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Endocrine system works with....
- Works in concert with the nervous system for body communication:
- Neuro endocrine system and circulatory system with hormones.
Endocrine System Controls _________
Assumes a role in....
Contributes to the basic processes....
- * Homeostasis
- * By regulating chem composition & volume of internal environment
- * Helps cope with trauma
- * Assumes a role in the smooth integration of growth and development
- * Contributes to the basic processes of reproduction
Target organ cells:
Cells acted on by....
Some are very.....
- * Cells that are acted on by a particular hormone
- * Some hormones have very widespread targets, some are very specific
Hormones act on target cells in three basic ways:
- a. They control the rates of enzymatic reactions
- b. They control transport of molecules across cell membranes
- c. They control gene expression and the synthesis of proteins
What are two regulatory chemicals in the body?
Hormones & CO2
General Organs of the Endocrine System
- small intestines
- adipose besides glands whose primary function is to secrete hormones
How do hormones act on the macroscopic level?
How do hormones act on the cellular level?
- Negative feedback usually
- Like a thermostat
- Hormone travels in the blood & is lipophobic
- Ex: Catecholamines & Polypeptides hormones
- Hormone attaches to specific mem. receptor
Lipophobic hormones use receptors such as _____________________ to get into the cell
c_AMP c_GMP CA++ IP3 DAg
Non-typical or Candidate Hormones:
Prostaglandins (Tissue hormones)
What are the 3 classes that we look at?
* Released by all cells but because they are so rapidly broken down, circulating levels are very low
3 Classes of hormones based upon structure.
* Amines -
N containing derivatives of tyrosine or tryptophan.
* Peptide Hormones -
polypeptides and glycoproteins secreted from ribosomes as preprohormones which have their signal sequences removed in rER (and then converted to hormone form in the vesicles. May also be neuromodulators.
- Steroids - not stored & all are derived from cholesterol made by the liver (sER)& travel bound to plasma proteins1.
- production by gonads, adrenal cortex and placenta in sER2.
- cholesterol stored as a non membrane bound lipid droplet.
- Steroids made in mitochondria and sER
Steroids are made in _________ and ________
Production in ADrenal cortex and GOnads
mitochondria and sER
Hormones are secreted in response to.....
Specific chemical stimuli usally in short bursts or pulses.
GH is secreted most.....
At the beginning of sleep
Pulsatile secretion of hormones may help in....
What are the 3 types of chemical stimuli or input?
How they are transported in blood affects....
- NS to Neurotransmitters
- Another hormone or Paracrine
- (Plasma) of mineral ions or nutrients
The amount of active hormone
Presence or absence of receptors affects how hormones work on the _________
- Most target cells have only a few receptors (a few thousand) so the cell has a lowcapacity
Thyroid is permissive to _______ on _____
Epinephrine - Adipocytes
TH is permisive to ____ ____ for the development of _____ ____
- Reproductive Hormones
- Reproductive System
Estrogen is permissive to?
Glucocorticoids are permissive for ________
Some hormones aren't activated until their target cells convert them to the active form.
Give an example:
- T4 --> T3
- Prehormone -> Prohormone -> active hormone (ex insulin)
Action of E & NE.....
Milk production requires....
*together, two hormone's effects are more than additive or complementary
*Action of E & NE on heart is Additive
*Milk production requires snergistic action of estrogen, cortosol, prolactin, oxytocin, etc
Antagonism - Some hormones are antagonistic to other hormones.
High estrogen antagonizes ______ actions
Insulin and ___ are antagonistic 2 1 another
GH is antagonistic to _____
Hormones are removed from blood via _____ or ___________
Rate of secretion....
Excretion or metabolic transformation
---The excretory rate is used to indicate the secretory rate
What two organs break down or metabolizes steroids?
Liver & Kidneys
Steroids have a _____ life than do....
Longer life than do peptide or amine hormones.
Location - Sella Turcica Under Diaphragma Sellae
hypothalamus via the infundibulum
Regulated by hypothalamus
Divided into 2 parts that are developmentally different: Anterior and Posterior Pituitary Gland
Pituitary Gland has 2 parts:
Neural secretions from......
^ process called?
* ANT Pit supplied by Hypothalamo-Pituitary Portal system
* Neural Secretions from hypothalmus travel from median eminence to the anterior pituitary controlling what hormones will be made.
* This process is called releasing hormones or inhibiting hormones
Endocrine gland makes up ____% of pituitary
Includes the ___ _____ which is _____ and secretes _____
- Pars intermedia
ANT PIT Contains 3 types of cells according to Azans Staining.
Secrete ACTH and MSH
Secrete FSH, LH, or ICSH
Posterior Pituitary Gland
Two hormones are syn......... What are they
Secretes _____ hormones..... but does not produce
- Neural Tissue
- Synthesized by neurons in 2 areas of hypothalamus: Vasopressin & Oxytocin
Secretes Antidiuretic Hormone (ADH) and Ocytocin (OT) but does not produce it
Stimulates............ Product produced?
What do they do?
- Target Organ ________?
- Promotes Body Growth
Decreases blood A.A levels
Stimulates protein anabolism, hormone production by liver, and by target cells of GH
- Hormone/Product produced =
- Somatomedins (IGF-1) - Main stimulator of fetal growth.
IGF-2 - Independent of GH, Stimulates tissue repair.
In both sexes PRL appears to.....
Target Organ: Breast or corpus luteum
- * Promote breast developmnt during pregnancy
- *Stimulates mammary glands to secrete milk after delivery
- *in both sexes, PRL appears to play a role in regulation of the immune system.
- * Inhibits gonadotrophins secretions inhibiting fertility
- *In male may facilitate reproductive function
TSH (Thyroid Stimulating Hormone)
- Stimulates thyroid gland to grow/ maintains it
- Secretion from basophils stimulated by TRH
FSH (Follicle Stimulating Hormone)
In females stimulates....
In males stimulates....
- Target Organ: ______
- F = Stimulates ovary to mature an ovum & stimulates follicle cells to secrete estrogen
M = Stimulates seminiferous tubules to develop, be maintained, and produce sprem.
Secretion from Basophils stimulated by FSH-RH
(Internal cell stimulating hormone ICSH)
In females stimulates....
In males stimulates...
F = Stimulates ovulation, corpus luteum to form, to secrete progestins, and estrogen
M = Interstitial cells of testes to develop & secrete testosterone
secretion from Basophils stimulated by LH-RH
Stimulates adrenal cortex to grow normally, be maintained and to secrete glucocorticoids
Production from basophils and release stimulated by ___________
MSH is a major....
Increases Synthesis & dispersion of melanin granules in skin causing hyperpigmentation
MSH is a major appetite inhibitor works with leptin to control the use of lipids.
Prohormone of several endogenous opioids
- Raises the pain threshold
- Stimulates release of PRL, GH, ADH
- Inhibits TSH, LH and FSH production
ADH (Antidiuretic hormone) or vasopressin
large amount cause...
Target organ ______.
Decreases water loss by decreasing urine production
Large amounts of ADH causes vasoconstriction of arterioles
Increases memory and secretion of ACTH
In hypothalamus detects and....
In the hypothalamus detect and increase in blood osmolarity (due to dehydration)
This increases water permeability of distal convoluted tubules and collecting ducts to increase water reabsorbtion.