Endocrine system Flashcards
how does the endocrine system help maintain homeostasis
Endocrine system makes chemical to help regulate levels in the body
2 organ systems incharge of internal control
1) Nervous system
2) Endocrine system
Endocrine system
contains glands that produce chemical messages called hormones
slower nerve impulses, regulate longer body processes (growth, reproduction)
Hypothalamus
part of the brain that connects the nervous system with the endocrine system
Glands
a group of cells that secrete a chemical substance called a hormone
Pituitary gland
main gland of the endocrine system
Completely controlled by the hypothalamus
what happens when pituitary gland receives messages from hypothalamus
releases its own chemicals or stimulates other glands to release theirs
Hormones
Chemical messages that get secreted into the blood
The info in hormones tells the body and cells what to do
Most hormones are released because of negative feedback system
hGH
human growth hormone
What happens to blood sugar levels when you grow
Blood sugar levels lower as growing cells use glucose
What does the hypothalamus do when blood sugar is low
It detects low blood sugar and signals the pituitary gland
What does the pituitary gland do in response to low blood sugar
releases hGH into the bloodstream
What is the role of hGH in blood sugar regulation
hGH signals liver cells to release more glucose into the blood
How do cells continue to grow with the help of hGH
Cells use the extra glucose released by the liver
What stops the production of hGH
Increased blood sugar signals the hypothalamus to stop hGH production
2 types of hormones
1) Steroid hormones
2) Amino acid based hormone
Steroid hormones
Made from lipids (fats)
Easily diffuse across the cell and nuclear membranes to combine with cell receptors in the nucleus
Amino acid based hormone
Made from proteins
Do not diffuse across cell membranes
Cannot go directly into the nucleus therefore they alter the behaviour of the other molecules in the cell
Adrenal glands
Prepare body for stressful situations
1) Outer portion
2) Inner portion
Outer portion of adrenal glands
Adrenal cortex
Secretes steroid hormones which cause increase in sugar available
helps increase blood pressure
Helps to deal with temperature changes, illnesses
Inner portion
aka adrenal medulla
fight or flight amino acids
secreted by inner portion of adrenal glands
Epinephrine - aka adrenaline
Norepinephrine
what do Epinephrine and Norepinephrine do
Responsible for “adrenaline rushes”
Increases heart rate, blood pressure, respiration, increase efficiency of muscles
