Biochemistry week 10 Flashcards
(41 cards)
Name the 3 types of endocrine signaling
- Classic endocrine signaling
-Paracrine signaling
-Autocrine signaling
In classic endorine signalling how does the hormones travel
Hormones travel from a secretory gland across long distances through the bloodstream to the target tissues
In paracrine signaling, how does the hormones act
They act locally on nearby cells without entering the systemic circulation
In autocrine signaling, what do hormones bind to
Hormones bind to receoptors on the same cell that secreted them, regulating its own function
Name the 7 major endocrine glands
-Pituitary gland
-Thyroid gland
-Parathyroids gland
-Testes
-Ovary
-Adrenal
-Endocrine pancrease
What can hormones be
- Peptides, metabolites of amino acids or cholesterol derivatives
Name the 2 different type of actions that hormones can be
- Complementary or antagonistic
Explain the general mechanism on how peptide hormones act
Act on cell surface receptors, triggering signaling cascades inside the cell
Explain the general mechanism on how steroid hormones act
Cross the cell membrane and bind to intracelluler receptors and modulate gene expression
What does Endocrine regulation depend
Feedback loops
What does feedback control ensure
- Stable hormone secretion
Where is the hypothalamus located
- In the forebrain near the the third ventricle
What does the hypothalamus connect to
Connects to the pituitary via the hypophyseal stalk
Name the 2 parts the pituitary glands has
Anterior pituitary and posterir pituitary
In the posterior pituitary, where are the horomonse synthesised + how are they transported
-Synthesised in the hypothalamic nuclei
- Hormones are transported down axons and stored in posterior pituitary for release
In the Anterior pituitary where are hormones synthesized + where do they travel to
- Hormones are synthesized in the arcuate and other hypothalamic nuclei
-They travel to the median eminence , then to the anterior pituitary via the portal venos system
What is the most numerous cell type the anterior pituitary contains+ its function
- Somatotrophs,which secrete growth hormone
Where does the pituitary integrate signals from
Hypothalamus
When is stimulation tests used
When hypofunction (underactivity)i suspected
What do stimulation tests asses
The Endocrine glands reserve capacity to produce hormones
When is suppression tests used
when hyperfunction (overactivity) is suspected
What does suppression tests check
- They check if the negative feedback loop is working o reduce hormone levels
What is growth hormone secreted by
Somatotrophs in the anterior pituitary
What is growth hormones stimulated by
- Growth hormone releasing hormone (GHRH) from the hypothalamus
- Ghrelin
