PHYS 215 Lecture Notes - Lecture 58: Zona Fasciculata, Zona Glomerulosa, Underarm Hair
31 Dec 2018
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Lecture 28 (part 2) – peripheral endocrine glands cont.
11/28/2018
• What is the anatomy of the adrenal gland?
o Fig 19-7
o Outer part – cortex
▪ Zona glomerulosa – makes aldosterone
▪ Zona fasciculata – makes cortisol
▪ Zona reticularis – makes DHEA and small amount of estrogen (males) or
testosterone (females)
▪ Fig 19-8
o Inner part – medulla
▪ Makes catecholamines (epinephrine, norepinephrine)
• What hormones are secreted by the adrenal cortex?
o Mineralocorticoids – aldosterone
▪ Affects Na reab in late DT and CD of kidney
o Glucocorticoids – cortisol primary one
o Androgens – DHEA
• How are adrenocortical hormones carried in blood?
o Steroids (lipophilic, hydrophobic)
o Albumin – binds aldosterone and DHEA
o Transcortin or corticosteroid binding globulin – binds cortisol
• What is the role of the androgen DHEA in females?
o Axillary hair
o Pubertal growth spurt
o Sex drive
o Hirsutism = inc DHEA in adult female; causes inc body hair
o Female pseudohermaphrodites = inc DHEA in female infants; cause inc male
characteristics
• What is the role of estrogen in males?
o Not clear
o It seems to dec spermatogenesis or sperm production
• What is the role of cortisol?
o Very important hormone
o We do not function well without this hormone
o Metabolic effects
▪ Inc plasma glucose conc by inc gluconeogenesis by the liver and dec
glucose utilization or uptake in muscle
▪ Inc protein breakdown in muscle
▪ Inc lipid breakdown in adipose tissue
o Permissive hormone
▪ Facilitates the effect of many hormones, in particular GH, glucagon, and
catecholamines
o Stress response
▪ Involves spec physiological changes that permit the body to cope with
“conditions perceived as challenges by the individual (phycological)
▪ Coordinated through the hypothalamus and sympathetic nervous system
▪ Inc glucose availability to the brain
▪ Handout 140A
• How does death occur when the body starts using protein as a source of energy in
starvation and extreme malnutrition?
o Irreversible destruction of important structures such as heart, skeletal muscle,
etc.
o Negative nitrogen balance
• Does the stress response involve other causes besides psychological?
o Yes
o Physiological, chemical, infectious, etc.
▪ Pg 682
• Suppression of the immune system
o Seen at high plasma conc
o Dec inflammation and allergy
• How is the secretion of cortisol regulated?
o Handout 140
o Fig 19-9
o Regulated by hypothalamus
o Stimulate cortisol release cis CRH (then ACTH) by stress and dec blood glucose
conc
o Cortisol limits its own release by negative feedback inhibition of CRH and ACTH
• What abnormalities occur in cortisol secretion?
o Hypersecretion
▪ Inc CRH or ACTH
▪ Glucose excess, protein shortage, and abnormal fat distribution
▪ Treatment: remove adrenal (or part of)
o Hyposecretion
▪ Dec CRH or ACTH
▪ Hypoglycemia, poor response to stress
▪ Treatment: give cortisol
• What is the role of catecholamines released by the sympathetic stimulation of adrenal
medulla?
o Mimics the effects of the sympathetic nervous system
o Epinephrine and norepinephrine stored in chromaffin granules
• What are the effects of the sympathetic nervous system?
o Inc heart rate, sweating, cortical alertness, vasoconstriction, pupil dilation, etc.
o Handout 140a – epinephrine listed as first hormone in stress response
• What are the anatomical features of the pancreas?
o Fig 19-15
