Endocrine System Flashcards
(125 cards)
1
Q
Communication in the endocrine system =
A
maintaining homeostasis
2
Q
What are the two components of intercellular communication?
A
- target/recipient
- messenger molecule/sender/signaler
3
Q
Receptors are typically what kind of molecules?
A
proteins
4
Q
What are the four types of communication?
A
- direct
- paracrines
- synaptic communication
- endocrine
5
Q
How does direct communication transmit signals?
A
through gap junctions
6
Q
What kind of signals are sent through direct communication?
A
ions, small solutes, lipid-soluble materials
7
Q
What is the distribution (take place) of signals done by direct communication?
A
limited to adjacent cells of the same type that are interconnected
8
Q
How does paracrine communication transmit signals?
A
through extracellular/interstitial fluid
9
Q
What kind of signals are sent through paracrine communication?
A
paracrines
10
Q
What is the distribution of signals done by paracrine communication?
A
primarily limited to local areas where paracrine concentrations are high
11
Q
How does synaptic communication transmit signals?
A
across synapses
12
Q
What kind of signals are sent through synaptic communication?
A
neurotransmitters
13
Q
What is the distribution of signals done by synaptic communication?
A
limited to very specific areas; target cells must have appropriate receptors
14
Q
How does endocrine communication transmit signals?
A
through the bloodstream/vessels
15
Q
What kind of signals are sent through endocrine communication?
A
hormones
16
Q
What is the distribution of signals done by endocrine communication?
A
target/receptors cells are mainly in other distant tissues and organs and must have appropriate receptors
17
Q
The endocrine system is composed of what?
A
glands and groups of specialized cells
18
Q
What are the types of endocrine system glands?
A
endocrine and exocrine
19
Q
How do exocrine glands function?
A
exocrine glands release their substances through the squeezing or contracting of a duct onto the surface of the skin.
20
Q
How do endocrine glands function?
A
endocrine glands are solid mass of cells that release hormones through exocytosis into the bloodstream
21
Q
What are the possible effects once a hormone reaches its target/receptor?
A
- Stimulate protein synthesis
- Increase/decrease rate of synthesis
- Alter activity of existing protein
22
Q
Define a hormone
A
A chemical substance that has an action on a particular cell type.
23
Q
What is the action of a hormone?
A
Bind to a receptor at the target cell.
24
Q
When the number of receptors vary with time the receptor site may undergo what?
A
Up-regulation or down-regulation
25
Up-regulation does what to the sensitivity to messenger molecules?
increases sensitivity
26
Down-regulation does what to the sensitivity to messenger molecules?
deceases sensitivity
27
What are the three classifications of hormones?
- amino acids
- peptides
- lipid derivatives
28
What are the two amino acids that act as hormones?
- Tyrosine
- Tryptophan
29
How is the target of a hormone determined?
the target will have receptors for that hormone
30
Tryosine makes up what kinds of hormones?
- thyroid hormones
- Catecholamines
31
What are examples of catecholamines?
epinephrine, norepinephrine, and dopamine
32
Tryptophan is a precursor to what hormone?
melatonin
33
What is a peptide?
a chain of amino acids
34
What kind of peptides act as hormones?
glycoproteins and short polypeptides
35
What are examples of glycoproteins?
TSH, LH, FSH
36
What are examples of short polypeptides?
ADH, growth hormone
37
What kinds of lipid derivatives act as hormones?
Eicosanoids and sterioid hormones
38
What are examples of eicosanoids?
prostaglandins and leukotrienes
39
Steroid hormones are made up of what?
cholesterol
40
What are examples of steroid hormones?
estrogen, testosterone, and corticosteroids
41
How does one classify hormones?
- number of receptors
- chemical classification
- receptor location
- response of target
- regulation of secretion
42
Where are receptors located?
- on the cell surface/membrane or
- intracellular :cytosol or nucleus
43
What happens when a hormone binds to a receptor on the surface of the cell?
it triggers the activation of the G protein inside the cell
44
What does the G protein produce?
produces a second messenger molecule
45
What are examples of G proteins/2nd messenger?
cAMP, cGMP, Ca+2
46
What does the activation of a G protein cause?
Set a cascade of reactions in motion
47
Set a cascade of reactions in motion aka....
amplification
48
What is the overall effect of binding to a receptor on the cell surface?
Alter activity of enzymes already present
49
Receptors attached to the cell membrane/surface have hormones that are what?
water-soluble
50
What are examples of the water-soluble hormones?
Catecholamines, peptides, eicosanoids
51
Receptors attached to the cytosol or nucleus (intracellular) have hormones that are what?
lipid-soluble
52
What are examples of the lipid-soluble hormones?
Thyroid hormones and steroids
53
What are the effects of a hormone binding to a receptor located intracellularly?
Stimulate synthesis of new proteins or alter the rate of protein synthesis (increase/decrease)
54
The response of the target/receptor is dependent on what?
- a. presence/absence of receptors: Number of receptors
b. hormone concentration/amount of hormone
c. influences exerted by other hormones
55
What are the three kinds of effects exerted by other hormones?
i. permissive effect:
ii. synergistic effect:
iii. antagonistic effects:
56
Permissive effect
a hormone cannot exert its full effects without the presence of another hormone
57
Synergistic effect
the effect in which two or more hormones work together to produce a combined effect, that cannot be observed by a single hormone alone
58
Antagonistic effect
when a hormone opposes or reverses the effect of another hormone.
59
What regulates the secretion of hormones?
