ADRENAL GLAND (Part 1) (Introduction, layers, synthesis, fate and transportation of the adrenal gland) Flashcards
Introduction, layers, synthesis, fate and transportation of the adrenal gland
the adrenal medulla, is ____% to ___% of the gland.
10% to 20%
Depending on blood flow, the adrenal medulla color ranges from ___ to ____
gray to dark red.
Surrounding the adrenal medulla is a much thicker _________,
adrenal cortex
The adrenal cortex, constituting ____% to ___ % of the gland
80% to 90%
The adrenal cortex is yellowishin color due to its high concentration of _________ and other lipids.
cholesterol
The adrenal medulla secretes __________ _____,
catecholamine hormones ( Epinephrine and Noreinephrine)
The adrenal medulla secretes catecholamine hormones, which complement the _______________ in the “fight-or-flight” reaction.
sympathetic nervous system
Catecholamine helps to respond to ____________ Situations
Emotionally Stressful
The adrenal cortex secretes ___1_____ Hormones called ____2_____
- steroid hormones
2. Corticosterioids
The adrenal cortex secretes steroid hormones (Corticosterioids) that participate in the regulation of _________ and ______ balance
mineral and energy balance
The Hormone Corticosteriod are all from steriod especially__________
CHOLESTEROL
The adrenal medulla is derived from embryonic neural crest __________
ectoderm
The adrenal cortex is derived from ___________
Mesoderm
The adrenal medulla secretes catecholamine hormones (mainly ___1_____, with lesser amounts of _____2____)
- epinephrine
2. norepinephrine
The catecholamine hormones are secreted in response to stimulation by _________sympathetic axons.
NB: Remember catecholamine complement the sympathetic nervous system
preganglionic
The adrenal cortex are stimulated hormonally by the ___________ secreted from the anterior pituitary
Adrenocorticotropic Hormone (ACTH)
The cortex consists of three zones:
- outer zona glomerulosa. (which secrete Aldosterone a MINERALCORTICOIDS)
- middle zona fasciculata. (which secrete Cortisol and Cortisone which are GLUCOCORTICOIDS)
- inner zona reticularis.(which secrete Androgens and Estrogens which are SEX STEROIDS)
The adrenal cortex, which surrounds the medulla, produces more than 25 steroid hormones, known collectively as the _____1______ or corticoids.
Only ____2____ of them, however, are produced in physiologically significant amounts;
The five most important corticosteroids fall into ____ categories
- corticosteroids
- five
- three (MINERALCORTICOIDS, GLUCOCORTICOIDS, SEX STERIOIDS)
The Zona glomerulosa (“full of little balls”) refers to the fact that many of its cells are arranged in____________
rounded clusters.
The zona glomerulosa secretes mainly _________, a mineralocorticoid
aldosterone
The zona glomerulosa contain the enzyme ______________ , which is necessary for synthesis of aldosterone.
aldosterone synthase
The Aldosterone secretions are stimulated by:
the extracellular fluid concentrations of _________ and _________
angiotensin II and potassium
Aldosterone in turn stimulates the kidneys to retain ______ in the body fluids and excrete _____ in the urine.
sodium, potassium
Sodium reabsorption is followed by water reabsorption.
Thus water is retained with sodium by osmosis, aldosterone helps to maintain ________ and __________.
blood volume , and blood pressure
FUNCTIONS OF:
MINERALCORTICOIDS -
GLUCOCORTICOIDS-
SEX STERIODS-
MINERALCORTICOIDS - Regulate the Body Electrolyte and Mineral Balance of Water
GLUCOCORTICODS - Regulate the metabolism of glucose, there release stress and they are anti - inflammatory.
SEX STERIODS- Involved in various Development and Reproductive Functions.
The cells of the zona fasciculata are called _________ because of a foamy appearance imparted by an abundance of cytoplasmic lipid droplets.
- spongiocytes
The zona fasciculata secretes _____1____ in response to ______2____ from the pituitary.
- glucocorticoids
2. Adrenocorticotropic hormone ACTH
The most potent of these is ____1____ (hydrocortisone), but some effect is due to the less potent _____2______.
