ADRENAL MEDULLA

heart

• ANS

• involutary control

• cardiac rate and output

Blood vessel smooth muscle

• ANS

• involutary control

• blood pressure control

adrenal medulla

• ANS

• involutary control

• secretion of catecholamines

smooth muscle in visceral organs:

• ANS

• involutary control

• GU and GI tract motility

paraganglia

where do the sympathetic preganglionic nerves terminate?

neuroendocrine

what do paraganglia contain which are similar to adrenal medulla cells?

mediastinum

where else can paraganglia be found?

aorta

where else can paraganglia be found?

abdomen

where else can paraganglia be found?

celiac axis

where else can paraganglia be found?

adrenal glands

where else can paraganglia be found?

renal medullae

where else can paraganglia be found?

adjacent to the bladder

where else can paraganglia be found?

sympathogonia

• embryology

• SNS arises from neural crest cells

sympathetic chain

• embryology

• 5th week AOG

• migrate from spinal ganglia to form _

dorsal

• embryology

• 5th week AOG

• sympathetic chain is posterior to _ aorta

anterior

• embryology

• 5th week AOG

• sympathetic chain is _ to remaining ganglia

fetal adrenal cortex

• embryology

• 6th week AOG

• cells migrate along central vein and enter the _

8

• embryology

• 6th week AOG

• Medulla is detectable by week _

pheochromoblasts

• embryology

• 6th week AOG

• Medulla is composed of sympathogonia and _

adult

• embryology

• 6th month

• very small and amorphous at birth but will resemble _ form

central

• anatomy

• In humans: occupies a _ position in the widest part

15

• anatomy

• mass = 1000mg (_% of both adrenal glands)

cortical

there is no clear demarcation between cortex and medulla, so there is possible presence of _ cells in medulla

pheochromocytes

• histology

• chromaffin cells

• contain proteins, lipids, ATP, neuropeptide Y, enkephalins, proopiomelanocortin, catecholamines

20

• histology

• chromaffin cells

• _% of vesicles contain catecholamines

vesicles

• histology

• chromaffin cells

• cytoplasm: large numbers of _

NE

• histology

• chromaffin cells

• _ vesicles are darker than E

preganglionic fibers

• adrenal gland: nerve supply

• innervated by _ of SNS

Ach

• adrenal gland: nerve supply

• releases _

enkephalins

• adrenal gland: nerve supply

• releases _

without

• adrenal gland: nerve supply

• arise from a plexus in the capsule of the adrenal gland _ synapsing

no

does the adrenal gland branch out into cortex?

pheochromocytes

• adrenal gland: nerve supply

• most fibers end by synapsing with _

stress

the adrenal medulla helps maintain homeostasis during _

catecholamines

main secretory products of the adrenal medulla which aid in stress response

increases

stress, physical exercise, and low blood glucose levels _ activity of the sympathetic nervous system, which _ epinephrine and norepinephrine secretion from the adrenal medulla

hypothalamus

• regulation of adrenal medulla secretions 1

• stress, physical activity, and low blood glucose levels act as stimuli to the _, resulting in increased sympathetic nervous system activity

SNS

• regulation of adrenal medulla secretions 1

• stress, physical activity, and low blood glucose levels result in increased _ activity

ANS

• regulation of adrenal medulla secretions 2

• an increased frequency of action potentials conducted through the sympathetic division of the _ stimulates the adrenal medulla

epinephrine

• regulation of adrenal medulla secretions 2

• the ANS stimulates the adrenal medulla to secrete _ into the circulatory system

norepinephrine

• regulation of adrenal medulla secretions 2

• the ANS stimulates the adrenal medulla to secrete _ into the circulatory system

