Endocrine System Flashcards
8.1 INTRO TO ENDOCRINE SYSTEM 8.2 HORMONES THAT AFFECT BLOOD SUGAR 8.5 REPRODUCTIVE HORMONES
In 1889, scientists removed the pancreas from dogs and found that:
Rapid weight loss
Fatigued
Ants began gathering in the kennel
Endocrine System
Is an
Designed to
Stimulated by
Is an information signal system that uses blood vessels as information channels
Designed to maintain control over a long duration
Stimulated by the pituitary, secrete chemicals that affect the nerve activity of the hypothalamus
Nervous System
Is an
Designed to
Stimulated by
Is an information signal system that uses nerves to conduct information
Designed to adjust quickly to changes in the environment
Hypothalamus regulates the pituitary gland through nerve stimulation
The nervous system and endocrine system interact and work together to
provide control of organs and tissues
The Endocrine System Instrumental in regulating bodily process such as
Metabolism
Growth/development
Tissue function
Mood
The Endocrine System
An integrated system of
small organs that involve the release of signaling molecules known as HORMONES
Hormone
chemical regulators produced by cells in one part of the body that affect another part of the body
Only a small amount required to alter cell metabolism
2 Types of Hormones
Steroid/Lipid Hormones
Protein/Peptide Hormones
Steroid/Lipid Hormones
Made from cholesterol and includes male and female sex hormones and cortisol
They are not soluble in water but are soluble in fat
Cortisol - hormone that stimulates the conversion of amino acids to glucose by the liver
Eg. estrogen
Protein/Peptide Hormones
They contain chains of amino acids of varying length and are soluble in water
Eg. insulin and growth hormone
Steroid Hormones
Hormone diffuse from capillaries and into the target cells
Then, it combines w/ receptor molecules in the cytoplasm
This Hormone-receptor complex moves into nucleus, attaches to a segment of chromatin that has a complementary shape, activating a gene
So a message is sent to the ribosome in the cytoplasm to produce a specific protein
Protein Hormones
Protein hormones combine with receptors on the cell membrane
Activates production of an enzyme which causes the cell to convert ATP into cAMP
cAMP functions as a messenger, activating enzymes in the cytoplasm to carry out normal function
Pancreas
Pancreas contains 2 types of cells: Hormone-producing cells and Digestive-enzyme-producing cells
Adrenal Glands location and made up of
Location: above each kidney
Made up of 2 glands encased in one shell: adrenal medulla & adrenal cortex
Insulin
Location of hormone production
Effect
Islet of Langerhans (pancreas)
Increases permeability of cells to glucose; increase glucose uptake
Allows for the conversion of glucose to glycogen
Result: decrease in blood sugar
Glucagon
Location of hormone production
Effect
Islets of Langerhans (pancreas)
Promotes the conversion of glycogen to glucose
Result: increase in blood sugar
Cortisol
Location of hormone production
Effect
Adrenal cortex
Promotes the conversion of amino acids to glucose
Promotes the breakdown of fats to fatty acids
Decreases glucose uptake by the muscles (no by the brain)
Results: increase in blood sugar in response to stress