Chapter 16 endocrine system Flashcards
1
Q
an organ that produces and secretes hormones
A
Endocrine gland
2
Q
hormones are released into
A
surrounding tissue fluid (“ductless” glands), taken into the blood, and distributed throughout the body
3
Q
pituitary, pineal, thyroid, parathyroids, adrenals, thymus, pancreas, and gonads are what kind of gland
A
Endocrine Glands
4
Q
The hypothalamus has what kind of functions
A
both neural and endocrine functions
5
Q
chemical messengers secreted by cells into the extracellular fluids
A
Hormones
6
Q
functions of hormones
A
Regulate metabolic functions of other cells (target cells)
o Have lag times ranging from seconds to hours
o Tend to have prolonged effects
7
Q
most hormones belong to this class,
A
Protein (amino acid) based
8
Q
synthesized from the amino acid tyrosine)
A
Amines (e.g., thyroxine
9
Q
short chains of amino acids
A
Peptides
10
Q
long chains of amino acids
A
Proteins
11
Q
the only steroids made by endocrine organs
A
Gonadal and adrenocortical hormones
12
Q
Steroids: Made from
A
cholesterol
13
Q
Hormones produce one or more of the following cellular changes in target cells
A
Alter plasma membrane permeability (may lead to muscle fiber depolarization and contraction) Stimulate protein synthesis Activate or deactivate enzymes Induce secretory activity Stimulate mitosis
14
Q
Hormones act at
A
receptors
15
Q
all amino acid based hormones except thyroid hormone is what kind of hormone recptor
A
Water soluble (hydrophilic) hormones
16
Q
Water soluble (hydrophilic) hormones act on ? receptor that can/cannot enter cells and act through ? messangers
A
plasma
cannot
2nd
17
Q
cAMP second messenger system
A
Adenylate cyclase
18
Q
steroid and thyroid hormones is what kind of hormone receptor
A
Lipid soluble (hydrophobic) hormones
19
Q
act on receptors inside the cell, directly activates genes
A
Direct gene activation
20
Q
The precise response depends on the type of
A
target cell and receptor molecules present
21
Q
Most protein-based hormones can’t cross the
A
plasma membrane, so they work through 2nd messengers
22
Q
A hormone binds to a receptor on the? that leads to ?
A
outer surface of the cell membrane
which leads to a cascade of chemical events, eventually to produce the hormone effect on the target cell
23
Q
(cAMP)Hormone (first messenger) binds to a receptor on the outer membrane surface, which leads to
A
a G protein binding to the receptor on the inner membrane surface
24
Q
(cAMP) once the G protein binds to the receptor it is then
A
activated
25
(cAMP)Activated G protein then converts ?
adenylate cyclase into its active form
26
(cAMP)Adenylate cyclase catalyzes a reaction to
generate cAMP (second messenger) from ATP
27
cAMP activates ? that lead to?
protein kinases
| leading to the cellular effects of the hormone
28
This enzymatic cascade has a large amplification effect
cyclic AMP (cAMP) – a 2nd messenger
29
Activated adenylate cyclase generates large numbers of
cAMP, which activates several protein kinase molecules
30
A single protein kinase can catalyze
hundreds of reactions
31
Steroids are what kind of soluables
lipids soluble, hydrophobic
32
an diffuse through cell membranes and into cells and the nucleu
steriods
33
the cell has a specific intracellular receptor for the steroid in its cytoplasm or nucleus, the steroid binds to the? to create?
receptor to create a hormone-receptor complex
34
The hormone-receptor complex binds with a
DNA-associated receptor protein
35
The associated gene in the DNA is ? by the ?
“turned on” by the hormone receptor binding with DNA
36
(protein synthesis) does what
Leads to gene expression
37
The protein may act as an ?
| to catalyze a chemical reaction associated with the hormone effect, or the protein may be part of a?
enzyme
| part of a secretion that is part of the hormone effect
38
Hormone release is stimulated in three ways that are
humoral, neural, and hormonal stimuli
39
In most instances, these control mechanisms ( humoral, neural, and hormonal stimuli) rely on
negative feedback to control homeostatic levels.
