Endocrine System Flashcards
1
Q
Glands that secrete substances through openings (ducts) onto your body surfaces
A
exocrine glands
i.e sweat glands, skin oil glands, earwax glands, breast milk glands
2
Q
Name at least two examples of endocrine glands that end in “gland”
A
- pituitary gland
- thyroid gland
- parathyroid glands
3
Q
Name three endocrine glands that don’t end in “gland”
A
- Hypothalamus
- adrenal cortex
- medulla
- pancreas
- gonads
4
Q
Name 2 organs that have both exocrine and endocrine functions
A
- Pancreas (releases digestive enzymes via ducts & hormones i.e insulin and glucagon)
- Liver (releases bile via ducts & secretes angiotensin hormone)
5
Q
When a cell secretes a signaling moleculethat acts on a nearby cell
A
paracrine signaling
heavily invlved in differentiation in embryonic development
para = next to
6
Q
when a cell releases a molecule that acts on itself
A
autocrine signaling
auto = Self
7
Q
Signaling that requires cells to be in close contact with each other
A
juxtacrine signaling
juxta - think just next to
8
Q
A cell that releases secretions via exocytosis
A
merocrine cells
9
Q
Cells that release secretions via membrane-bound vesicles
A
apocrine cell
10
Q
Results from rupture of the plasma membrae, destroying the cell and relesing its product from the cytoplasm into the lumen
i.e sebaceous glands of the skin
A
holocrine secretion
11
Q
Hormones can be classified according to their chemical structure as ____ hormones, ____ hormones, or ____ derivatives
A
Peptide hormones, steroid hormones, or amino acid derivatices
12
Q
True or False
Peptide hormones can diffuse freely in the blood, but cannot cross the lipid bilayer membrane of their target cells
A
True
due to their hydrophillic nature
Thus, they have to exert their effects via receptors embedded on the plasma membrane surfce
13
Q
Peptide or Steroid Hormone?
Which type of hormone is associated with signal cascades, amplificiaction, and rapid, intense, short-term impacts on cellular functions?
A
Peptide hormones
due to second messenger systems (i.e cAMP) resulting in signal cascades
14
Q
The image below describes what process?
A
Second-messenger systems
in peptide hormones
15
Q
Steroid or Peptide hormones?
Which hormone category requires transport proteins to reach their targets?
A
Steroid hormones
their hydrophobic nature prevents them from being soluble in bloodstream
16
Q
Albumin and sex-hormone binding globulin are examples of …
A
transport proteins
17
Q
Peptide or Steroid?
____ hormones can diffuse directly through the lipid bilayer membrane and enter their target cells
A
Steroid hormones
due to their hydrophobicity and small size
18
Q
Peptide or Steroid hormone?
Works by modulating gene transcription
receptor-hormone complex binds directly to DNA to affect transcription
A
Steroid hormones
associated with a slower-onset and longer-lasting physiological response
19
Q
Name at least 4 steroid hormones
A
- Estradiol
- Testosterone
- Aldosterone
- Cortisol
Note: steroid hormones have 4-ring structure!!!
20
Q
peptide or steroid
____ are first translated as preprohormones, then (in the rough ER) modified into prohormones. Prohormones are processed in the Golgi apparatus, then are cleaved by endo____ases and may be modified by the addition of carbohydrates to generate the final, active form of the hormone. The hormones are then packaged into vescicels to be releasex via exocytosis
A
Peptide hormones
21
Q
Peptide or Steroid?
Synthezides from cholesterol in the smooth ER and *diffuse directly through the cell membrane *
A
Steroid
22
Q
Peptide or Steroid (function)
Regulation of other hormones
A
Peptide
+ short term responses
23
Q
Peptide or Steroid (function)
Sex, sugar, and salt
The 3 S’s!
A
Steroid
salt = mineralocorticoids
sugar = glucocorticoids
steroid hormoes affects the 3 S’s
24
Q
Which amino acid derived hormones are lipid soluble and behave much like steroid hormones?
A
T3 and T4
25
Which amino acid derived hormones are water-soluble and act similar to peptide hormones, exerting powerful, short term responses?
