Noradrenaline Synthesis, Storage Release Flashcards
Sympathetic system dominates in
________ or ________ (“____ or _____”)
situations
emergency or stressful
fight-or-flight
Sympathetic Promotes responses that prepare body for _________ activity
strenuous physical
Parasympathetic system dominates in _______,______ (______ and ____) situations
quiet, relaxed (“rest-and-digest”)
Parasympathetic Promotes body-maintenance activities such as digestion
T/F
T
_______ is released at all preganglionic terminals of ANS
Ach
_______ is released at most sympathetic postganglionic terminals
Noradrenaline
_______ is released at all parasympathetic postganglionic terminals
Ach
_______ is released at sympathetic postganglionic terminals at sweat glands and some blood vessels in skeletal muscle
Ach
_______ is released at terminals of efferent neurons supplying skeletal muscle ( motor neuron)
Ach
Noradrenaline is released at the adrenal medulla
T/F
T
Effect of sympathetic stimulation on the heart
In terms of rate and contraction
Increased rate and Increased contraction of the whole heart
Effect of parasympathetic stimulation on the heart
In terms of rate and contraction
Decreased rate and decreased force of contraction on the atria only
Effect of sympathetic stimulation on blood vessels
Constriction
Effect of parasympathetic stimulation on blood vessels
Dilation of the blood vessels supplying the penis and clitoris only
Effect of sympathetic stimulation on lungs
In terms of airway and mucus secretions
Dilation of bronchioles (airway)
Inhibition of mucus secretion
Effect of parasympathetic stimulation on lungs
In terms of airway and mucus secretions
Constriction of bronchioles (airway)
Stimulation of mucus secretion
Effect of parasympathetic stimulation on digestive tract
In terms of motility, sphincters, and digestive secretion
Increased motility
Relaxation of sphincters
Stimulation of digestive secretions
Effect of sympathetic stimulation on digestive tract
In terms of motility, sphincters, and digestive secretion
Decreased motility
Contraction of sphincters
Inhibition of digestive secretions
Effect of sympathetic stimulation on urinary bladder
Relaxation
Effect of parasympathetic stimulation on urinary bladder
Contraction
Effect of sympathetic stimulation on eyes
In terms of the pupil and adjusting the eye
Dilation of pupil
Adjustment of eye for far vision
Effect of parasympathetic stimulation on eyes
In terms of the pupil and adjusting the eye
Constriction of pupil
Adjustment of eye for near vision
Effect of parasympathetic stimulation on liver’s glycogen stores
Nothing
Effect of sympathetic stimulation on liver’s glycogen stores
Glycogenolysis
Gluconeogenesis
Effect of parasympathetic stimulation on adipose cells’ fat stores
Nothing
Effect of sympathetic stimulation on adipose cells’ fat stores
Lipolysis
Effect of parasympathetic stimulation on brain
None
Effect of sympathetic stimulation on brain
Increased alertness
Effect of sympathetic stimulation on genitals
In males and females
Ejaculation and orgasmic contractions in males
orgasmic contractions in females
Effect of parasympathetic stimulation on genitals
In males and females
Erection
Effect of sympathetic stimulation on adrenal medulla
Stimulation of epinephrine and norepinephrine secretion
Effect of parasympathetic stimulation on adrenal medulla
None
Effect of sympathetic stimulation on endocrine pancreas
In terms of insulin secretion and glucagon secretion
Inhibit insulin secretion
Stimulate glucagon secretion
Effect of parasympathetic stimulation on endocrine pancreas
In terms of insulin secretion and glucagon secretion
Stimulate both insulin and glucagon secretion
Effect of sympathetic stimulation on salivary glands
Stimulation of small volume of thick saliva rich in mucus
