivity to insulin.
• Can result in diabetes mellitus.
o Type I: insulin-dependent, autoimmune destruction of the beta cells of the pancreas resulting in little or no insulin production.
o Type II: non-insulin dependent, receptor-level resistance to the effects of insulin.
93
polyuria
increased frequency of urination
94
polydipsia
increased thirst
95
somatostatin
an inhibitor of both insulin and glucagon secretion. High blood glucose and amino acid concentrations, also released by hypothalamus to decrease growth hormone secretion.
96
gonads
o Testes: secretes testosterone in response to gonadotropins (LH and FSH)
Testosterone causes sexual differentiation of the male during gestation and promotes development and maintenance of secondary sex characteristics in males.
o Ovaries: secrete estrogen and progesterone in response to gonadotropins (LH and FSH)
Estrogen is involved in the development of the female reproductive system during gestation and also promotes development and maintenance of secondary sex characteristics in females.
Estrogen and progesterone also govern the menstrual cycle
97
testes
secretes testosterone in response to gonadotropins (LH and FSH)
Testosterone causes sexual differentiation of the male during gestation and promotes development and maintenance of secondary sex characteristics in males.
98
ovaries
secrete estrogen and progesterone in response to gonadotropins (LH and FSH)
Estrogen is involved in the development of the female reproductive system during gestation and also promotes development and maintenance of secondary sex characteristics in females.
Estrogen and progesterone also govern the menstrual cycle
99
pineal gland
o Located deep within the brain and secretes melatonin.
Melatonin is involved in circadian rhythms.
Receives projections from the retina, responds to decreases in light intensity possibly.
100
melatonin
Melatonin is involved in circadian rhythms.
| Receives projections from the retina, responds to decreases in light intensity possibly.
101
gastrointestinal tract endocrine secretions
secretin, gastrin, and cholecystokinin
102
kidneys endocrine secretions
o Kidneys produce erythropoietin which stimulates bone marrow to increase erythrocyte production (red blood cells) when low blood oxygen levels are sensed.
103
heart endocrine secretions
o The heart releases atrial natriuretic peptide (ANP) to help regulate salt and water balance.
Functionally antagonistic to aldosterone.
104
thymus endocrine secretions
o The thymus releases thymosin which is important for proper T-cell development and differentiation.
105
Type I diabetes vs. Type 2 diabetes
Type I: no insulin is produced
Type 2: insensitivity to insulin
blood glucose levels rise to dangerous levels.
106
what do hormones change when they reach their receptor?
cellular functioning or gene expression
107
amplification during the peptide hormone signaling cascade
each step can result in an increase in signal intensity.
108
What are some examples of second messengers in the peptide hormone pathway?
cyclic adenosine monophosphate (cAMP), inositol triphosphate (IP3) and calcium
109
albumin
nonspecific protein that binds to steroid hormones and transports them in blood
110
steroid hormones are _____ when bound to their carrier protein
inactive
111
what receptors do catecholamines use?
| what receptors do thyroid hormones use?
GPCR (making them more like peptide hormones)
| intracellular (making them more like steroid hormones)
112
the thyroid hormones regulate _____
metabolic rate
113
where are some of the locations the hypothalamus receives input from?
light input from the retinae to control sleep-wake cycles, increases in blood osmolarity, regulates appetite and satiety.
114
what is another name for the pituitary gland?
the hypophysis
115
what is another name for prolactin inhibiting factor?
dopamine
116
three organ systems are referred to as ____
axes
117
all of the final products of the hypothalamus endocrine system have _____ effects on the hypothalamus and the anterior pituitary
negative feedback
118
milk production in makes is always ____
pathogenic
119
oxytocin vs. prolactin
oxytocin is released from the posterior pituitary and is responsible for milk let down during lactation
prolactin is released from the anterior pituitary and is responsible for milk production during lactation
120
where does bone growth originate?
epiphyseal plates
121
the posterior pituitary does not actually produce oxytocin or ADH, it just _______ them after they are produced by the hypothalamus
stores
122
which hormone has a positive feedback loop?
oxytocin has a positive feedback loop with uterine contractions. Uterine contractions promote more oxytocin release which promotes greater uterine contractions.
123
what occurs if blood concentration is too high or if blood volume is low?
triggers ADH release from the hypothalamus/posterior pituitary
124
how are T3 and T4 produced?
via the iodination of the amino acid tyrosine in the follicular cells of the thyroid
125
what is the disease cretinism caused by?
a deficiency in T3 and T4 during childhood. Characterized by disability and developmental decay.
126
in the thyroid, ____ cells produce thyroid hormones and ____ cells produce calcitonin
follicular cells
| C-cells (or parafollicular cells)
127
calcitonin ____ calcium levels in the blood
decreases
| calciton-INTO bones, excretion from kidneys, decreased absorption from gut.
128
what are the important roles of calcium?
bone structure and strength
release of neurotransmitters from neurons
regulation of muscle contraction
clotting of blood (calcium is a cofactor)
calcium is also involved in cell movement and exocytosis
129
what does bone resorption entail?
brings bone back into blood (parathyroid hormone)
130
parathyroid hormone activates vitamin _____ which is required for the absorption of _______ and _____ in the gut
calcium and phosphate
131
plasma phosphate ____ plasma Ca+2
decreases
132
many people who suffer from joint pain are treated with _______ injections into the joint space to decrease ____
glucocorticoids
| inflammation
133
aldosterone
released from the adrenal cortex
type of mineralcorticoid
plays a role in salt and water homeostasis. Reabsorbs salt and water from the collecting duct and the distal convoluted tubule of the nephron.
134
what are ACE inhibitors?
block the conversion of angiotensin I to angiotensin II which inhibits vasoconstriction and allows the heart to not work as hard (treatment of high blood pressure and congestive heart failure).
135
what are the functions of the corticosteroids?
adrenal cortex
salt (mineralcorticoids)
sugar (glucocorticoids)
sex (cortical sex hormones)
136
cortisol is for _____ stress responses while catecholamines are for ____ stress responses
long term
| fast
137
the pancreas has both ___ and ___ functions
endocrine and exocrine
138
exocrine means
into digestive tract/for that purpose
139
the hormone producing cells of the pancreas are grouped together into _____ which contain what types of cells
islets of Langerhans
| alpha, beta, and delta cells
140
alpha cells of the pancreas produce ____
glucagon
141
beta cells of the pancreas produce ___
insulin
142
delta cells of the pancreas produce ____
somatostatin
143
what is often reported by diabetics?
polyuria and polydipsia.
144
what are counterregulatory hormones?
raise blood glucose levels: growth hormone, glucocorticoids, epinephrine, glucagon.
145
oxytocin and antidiuretic hormone are ____ hormones
peptide
146
ANP is a ____ hormone
peptide
147
reabsorption of something from the kidneys means ______
it is taken out of the kidneys (not excreted) but reabsorbed into the blood stream
148
gallactorhea
is a milky nipple discharge unrelated to the normal milk production of breast-feeding.
caused by prolactin overabundance
149
all of the hormones released from the adrenal cortex are _____ hormones
steroid
150
somatostatin release is triggered by ______
high blood glucose or amino acids or certain gastrointestinal hormones.
151
for hormones, the suffix "in" indicates ______
peptide hormone or amino acid derived hormone
