Endocrine System Basics
This major control system works with the nervous system but acts slower and lasts longer.
What is the endocrine system
Water-soluble hormones bind to receptors located here.
What is the plasma membrane
Low Ca²⁺ levels stimulate this hormone through humoral control.
What is parathyroid hormone (PTH)
This structure connects the hypothalamus to the pituitary gland.
What is the infundibulum?
Cells respond to a hormone ONLY if they contain these.
What are specific receptors?
Endocrine glands release hormones into this, allowing long-distance signalling.
What is the bloodstream / lymph?
cAMP is turned off by this enzyme.
What is phosphodiesterase
Sympathetic nerves stimulating the adrenal medulla is an example of this type of endocrine stimulus.
What is neural stimulation
The anterior pituitary is controlled by hormones delivered through this unique vascular system.
What is the hypophyseal portal system?
Persistently high hormone levels lead to this decrease in receptor number.
What is down-regulation
These glands have both endocrine AND exocrine functions.
What are the pancreas, gonads, and placenta
Steroid hormones act by initiating this nuclear process.
What is gene transcription?
The hypothalamus releasing TRH to control TSH is an example of this stimulus type.
What is hormonal stimulation
This hypothalamic hormone inhibits prolactin release.
What is PIH (dopamine)?
Steroid hormones have long half-lives because they circulate this way.
What is bound to plasma proteins?
Steroid hormones are synthesized from this molecule.
What is cholesterol
This intracellular transcription factor is activated by cAMP signalling.
What is CREB?
Under severe stress, this system overrides insulin release to increase blood glucose.
What are the hypothalamus and sympathetic nervous system
Oxytocin and ADH are synthesized here before being stored in the posterior pituitary.
What are the PVN (oxytocin) and SON (ADH) nuclei?
T3/T4 inhibiting release of TRH and TSH is an example of this homeostatic mechanism.
What is negative feedback
This endocrine organ is considered neuroendocrine because it links neural activity to hormonal output.
What is the hypothalamus?
Steroid hormone responses take longer because proteins must be made through these two processes.
What are transcription and translation?
High K⁺ directly stimulates the adrenal cortex to release this hormone.
What is aldosterone
ACTH, TSH, FSH, and LH are all considered this type of hormone because they control other glands.
What are tropic (tropin) hormones
This determines how strongly a receptor binds to its hormone.
What is receptor affinity