40
Humoral Control secretion of hormones occurs in response to changes in
ion or nutrient concentration
41
Example of Humoral Control
Regulation of Blood Calcium Ions:
42
Example of Humoral Control
| When blood Ca++ concentrations get too low:
stimulates the parathyroid glands to secrete PTH (parathyroid hormone)
PTH stimulates osteoclast activity, which causes blood Ca++ concentrations to rise
43
Example of Humoral Control
| When blood Ca++ levels reach their set point is release?
PTH release is inhibited
44
nerve fibers conduct impulses, which stimulates the release of hormones from axonal nerve fibers or cells that are innervated by the nerve fiber
Neural Control
45
Examples of Neural Control:
| Sympathetic nervous system fibers stimulate the
adrenal medulla to secrete epinephrine and norepinephrine during periods of acute stress
46
Examples of Neural Control:
Posterior pituitary hormones (ADH & oxytocin) are released by? whose cell bodies are in the?and whose axons extend into the?
neurosecretory cells
hypothalamus of the brain
posterior lobe of the pituitary
47
release of hormones in response to hormones produced by other endocrine organs
Hormonal Control
48
Hormonal Control involves what kind of hormone
tropic hormones
49
example of hormonal control
A hormone that regulate anterior pituitary hormone release and many anterior pituitary hormones stimulate other endocrine organs
Hypothalamic releasing and inhibiting hormones
50
example of hormonal control
hormone released by the anterior pituitary targets follicular cells of the thyroid gland, which respond by increasing their release of thyroxines
Thyroid stimulating hormone (TSH)
51
two-lobed organ that secretes eight major hormones, connected to the hypothalamus by the infundibulum
Pituitary gland
52
posterior lobe (neural tissue), connected via hypothalamic-hypophyseal tract
Neurohypophysis
53
posterior lobe (neural tissue Neurohypophysis Receives, stores, and releases hormones from the
hypothalamus
54
anterior lobe, made up of glandular tissue, connected via hypophyseal portal system
Synthesizes and secretes a number of hormones
adenohypophysis
55
Primary capillary plexus and secondary capillary plexus; capillary beds
are interconnected by hypophyseal portal veins
Capillary Plexuses
56
Anterior pituitary hormones: list
Growth Hormone (GH)
Thyroid Stimulating Hormone (TSH) Adrenocorticotropic Hormone (ACTH) Follicle Stimulating Hormone (FSH)
Luteinizing Hormone (LH)
Prolactin (PRL)
57
Posterior pituitary hormones list
```
Oxytocin
Antidiuretic Hormone (ADH) also known as vasopression
```
58
makes many hormones and releases them in response to activity of the
hypothalamus (releasing factors secreted by neurosecretory cells).
Anterior pituitary
59
is actually an outgrowth of the embryonic brain and continues to function as
nervous tissue throughout life
The posterior pituitary
60
their source gland/hormone
| Pineal Gland
melatonin
61
their source gland/hormone
| Alpha cells of pancreatic islets
glucagon
62
their source gland/hormone
| Thyroid
thyroxine
63
their source gland/hormone
| Hypothalamus
antidiutic hormone
64
their source gland/hormone
| Anterior pituitary
growth hormone
65
with their target tissue/organ.
| uterus
oxytocin
66
with their target tissue/organ.
| anterior pituitary
growth hormone releasing hormone
67
with their target tissue/organ.
| most cells of the body
T3 and T4
68
with their target tissue/organ.
kidney
adrenal cortex – zona glomerulosa
aldosterone
69
with their target tissue/organ.
| ovaries and testes
luteinizing hormone
70
the cells that produce testosterone
Interstitial cell
71
During the first phase of the ovarian cycle FSH stimulates the growth of what structure
follicle
72
The surge of luteinizing hormone approximately midway through the ovarian cycle causes
ovulation
73
An increased level of estrogen promotes the growth of the functional layer of the endometrium during what phase of the menstrual cycle
Proliferative
74
The corpus luteum primarily produces what hormone
progestrone
75
Assume a steroid hormone has reached a target cell. Select the choice representing the correct sequence of events.
