unit 1 Flashcards
how many neurons in ANS?
2
where does the preg of ANS go from?
cell body in brain stem or spinal cord
axon goes to ganglion (outside CNS) and synapses
where does postg go from?
cell body in ganglion
extends to target
is preg myelinated or unmyelinated?
myelinated
is postg myelinated or unmyelinated?
unmyelinated
what types of neurotransmitters are in ANS?
ACh and NE
what type of effect does ANS have on target cells?
excitatory or inhibitory
where do pathways begin in symp?
thoracic and lumbar regions of spinal cord axon goes
where are symp preg cell bodies located?
lateral horns (and near gray matter of spinal cord)
how do symp preg axons exit spinal cord?
via spinal nerves
nerve cords can ascend and descend
pattern from preg to target
1- preg cell body in lateral horn
2- myelinated axons pass out ventral/anterior root
3- axon travels short distance in spinal nerve
4- axon leaves nerve and travels to symp ganglion via white communicating ramus
5- synapse with postg in ganglion
6- postg axon leaves ganglion via gray communicating ramus
7- postg returns to spinal nerve
8- postg goes to target
3 courses preg may follow after entering symp chain
1- spinal nerve route
2- sympathetic nerve route
3- sphlanic nerve route
symp spinal nerve route
preg end in ganglion they enter and synapse immediately with postg
postg exit ganglion via gray ramus, go to spinal cord, and travel to target
done by most sweat glands, arrector muscles, and blood vessels
symp nerve route
preg travel up/down chain and synapse at other levels
postg leave via sympathetic nerves that reach heart, lungs, esophagus, thoracic blood vessels
symp sphlanic nerve route
preg pass through chain without synapsing and continue to sphlanic nerves along vertebral column
sphlanic nerves lead to second set of ganglia called collateral ganglia and synapse there
para preg cell bodies location
cranium (brain) and sacrum region of spinal cord
where are terminal ganglia?
in or near target organization
does para have more or less neural divergence than symp?
less
and less selective in its stimulation of targets
what are the 4 cranial nerves that fibers leave brain stem through?
1- oculomotor nerve CN III
2- facial nerve CN VII
3- glossopharyngeal nerve CN IX
4- vagus nerve CN X
what types of neurotransmitters and receptors does para have?
preg neurotransmitter: ACh
postg receptor: nicotinic
postg neurotransmitter: ACh
target receptor: muscarinic
what types of neurotransmitters and receptors do most symp have?
preg neurotransmitter: ACh
postg receptor: nicotinic
postg neurotransmitter: NE
target receptor: adrenergic alpha or beta
cholinergic receptors
receive ACh
types: nicotinic and muscarinic
adrenergic receptors
receive NE
types: alpha and beta
3 places to find symp postg cell bodies
symp chain ganglia
collateral ganglia
adrenal medulla
symp above diaphragm
postg fibers begin in chain ganglia collateral ganglia
symp below diaphragm
postg fibers begin in collateral ganglia
are nicotinic receptors stimulatory, inhibitory, or either?
stimulatory
are muscarinic receptors stimulatory, inhibitory, or either?
either
alpha receptors
a1- widespread, generally stimulatory
a2- generally inhibitory, presynaptic
beta receptors
b1- heart, kidneys, liver, adipose
b2- smooth muscle tissue (blood vessels, lungs, bronchi, intestine)
b3- adipose tissue
symp with postg neurotransmitter ACh and target muscarinic receptors is found where?
sweat gland cells
paracrine mechanism
chemical released from cell and target cell is close to releasing cell
autocrine mechanism
chemical released from a cell and goes to receptors on same exact cell
up-regulation
increase in number and sensitivity of target cell
happens when hormone is scarce
down-regulation
decrease in number and sensitivity of receptors at target
makes sure there is not an excessive or dangerous response
examples of chemicals that are both neurotransmitters and hormones
norepinephrine
dopamine
antidiuretic hormone
what is the pitu made of and how is it connected to hypo?
made of glandular tissue
linked to hypo by hypophyseal portal system
hypophyseal portal system
1- artery to primary capillaries in hypo
2- primary capillaries to portal vein/venule
3- portal vein/venule to secondary capillaries in anterior
4- secondary capillaries to vein
how does hypo control anterior?
by secreting hormones into primary capillaries and hormones diffusing out secondary capillaries
what is posterior made of and how is it connected to hypo?