Epinephrine and norephinephrine
26
# True or False
Water-soluble amino acid derived hormones are either water soluble or lipid-soluble
False
| Some are both! i.e Melatonin
27
# Name the hormone category
any of a class of hormones from the anterior pituitary gland that affect the secretion of other endocrine glands
Tropic hormones
| tropic hormones --> target cells --> other hormones
28
hormones that directly stimulate target cells to induce effects
nontropic hormones
| nontropc hormones --> target cells --> physiological effects
29
the hypothalamus-anterior pituitary-adrenal cortex (HPA) axis is an example of a ____ loop
Negative feedback loop
30
What is the tropic hormone that the hypothalamus releases in the HPA axis?
Corticotropin-releasing hormone (CRH)
31
Which hormone acts on the anterior pituitary gland and stimulates the release of adrenocorticotropic hormone (ACTH)
Corticotropin-releasing hormone (CRH)
32
This hormone is tropic and acts on the adrenal cortex, causing the release of cortisol
adrenocorticotropic hormone (ACTH)
33
What is the physiological function of the negative feedback loop of the HPA axis?
The negative feedback exerted by cortisol on CRH and ACTH inhibits further cortisol production, which prevents levels of cortisol from getting out of control and inducing an overly intense long-term stress response
34
Name one hormone involved in the **positive feedback loop** of labor?
oxytocin
## Footnote
uterine contactions stimulate the release of more oxytocin, which stimulates stronger contractions, and the process continues to amplify itself until childbirth
35
Which type of feedback loops have a distinct physiological endpoint?
Positive feedbak loops
## Footnote
without an endpoint, these loops would spiral out of control
36
the branch of biology (specifically of physiology) which studies the interaction between the nervous system and the endocrine system; i.e. how the brain regulates the hormonal activity in the body.
Neuroendocrinology
37
In general, when thinking about endocrine regulation or the regulation of any biochemical pathway, you should (probably) be thinking about ____ feedback
Negative
## Footnote
You should hesitate choosing positive feedback on the MCAT! Positive feedback loops are rare.
38
The two main hormones associated with glucose regulation are
Insulin and glucagon
## Footnote
growth hormone (GH), epinephrine, and cortisol also affect glucose levels
39
____ is a peptide hormone released by the pancreas in response to high glucose levels
Insulin
| function: reduce blood glucose levels by promoting the transport
## Footnote
function: reduce blood glucose levels by promoting the transport of glucose into the cells via insulin receptors
40
promotes the transport glucose into the cells
insulin receptors
## Footnote
these receptors then activate **glucose transporters** and increases the transport of glucose into the cell
41
What can 3 options do cells have with increased glucose uptake?
1. use glucose immediately via **glycolysis**
2. storage as **glycogen** in muscle and liver
3. adiptocytes can store downstream byproducts of glucose metabolism as **triglycerides**
## Footnote
insulin upregualtes all of these proceses, as well as protein synthesis
42
the technical term for a fat cell
adiptocytes
43
what hormone reduces the rate of glyconeogenesis, lipolysis, and fatty acid oxidation, and protein breakdown
Insulin
44
What hormone is released by the pancreas when there are **suboptimal** levels of glucose?
glucagon
## Footnote
glucose is gone
45
Which hormone *promotes* glycogenolysis and gluconeogenesis in liver cells?
glucagon
46
the biochemical pathway in which glycogen breaks down into glucose-1-phosphate and glucose when blood glucose levels drop
glycogenolysis
47
the synthesis of glucose from non-carbohydrate sources like lactic acid, glycerol, amino acids and occurs in liver and kidneys.
gluconeogenesis
48
graphically describe the relationships between blood glucose levels, insulin, and glycogen
49
which hormone released by the adrenal cortex increases blood glucose levels in response to stress?
Cortisol
50
which hormone released by the adrenal medulla plays a major role in the fight-or-flight response and increases blood glucose levels
epinephrine
51
state where adrenal hormones are secreted from
52
what hormone is released in response to physical stress and growth, but also increases blood glucose levels?