Effect of parasympathetic stimulation on salivary glands
Stimulation of large volume of watery saliva rich in enzymes
Effect of parasympathetic stimulation on sweat glands
Stimulation of secretion by some sweat glands
Effect of sympathetic stimulation on sweat glands
Stimulation of secretion by most sweat glands
Effect of sympathetic stimulation on exocrine pancreas
In terms of pancreatic exocrine secretion
Inhibition of pancreatic exocrine secretion
Effect of parasympathetic stimulation on exocrine pancreas
In terms of pancreatic exocrine secretion
Stimulation of pancreatic exocrine secretion
Exceptions to general rule of dual reciprocal innervation by the two branches of autonomic nervous system
– Most arterioles and veins receive only ______ nerve fibers
– Most sweat glands are innervated only by ________ nerves
– Salivary glands are innervated by _______ nerves
sympathetic
sympathetic
both ANS divisions
arteries
capillaries
Arterioles
Veins
Which ones are Innervated And which ones aren’t
Not Innervated
Not Innervated
Innervated
Innervated
Adrenal Cortex
• Produces _____ hormones
•________-processing enzymes in sER, inner mitochondria membrane
steroid
Cholesterol
Parenchymal cells of the adrenal cortex can produce _____ de novo
– Mainly by ______ of ——-
– Cholesterol-rich ______ in cytoplasm
cholesterol
endocytosis; LDL
lipid droplets
Capsule of adrenal cortex has _______ layers
List them
3 cell
Zona glomerulosa
Zona fasciculus
Zona Reticularis
Adrenal Medulla
• Modified ______ ganglion
– Release _______ to ECF
sympathetic
catecholamines
Adrenal medulla give axons to it’s target
T/F
F
no axons at targets
Cells of the adrenal medulla = _________
pheochromocytes
Cells of the adrenal medulla
Axon or Axonless
secretory or non secretory cells
Axonless
Secretory
Cells of the Adrenal medulla
Has ___ cell subpopulations
Two
Cells of the adrenal medulla
___________ producing cells
• __________ producing cells
– Secrete products from granules to ECF by _______
Norepinephrine (noradrenaline)
Epinephrine (adrenaline)
exocytosis
Adrenal medulla is a modified part of ______ nervous system
sympathetic
An example of a Modified sympathetic ganglion that does not give rise to postganglionic fibers
Adrenal medulla
Adrenal medulla
Stimulation of preganglionic fiber prompts secretion of hormones into blood
• About ____% of hormone release is norepinephrine
• About ___% of hormone released is epinephrine (adrenaline
20
80
Difference between the structures of norepinephrine and epinephrine
Epinephrine has a methyl group that NE doesn’t
Adrenal Medulla
• Releases epinephrine and norepinephrine
– Secreted into blood by ____ of _____
exocytosis
chromaffin granules
Epi and NE
Same affinities for different adrenergic receptor
T/F
F
Vary in their affinities for the different adrenergic receptor types
Epinephrine
– Reinforces sympathetic system in mounting general systemic “________” responses
– Maintenance of ______ pressure
– Increases blood _____ and blood _____
fight-or-flight
arterial blood
glucose
fatty acids
Catecholamines
• Stimulators:_____ , elevated
sound levels, intense _____, ___ blood sugar levels
stress; elevated; light
low
Catecholamines
Synthesized from _______ to ______
L-tyrosine L-Dopa
• L-tyrosine in plasma (_____ mg/dL)
1-1.5
Catecholamines are (Passively or Actively?) transported into cells
Actively
Adrenal medulla catecholamine output approx. ___% epinephrine
80
plasma ratio is __:__ norepinephrine: epinephrine
8:2
Adrenergic receptor
• α1: excitatory or inhibitory
•β1: excitatory or inhibitory
• α2: excitatory or inhibitory
•β2: excitatory or inhibitory
excitatory
excitatory
inhibitory
inhibitory
Adrenergic receptor
• α1: NE or E?
•β1: NE or E?
• α2: NE or E?
•β2: NE or E?
