Endocrine 1 Flashcards
The major glands (pppta) (me at the pta)
The major glands: Pituitary, thyroid, parathyroid, adrenal and pancreas
The endocrine system has five general functions: (me and children)
reproductive and CNS development in the fetus
Stimulation of growth and development during childhood and adolescence
Hormones have specific rates and rhythms of secretion (circadian rhythm of cyclic pulsating hormones)
Circadian or diurnal pattern
Pulsatile and cyclic pattern
A pattern that depends on circulating substrates (circle the milk - think)
Ca+, K+, Na+, glucose, etc.
hormones
They operate on a feedback system: negative or positive
They affect only the cells with the appropriate receptors
hormones are eliminated (2 main places)
by the kidneys or metabolized in the liver into water soluble compound ready for renal excretion
HORMONE CLASSIFICATION
Water soluble
Lipid soluble
Water soluble hormones - where are the receptors? (receptive water)
-circulate freely in blood to act on target tissues. Receptors on cell membrane
Lipid soluble hormones - where is the receptor? Andhow does it cross membranes?
(fat is bound and diffues)
Lipid soluble
- bound by plasma proteins; cross membranes through diffusion
-receptor inside cell
Hypothalamus – The Master Gland - what are the cells called? (hippo has a secretary)
Located superior and anterior to the brain stem
Responsible for the direct control of the endocrine system through the pituitary gland
Contains special cells called neurosecretory cells—neurons in the hypothalamus receive input from the CNS then coordinates release of hormones
The Hypothalamus-pituitary Axis (HPA) - what 2 systems work together? (you know this)
Forms the structural and functional basis for the central
integration of the nervous and endocrine systems
The Neuro and Endocrine systems work together to maintain homeostasis in response to internal and external demands
In the HPA a number of releasing/inhibitory hormone as well as *tropic hormones are produced that affect body function:
Corticotropic releasing hormone (CRH) (cort sneezes in the tropics)
→ anterior pituitary (ACTH- Adrenocorticotropic hormone)→ adrenal glands
Prolactin releasing hormone (PRH) → (pro mammary)
Prolactin releasing hormone (PRH) → anterior pituitary (Prolactin) → mammary glands
Thyrotropin releasing hormones (TRH)→ (TRH is tsh)
Thyrotropin releasing hormones (TRH)→ anterior pituitary (TSH) → thyroid gland (thyroxine)
Gonadotropic releasing hormone →(fish for gonads)
Gonadotropic releasing hormone → anterior pituitary (gonadotropic hormones FSH and LH) → testes and ovaries
Growth hormone releasing/inhibitory hormone (growth everywhere)
Growth hormone releasing/inhibitory hormone → anterior pituitary (GH or GIH) →all body tissue
Prolactin releasing hormone →
Prolactin releasing hormone → anterior pituitary (PRL or PIH) →mammary glands
Hormones secreted by the hypothalamus and stored in the Posterior Pituitary (just 2)
Antidiuretic hormone (ADH):
Oxytocin:
ADH - what does it do to urine?
Regulates fluid volume by acting on collecting renal tubules to reabsorb water → concentrated urine
oxytocin does 2 things (you know this)
Stimulates uterine contraction and milk production
THE ADRENALS - do the medulla and cortex work together?
Located in the upper portion of both kidneys
Consists of the adrenal medulla and adrenal cortex both acting independently
Adrenal MEDULLA “Fight or Flight response” (fight medusa)
Inner part of adrenal gland
Makes up 10 to 20 % of the mass of adrenal gland
Secretes catecholamines: Epinephrine (75%) and Norepinephrine (25 %) and dopamine
Adrenal CORTEX - what does it secrete?
(cotex is on steroids)
Outer part of adrenal gland
Makes 80 to 90 % of the mass of adrenal gland
Secretes over 50 steroids (need cholesterol to make steroids)
corticosteriods - 2 types
glucocorticoids
mineralcorticoids
androgrens
convert testosterone in men and estrogen in women in the peripheral tissue
Cortisol released in response to (too much or too little sugar)
stressful situations: hypoglycemia, burns, infection, fever, anxiety, surgery
cortisol (cort is not inflammed when he eats sugar)
Anti-inflammatory properties
Glucose metabolism
ADRENAL CORTEX HORMONE: MINERALOCORTICOID (Aldosterone) - when is it released - relationship btwn aldosterone and K+
Released in response to low plasma volume and high serum osmolarity, hyperkalemia (aldosterone releases K+ out of the body), angiotensin II
ADRENAL CORTEX HORMONE: (cotex is a man) Androgens
The adrenal cortex secrets small amounts of androgens
Stimulates pubic and axillary hair growth and libido in females
Androgens are converted into estrogen in the peripheral tissue
After menopause, the adrenal cortex is the major source of endogenous estrogen
In men, adrenal secretion of androgen is minimal compared to testicular production of testosterone
THE PINEAL GLAND (pictures of pineal)
Composed of photosensitive cells
Secretes Melatonin
Stimulated by exposure to dark and inhibited by light exposure
THE THYROID GLAND
- Two encapsulated lobes connected by the isthmus
Regulated by TSH from the Anterior Pituitary
Iodine is needed for the synthesis of these hormone
FUNCTION OF THYROID GLAND - just salt
To take in iodine found in many foods and converts it into thyroid hormones
Release is controlled by a feedback mechanism
FUNCTIONS OF THE THYROID HORMONES (2 things)
(fat and hot thyroid)
Metabolic rate
Temperature regulation