Unit 2 Exam Flashcards
(159 cards)
1
Q
What are hormones?
A
Chemical messengers = controls and regulates the activity of certain cells or organs
2
Q
What is the function of neurotransmitters?
A
released by axon terminals of neurons → the synaptic junctions and act locally to control nerve cell functions
3
Q
What is the function of endocrine hormones?
A
secreted by glands/specialized cells → released into circulating blood to act on target cells at another part of body
4
Q
What is the function of neuroendocrine hormones?
A
secreted by neurons → released into circulating blood to act on target cells at another part of body
5
Q
What are paracrines?
A
secreted by cells of one tissue into ECF → affect different tissue of the same organ
6
Q
What are autocrines?
A
secreted by cells into ECF → affects same cell type
7
Q
What are cytokines?
A
peptides secreted by cells into ECF
- acts as autocrines, paracrines, or endocrine hormones
8
Q
Where is norepinephrine produced?
A
adrenal medulla of adrenal gland
9
Q
What kind of chemical messenger is norepinephrine?
A
neurotransmitter
10
Q
What neurotransmitter do somatic motor neurons release?
A
acetylcholine
11
Q
What kind of effects (stimulatory or inhibitory) do neurons of the somatic nervous system have?
A
always simulatory
12
Q
In the autonomic nervous system, what neurotransmitter do preganglionic fibers always release?
A
acetylcholine
13
Q
In the autonomic nervous system what neurotransmitters do post-ganglionic fibers release?
A
norepinephrine
acetylcholine
14
Q
What kind of effects (stimulatory or inhibitory) do neurons of the autonomic nervous system have?
A
both stimulatory or inhibitory depending on type of receptor
15
Q
Which nervous system (somatic or autonomic) is heavily myelinated?
A
somatic nervous system
16
Q
What is the effector organ of the somatic nervous system?
A
skeletal muscles
17
Q
How many neurons does it take to reach the effector organ in the somatic nervous system?
A
1 neuron
18
Q
How many neurons does it take to reach the effector organ in the autonomic nervous system?
A
2 neurons (pre-ganglionic and post-ganglionic)
19
Q
What are the effector organs of the autonomic nervous system
A
smooth muscle
cardiac muscle
glands
20
Q
What are the 2 branches of the Autonomic Nervous system?
A
parasympathetic
sympathetic
21
Q
What neurotransmitter does the Parasympathetic Nervous System release?
A
acetylcholine
22
Q
What neurotransmitter does the Sympathetic Nervous System release?
A
norepinephrine
23
Q
What type of nerve fibers are the pre-ganglionic neurons of the autonomic nervous system made out of?
A
Type B
24
Q
What type of tissue are glands made out of?
A
epithelia
25
What is a gland?
one or more cells that makes and secretes an aqueous fluid
26
What are the 2 things that glands are classified by?
- site of product release
- relative number of cells forming the gland (unicellular or multicellular)
27
What are the 2 different glands?
endocrine
exocrine
28
What is an endocrine gland?
**internally** secreting directly into the blood or nearby tissue/interstitial fluid
ductless gland
29
What is an exocrine gland?
*externally* secreting through a duct = multicellular
glands of external secretion
30
What are the 3 different ways exocrine glands secrete material?
holocrine
merocrine
apocrine
31
What are 3 examples of exocrine glands?
salivary; sweat; that in GI tract
32
What are 2 examples of unicellular exocrine glands?
globet cells and mucus
33
What are the 3 types of cell signaling that intracrine glands use?
autocrine
paracrine
endocrine
34
What is the mode of apocrine secretion of exocrine glands?
glands lose portion of cell membrane to secrete hormones
35
What is the mode of merocrine secretion of exocrine glands?
vesicle and exocytosis
36
What is the mode of holocrine secretion of exocrine glands?
whole secretory cell ruptures
37
What are the 4 precursors from which hormones can be made from?
fatty acids
amino acids
peptides
steroids
38
What is the mode of intracrine cell signaling with endocrine glands?
cell makes hormones that will act within itself
39
What are the 6 ways hormones control body functions?
- reproduction
- growth and development
- mobilization of body defenses
- maintenance of electrolyte, water, and nutrient balance
- regulates cellular metabolism
- regulates energy balance
40
What are the 3 general classes of hormones?
