Lecture 6 2/11/14 Flashcards
Pancreas is both what type of organ?
Endocrine and Exocrine
Give an example of an Exocrine Component?
Acinar cells
Acinar cells make up majority of the mass of the pancreas
Give an example of an Endocrine Component?
Islet of Langerhans, small clumps of cells
Name the 3 Cell Types
Alpha Cells
Beta Cells
Delta Cells
What are Alpha Cells?
They produce glucagon. Glucagon and insulin are involved in blood homeostasis. One will increase blood glucose, and the other one will decrease blood glucose.
Describe Glucagon
break glycogen down at the liver and release it into the bloodstream as glucose.
Increases blood glucose levels by breaking down glycogen specifically at the liver.
Two main areas where Liver and Muscles are glucose stores. Muscle glycogen for energy source. The liver stores glycogen, which is released as glucose in the bloodstream for over a long period of time.
Function of Glucagon
Increase blood sugar levels
Glucagon Inhibits what?
Somatostatin. It is an HGH-IH, Human Growth Hormone Inhibitor. Produced by the Hypothalamus.
What are Beta Cells?
They produce insulin
What is insulin’s job?
job is to shuttle the sugar, that is in the blood into the cells that need it.
Insulin’s job is to decrease blood sugar. Insulin is highly anabolic; build something up. Also to lower blood sugar levels.
It also transports amino acids into the cells.
Example: Coke and a Snickers bar. You get a huge spike in blood sugar, so you have a rebound, insulin secretion, large insulin secreted, because there’s a huge drop in blood sugar levels.
Also what else is insulin’s function?
Lowers blood sugar levels. Makes you feel tired. Systemic and also due to what is happening to the brain.
What is diabetic coma?
not enough insulin. Increases in blood sugar in the blood, but not enough sugar in the cells.
What is insulin shock?
is, take too much insulin and shuttle all that sugar, from the bloodstream into the cells to be stored but there’s no more flowing around for the brain to use and you can die. Brain loves oxygen and glucose.
What are Delta Cells?
are the 3rd cell type found in the islets and their job is to produce the somatostatin.
Pineal Gland
cone shape/pea gland at the roof of the 3rd Ventricle. It is found in the brain. Produces melatonin which is Pinealcytes
What are Pinealcytes?
is the main cell type of the Pineal Gland, that produces melatonin. Plays an important role in regulating the sexual endocrine glands and internal biological clocks.
Describe the daylight hours and levels of production of melatonin?
During daylight hours, you see a decrease in melatonin production.
Based on the amount of light brought into the eyes. So an increase in the amount light brought in, causes a decrease in melatonin production, which causes an increase ovarian function.
What does a decrease in daylight hours do to levels of production of melatonin?
A decrease in daylight, at night time, brought into eyes, causes an increase in melatonin production and a decrease in ovarian function (hormone production).
Thymus Gland
Lies behind the sternum, anterior to and superior, on top of, the heart.
It has a number of different cell types in there, but a large number of those are known as Thymocytes.
It is large in young children and gets smaller as we get older.
T-Cells, T-Lymphocytes, mature here. Implicated in auto-immune diseases. Helps us develop the immune system early on and our survival.
Thymus Gland Produces What?
Thymocin
4 Mechanisms to Increase Blood Pressure
Angiotensin, ADH: vasoconstriction and retention of fluids at the collecting ducts, the kidneys, aldosterone, thirst, Angiotensin II.
What mechanism decreases blood pressure?
ANH - Atrial Natriuretic Hormone
Atrial Natriuretic Hormone
Secreted by specialized cells within the atrial walls;
Produced by Atria, upper chamber in heart and to decrease blood pressure.
When the walls of the atria stretch too much, they produce this hormone and release it into the bloodstream.
Shuts down the other 4 mechanisms to decrease blood pressure. Beta Blockers and ACE inhibitors are used to decrease blood pressure.
Prostaglandins
Local tissue hormones that function to alter activities of adjacent cells.
Local tissue hormones, which is part of the healing process.
Act on Cyclic AMP to cause varied effects.
Involved in Vasoconstriction, Vasodilation, activating white blood cells, allergy and asthma response.