increased glucose release

• epinephrine and norepinephrine effect in the target tissues

• _ from the liver into the blood

increased fatty acid release

• epinephrine and norepinephrine effect in the target tissues

• _ from adipose tissue into the blood

increased heart rate

• epinephrine and norepinephrine effect in the target tissues

• _

decreased blood flow

• epinephrine and norepinephrine effect in the target tissues

• _ through blood vessels of most internal organs

increased blood flow

• epinephrine and norepinephrine effect in the target tissues

• _ through blood vessels of skeletal muscle and the heart

increased blood pressure

• epinephrine and norepinephrine effect in the target tissues

• _

decreased visceral organ

• epinephrine and norepinephrine effect in the target tissues

• _ function

increased metabolic rate

• epinephrine and norepinephrine effect in the target tissues

• _ of skeletal muscles

norepinephrine

• biosynthesis of chromaffin cells

• catecholamine

• direct arterial supply to the medulla

15-20

percentage of the medulla composed of norepinephrine

CNS

norepinephrine is found primarily in the _

sympathetic paraganglia

norepinephrine is found primarily in the _

epinephrine

• biosynthesis of chromaffin cells

• catecholamine

• blood supply comes from the adrenocortical cells

corticosteroids

increased levels of _ induces PNMT

epinephrine

main hormone in adrenal medulla

not

• storage

• _ truly stored in intracellular vesicles

dynamic equilibrium

• storage

• exist in _ between the vesicle and surrounding cytoplasm

80

• storage

• epinephrine: _% of stored catecholamines

different

storage vesicles for epinephrine and norepinephrine are _

metanephrines

• metabolism of catecholamines

• 50% _

• COMT

• most tissues

VMA

• metabolism of catecholamines

• 35% _

• MAO

conjugated catecholamines

• metabolism of catecholamines

• 10% _

norepinephrine sulfate

• metabolism of catecholamines

• gastrointestinal cells: norepinephrine → _

5%

how much percent of catecholamines are free?

urine

how are catecholamines excreted?

G-protein coupled receptors

catecholamine receptors are activated by norepinephrine and epinephrine

fight or flight

catecholamine receptors mediate _ response

vasoconstriction

effect of alpha 1 receptors

increased peripheral resistance

effect of alpha 1 receptors

increased blood pressure

effect of alpha 1 receptors

mydriasis

effect of alpha 1 receptors

increased closure of internal bladder sphincter

effect of alpha 1 receptors

alpha 1 agonists

• alpha 1 receptors

• treatment of nasal congestion and ophthalmic hyperemia

alpha 1 blockers

• alpha 1 receptors

• hypertension treatment

• treatment of benign prostatic hyperplasia

alpha 2 agonists

• alpha 2 receptors

• hypertension treatment

alpha 2 blockers

• alpha 2 receptors

• yohimbine

heart

• beta 1 receptor

• increased chronotropy and inotropy

• Increased AV-node conduction velocity

renal juxtaglomerular cells

• beta 1 receptor

• increased renin release

bronchial smooth muscle

• beta 2 receptor

• bronchodilation

uterine muscle

• beta 2 receptor

• uterine relaxation (tocolysis)

bladder detrusor muscle

• beta 2 receptor

• relaxation

eye ciliar muscle

• beta 2 receptor

• relaxation

Gl tract

• beta 2 receptor

• decreased motility

liver

• beta 2 receptor

• Increased glucose metabolism, lipolysis

smooth muscle

• beta 2 receptor

• relaxation

decreased heart rate

effect of beta blockers on the heart

decreased contraction force

effect of beta blockers on the heart

decreased AV conduction rate

effect of beta blockers on the heart

propanolol

• beta blocker example

• inderal

atenolol

• beta blocker example

• tenormin

bradycardia

side effect of beta blockers

lethargy

side effect of beta blockers

GI disturbance

side effect of beta blockers

CHF

side effect of beta blockers

decreased blood pressure

side effect of beta blockers

depression

side effect of beta blockers

pheochromocytomas

chromaffin tumors arising from medulla

unilateral

direction of pheochromocytomas