- proteins/polypeptides
- steroids
- derivatives of tyrosine amino acid
41
What are 3 glands that produce protein/polypeptide hormones?
pituitary gland
pancreas
parathyroid gland
42
What are the 4 organs/glands that produce steroid hormones?
Testes
Ovaries
Placenta
Adrenal Cortex
TOPAc
43
What are the 2 glands that secrete hormones that are derived from tyrosine?
Thyroid
Adrenal Medulla
TAm
44
What are the 3 locations for the different types of hormone receptors?
Cell membrane surface
Cytoplasm
Nucleus
45
What hormones are cell membrane receptors specifically mostly for?
Protein
Peptide
Catecholamines
46
What hormones mainly bind to hormone receptors found in the cell's cytoplasm?
steroid hormones
47
What hormones bind to hormone receptors found in the nucleus?
thyroid hormones
48
In endocrine cells, where are protein/polypeptide hormones made? What are they called?
rough endoplasmic reticulum
preprohormones
49
What happens after the protein/polypeptide hormones are made?
cleaved to form smaller prohormones → Golgi apparatus → packaged into secretory vesicles
50
What happens after the prohormones are packaged?
enzymes in secretory vesicles cleave prohormones = become active hormones
51
How are protein/polypeptide hormones secreted?
secretory vesicles containing prohormones stay within cytoplasm or bound to cell membrane UNTIL secretion is needed = stimulus needed for exocytosis
52
What are the 2 ways exocytosis is stimulated when releasing protein/polypeptide hormones?
↑ cytosolic [Ca2+]
-or-
stimulation of endocrine cell surface receptor = ↑ cAMP
53
Are peptide hormones water insoluble or soluble?
Water soluble
54
What are the 5 endocrine glands?
Thyroid
Adrenal
Pineal
Pituitary
Parathyroid
55
What does nervous system modulation mean?
nervous system can override normal endocrine controls when it is in stress
56
What is an example of nervous system modulation in action?
Stress: low glucose level
Normal = endocrine system maintains blood glucose levels
Under stress: hypothalamus and sympathetic nervous system are activated to supply enough glucose
57
What are the 5 actions hormones have on target cells?
- alter plasma membrane permeability of membrane potential via ion channels
- stimulate synthesis of proteins or regulatory molecules
- activate/deactivate enzyme systems
- induce secretory activity
- stimulate mitosis
58
What are the 2 mechanisms of hormone action?
water soluble hormones (amino-acid based hormones except thyroid hormones) = receptors on cell surface → G-protein coupled receptors
lipid soluble hormones (steroid and thyroid hormones) = intracellular receptors = directly activate genes
59
What are the 6 major hormones that contribute to homeostasis?
- thyroid hormone
- cortisol
- mineralcorticoids
- vasopressin (ADH)
- parathyroid hormone
- insulin
60
How does the Thyroid Hormone contribute to homeostasis? Where is it typically found?
controls basal metabolism in most tissues
found in thyroid
61
How does Cortisol contribute to homeostasis? Where is it typically found?
- energy metabolism
- permissive action for other hormones
found in adrenal cortex
62
How do Mineralocorticoids contribute to homeostasis? Where is it typically found?
regulates plasma volume via effects on serum electrolytes
found in the adrenal cortex
63
How does Vasopressin contribute to homeostasis? Where is it typically found?
regulates plasma volume via effects on water secretion
found in the posterior pituitary
64
How does the Parathyroid Hormone contribute to homeostasis? Where is it typically found?
regulates Ca2+ and phosphorus levels
found in parathyroids
65
How does Insulin contribute to homeostasis? Where is it typically found?
regulates plasma glucose concentration
66
What are the 5 simple steps of cAMP signaling mechanism to activate protein kinases upon hormone-receptor binding?
hormone binds to receptor → G-protein activated = activates adenylate cyclase → ATP to cAMP → cAMP activates protein kinases
67
How is cAMP rapidly degraded?
by enzyme phosphodiesterase
68
What are the 15 hormones that use the cAMP second messenger system?