- Cortisol
2. Corticosterone
Glucocorticoids (cortisol and corticosterone) stimulate:
3.
- fat and protein catabolism ( increase the rate at which adipose tissue breaks down Triglycerides into fatty acid and decrease protein synthesis)
- gluconeogenesis,
- the release of fatty acids and glucose into the blood.
NB: Catabolism is a set of metabolic pathway that breaks down molecules into smaller units.
Glucocorticoids (cortisol and corticosterone) stimulate:
- fat and protein ________ ( increase the rate at which adipose tissue breaks down Triglycerides into fatty acid and decrease protein synthesis)
- glucon___nesis,
- the release of fatty acids and _____ into the blood.
NB: Catabolism is a set of metabolic pathway that breaks down molecules into smaller units.
- catabolism
- gluconeogenesis,
- glucose
_________ has body adapt to stress and repair damaged tissues.
Glucocorticoids
______ also have an anti-inflammatory effect and are widely used in ointments to relieve swelling and other signs of inflammation.
Glucocorticoids
NB; Glucocorticoids decrease the effectiveness of our immune system
The Zona Reticularis is the secrete ___________________
SEX STERIODS (ANDROGEN FOR MALE and ESTROGEN FOR FEMALE)
The adrenal androgens Hormones are:
2.
- dehydroepiandrosterone (DHEA) (More Amount)
2. androstenedione (Lesser Amount)
The adrenal androgens Hormones are:
- de_______sterone (DHEA) (More Amount)
- ____stenedione (Lesser Amount)
- dehydroepiandrosterone (DHEA) (More Amount)
2. androstenedione (Lesser Amount)
The adrenocortical hormones belongs to the ______ class of hormones.
NB: Adrenocortical Hormones are Hormones of the adrenal gland i.e glucocorticoids (Cortisol and Cortisone), Mineralcorticoid (Aldosterone), Sex Steroid (Androgen and Estrogen)
steroid
NB: Adrenocortical Hormones are Hormones of the adrenal gland i.e glucocorticoids (Cortisol and Cortisone), Mineralcorticoid (Aldosterone), Sex Steroid (Androgen and Estrogen)
The precursor for the synthesis of this Aderenocortical hormone is ___________
cholesterol
Adrenocortical Hormones are Hormones of the ___________ i.e glucocorticoids (Cortisol and Cortisone), Mineralcorticoid (Aldosterone), Sex Steroid (Androgen and Estrogen)
adrenal gland
The cholesterolis either obtained from:
2.
- diet (approximately 300mg cholesterol is gotten from diet)
- acetate by a CoA reductase enzyme (approximately 600mg cholesterol is gotten from acetate)
dehydroepiandrosterone (DHEA) (More Amount) and androstenedione (Lesser Amount) are weak androgens with little biological activity in themselves, but many tissues convert them to the much more potent androgen, ____________.
testosterone
In both sexes, androgens induce:
- the growth of pubic and axillary hair
- apocrine scent glands in puberty
- stimulate the libido (sex drive)
In both sexes, androgens induce:
- the growth of _____ and axillary hair
- apocrine _____ glands in puberty
- stimulate the _____ (sex drive)
- pubic
- scent
- libido
The main adrenal estrogen (for female) is ________
Estradiol
In men, the large amount of testosterone secreted by the______ overshadows that produced by conversion of adrenal DHEA.
testes
The Adrenal estrogen (estradiol) is ____________ compared with estrogen from the ovaries.
Small in quantity
After ________, however, the ovaries no longer function and only the adrenals secrete estrogen.
menopause
Both androgens and estrogens promote:
- adolescent skeletal growth
2. help to sustain adult bone mass.
Both androgens and estrogens promote:
- adolescent ________ growth
- help to sustain adult _____ mass.
- skeletal
2. bone
In the adrenal cortex, about 80% of cholesterol required for steroid synthesis is captured by receptors which bind ____________
low-density lipoproteins (LDL)
Nb: high-density lipoprotein (HDL) cholesterol may also be taken up by adrenal cells.