NE
Equal
NE
Just E
Adrenergic receptor
Location
• α1: _____
•β1: _______
• α2:_______
•β2: _______
Most sympathetic target cells
Heart
Digestive system
Skeletal muscle; smooth muscle of some blood vessels and organs
Adrenergic receptor
Example of response generated
• α1: _____ (____)
•β1: _______
• α2:_______(_____)
•β2: _______
Generalized arteriolar vasoconstriction ; increased smooth muscle contraction
Increased rate and strength of cardiac muscle contraction
Decreased motility in digestive tract; reduced smooth muscle contraction
Decreased Smooth muscle contraction
Secretory Vesicles of catecholamines
• Active transport via _______ which are __________ pump that pump catecholamines Into _____
– pH, electrical gradient
– Antiporter
• ___________________ segments
– Related to plasma membrane _______ transporters
VMATs
ATP-driven proton; vesicle membranes
12 transmembrane helical
monoamine
Catecholamine Release from Storage Vesicles
• ACh released from preganglionic fibers binds to ______ receptors leading to _____ of _____ , causing the _____-gated ___ channels to open and there’s influx of ____
Eventually, there is ______ of secretory vesicles such as _____,______,______, and other peptides released
Nicotinic
depolarization of pheochromocytes
Ligand ; Ca2+
Ca2+
exocytosis
Chromogranins, DBH, ATP
Actions of Catecholamines
• Fetus
– Fetal production (mostly _____) through fetal zone
norepi
• Circulating catecholamines reach most tissues
T/F
Mention any exception, with reason
T
BUT cannot penetrate because of BBB and Fetus
Catecholamines are important in intrauterine life
T/F
With reason
T
for cardiovascular responses
fetal production of Catecholamines is (small or Large?)
Large
Placenta expresses catecholamine degrading enzymes
T/F
T
Placental norepinephrine transporter
– Delivers circulating fetal catechol’s for _____
Degradation
Catecholamine Elimination
•____% associated with _____ protein
50-60; albumin
Catecholamines are (short or long?) lived molecules
Short
Life span of catecholamines is about _____ to ____
10 sec to 1.7 min
Catecholamine elimination
Elimination
– At synapse, the ___ near sympathetic neurons contains the catecholamines and there is _____ into _______ where they could either _______ via ____ OR Become ______ by ______
ISF
Reuptake; nerve terminals
Reenter vesicles ; VMAT
degraded; monoamine oxidase
MAOIs bind to ____ for inhibition
MAO
– In target cells, catecholamines are Degraded by ________
Catechol-O-MethylTransferase (COMT)
Catecholamines elimination
-__% is directly filtered into urine
5
MAO
– found In ______________
– Substrates also include _____,____
–it _____ amino groups into ______
– Further ____ by (specific or nonspecific?) _____
– Ultimate production of ______
outer mitochondria membrane
serotonin, histamine
Oxidizes; aldehydes
oxidation; non specific ; aldehyde deHase
dihydroxymandelic acid (DOMA)
For MAO, we have ____ and _____ subtypes
MAO-A
MAO-B
COMT –for (intra or extra?) neuronal degradation
– Uses _________ as _____ donor
Extra
S-Adenosyl methionine (SAM); methyl
COMT is not Important to circulating catecholamines
T/F
F
It is
The final conjugation of catecholamines in its elimination
- ———,——— in liver, gut
– Excretion through ____
Sulfate, glucuronate
urine
AMPT inhibits the conversion of ______ to ______
Tyrosine
DOPA
AMPT??
Alpha methyl para tyrosine
Disulphiram inhibits the conversion of ____ to _____
Dopamine to norepinephrine
Reserpine serves to inhibit ________
Noradrenaline vesicular reuptake
Tetrabenezine serves to inhibit ________
Noradrenaline vesicular reuptake
Imipramine serves to inhibit _______
Noradrenaline neuronal reuptake
Iproniazid is a ________
MAO inhibitor
Sympathoadrenal functions
1) Catecholamines regulate intermediary metabolism.
-Carbohydrate metabolism (β-AR ): blood glucose levels ___eased
-Fat metabolism (β-AR ): activates a _____, ______ lipase that metabolizes fats into ______ and _____
- Protein metabolism (β-AR ): ___eases the release of amino acids from skeletal muscle
Incr
hormone-sensitive lipase; triglyceride
fatty acids (FFAs) and glycerol
Decr
Sympathoadrenal functions
The sympathetic nervous system regulates thermogenesis.
-______thermogenesis:
-______(____) thermogenesis: occurs in _____ tissue in the rat
Shivering
Nonshivering; chemical
brown adipose
Nonshivering thermogenesis is defined as an increase in _____ (above the basal metabolism) that is not associated with _____. It occurs mainly through metabolism in _____ and to a lesser degree also in ______,______,_____ and _____
metabolic heat production
muscle activity
brown fat
skeletal muscle, liver, brain, and white fat.
Adrenergic receptors mediate cardiovascular responses to stress
T/F
T
Physiological implications of sympathoadrenal catecholamines
• General: activates _______ mechanisms.