- Adrenocorticotropic hormone (ACTH)
- Corticotropin releasing hormone (CRH)
- angiotensin II (epithelial cells)
- calcitonin
- catecholamines
- follicle-stimulating hormone (FSH)
- glucagon
- growth-hormone-releasing hormone (GHRH)
- human chorionic growth hormone (hCG)
- luteinizing hormone (LH)
- parathyroid hormone (PTH)
- secretin
- somatostatin
- TSH (thyroid stimulating hormone)
- vasopressin
69
What is the PIP2-calcium signaling mechanism?
amino-acid based hormone binds to GPCR → activates Gq → activates phospholipase C → splits PIP2 = DAG and IP3 → DAG activates protein kinases; IP3 = release Ca2+ → Ca2+ alters enzyme/channel/or binds to calmodulin (regulatory protein)
70
What is the function of Phospholipase C?
breaks down phospholipid PIP2 (found within the membrane bilayer) into 2 secondary messengers = DAG and IP3
71
What is the function of IP3?
mobilizes Ca2+ ions from mitochondria and endoplasmic reticulum
72
How do hormones with intracellular target receptors direct gene activation? (steps)
hormone diffuses into target cell → bind to intracellular receptor → receptor-hormone complex enters nucleus → complex binds to specific DNA region = prompts transcription = mRNA = protein synthesis
73
Which hormone mechanism is faster? GPCR on cell surfaces OR intracellular target receptors?
GPCR on cell surfaces = faster
intracellular target receptors = slower
74
What are the 3 factors target cells require to be activated?
- hormone concentration in bloodstream
- relative number of receptors on/in target cell
- binding-affinity btwn hormone and receptor
75
What are the 2 mechanisms in which hormones influence the number of their receptors?
upregulation
down-regulation
76
How are hormone receptors up-regulated?
target cells form receptors in response to the hormone
77
How are hormone receptors down-regulated?
target cells lose receptors (via some degradation) in response to hormone
78
What are the 2 ways in which hormones circulate in the bloodstream?
*Free* = water soluble hormones that circulate w/o carriers
*Bound* = steroids and thyroid hormone (lipid soluble hormones) = attached to plasma proteins
79
What are the 2 things the concentration of a circulating hormone relfects?
rate of release
speed of inactivation/removal from body
80
What are the 4 ways hormones are removed from the bloodstream?
- degrading enzymes
- kidneys
- liver
- half-life
81
What controls the hormone concentration in the bloodstream?
negative feedback systems
82
What are the 3 stimuli that affect the synthesis and release of hormones?
- humoral
- neural
- hormonal
83
What is humoral stimuli?
change in ion and nutrient concentration in bloodstream = directly stimulates secretion of hormones
84
How does the body increase levels of Ca2+ in the bloodstream when levels are low?
declining blood [Ca2+] = stimulates parathyroid to secrete PTH → PTH causes [Ca2+] to increase = removes humoral stimulus = stops secretion of PTH
85
How does a neural stimuli affect the synthesis and release of hormones?
nerve fivers stimulate hormone release
ie: sympathetic nerve fibers in Sympathetic Nervous System stimulate adrenal medulla to secrete catecholamines
86
How does a hormonal stimuli affect the synthesis and release of hormones?
release of hormones in response to hormones produced by other endocrine organs
Hypothalamic hormones → stimulate release of anterior pituitary hormones → stimulate target organ hormones
87
What is the hypothalamic-pituitary-target endocrine organ feedback loop?
target organ hormones inhibit the release of the anterior pituitary hormones
88
What is another term for anterior pituitary hormones?
releasing hormone
89
How does the hypothalamus inhibit hormone secretion from anterior pituitary?
hypothalamus releases hypothalamic hormone = inhibitory hormone → inhibits anterior pituitary hormone secretion
90
Differentiate between "free" and "bound" hormones that circulate in the blood stream in terms of their "active" state.
Hormones are inactive when they are bound to a substance (ie: in secretory vesicle or carrier protein)
Hormones are active when they are no longer bound to anything
91
What is the difference between genomic and nongenomic?
genomic = hormone action directly interacts with or affects DNA
non-genomic = hormone doesn't interact/touch DNA
92
What are the typical hormones and receptors involved in non-genomic effects of hormones?
Onset of action (slow or fast)?
Resulting affect?
protein/polypeptide hormones & cell surface receptors
rapid onset of action
activation/repression of pre-existing cell proteins
93
What are the typical hormones and receptors involved in genomic effects of hormones?
Onset of action (slow or fast)?
Resulting affect?
steroid/thyroid hormone & intracellular hormone receptors
slow onset of action
gene expression and new protein synthesis
94
What are the 4 things of the autonomic nervous system that the hypothalamus controls to regulate?
- sexual behavior
- thirst/hunger
- body temperature
- defensive reactions
95
What are the 4 things that the hypothalamus and pituitary glands affect?
