Endocrine 1 Flashcards
Neurotransmitters
Released from what and act where and ex
From axon, locally, NPY
Endocrine hormones: released by what into what, act where, example
Glands/cells into blood, target cells away, GH
Neuroendocrine hormones: released where by what, act where, ex
Secreted by neurons into blood, act at target away cells, ADH
Paracrine
Released by what into where, act where
Secreted by cells into EF and affect neighboring target cells that are different than themselves
Autocrine
Secreted by what into where, act where
Cells into EF, affect same cells/self
Cytokines can be what, ex
Autocrine, paracrine, or endocrine hormones. Leptin
Chemical structures
3, ex
Proteins and polypeptides: insulin
Steroids: cortisol
AA tyrosine derivative: NE/epi
Polypeptides and proteins
Produced where, tend to be what
Process of activation
Produced in ER, preprohormones
Cleaved to prohormone, golgi apparatus packages into secretory vesicles, exocytosis due to Ca
What kind of release is required of polypeptides and proteins
Immeadiate
Steroids Synthesized from what Storage Soluble in what Structure Have large amount of what
Cholesterol
Not stored
Lipids
3 cyclohexyl rings and 1 cyclopentyl ring
Cholesterol, ready to mobilize in vesicles
4 hormones that are chronic and aren’t needed emergently
Cortisol, testosterone, aldosterone, estradiol
What structure do cortisol, estradiol, aldosterone, and testosterone have
3 cyclohexyl rings and 1 cyclopentyl
Amine hormones Derived from what Where they are 2 ex and ratio Stored where
Tyrosine
Adrenal medulla
Epi and norepi, 4:1
Vesicles until exocytosis
Thyroid hormones
Synthesized and stored where
Stored w what, how they get into blood, how they get to tissues
Thyroid gland
W globulins, split and become free hormone in blood. Bind to plasma proteins which release hormone to target tissues slowly
Negative feedback prevents what
Over secretion of hormone or over activity at target tissue
How target organ responds, process
Long feedback.
Target organ to hypothalamus, to anterior pituitary, back to target organ
Short feedback loop
Hypothalamus communicates w anterior pituitary to release something, once released it stops hypothalamus from telling it to release more
Ultra short feedback loop
Hypothalamus communicates with itself
Which hormones are water soluble, dissolved in what
Peptides and catecholamines. Plasma
Which hormones bound to plasma proteins
Steroid and thyroid
Clearance
Metabolism, bind to tissues, excreted by liver or kidneys
Hormone receptors
Bind where 3 and ex
In or on surface of cell membrane (proteins and catecholamines)
In cytoplasm (steroids)
Nucleus (thyroid)
Increased hormone will do what to receptors
Down regulate them
Ways of down regulating receptors
Inactivating molecules Inactivate protein signaling molecules Sequester receptor away from site of action Destroy receptors w lysosomes Decrease production of receptors
Intracellular signaling
1st forms what
Process
Hormone receptor complex
Ion channel linked receptors stim by NT, causes ion channel linked receptor to open or close for ions. Ion changes cause postsynaptic cell effects
G protein linked hormone receptors Mechanism of what How many transmembrane seg G proteins include what How to cause change
Intracellular signaling
7
Trimeric subunit: alpha, gamma, beta
Conformational changes
How g protein activated/inactivated
Activated by GTP, inactivated by GDP
How enzyme linked hormones work. Example
Proteins pass membrane w enzyme binding site on inside. Binding hormone causes enzyme activ or inactiv.
Leptin signals via tyrosine and JAK2, activate signal transducer and activate transcription of STAT proteins, downstream Fx
How ca calmodulin works
Ca binds to calmodulin once it enters cell, calmodulin changes shape and activates or inhibits protein kinases
How IP3 second messenger works
Activates phospholipase c, catalyzes breakdown of PIP2 into IP3 and DAG. IP3 mobilizes Ca (also acts as 2nd messenger), DAG activates PKC, works for local hormones
How steroid hormones work on cells
Increase protein synthesis: enter cell, bind to receptor protein, bind to dna and form mrna, mrna diffuses to cytoplasm to promote translation at ribosomes, new proteins made
Thyroid hormones do two things to cells
Activate genetic mechanism and increase metabolic activity
Pituitary gland
Connected to what
5 types
Hypothalamus Somatotropes- hgh Corticotropes-acth Thyrotropes- tsh Gonadotropes- fsh and lh Lactotropes- prl
Parts of pituitary, do what, connected by what, controlled by what
Anterior and posterior, both make different hormones, hypophysial stalk, hypothalamus
Anterior pituitary hormones: 6
Thyrotropin, GH, corticotropin, FSH, LH, prolactin
Hypothalamic hormones stim 6 which lead to which 6 ant pituitary hormones and act where
CRH- ACTH- adrenal TRH- TSH- through GnRH- FSH-ovary.teste GnRH- LH- ovary.teste PIH/PRH- PRL- mammary GHRH/SS-GH-skeletal muscle and bone
Posterior pituitary hormones
Controlled by what
Make what
Hypothalamus
ADH and oxytocin
Control of pituitary secretion
Which vessels
Process
Hypothalamic and hypohysial portal vessels
Hypothalamic releasing/inhibiting. Receives NS signals, reacts by controlling hormones.