– Mobilizes _____, ____ blood
fight/flight
Energy
Redistributes
Physiological implications of sympathoadrenal catecholamines
• Opposes ________ system
– Promotes digestion, storage of energy
– BUT distinct target cell pop’ns within organs
parasympathetic
Physiological implications of sympathoadrenal catecholamines
• Many targets; overall
– ____ease cardiac output, blood pressure
– Broncho______ leading to matched _____ w/ increased _____
– Blood diverted from ____ and _____ to ___
• Retain blood to _____
– Mobilize fuel from energy stores
Incr
dilation; perfusion; ventilation
viscera and skin; muscle
brain
Catecholamines synthesis
From phenylalanine to _______ by ______
To _________ by _________
To ________ by ________
To _______ by ______
To ________ by _______
Tyrosine; phenylalanine hydroxylase
Dopa; Tyrosine hydroxylase
Dopamine ; Dopa decarboxylase
Norepinephrine;Dopamine -beta-hydroxylase
Epinephrine; Phenyethanamine N-methyl transferase
Tyrosine Hydroxylase
• aids the Ring hydroxylation from ______ to _____
• Contains ___;_______ cofactor
• Activity regulated by _____ nerves
– Get phosphorylation ____,_____, and _____ kinases
Tyrosine; L-DOPA
Fe2+; tetrahydrobiopterin
preganglionic
PKA, PKC and
calmodulin-dependent
Long-term stimulation of tyrosine hydroxylase leads to ____ of _____ and _____ but Increased L-DOPA leads to _____
upregulation of transcription and translation
product inhibition
DOPA Decarboxylase
(L-aromatic amino acid
decarboxylase)
•________ cofactor
• End product in ____
Pyridoxal phosphate
CNS
DOPA Decarboxylase
(Aka ____________ decarboxylase)
L-aromatic amino acid
DOPA Decarboxylase’s end product is Stored in secretory vesicles
T/F
T
Dopamine is Stored in secretory vesicles and Enter by (active or passive?) transport using ______
Active
MVATs
VMATs = _______
Vesicular MonoAmine Transporters
Dopamine Hydroxylase (DBH)
It aids a _____ hydroxylation to
________
• Contains ___; ____ cofactor
• reaction occurs within ______
• End product in _____ nerves, most central catecholaminergic neural
tracts
side chain; noradrenaline
Cu ; Vit C
secretory vesicle
sympathetic
Phenylethanolamine N-MethylTransferase (PNMT)
•aids ________ of _____ to ______
• Methyl donor =___________
N-methylation; norepinephrine ; epinephrine
S-Adenosylmethionine
Phenylethanolamine N-MethylTransferase (PNMT)
• Cytoplasmic –Norepinephrine leaves
vesicle by (active or Passive?) transport , (with or against?) concentration gradient
–Epinephrine must then reenter secretory vesicle by (active or Passive?) transport
Passive ; with
Active
PNMT
• Expression depends on (high or low?) (local or foreign ?) _____ From ______ through ____ system
• Transcriptional activation of PNMT gene through _____-activated _____ receptor and also other ______ factors
High; foreign ; cortisol; adrenal cortex; sinusoid
ligand; glucocorticoid
transcription
PNMT
activity is inhibited by glucocorticoid
T/F
F
Stimulated
PNMT
• increase in Adrenaline leads to ________
product feedback inhibition
PNMT
Besides the adrenal gland is Also found in ______,_____,______
kidney, lung, pancreas
nonspecific NMT Contributes to peripheral conversion norepinephrine to epinephrine
T/F
T
Norepinephrine +COMT=
The. + MAO=
Normetanephrine
Vanillylmandelic acid
Amphetamines (stimulate or inhibit?) release of NE
Stimulate
_______ and ——— inhibit the release of NE from the neuron
Guanethidine
Bretylium
Cocaine prevents the _______ of norepinephrine
Reuptake
Tricyclic antidepressants prevents the _______ of norepinephrine
Reuptake
What organ lacks alpha 1 receptor besides the heart
Lungs and bronchioles
kidney
What organ lacks beta 2 receptor besides the heart
Pilomotor organs
Sweat glands
Skin
Beta2- ____ of git
Alpha 1- ______ of git
wall
sphincter
In blood vessels, alpha 1 mediates vaso____ while beta2 mediates vaso_____
Constriction
Dilation