- growth
- development
- metabolism
- homeostasis
96
What are the 6 hormones released by the anterior pituitary gland?
- GH = growth hormone
- TSH = thyroid-stimulating hormone
- ACTH = adrenocorticotropic hormone
- FSH = follicle stimulating hormone
- LH = luteinizing hormone
- PRL = prolactin
97
What is adenohypophysis and hypophysis?
adenohypophysis = anterior pituitary portion
hypophysis = pituitary gland
98
What is the hypophyseal portal system?
blood vessels that link the hypothalamus and anterior pituitary together = allows for transport of hormones from hypothalamus to anterior pituitary
99
What are the 5 cell types that make up the anterior pituitary gland and secrete hormones?
- Corticotrophs
- Lactotrophs
- Gonadotrophs
- Somatotrophs
- Thyrotrophs
100
What hormones do Corticotrophs secrete?
adrenocorticotropic hormone (ACTH)
(corticotropin)
101
What hormones do lactotrophs secrete?
prolactin
102
What hormones do gonadotrophs secrete?
follicle stimulating hormone (FSH)
luteinizing hormone (LH)
103
What hormones do somatotrophs secrete?
human growth hormone (GH)(somatotropin)
104
What hormones do thyrotophs secrete?
thyroid stimulating hormone (thyrotopin)
105
What hormone does the hypothalamus release to stimulate the secretion of somatotropin human growth hormone (GH)?
growth hormone releasing hormone (GHRH)
106
What hormone does the hypothalamus release to stimulate the secretion of thyrotropin thyroid stimulating hormone (TSH)?
thyrotropin releasing hormone (TRH)
107
What hormone does the hypothalamus release to stimulate the secretion of gonadotropins follicle stimulating hormone (FSH) and luteinizing hormone (LH)?
gonadotropin releasing hormone (GnRH)
108
What hormone does the hypothalamus release to stimulate the secretion of corticotropin adrenocorticotropic hormone (ACTH) ?
corticotropin releasing hormone (CRH)
109
What hormone does the hypothalamus release to inhibit the secretion of somatotropin human growth hormone (GH)?
somatostatin = growth hormone inhibiting hormone (GHIH)
110
What hormone does the hypothalamus release to inhibit the secretion of prolactin?
Dopamine (prolactin-inhibiting hormone)
111
What are the hormones secreted by the hypothalamus made up of?
polypeptides/proteins
112
Which structure of the pituitary gland is glandular tissue and which one is neural tissue?
anterior pituitary = adrenohypophysis = glandular tissue = makes hormones
posterior pituitary = hypophysis = neural tissue = releases hormones (has its own blood supply)
113
What is the neurohypophysis?
comprised of the posterior pituitary and infundibulum (narrow part of hypophysis)
acts as a storage and release center for hormones made by hypothalamus
114
What hormones does the hypophysis release?
oxytocin
ADH (vasopressin)
115
What structure within the hypothalamus is oxytocin produced in?
paraventricular nucleus
116
What structure within the hypothalamus is vasopressin (ADH) produced in?
supraoptic nucleus
117
Describe the feedback loop for maintaining blood osmolality when it is higher than normal.
Trigger = ↑ blood osmolality → hypothalamus releases vasopressin = activates thirst mechanism and renal retention of H2O = ↓ blood osmolality to normal → stops hypothalamic signaling
118
Which hormone secretion stimuli does short-term stress trigger?
neural stimuli
119
Which hormone secretion stimuli does prolonged stress trigger?
hormonal stimuli
120
How does the hypophysis release hormones from the hypothalamus?
Hypothalamus sends neural signals to hypophysis = triggers exocytosis of hormones
121
Differentiate the signals the hypothalamus gives to the adenohypophysis and hyphophysis.
Anterior pituitary gland = hypothalamus signals it to start/stop producing hormones
Posterior pituitary = hypothalamus signals it to release hormones via exocytosis
122
If ADH increases water conservation in the kidney, what process does it likely impact?
aquaporins
123
Where are gonadotrophs present and what organs do they impact?
found in the adenohypophysis and impact sex organs like the ovaries
124
What is the circulatory route in the anterior pituitary to which hormones from the hypothalamus travel through? (3 steps in route)
primary capillary plexus → hypophyseal portal vein → secondary capillary plexus
125
What is the metabolic action of growth hormone (GH)?
can act on itself or on other factors
126
What cells in the parathyroid glands secrete parathyroid hormone (PTH)?
chief cells
127
What cells sense the level of [Ca2+] in the bloodstream and what structure do they have that allows them to do this?
chief cells have calcium sensing receptors that allows them to determine [Ca2+] in the bloodstream
128
What kind of receptors are calcium sensing receptors (CaSR)?