made of nervous/brain tissue (not a true gland)
stalk from hypo is part of posterior
how are posterior hormones made?
made by neuroendocrine cells in hypo
made in cell bodies and move down axons in stalk to posterior bulb
hormones stored as nerve endings until nerve signal triggers release
HYPO hormones that regulate anterior
TRH thyrotropin releasing hormone
CRH corticotropin releasing hormone
GHRH growth hormone releasing hormone
GnRH gonadotropin releasing hormone
PIH prolactin
somatostatin
The Cool Girl Goes Prowling Sometimes
TRH thyrotropin releasing hormone
promotores secretion of TSH thyroid stimulating hormone (and PRL prolactin)
CRH corticotropin releasing hormone
promotes secretion of ACTH adrenocorticotropic hormone
GnRH gonadotropin releasing hormone
promotes excretion of FSH follicle stimulating hormone and LH lutenizing hormone
PIH prolactin inhibiting hormone
inhibits secretion of PRL prolactin
PIH is DOPAMINE
somatostatin/GHIH growth hormone inhibiting hormone
inhibits secretion of GH growth hormone and TSH thyroid stimulating hormone
posterior pitu hormones
OT oxytocin
ADH antidiuretic hormone
ADH antidiuretic hormone
target: kidneys
effects: water retention
OT oxytocin
target: uterus, mammary glands
effects: labor contractions, milk release; possibly ejaculation, sperm transport, sexual affection, mother-infant bonding
anterior pitu hormones
FSH follicle stimulating hormone
LH lutenizing hormone
TSH thyroid stimulating hormone
ACTH adrenocorticotropic hormone
PRL prolactin
GH growth hormone
FSH follicle stimulating hormone
target: ovaries, testes
effects: female- growth of ovarian follicles and secretion of estrogen; male- sperm production
gonadotropic cells
LH lutenizing hormone
target: ovaries, testes
effects: female- ovulation, maintenance of corpus luteum; male- testosterone secretion
gonadotropic cells
TSH thyroid stimulating hormone
target: thyroid gland
effects: growth of thyroid, secretion of thyroid hormone
thyrotropic cells
ACTH adrenocorticotropic hormone
target: adrenal cortex
effects: growth of adrenal cortex, secretion of glucocorticoids
corticotropic cells
PRL prolactin
target: mammary glands
effects: milk synthesis
prolactin cells
GH growth hormone
target: bone, muscle, cartilage, liver, fat
effects: widespread tissue growth, especially in stated tissues
somatotropic cells
list process from hypo to ultimate effect
1- hypo secretes releasing hormone
2- induces pitu to secrete hormone
3- pitu hormone targets different endo gland
4- endo gland secretes hormone with its own effect
what type of feedback system does the endo system have?
negative feedback inhibition
list negative feedback inhibition process
1- pitu stimulates another endo gland to secrete hormone
2- hormone feeds back to pitu OR hypo and inhibits further secretion of pitu AND hypo hormone
anterior pitu 2 cell types
acidophils
basophils
what do acidophils produce?
PRL/PL prolactin (from lactotrophs)
GH growth hormone (from somatotrophs)
what do basophils produce?
FSH follicle stimulating hormone and LH lutenizing hormone (from gonadotrophs)
ACTH adrenocorticotropic hormone (from corticotrophs)
TSH thyroid stimulating hormone (from thyrotrophs)
lipid soluble hormones
steroid hormones (aldosterone)
thyroid hormones (T3 triiodothyronine)
water soluble hormones
amines (NE)
peptides and proteins (oxytocin)
eicosanoids (leukotriene LTB4)
water soluble hormone process
1- hormone binds to receptor and activates G protein
2- G protein activates adenulate cyclase enzyme
3- adenylate cyclase produces cAMP
4- cAMP activates protein kinases enzyme
5- protein kinase adds phosphate group to protein/enzyme
6- activated enzymes cause metabolic effects
single hormone can activate lots of cAMP (second messenger)
net result of water soluble hormone mechanism
phosphorylation proteins
when does biochemical cascade of water soluble hormone mechanism stop?
when cAMP is broken down by phosphodiatrase
lipid soluble hormone mechanism
1- hormone diffuses across plasma membrane; was transported through blood via water soluble protein
2- binds either to cytosol or nucleus
3- activated receptor-hormone complex interacts directly with DNA and alters gene experession
4- initiated transcription and mRNA produced leaves nucleus
5- mRNA translated into new proteins
