Lecture 5 2/6/14 Flashcards
Calcitonin
is a hormone produced by the c-cells, also known as parafollicular cells, cells around the outside of the follicle. Calcitonin tones down blood calcium. We are pulling out calcium out of the blood and storing it into bone. Clasts are ones that gobble up bony matrix to release calcium into the blood. Osteoblastic activities increase and osteoclastic activities decrease.
What else produces calcitonin
Thyroid Gland or Thyrocalcitonin
Parathyroid Glands
lie on the back of the thyroid, but cannot differentiate.
Only cell histologic slices that you can see the difference between the thyroid and parathyroid tissue.
Principle or Chief Cells Produce what?
Parathyroid Hormone
Parathyroid Hormone is antagonistic to what?
Calcitonin
Osteoblasts for Parathyroid hormone increase or decrease activity?
Osteoblastic activity is decreased while osteoclastic activity is increased.
Function of Parathyroid Hormone
Increase blood calcium
Helps absorb more calcium from our diet
Works in conjunction with Vitamin D
Bones are dynamic structures because why?
They are constantly remodeling, laying down bone and then re-absorbing them back up to maintain blood calcium level.
Calcitonin and Parathyroid help maintain what?
Calcium homeostasis in the blood
Adrenal or Suprarenal Glands Location
Sit atop the kidneys
Cats: Superior and Medial
Adrenal Cortex of Adrenal Gland
Outer region of the adrenal gland
Zona of Glomerulosa
Outermost zone
Secretes Mineralcorticoids: Aldosterone
Aldosterone General Function
Hormone is involved in retaining sodium and water in the kidney tubules
Helps maintain proper electrolyte composition
Renin Angiotensin Pathway Process 1:
If we have a decrease in blood volume, what’s gonna happen to blood pressure in general, leads to a decrease in blood pressure. Kidneys are a perfect organ to monitor the blood pressure. As the blood pressure drops as it travels through the kidneys it stimulates a release of a hormone called renin. Kidneys are a endocrine organs because they produce a hormone that has affects the body.
Renin Angiotensin Pathway Process 2:
Renin’s job is to convert angiotensinogen. Angiotensinogen is a precursor molecule produced by the liver. Liver produces angiotensinogen. It blowing through the body and through the bloodstream all the time. If renin is not in the bloodstream it’s not then released by the kidneys due to the low blood pressure, then the angiotensinogen is never converted over.
Renin Angiotensin Pathway Process 3
But if there is renin available. Renin’s job is to convert to angiotensinogen I. Angiotensinogen I is a mild vasoconstrictor. Vasoconstrict increases the pressure. We’re releasing hormones to increase blood pressure, because we lost blood volume. The angiotensinogen I travels through the lungs, and the lungs have an enzyme called ACE (Angiotensin Converting Enzyme). Commonly used to help decrease blood pressure. ACE converts Angiotensin I into Angiotensin II, which is a powerful Vasoconstrictor. If you take an ACE inhibiting, you’re inhibiting the conversion of Angiotensin I to Angiotensin II. If you prevent vasoconstriction, then you can decrease your blood pressure. Two of the most common blood pressure medications are beta blockers, which help to inhibit the sympathetic nervous system from causing vasoconstriction. Then ACE inhibitors prevent conversion to Angiotensin II.
Renin Angiotensin Pathway Process 4
Angiotensin II is a powerful vasoconstrictor, it also does is it stimulates the release of Aldosterone. Aldosterone also brings in Sodium to keep water. So the ultimate goal is to increase blood fluid volume by bringing in more water in. So that we can vasoconstrict.
Renin Angiotensin Pathway Process 5
Angiotensin II also increases ADH production, which prevents you from losing fluid through the kidneys. We also call ADH, vasopressin, which means it causes vasoconstriction.
Renin Angiotensin Pathway Process 6
The last thing that Angiotensin II does, is that it increases thirst.
Overarching or Ultimate goal of Renin Angiotensin Pathway Process?
Increasing Thirst
Increasing ADH
Increasing Aldosteron
And a Powerful Vasoconstrictor
Ultimately increasing blood pressure and blood fluid volume through many ways
Zona Fasciculata
Next Deepest Layer
Secretes: Glucocorticoids - Cortisols
Function of Gluconeogenesis
To make glucose from other molecules especially from fats and proteins
Promote normal metabolism
Cortisol is what?
Our stress hormone
Main Function of Cortisol?
Increase blood sugar levels
Reduce inflammation