GPCR
129
How does the body decrease levels of Ca2+ in the bloodstream when levels are high?
C-cells in thyroid gland secrete calcitonin hormone → suppressies osteoclast activity in the bones = ↑ Ca2+ excreted in urine
130
What is the 25OH-D hormone? Where is it secreted? What is its function?
steroid hormone, active form of Vitamin D secreted by the kidneys
affects intestine to ↑ Ca2+ absorption from diet when low [Ca2+] in bloodstream
131
What are the 3 hormones produced by the thyroid gland?
calcitonin
T3
T4
132
What are T3 and T4 hormones made up of?
iodine-containing amino acids derived from Tyrosine
133
What happens to T3 and T4 hormones when they enter their target cells?
T4 deiodinized into T3 → → T3 binds to hormone receptor → increased metabolism in cells
134
How are thyroxine hormones T3 and T4 part of the negative feedback loop?
act on thryotropin-releasing hormone (TRH)
135
What is target cell specificity?
hormones have specific receptors that are only found on certain cells
136
What 2 hormones does the adrenal cortex secrete?
glucocorticoids (cortisol) and mineralcorticoids (aldosterone)
137
What are the 3 zones of the adrenal gland?
zona glomerulosa → zona fasiculata → zona reticularis
138
What is to note about the blood supply of the adrenal gland?
dense blood supply with about 60 arterioles entering EACH adrenal gland
139
Which part of the adrenal gland is glandular tissue and which part is nervous tissue?
glandular tissue = cortex
nervous tissue = medulla
140
What are chromaffin cells?
cells within the adrenal gland that secrete catecholamines (epinephrine and norephinephrine)
141
Which hormone does the adrenal medulla secretes the most of?
epinephrine
142
What are the 2 types of adrenergic receptors? How many subtypes are of each receptor?
Alpha adrenergic receptors = 2 subtypes
Beta adrenergic receptors = 3 subtypes
143
What molecule are steroids synthesized from?
cholesterol
144
What is the difference between C21, C19 and C18?
C21 = progesterone
C19 = androgens (derivative from progesterone, ketone group clipped off)
C18 = estrogen (derivative from androgen, methyl group clipped off)
145
What is the mechanism of action of aldosterone?
affects function of sodium efflux pump through gene expression
146
What are the 4 mechanisms does cortisol regulate?
- gluconeogenesis
- protein mobilization
- fat mobilization
- stabilizes lysosomes
147
What is the major function of aldosterone?
↑ renal Na+ reabsorption, K+ and H+ secretion
148
What is aldosterone hormone made up of?
steroids
149
What is cortisol hormone made up of?
steroids
150
What are the 6 hormones released by the hypothalamus?
- TRH = thyrotropin releasing hormone
- GHRH = growth hormone releasing hormone
- GHIH - growth hormone inhibiting hormone
- CRH = corticotropin releasing hormone
- GnRH = gonadotropin releasing hormone
- Dopamine (prolactin-inhibiting hormone)
151
What is the function of oxytocin?
stimulates milk ejection from breasts and uterine contraction
152
What is the function of luteinizing hormone?
stimulates testosterone synthesis, ovulation, corpus luteum formation, estrogen and progesterone synthesis
153
What is the function of follicle-stimulating hormone?
causes growth of ovarian follicles and sperm maturation
154
What is the function of prolactin?
promotes development of female breasts and milk secretion
155
What is the function of adrenocorticotropic hormone (ACTH)?
stimulates synthesis/secretion of adrenocortical hormones - cortisol, androgens, and aldosterone
156
What is the function of growth hormone (GH)?
stimulates protein synthesis and overall growth of most cells and tissues
157
What is the function of gonadotropin releasing hormone (GnRH)?
causes release of luteinizing hormone and follicle stimulating hormone
158
What is the function of corticotropin releasing hormone (CRH)?
causes release of adrenocorticotropic hormones
159
What is the function of thyrotropin releasing hormone (TRH)?
stimulates secretion of thyroid stimulating hormone and prolactin
