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)
Fill in the blank -
The hormones secreted by the anterior pituitary (pars distalis) are called [] hormones…
trophic
List the 6 hormones released by the par distalis -
Growth Hormone, GH (somatotropin)
Thyroid-Stimulating Hormone, TSH (thyrotropin)
Adrenocorticotropic Hormone, ACTH (corticotropin)
Follicle-stimulating hormone, FSH (folliculotropin)
Luteinizing hormone, LH (luteotropin)
Prolactin (PRL)
- Growth hormone -
- Promotes [] movement into cells and thus the growth of cells
amino acids (and thus proteins)
Thyroid Stimulating hormone (TSH)
Stimulate the [] gland to produce and secrete [], (T4) and triodothronine ([]).
Thyroid
Thyroxin
T3
Adrenocorticotropic hormone (ACTH) -
stimulates the [] cortex to secrete the glucocorticoids such as []
adrenal
cortisol
Follicle stimulating hormone (FSH)
Stimulates the growth of ovarian [] in femals and production of [] in the [] of males
follicles
sperm in the testes
Lutenizing Hormone -
Stimulates [] and conversion of ovulated ovarian follicle into an endocrine structure called a [] []
ovulation
corpus luteum
Prolactin (PRL) -
Best know function is the stimulation of [] production in mammary glands of women after the birth of a baby
milk
What two hormones are considered the gonadotropic hormones?
Lutenizing Hormone
Follicle stimulating Hormone
What 2 hormones does the pars nervosa store and release?
Where are these hormones produced?
ADH - antidiuretic hormone
Oxytocin
Paraventricular & Supraoptic Nucleus
What 2 functions does oxytocin stimulate?
- contractions of uterus during child birth
- contractino of mammary gland alveoli and duct - which leads to milk let-down.
What two neuron cell bodies in the hypothalamus make ADH and Oxytocin?
Supraoptic and paraventricular nuclei
The 2 hormones produced in the hypothalamus travel down what tract to the posterior pituitary?
hypothalamo-hypophyseal tract
The hypothalamo-hypophyseal portal system connects 2 “things” via the [] eminence with blood flow. What are the 2 things.
- it connects the hypothalamus with the anterior pituitary.
- The median eminence sits on the basilar portion of the hypothalamus and is connected to the anterior pit through 2 portal beds of capillaries.
- this is how the hypothalamus sends releasing or inhibiting hormones to the ant pit.
State the hormone released by each hormone regulator made in the hypothalamus and sent to the Anterior Pituitary
- Thyrotropin-releasing hormone (TRH) -
- Corticotropin-Releasing Hormone (CRH) -
- Gonadotropin Releasing Hormone (GnRH) -
- Growth Hormone-Releasing Hormone (GHRH) -
- Somatostatin -
- Prolactin inhibiting hormone (actually just dopamine) -
- Secretion of TSH - thyroid stimulating hormone
- Secretion of ACTH
- Secretion of both FSH and LH
- secretion of growth hormone (GH)
- inhibits the secretion of growth hormone
- Inhibits the secretion of prolactin
What are the two sections of the Adrenal Gland?
Medulla (Inner)
Cortex (Outer)
The adrenal cortex secretes what type of hormones []? Do these hormones complement the sympathetic or parasympathetic nervous system?
Catecholamines (Epin, Norepin, Dopamin)
These complement the sympathetic nervous system
What is the dominate steroid secreted by the adrenal gland?
Cortisol
What are the 3 zones of the adrenal cortex?
- Zona Glomerulosa
- Zona Fasciculata
- Zona Reticularis
Which adrenergic receptors aid in the stimulation of the adrenal cortex?
None - the adrenal cortex is not innervated. It is stimulated, hormonally, by ACTH secreted from the ant pituitary.
What is the name of the type of steroids that the adrenal cortex secretes?
Corticosteroids (corticoids)
What are the 3 functional categories of corticosteroids?
- Mineralocorticoids
- Glucocorticoid
- Adrenal Androgens
This type of corticoid is produced in the zona glomerulosa and stimulates the kidney to retain [] and [] while excreting K+ in the urine
What is this type of corticoids most potent steroid?
- Mineralocorticoid
- Na+ and Water
- Aldosterone
- What is the predominant glucocorticoid?
- Where is this corticoid secreted (mainly)
- Stimulation by what [] causes the secretion of this hormone?
