Adrenal Glands Flashcards
Where are the adrenal glands located?
Found within renal perinephric fascia (fascia attaches to crura of the diaphragm).
Separated from kidneys by perirenal fat.
Describe the R + L adrenal gland shapes and general location (which organs are they near?)
Right: Pyramid shape. Near right lobe of liver.
Left: (Larger): Semilunar shape. Near stomach, pancreas, spleen.
Describe the embryological differences of the adrenal cortex and medulla.
Cortex: Mesoderm
Medulla: Neural crest cells
Describe the blood supply of the adrenals (arteries)
Superior adrenal arteries: From inferior phrenic artery near solar plexus
Middle adrenal artery: From abdominal aorta, adjacent to celiac trunk
Inferior adrenal artery: Branches off renal artery.
Describe the general venous drainage of L vs R adrenal
Left: Left adrenal vein > left renal vein > IVC
Right: Right adrenal vein > IVC
Describe the lymph drainage of adrenals
Drain to lumbar lymph nodes via adrenal lymphatic vessels; vessels originate from 2 lymphatic plexuses (1 in cortex, 1 in medulla).
Drains to cisterna chyli, thoracic duct to L subclavian vein
Describe the nerve supply of the adrenal glands
Primary innervation via sympathetic nervous system to the chromaffin cells of adrenal medulla.
Sympathetic Supply:
- Arise from splanchnic nerves and celiac plexus
- Preganglionic fibers originate from T5-T11 and terminate in medulla
- No synapses to postganglionic fibers
Fetal adrenal hormones are needed for prenatal development of organs, especially _______ maturation, as they signal the release of _______.
Fetal adrenal hormones are needed for prenatal development of organs, especially LUNG maturation, as they signal the release of SURFACTANT.
What is adrenarche?
- Early stage of sexual maturation.
- Zona reticularis begins to enlarge.
- Adrenals secrete more androgens.
- Starts around age 6-8, peaks around 10-14.
- Results in pubic hair, body odor, skin oiliness, acne.
What is adrenopause?
- Decline in secretion of adrenal androgens
- Peak secretion around 20-25Y, then declines 2%/year
- Levels at 80Y, only 10-20% remaining
- Caused by involution of zona reticularis
What is the function of chromaffin cells?
Modified sympathetic ganglion cells, lacking dendrites and axons.
Synthesize and store epinephrine and norepinephrine
Name the 3 adrenal cortex layers and the main steroids they produce.
- Zona Glomerulosa: Mineralocorticoids (Aldosterone)
- Zona Fasciculata: Glucocorticoids (Cortisol)
- Zona Reticularis: Androgens (DHEA)
What is the General Adaptation Syndrome?
How organisms respond to stress. 3 stages;
- Alarm
- Resistance
- Recovery/Exhaustion
General support (non-pharmacologic) for General Adaptation Syndrome phases (3)
- Alarm: Nervines, GABA
- Resistance: Sedating adaptogens (Ashwagandha, bacopa)
- Exhaustion: Stimulating adaptogens (Rhodiola, Shisandra)
Stress and disease can lead to ________ dysregulation
Stress and disease can lead to HPA-AXIS dysregulation
Chronic over-activated HPA-axis leads to:
Atrophy of the hippocampus (decreased memory) , depression, mood disorders
Chronically under-activated (flattened) HPA-axis conditions:
Chronic fatigue syndrome (CFS), PTSD, insomnia, burnout
Adrenal Stress Index tests ______ samples (#) times per day
Adrenal Stress Index tests SALIVA samples 4 times per day
Adrenal Stress Index tests ______ samples (#) times per day
Adrenal Stress Index tests SALIVA samples 4 times per day
(T or F) Cortisol is hydrophilic, and is mostly carried by plasma proteins
True
(T or F) Cortisol half-life is 60-90 mins, and is determined by extent of plasma binding and by rate of metabolic inactivation
True
80% of cortisol is bound by this carrier protein
Corticosteroid-binding globulin (CBG) aka “Transcortin”
Increased CBG levels in:
- High estrogen states (pregnancy, birth control)
- Hyperthyroidism
- T2DM, insulin resistance
- Genetic disorders
Decreased CBG in:
- Hypothyroidism
- Protein deficiency states (liver disease, nephrotic syndrome)
- Genetic disorders (familial CGB deficiency)
