Lecture 7 Block 3 Flashcards
(21 cards)
where are catecholamines stored
in secretory vesicles
how are catecholamines released
through exocytosis
what do catecholamines act on
cell membrane receptors
what do catecholamines do
activate second messenger systems and modify existing proteins via protein phosphorylation
where are thyroid hormones stored
secretory vesicles
what do thyroid hormones do
act on nuclear receptors to induce protein synthesis
how are steroid hormones released
through simple diffusion
what do steroid hormones act on
cytoplasmic or nuclear receptors
what do steroid hormones do
gene activation or nongenomic actions
when are steroid hormones synthesized
on demand from precurosors
where are peptide hormones stored
secretory vesicles
how are peptide hormones released
through exocytosis
what do peptide hormones do
act on cell membrane receptors, activate second messenger systems resulting in modification of existing proteins and new protein synthesis
what do the neurons in the posterior pituitary gland synthesize
vasopressin and oxytocin
what type of peptides are vasopressin and oxytocin
neurohormones
what is the hypothalamic pituitary portal system
consists of two capillary beds one at the median eminence and the next at the anterior pituitary gland connected by portal vein
why is the hypothalamic pituitary portal system special
because capillary beds are typically arranged in parallel not in series
what is the physiological reflex
stimulus acts upon the sensor, the sensor produces input signal, which is sent to the integration center. the efferent signal is then secreted into the blood and acts upon target organs to produce a physiological response
what is the simple endocrine reflex
the endocrine tissue is the sensor and integrating center: endocrine tissue senses and integrates information about external and internal changes, released hormone to regulate target tissue
what is the neuroendocrine reflex
the sensory receptors sense changes, send input signal through sensory nerve to neural integration centers which then releases neural hormones
what is the complex neuroendocrine reflex
multiple integration centers in the same pathway with one integration center send out signals to modulate the next
