16.11 Pancreas, Gonads, Other Organs Flashcards
Triangular endocrine organ partially behind the stomach
Pancreas
Cell located outside of pancreatic islet; Produce enzyme rich juice for digestion
Acinar cells
Contain endocrine cells in the pancreas
Pancreatic islets
Cell that produces glucagon; within pancreatic islet
Alpha cells
Cell that produces insulin; within pancreatic islet
Beta cells
Raises blood glucose levels by targeting liver
Breaks down glycogen into glucose (glycogenolysis)
Synthesizes glucose from lactic acid
Releases glucose into blood
Glucagon
Lowers blood glucose levels; Enhances membrane transport of glucose into fat and muscles
Inhibits breakdown of glycogen to glucose
Inhibits conversion of amino acids or fats; Plays a role in neuronal development
Insulin
Pyramid shaped organs atop kidneys ; made of cortex and medulla
Adrenal glands
Three outer layers of glandular tissue that synthesize and secrete several different steroid hormones; produces corticosteroids (24)
1. Zona glomerulosa - mineralocorticoids
2. Zona fasciculata - glucocorticoids
3. Zona reticularis - gonadocorticoids
Adrenal cortex
Inner region of nervous tissue within adnrenal gland that is part of sympathetic nervous system
Adrenal medulla
Produced by zona glomerulosa; Regulate electrolyte concentrations in blood (Na+ and K+)
Na+ = blood volume
K+ = action potentials
Aldosterone production
Mineralocorticoids
Most potent mineralocorticoid; Stimulates Na+ reabsorption by kidneys in increased blood volume and blood pressure
Eliminates K+ by kidneys
Aldosterone
- Renin-angiotensin-aldosterone mech.
- Plasma concentration of K+
- Adrenocorticotropic hormone
- Atrial natriuretic peptide (ANP)
Aldosterone regulation
Hypersecretion of aldosterone
Due to adrenal tumors; Hypertension and edema from too much Na+
Excess loss of K+ (muscle weakness and paralysis)
Aldosteronism
Produced by zona fasciculata; Influence nutrient metabolism of most cells and help us resist stressors
Primary hormone: Cortisol
Glucocorticoids
Hypothalamic corticotropin-releasing hormone stimulates release of ACTH, triggers cortisol release
Cortisol levels rise and fall based on eating and activity
Infection, physical trauma, emotional trauma will interrupt cortisol level
Regulation of glucocorticoids
Only glucocorticoid significant in humans; Increase in blood glucose
Causes gluconeogenesis
Cortisol
Hypersecretion of cortisol; tumors in pituitary, adrenal cortex
Causes high blood glucose, dramatic loss of muscle proteins, water retention, immunosuppression medication, easy bruising
“Moon face”
“Buffalo hump”
Treatment: Removal of tumor
Cushing’s disease
Involves deficits in both glucocorticoids and mineralocorticoids; Decrease in glucose and Na+ levels
Weight loss, severe dehydration, hypotension
Early sign: bronzing of skin
Treatment: Corticosteroid replacement therapy
Addison’s disease
Produced by zona reticularis; Starts as weak androgens, converted into sex hormones (DHEA, androstenedione –> testosterone)
Contribute to appearance of secondary sex traits; Sex drive in women; Estrogens for post-men women
Gonadocorticoids
Masculinization via hypersecretion of gonadocorticoids; Not noticeable in men already masculinized
Effects females and prepubertal males
Females: masculine pattern of body hair
Males: early sex drive
Adrenogenital syndrome
Epinephrine and norepinephrine hormones
Increases blood pressure, blood diverted from nonessential organs to heart and skeletal muscle
Blood glucose levels rise
Catecholamines
Stimulated to secrete catecholamines by nervous system during the fight or flight response
Chromaffin cells
Anything that creates stress and triggers stress response
Coordinated by hypothalamus
Stressor
Fight or flight response
Ex. Sitting through a test
Short term stress
Slower resistance reaction mediated by adrenal corticosteroids
Long term stress
Occurs if long term stress is too long, causing stress hormones themselves to disrupt homeostasis
Exhaustion