1. hormone diffuses through the cell membrane
2. hormone molecules bind to receptor molecules within the cell
3. hormone-receptor complex migrates and binds to DNA
4. genes become activated
5. mRNA transcript is built/protein synthesis follows
76
Hormones that act on plasma membrane receptors are
Hydrophilic
77
Hormone release caused by altered levels of critical ions or nutrients is caused by
Humoral stimuli
78
Is part of the infundibulum
The hypothalamic-hypophyseal tract
79
Hormones are transported from the hypothalamus to anterior pituitary gland through the
Hypophyseal portal system
80
What is the primary effect of thyroid hormones, T3 and T4:
Increases metabolic rate
81
The parafollicular cells of the thyroid produce
Calcitonin
82
Grave’s disease is due to:
Hypersecretion of thyroid hormone and increases metabolic rate
83
is a parathyroid gland mechanism to maintain adequate levels of blood calcium
Activation of osteoclasts
Increase calcium ion reabsorption by the kidneys
Increase in intestinal absorption of calcium ions
84
Mineralocorticoid is to aldosterone as glucocorticoid is to
Cortisol
85
Epinephrine is produced by the
adrenal medulla
86
A disorder caused by hypersecretion of growth hormone in a child is called
Gigantism
87
A disorder caused by hypersecretion of growth hormone in a adults is called
Acromegaly
88
Release of follicle stimulating hormone is caused by:
Hormonal stimuli
89
The target tissue of adrenocorticotropic hormone is:
Adrenal Cortex
90
Hypersecretion of growth hormone after the epiphyseal plates closes causes a disorder known as:
acromegaly
91
Endocrine cells that increase hormone secretion in response to other hormones are controlled by:
hormonal stimuli.
92
With which gland does the hypothalamus have a close anatomical and physiological relationship?
pituitary gland
93
What does thyroid-stimulating hormone (TSH) target?
thyroid gland
94
When growth hormone levels are low, which hormone stimulates its release?
growth hormone-releasing hormone (GHRH)
95
Aldosterone regulates
extracellular sodium and potassium ion levels.
96
Excess cortisol could result in:
high blood glucose levels.
97
Glucosuria and ketonuria are characteristic of:
diabetes mellitus.
98
The majority of amino acid hormones exert their effects through:
Second messengers
99
The ability of a specific tissue or organ to respond to the presence of a hormone is dependent on:
The presence of specific receptors on the cells of the target tissue or organ
100
Growth hormone indirectly mediates many of its long term growth enhancing effects through
Insulin-like growth factors (IGFs)
101
Which of the following is not an action of glucagon?
Transport of glucose into most body cells
102
From superficial to deep, the three layers of the adrenal cortex are:
zona glomerulosa, zona fasciculata, zona reticularis.
103
anterior pituitary produces what kind of hormone
Adrenocorticotropic hormone
104
most cells of the body
thyroid hormone
105
ovaries and testes
follicle stimulating hormone
106
mammary glands
prolactin
107
kidney tubules
antidiuretic hormone
108
What stimulates melatonin production
light and dark cycles
109
Hormones only affect certain types of cells known as target cells T/F
true
110
What type of hormone can cross the plasma membrane to bind to a receptor in the cytosol or nucleus?
hydrophobic hormones
111
What hormones are released from the adrenal medulla?
catecholamines
112
What does thyrotropin-releasing hormone target?
anterior pituitary (adenohypophysis)
113
What is the primary effect of antidiuretic hormone (ADH, or vasopressin)?
water retention by the kidneys
114
What connects the hypothalamus and pituitary gland?
infundibulum
115
Where are releasing and inhibiting hormones made?
hypothalmus
116
Upon binding to a receptor to form a hormone-receptor complex, steroid hormones may cause:
an increase in protein synthesis
117
What element is necessary for the production of triiodothyronine (T3) and thyroxine (T4)?
iodine
118
Excess cortisol could result in:
high blood glucose levels
119
What hormones are made by the posterior pituitary?
none
120
What stimulates the release of parathyroid hormone (PTH
hypocalcemia
121
What hormones are produced by zona glomerulosa of the adrenal cortex?
mineralocorticoids