Growth hormone (GH)
53
# List 3+ things
the physiological functions of calcium include:
* Bone density
* NT release
* muscle contractions
* second messenger within the cell
54
What are the three primary hormones that perform Calcium level maintencance
1. parathyroid hormone (PTH)
2. calcitonin
3. calcitriol
55
# Name the hormone
secreted in response to **low blood calcium levels**; elevates Ca levels by stimulating increased activity of osteoclasts. *Increases calcium **absorption*** from the intestine indirectly by **promoting the activation of vitamin D**, decreases calcium storage in the bones, and in the kidneys promotes calcium retention
parathyroid hormone (PTH)
56
cells that break down bone, releasing calcium into the bloodstream
osteoclasts
57
# Name the hormone
released by C cells of thyroid gland and ***inhibits* osteoclast** activity; **decreases plasma calcium levels** by increasing calcium storage in the bones and increasing calcium excretion from the body
calcitonin
58
cells that help build bone and therefore reduce blood Ca levelsby storing Ca in bone tissue
osteoblasts
59
plays a crucial role in regulation of serum calcium and phosphate levels
vitamin D
60
inactive form of vitamin D3, which is processed to form calcitriol and is the biologically active form that affects calcium and phosphate levels
cholecalciferol
61
form of vitamin D that increases serum calcium levels through the absorption of Ca2+ from the GI tract
calcitriol
62
How does a lack of fluid manifest physiologically?
| think of fluid as *blood volume* and *blood osmolarity*
- **reduced blood volume** (relatively little water is present in the blood plasma)
- **reduced BP** (consequence of reduced blood volume; less liquid to exert pressure againt walls of blood vessels)
63
How does a surplus of fluid manifest physiologically?
| think of fluid as blood volume and blood osmolarity
* increased blood volume
* increased blood pressure
64
What two hormones primarily respond to low fluid levels by increasing fluid retention?
1. aldosterone
2. antidiuretic hormone (ADH)
65
ADH is also known as....
vasopressin
66
Vasopressin is also known as....
antidiuretic hormone (ADH)
67
How does aldosterone increase fluid retention?
* *increasing Na+ *absorption in the _distal convoluted tubule_ and _collecting duct_ of the **nephron**
* increasing excretion of potassium and hydrogen ions in urine
| does not affect osmolarity bc Na+ reabsorption drives H2O absorption
68
How does ADH increase fluid retention?
increases the *permeabilitiy* of the **collecting duct** to water, thereby increasing *water absorption*
| ADH ↓ the osmolarity of blood by ↑ amount of H2O present
69
ADH is released by the ____ in response to **low blood pressure** and **high plasma osmolarity**
posterior pituitary gland
70
ADH is released by the posterior pituitary gland in response to ____ and ____
1. low blood pressure
2. high plasma osmolarity
71
aldosterone is released by the ____ in response to **low blood pressure**, but is regulated by the renin-angiotensin-aldosterone system
adrenal cortex
72
aldosterone is regulated by the ____
renin-angiotensin-aldosterone system (RAAS)
## Footnote
[link](https://youtu.be/6EUSEa6Lw8g)
73
aldosterone is released in response to ...
low blood pressure
74
in response to low BP, the ____ cells of the kidney release the enzyme renin
juxtaglomerular
| aka **granular cells**; synthesize, store, and secrete the enzyme renin
75
Renin converts **angiotensinogen** into ____
angiotensin 1
76
in the lungs and in blood vessels in the body, angiotensin-converting enzyme converts angiotensin 1 to ____
angiotensin 2
77
____ is the immediate stimulus of aldosterone release
angiotensin 2
78
____ restores BP, which in turn inhibits the release of renin (another example of of a negative feedback loop)
aldosterone
79
hormone used to combat excess blood volume; it's realeased in response to high blood volume and decreased Na+ reabsorption in the kidney as well as increasing glomerular filration rate (GFR) and inhibiting aldosterone release
atrial natriuretic peptide ANP
80
____ is the hormone associated with long-term responses to stress
cortisol
81
cortisol is in what class of hormones?
glucocorticoids
82
cortisol is released from the ....
adrenal cortex
83
cortisol's two main effects are:
1. **increasing blood glucose** levels by stimulating gluconeogenesis and acting as an insulin antagonist, facilitating insulin resistance
2. **reduces inflammation** by inhibiting certain inflammatory immune responses
84
short term resposes to stress (fight flight or freeze) are assoicated with what two hormones?
Epinephrine and norephinephrine
| these two hormones are derived from tyrosine
85
norephinephrine, epinephrine, and dopamine are neurohormones that fall under which category?
catecholoamines
86
A type of neurohormone important in stress responses. High levels cause high blood pressure which can lead to headaches, sweating, pounding of the heart, pain in the chest, and anxiety
catecholoamines
87
a chemical that is made by nerve cells and used to send signals to other cells
neurohormone
88
epiephrine and norephinephrine are released from the
adrenal medulla
89
Epinephrine and norephinephrine increase blood glucose levels via what three mechanisms?
