Endocrine system Flashcards
Bootcamp
what are the ways hormone can be secreted?
Endocrine, Paracine, autocrine
Endocrine
through the blood stream
Paracrine
to neighboring cells
autocrine
onto the same cell that is secreting the hormone
what are the three types of hormones
Peptide hormone, steroid hormone, and amino acid derived hormone
peptide hormone
(protein hormone)
- produced in the Rough ER and made of amino acid connected peptide bonds
what action does peptide hormone perform
binds to cell surface receptors because they cannot pass freely through the cell membrane as a result of being water-soluble (and not soluble).
- indirect stimulation
what are two ways the peptide can receive a signal
Secondary messenger and ligand-gated io channels
what are some common secondary messengers
- cAMP (cyclic AMP)
- IP3 (inositol triphosphate)
- DAG (diacylglyercol)
- Calcium ions (CA+2)
G protein coupled receptors (GPCRs)
are cell surface receptors that can initiate a secondary messenger response after binding to a peptide hormone extracellularly
Receptor Tyrosine Kinases
are another cell surface receptor that dimerizes and intimates secondary messenger responses upon binding to a peptide hormone
Signal amplification
the second messenger system of peptide hormone signaling allows for quick and immediate pychsiological changes
ligand-gated ion channels
change the shape upon binding to peptide hormones allowing ions to flow across the cell membrane
- no secondary messenger involved
steroid hormones
produced in the smooth ER and made up of a fused 4-ring structure
- all steroid hormones are derived from cholesterol
what action does steroid hormone perform
requires a protien carrier to travel through the blood stream due to being lipophilic
- Freely crosses the cell membrane and binds to receptors either int he cytoplasm or the nucleus to form molecule-receptor complexes that bind to DNA and influence gene transcription
direct stimulation
Freely crosses the cell membrane and binds to receptors either int he cytoplasm or the nucleus to form molecule-receptor complexes that bind to DNA and influence gene transcription
amino acid derived hormones
can have both properties of peptide hormones and steroid hormones
- produced in rough ER and cytosol
- mainly derived from the amino acid tyrosine
hypothalamus
coordinates the bodies internal enviorment and maintains homeostasis
pituitary gland (hypophysis)
is under the hypothalamus and is composed of tow lobes: Anterior pituitary and posterior pituitary
posterior pituitary
known as neurohypophysis because it was made of neuronal tissue and a direct neuronal extension of the hypothalamus
what are the two hormones that are stored and released by the posterior pituitary (and produced by the hypothalamus)
Antidiuretic hormone (ADH aka vasopressin) and Oxytocin
Antidiuretic hormones (ADH aka vasopressin)
decreases urination by increasing water retention
- targets nephrons increasing the number of aquaporins for water reuptake
oxytocin
causes uterine contraction during child labor and the release of milk during breastfeeding (mammary gland)
- also plays a important role in facilitating maternal behavior )drive to be a good parent)
anterior pituitary
- Known as the adenohypophysis, it is made of glandular tissue, and produces its own hormones.
- It is connected to the hypothalamus through a hypophyseal portal system, which allows for quick diffusion of hormones through a portal vein.
- Hypothalamic-releasing hormones are released by the hypothalamus to stimulate the
anterior pituitary to release other hormones.
GnRH (gonadotropin-releasing hormone)
causes release of luteinizing hormone (LH) and follicle stimulating hormone (FSH).
TRH (thyrotropin -releasing hormone)
causes
release of thyroid stimulating hormone (TSH).