Chapter 11 - Endocrine Glands Flashcards
Endocrine glands lack []s, which are present in exocrine glands?
ducts
Which portion of the pancrease acts as an endocrine gland?
The pancreatic islets (islets of Langerhans)
What are the 4 chemical classes of hormones?
Amine
Polypeptide and Protein
Glycoproteins
Steroids
Amine hormones are derived from tyrosine and [].
They include hormones secrete by what 3 endocrin glands?
- tryptophan
- adrenal medulla, thyroid, pineal glands
What are the different types of protien/polypeptide hormones?
ADH (vasopressin)
Oxytocin
Insulin
Glucagon
ACTH
Parathyroid hormone
What are 2 examples of glycoproteins…hint - reproductive things
FSH - follicle stimulating hormone
LH - luteinizning hormone
Steroid hormones are derived from [].
What are 4 examples?
cholesterol
Testosterone, estradiol, progesterone, cortisol
Which types of hormones can enter through cell membranes, yes or no?
Amine
Protein
Peptide
Steroid
Glycoprotein
Amine - maybe?
Protien - no too large
Peptide - no too large
Steroid - yes, lipidphilic
Glycoprotein - reacts on outside of cell membrane
Lipophilic hormones include [] hormones and [] hormones?
Steroid
Thyroid
What are the 2 derivatives of thyroid hormones? Are the steroids?
T4 - thyroxine
T3
No, these are not steroids - they are just small and nonpolar like steroids.
There are 3 requirements for a chemical to act as a hormone (or neurotransmitter) on regulation…what are the 3 requirements?
- Target cells must have specific receptor proteins that combine with the regulatory molecule
- combination of the regulatory molecule with its receptor proteins must cause a specific sequence of changes in target cells
- must be a mechanism to turn off the action of the regulator
Lipid soluble hormones can pass through the plasma membrane…so they don’t need receptor proteins, right?
No, they have receptor proteins in the cytoplasm. These receptor proteins bind the hormone ligand and then enter the nucleus to interact with a specifc DNA sequence to being mRNA synthesis
Receptors for lipophilic hormones are called [] receptors, and they function like [] factors.
Nuclear hormone
transcription
When a steroid hormone binds to its receptor, it must first [] before stimulating genetic transcription…
Dimerize
(specifically the steroid hormones make a homodimer - 2 of the same type of receptors.)
- The steroid hormone influencing their target tissue by stimulating genetic trasncription is known as []…
- Requires rougly [] minutes to work
Genomic action
30 minutes
Are thyroid hormone receptor proteins located in the nucleus bound to DNA?
Yes
What are the 2 receptors that bind to the thyroid hormone response element of DNA?
What is the association of 2 thigns called?
- Throid hormone receptor (for T3) and 9-cis-retinoic acid (a receptor for Vitamin A)
- Heterodimer
What is the primary (blood) carrier of T4?
Thyroxine-binding-globulin (TBG)
Which type of hormones ustilize a 2nd messenger system?
Catecholamines
polypeptides
glycoproteins
What are the 3 different membrane enzymes that a secondary messenger could activate?
Adenylate cyclase
Phospholipase C
Tyrosine Kinase
What reaction does adneylate cyclase catalyze in the cytoplasm?
ATP –> cAMP + PPi
Which enzyme within the cytoplasm only becomes active when cAMP binds to its regulatory subunit?
Protein Kinase
What enzyme within the cell hydrolyzes cAMP into its inactive form?
phosphodiesterase
Fill in the Blank -
Stimulation of alpha1-adrenergic receptors by epinephrine, activates the target cell via the [] Second messenger system…
Ca2+
What membrane protein is known to be activated by epinephrine binding Alpha1 receptrs (that precede Ca2+ second messenger system)
Phospholipase C
Phopholipase C splits a membrane phospholipid into 2 parts, what are they? And which one is involved in Ca2+ 2nd messaging?
- Inositol triphosphate (IP3)
- Diacylglycerol (DAG)
IP3 is used in Ca2+
Which protein does Ca2+ bind to in a cell to cause then cause protein kinases to become active?
calmodulin
What is the membrane receptor for insulin (and other growth factors) known as?
Tyrosine kinase
This organ is on the ingerior aspect of the brain in the region of the diencephalon and is also called the hypophysis
pituitary gland
What is another name for the anterior pituitary?
What is another name for the posterior pituitary?
adenohypophysis
neurohypophysis
The adenohypophysis consists of 2 parts - what are they?
- Pars Distalsi (or anterior pituitary) = round portion and major endocrine part
- Pars tuberalis = sheath around the infundibulum
The pituitary gland and the hypothalamus are connected via what stalklike structure?
infundibulum
The par nervosa is a part of what section on the pituitary gland?
neurohypophysis (or posterior pit)