- Cortisol (hydrocortisone)
- Zona fasciculata
- ACTH
The following are some of the effects on metabolism of CORTISOL:
- Stimulation of [] degradation
- Stimulation of [] (production of glucose from amino acids) and inhibition of glucose utilization - which helps to raise [] glucose levels
- stimulation of [] (breakdown of fat) and the release of [] [] acids into the blood
- protein
- gluconeogenesis, blood
- lipolysis, free fatty
Why would inadequate levels of cortisol lead to hypoglcemia?
Cortisol does several metabolic functions that increase blood glucose levels -
stimulates gluconeogenesis, lipolysis - giving more energy molecules of glucose and fatty acids in the blood
What is the precuros for all of the corticoids produced by the adrenal cortex?
Cholesterol
What do the hormones from the adrenal medulla do?
- [] cardiac output
- [] coronary blood vessels
- increase [] alertness
- increase [] rate
- [] metabolic rate
- Rise
- Dilation
- mental
- respiratory
- Elevated
Since glucocorticoids are known to breakdown muscle proteins/fats (gluconeogenesis and lipolysis) - they could be said to be [] towards the anabolic hormones?
Antagonistic
- What are the spherical hollow sacs in the thyroid called?
- These “sacs” contain a cuboidal epithelium layer called [] that synthesize the principal throid hormone - [] ?
- Thyroid follicles
- follicular cells, thyroxin
The interior of thyroid follicles contain what fluid?
Colloid
The thyroid follicles also contain these cells [] that secrete the hormone known as calcitonin?
parafollicular cells
What protein within the colloid of the thyroid follicle binds to oxidized Iodide?
thyroglobulin
Iodide + thyroglobulin can yield 2 different complexes…what are they?
- monoiodotyrosine (MIT)
- attachment of 1 iodide to tyrosine (of thyroglobulin)
- diiodotyrosine (DIT)
- attachment of 2 iodide to tyrosine (of thyroglobulin)
Stimulation by [] allows the T3 and T4 to be hydrolyzed and secrete into the blood…
TSH
[] promotes the inhibition of osteoclasts.
Also this hormone lowers the blood Ca2+ concentration through what?
- Calcitonin
- Urinary excretion of Ca2+
Iodine deficiency goiteris the…
abnormal growth of the throid gland
What is 1 cause of the thyroid going through hypertrophy, goiter?
- Low levels of iodine would lead to low levels of T3 and T4.
- SInce T3 and T4 are low in quantity they cannot provide the negative feedback to shut of TSH from the Ant Pit…so hypertrophy occurs from too much TSH
Hypothyroidism during the brains greatest rate of development period - end of first trimester to sic months after birth - can lead to []?
This can almost be completely reversed by treatment with []
- Cretinism - severe retardation
- Thyroxine
What is the 1 hormone that the parathyroid glands produce/secrete?
Parathyroid Hormone (PTH)
Parathyroid hormone [] blood calciums levels by acting on the [], [], and []
- Increases
- Bone (stimulates osteclast activity), Kidneys (stimulates reabsorption of Ca2+), Intestine
The pancrease is a [] gland, both endocrine and exocrine.
mixed
What are the endocrine portions of the pancrease called?
Pancreatic islets or the Islets of Langerhans
The [] cells of the pancrease secrete glucagon and the [] cells of the pancrease secrete insulin
- alpha - secretes glucagon
- Beta - secretes insulin
How is Glycogen synthetase indirectly stimulated by insulin within skeletal muscles and the liver?
- Glycogen synthetase converts glucose to glycogen. So by insulins action of taking plasma glucose and getting it into the cell…the synthetase can work more to create stored glycogen from glucose.
What process does glucagon start inside the liver? What does this process do?
- Glucogenolysis
- Glucagon stimulates the liver to hydrolyze glycogen into glucose
Glucagon works with several other hormones to aid in raising plasma glucose levels:
- Works with [] to stimulate gluconeogenesis (noncarbs –> glucose)
- Formation of keton bodies from free fatty acids by the liver - []
- hydrolysis of stored fat - []
- glucocorticoids
- Ketogenesis
- Lipolysis
Melatonin is secreted by which gland?
Pineal Gland
Which nucleus from the hypthalamus regulates pineal secretin of []?
- Suprachiasmatic Nucleus (SCN)
- melatonin
What type of nerves inhibit the pineal gland from secreting melatonin at night?
- No nerves do this. Sympathetic nerve inhibit the pineal gland from secreting melatonin during the day
The [] tract acts as the connection between the eyes and the suprachiasmatic nucleus, relaying light/dark information, to either inhibit the pineal gland during the day or stimulate the secretion of melatonin at night?
retinohypothalamic tract