The remaining 20% is synthesized from _______ within the adrenal cells
acetate
Cholesterol can be stored as ________ in lipid Droplets
esters
The first stage in the synthesis of adrenal steroids:
- Hydrolysis of cholesterol esters
- Active transfer of free cholesterol
To the outer membrane of the mitochondria by a _____________________
Sterol Transfer Protein
The first stage in the synthesis of adrenal steroids:
To the OUTER MEMBRANE of the MITOCHONDRIA by a Sterol Transfer Protein
- Hydrolysis of cholesterol esters
2. Active transfer of free cholesterol
Second step on the synthesis of adrenal steriods:
- The transfer of hydrophobic cholesterol to the INNER MITOCHONDRIAL MEMBRANE is chaperoned by a_____________________ protein
NB: It is during the second step that the first enzymatic process in steroid hormone synthesis occurs.
The enzyme, known as side chain cleavage enzyme P450scc Cholesterol Desmolase
steroidogenicacuteregulatory (StAR)
NB: It is during the second step that the first enzymatic process in steroid hormone synthesis occurs.
The enzyme, known as side chain cleavage enzyme P450scc Cholesterol Desmolase
Cholesterol Desmolase or side chain clevage enzyme, P450 convert cholesterol to _________
Pregnenolone
Cholesterol is converted to Pregnenolone by _______________
Cholesterol Desmolase or side chain clevage enzyme P450n
Pregnenolone is converted to Progesterone or 17α-hydroxypregnenolone in the ________________
Smooth endoplasmic reticulum
Pregnenolone is converted to ________ or ____________ in the Smooth endoplasmic reticulum
REMEMBER: Cholesterol is converted to Pregnenolone via Cholesterol Desmolase
Progesterone or 17α-hydroxypregnenolone
REMEMBER: Cholesterol is converted to Pregnenolone via Cholesterol Desmolase
Progesterone ( a derivative of pregnenolone) is converted ___________ and then _________by the process of Hydr__lation
Corticosterone, aldosterone, Hydroxylation
17α-hydroxypregnenolone is converted to __________ and __________
androgens, cortisol
Expression of cholesterol desmolase depends on the presence of __________________ a hypothalamic hormone.
Adrenocorticotropic Hormone ACTH
In the absence of _______________ no adrenocortical hormones are produced.
adrenocortical hormones ACTH
cortisol (majority, 90 - 95) in the plasma binds to plasma proteins (globulin) known as ______________ or _______ and,
1to a lesser extent, to albumin.
NB: cortisol binds to
- Globulins or plasma proteins majorly and
- Albumin
- cortisol-binding globulin or transcortin
- albumin
NB: cortisol binds to
- Globulins or plasma proteins majorly and
- Albumin
, cortisol has a relatively long half-life of _____ to ____ minutes
60 to 90 minutes
Aldosterone bind to
- ______________
NB: About 60% of aldosterone bind to plasma protein thereby leaving the remaining 40%in its free form
- plasma protein or Globulins
NB: About 60% of aldosterone bind to plasma protein thereby leaving the remaining 40%in its free form
Aldosterone to have a relatively short half-life of about _____ minutes.
20 minutes
elimination of cortisol form the plasma is slow due to its _____binding affinity to plasma proteins
high
Adrenocortical hormones are degraded in the ___1___
THEN
There are CONJUGATED to from _____2____ and _____2_____
THEN
These conjugates ( Glucuronic acid and Sulfate) are filtered by the ___3__ and Excreted in the ___3__
NB:
GLUCURONIC ACID and SULFATE are Inactive and do not have MINERALCORTICOID and GLUCOCORTICOID ACTIVITIES.
- LIVER
- GLUCORONIC ACID (majorly) and SULFATE (minority).
- kidney and urine
NB:
GLUCURONIC ACID and SULFATE are Inactive and do not have MINERALCORTICOID and GLUCOCORTICOID ACTIVITIES.
Adrenocortical hormones are degraded in the Liver
then there are conjugated to form GLUCORONIC ACID (majorly) and SULFATE (minority).
The conjugates ( Glucuronic acid and Sulfate) are filtered by the Kidney and Excreted in the Urine
thus :
- Diseases of the liver markedly depress the rate of ________ of adrenocortical hormones
- kidney diseases reduce the _____ of the inactive conjugates.
- inactivation
2. excretion