1. glucogenolysis
2. gluconeogenesis
3. glucagon release
90
name 5 physiological stress responses that epinephrine and norepinephrine are responsible for
1. increased HR
2. respiratory rate
3. lipolysis
4. vasodilation of blood vessels supplying skeletal muscles
5. vasoconstriction of most other blood vessels
91
norephinephrine is a ____ when it is used to relay signals between neurons in the sympathetic NS, but is a ____ when it is released into the blood to induce systemic affects in other organ systems
neurotransmitter; hormone
92
what thyroid hormones regulate the metabolic rate?
T3 and T4
93
what thyroid hormones regulate the metabolic rate?
T3 and T4
94
T3 and T4 are released in response to which hormone?
thyroid stimulating hormone (TSH)
95
insufficient levels of thyroid hormones (often caused by iodine sufficiencies) leads to ....
**hypo**thyroidism
96
_steroid hormone_ released from the **testes** involved in reprouduction and secondary sex characteristics
testosterone
97
_steroid hormone_ released from the **ovaries** involved in reprouduction and secondary sex characteristics
estrogen
| stimulated by FSH
98
steroid hormone that prepares the uterus for implantation and maintaines it througout pregnancy
progesterone
99
the release of estrogen and testosterone is stimulated by
lutenizing hormone (LH)
100
____ is a peptide hormne secreted in response to low levels of testosterone and estrogen
LH
| lutenizing hormone
101
LH is released in response to which hormone?
gonadotropin releasing hormone (GnRH)
102
a surge in which hormone leads to ovulation?
LH
103
a peptide hormone released in response to GnRH that promotes the growth of ovarian follicles in females, and spermatogenesis in males. Stimulates the ovaries to release estrogen
follicile-stimulating hormone (FSH)
104
GnRH triggers the anterior pituitary to release what two peptide hormones?
LH and FSH
105
what hormone maintains te corpus luteum and induces it to secrete progesterone during the first trimester?
human chronic gonadotropin (hCG)
106
# Name. the hormone
Released in response to reduced levels of dopamine tha occur after the placenta is expelled during childbirth. Acts on the mammary glands to enable milk production
prolactin
107
# True or False
TSH is a tropic hormone
True. It stimulates the release of other hormones (T3 and T4) therefore it is a tropic hormone
108
adrenocorticotropic hormone (ACTH) stimulates the release of which hormones?
cortisol and androgens
| note: ACTH is released by the anterior pituitary
109
# True or False
LH is a tropic hormone
True. It stimulates the release of other hormones - estrogen and testosterone
110
# True or False
FSH is not a tropic hormone
False. A tropic hormone is any hormone that that work on other endocrine glands. FSH acts on the ovaries in women, stimulating the maturation of ovarian follicle for the release of an egg during ovulation. In men, it stimulates the testes to produce sperm. It also _causes the ovaries to release the hormone, estrogen_
111
GnRH is secreted from the ....
hypothalamus
112
what hormone is secreted from the hypothalamus and stimulates the release of TSH?
thyrotropin releasing hormone (TRH)
113
# True or False
CRF and CRH are different hormones
False. Corticotropin releasing *factor* (CRF) is also called corticotropin releasing *hormone* (CRH)
114
oxytocin's two main functions are:
1. promotion of uterine contractions leading up to childbirth
2. milk ejection resulting from the contraction of smooth muscle tissues in the milk ducts
## Footnote
also promotes social bonding
115
corticosteroids can be broken down into which three categories?
**glucocorticoids** (i.e cortisol)
**mineralcorticoids** (i.e aldosterone)
and **cortical sex hormones** (i.e testosterone and estrogen)
116
# Name the hormone
slows down the rate of digestie hormone secretion in response to high levels of glucose and amino acids. Also inhibits secretion of insulin and glucagon
somatostatin
117
hormone important for the development and maturation of T cells
thymosin
118
Caused by increasingly severe insulin resistance
Type 2 diabetes
119
Caused by an autoimmune reaction that destroys the beta cells of the pancreas (which secrete insulin)
Type 1 diabetes
