T1- Hormone Reg Flashcards
What are the three rates and rhythms of hormone secretion?
Dinurnal, pulsatile and cyclic.
- These operate within feedback systems, affecting only cells with appropriate receptors!
What are the organs of the endocrine system?
- Hypothalamus
- Pineal Gland
- Pituitary
- Thyroid
- Parathyroid
- Thymus
- Adrenals
- Pancreas
- Testes
- Ovaries
Which organ in the body has the ability to inactivate hormones, rendinger the hormone more water soluble for renal excreation?
The lovely LIVER.
What are two main causes of hormone release?
- Response to an alteration in the cellular environment.
2. To maintain a regulated level of certain substances or other hormones.
Hormone transport: Differentiate the difference between water and lipid soluble hormones regarding their circulation.
Water-soluble hormones circulate in FREE, UNBOUND forms
Lipid soluble hormones primarily circulate BOUND TO A CARRIER
Cellular mechanism of Hormone action: Differentiate between up and down regulation.
Up regulation: low concentrations of hormone INCREASE the number of receptors per cell.
Down regulation: High concentrations of the hormone DECREASE the number of receptors.
Where are hormone receptors located?
in or on the plasma membrane or in the intracellular compartment of the target cell
Which type of hormone (water-soluble or lipid-soluble) are of high molecular weight and cannot diffuse across the plasma membrane?
Water soluble
Which type of hormone (water-soluble or lipid-soluble) easily diffuse across the plasma membrane and bind to _________ or _________ receptors?
lipid-soluble
cytosolic or nuclear
Under what type of hormones are both first and second messengers?
water soluble hormones
Name 3 water soluble hormones that act as second messengers.
calcium
cyclic adenosine monophosphate (cAMP)
cyclic guanosine monophosphate (cGMP)
Steroid hormones are lipid soluble hormones. What are some of them?
androgens, estrogens, progestins, glucocorticoids, mineralocorticoids, thyroid
What do lipid soluble hormones activate?
RNA polymerase
DNA transcription and translation
Posterior pituitary hormones are synthesized with binding proteins in ______ and _______ nuclei of the hypothalamus.
supraoptic and paraventricular nuclei
What two hormones are secreted by the posterior pituitary?
Antidiuretic hormone (ADH) - formerly called vasopressin
Oxytocin
Which hormone secreted by the posterior pituitary controls plasma osmolarity
ADH
What is the function of oxytocin?
Oxytocin is responsible for uterine contractions and milk ejaculation in lactating women (suggested that it reduces the brain’s responsiveness to stressful stimuli, especially in the pregnant and postpartum states)
Use in treatment of anxiety disorders and autism is being explored.
Which hormone of the pancreas likely controls the secretion of glucagon?
Gastrin
What are the functions of Grehlin from the pancreas?
- stimulates GH secretion
- controls appetite
- regulation of insulin sensitivity
___ is released by F cells in response to hypoglycemia and protein-rich meals.
Pancreatic polypeptide
Which pancreatic hormone signals satiety, inhibits gallbladder contraction and exocrine pancreas secretion, and increases gastric acid secretion?
pancreatic polypeptide
Pancreatic polypeptide is frequently increased in _____.
pancreatic tumors and in diabetes
80% of an adrenal gland’s total weight is attributed to which section?
adrenal cortex
What are the 3 layers of the adrenal cortex?
Zona glomerulosa
Zona fasiculata
Zona reticularis
Which region of the adrenal gland is innervated by the sympathetic and parasympathetic nervous systems?
adrenal medulla
The adrenal cortex is stimulated by ____.
ACTH
The adrenal cortex releases which hormones?
glucocorticoid hormones
mineralocorticoid hormones
adrenal estrogens and androgens
What are the effects of glucocorticoid hormones?
- direct effects on carbohydrate metabolism
- anti-inflammatory, growth-suppressing effects
- influence awareness and sleep habits
The most potent naturally occurring glucocorticoid is ____.
cortisol
Which hormones of the adrenal cortex affect ion transport by epithelial cells?
mineralocorticoid hormones
How do mineralocorticoid hormones affect ion transport by epithelial cells?
- they increase the activity of the sodium pump of the epithelial cells
- cause sodium retention and potassium and hydrogen loss
The most potent naturally occurring mineralocorticoid is ____.
aldosterone
What is aldosterone regulated by?
the renin-angiotensin-aldosterone system
What cells in the adrenal medulla secrete catecholamines (epi and norepi)?
Chromaffin cells
T/f Catecholamines promote hyperglycemia.
T
You need that suga to run away
Endocrine system reacts with the nervous system to respond to ___
stressors
The stress response involves the ___ system
immune
Neuroendocrine response to stress is influenced by what hormone from the hypothalamus?
CRH - Corticotropin-releasing hormone
Name the 3 tests of the endocrine function.
Radioimmunoassay
ELISA
Bioassay
T/f As the thyroid gland ages, it becomes glandular atrophy, fibrosis, nodularity and increased inflammatory infiltrates
True
What are the alterations in calcium balance the parathyroid gland undergoes?
Inadeaquate intake, malabsorption or renal changes
As we age, we decreased the clearance of what hormone from the adrenal glands?
cortisol
When we are old and in retirement we won’t have any stress hormone!
What gland contains two lobes lateral to the trachea?
thyroid gland
What is the small band of tissue that joins the two lobes of the thyroid gland?
isthmus
The thyroid gland is composed of FOLLICLES. THe follicles are composed of follicular cells that surround a viscous substance called _______.
colloid
What do the parafollicular cells of the thyroid gland secrete?
calcitonin and somatostatin
What is another name for calcitonin?
What is the action of calcitonin?
thyrocalcitonin, acts to lower serum calcium levels by inhibition of bone resorbing osteoclasts
What are the main two hormones involved in thyroid hormone secretion regulation?
thyrotropin releasing hormone and thyroid stimulating hormone
What are the two hormones secreted by the thyroid gland?
90% T4 and 10% T3
What 3 carrier proteins does T3 and T4 bind to in the circulation?
- thyroxine -binding globulin
- thyroxine - binding prealbumin
- albumin
How does thyroid hormone effect cell metabolism?
altering protein, fat, and glucose metabolism, and as a result, heat production and oxygen consumption are increased.
What are the small glands located behind the upper and lower poles of the thyroid gland?
Parathyroid glands
What are the actions of parathyroid hormones?
Regulator of serum calcium
Antagonist of calcitonin
Is the pancreas and endocrine or exocrine gland?
BOTH!
endocrine = producing insulin and glucagon
exocrine = producing digestive enzyme
Endocrine Houses what cells involved in the regulation of serum glucose?
name each cell and what they secrete
Islets of langerhan cells alpha = glucagon secretion beta = insulin secretion delta = somatostatin and gastrin F cells = pancreatic polypeptide
Insulin is secreted by the beta cells, and regulated by chemical, hormonal, and neural mechanisms.
-Does an increase or decrease in blood glucose level stimulate insulin production?
increase
Insulin facilitates the rate of glucose uptake into body’s cells. What is the key component in maintaining this normal cellular function?
sensitivity of the insulin receptor
–insulin resistance can be caused by decreased sensitivity to the receptor