- neural stimuli
- humoral stimuli/chemical changes in the body fluids
- negative feedback
- other hormones
60
What is the location of the hypothalamus?
in the brain below the thalamus
61
What two things does the hypothalamus control?
the autonomic nervous system and the secretion of regulatory hormones
62
What five things is the hypothalamus responsible for regulating?
- thirst
- hunger
- body temperature
- sexual behavior
- defensive reactions (fear/anger)
63
How many total hormones does the hypothalamus produce?
nine
64
The hypothalamus has seven hormones responsible for what?
affecting the release of hormones from the anterior(front) pituitary
65
The hypothalamus has two hormones stored where?
stored in and released by the posterior(back) pituitary gland
66
How is the pituitary gland connected to the hypothalamus?
by the infundibulum
67
What are the two parts of the pituitary gland?
the anterior and posterior pituitary gland
68
What unique feature does the anterior pituitary gland have?
Hypophyseal portal system
69
Hypophyseal portal system is what?
- group of blood vessels
- 2 sets of capillaries in series
70
What is the hypophyseal portal system responsible for?
Direct delivery of hypothalamic hormones from hypothalamus to anterior pituitary gland
71
What seven hormones are produced by the pituitary gland?
- prolactin
- melanocyte-stimulating hormone
- human growth hormone (somatotropin)
- thyroid-stimulating hormone
- follicle stimulating hormone
- luteinizing hormone
- adrenocotropin hormone
72
What conditions are associated with discrepancies in the human growth hormone?
- gigantism
- dwarfism
- acromegaly
73
Does the posterior pituitary gland produce its own hormones?
no, they are stored there by the hypothalamus
74
What two hormones are stored in the posterior pituitary gland?
oxytocin and Antidiuretic hormone (ADH)/
vasopressin
75
What is the target of prolactin?
the mammary glands
76
What is the target of melanocyte-stimulating hormone?
we don't know; still being studied
77
What is the target of human growth hormone (somatotropin)?
all cells/musculo-skeletal system
78
What is the target of thyroid-stimulating hormone?
thyroid/gland
79
What is the target of follicle stimulating hormone and luteinizing hormone?
gonads (ovaries/testis)
80
What is the target of adrenocotropin hormone?
adrenal glands
81
What is the target of oxytocin?
the smooth muscle of the reproductive system
82
What is the target of Antidiuretic hormone (ADH)?
the kidneys
83
Where is the pineal gland located?
in the diencephalon
84
What hormone does the pineal gland produce?
melatonin
85
What is the target of melatonin?
not specific/specified
86
What is the location of the thyroid gland?
in the throat in front of the larynx
87
What hormones are released by the thyroid gland?
1) T3 &Thyroxine (T4)
2) calcitonin
88
What is the target of T3 &Thyroxine (T4)
most tissues
89
What is the target of calcitonin?
bones
90
What is the function of T3 &Thyroxine (T4)?
regulating metabolism
91
Calcitonin does what to the Ca2+ in bone, intestines and kidneys?
Bone: Increases Ca2+ deposition
Intestines: decreases Ca2+ uptake
Kidneys: increases Ca2+ removal
92
What is the location of the parathyroid gland?
posterior surface of thyroid
93
What hormone does the parathyroid gland release?
parathyroid hormone
94
What is the function of the parathyroid hormone?
increases blood calcium
95
Parathyroid hormone does what to the Ca2+ in bone, intestines and kidneys?
Bone: Increases Ca2+ release
Intestines: increases Ca2+ uptake
Kidneys: increases Ca2+ retention
96
What is the location of the thymus?
in the throat just below the larynx
97
What hormone does the thymus release?
thymosin
98
What is the function of thymosin?
responsible for the development/maturation of lymphocytes
99
What is the location of the adrenal glands?
above each kidney
100
What are the two sections of the adrenal glands?
adrenal cortex and adrenal medulla
101
adrenal cortex =
outside
102
adrenal medulla =
inside
103
What three hormones are produced by the adrenal cortex?
- Mineralocorticoids
- Glucocorticoids (stress
hormones)
- Androgens
104
Mineralcorticoids function
influencing salt and water balance
105
What is an example of a Mineralocorticoid?
aldosterone
106
Glucocorticoids =
hormones that regulate stress on the body
107
Androgens =
sex hormones/puberty
108
What hormones are produced by the adrenal medulla?
Epinephrine and norepinephrine
109
Epinephrine and norepinephrine function
responsible for the body's fight or flight response and the mobilization of glucose for ATP
production
110
The pancreas has what kind of functions?
endocrine and exocrine
111
What is the exocrine function of the pancreas?
secrets digestive enzymes
112
What is the endocrine function of the pancreas?
produces four horomes
113
What four hormones does the pancreas produce?
- glucagon
- insulin
- somatostatin
- pancreatic peptide
114
Glucagon function
increases blood sugar/glucose levels
115
What cells produce glucagon?
alpha cells
116
Insulin function
stimulates cells to take up glucose; lowers blood sugar
117
Glucagon and insulin indirectly regulate what?
how much energy is available for the body to use
118
What cells produce insulin?
beta cells
119
Somatostatin function
growth hormone-inhibiting hormone
120
What cells produce Somatostatin?
delta cells
121
Pancreatic peptide function
regulates pancreatic secretions/digestive enzymes
122
What cells produce Pancreatic peptide?
F cells
123
What do gonads produce?
sex hormones and gametes
124
What hormones are produced by the ovaries?
- estrogen
- progesterone
- inhibitin
- relaxin
125
What is the male sex hormone?
testosterone
