The Endrocrine System Flashcards
Endo
Means within
Crine
To secrete
Glands
Organs which produce and secrete substances
Chemical messenger
A compound which transmits a message
What hormone does the heart produce
Atrial naturietic hormone
Why do we need the endocrine system
To maintain homeostasis
Homeostasis
The maintenance of relatively constant states within the body
Target cells
Cells processing the receptors for a specific hormone and so are receptive to their effects
Target organ
Organ/tissue containing the target cells for a specific hormone
Difference between endocrine systems exo and endo
What do endocrine glands do
Secrete hormones
Released direcetly into blood stream
Exocrine glands long answer
Secrete eg sweat and tears
Exo external
Release secretions out of the body via ducts
Referred to as ducted glands
Not apart of endocrine systems
10 major endocrine organs
MAIN IN EXAM ALWAYS multiple choice know the table well
Hypothalamus and pit where they found
Within lungs two primary endocrine organs what are they
Function of hormone
Hormones primarily serve to regulate the
metabolic function/cellular activity of other cells
Common hormone effects
– Alteration of plasma membrane permeability/electrical
state
– Stimulation of protein/enzyme synthesis
– Activation/deactivation of enzymes
– Stimulation of secretions
– Stimulation of mitosis
What is the functional classification of hormone
- Trophic hormones
- Sex hormones
- Anabolic hormones
What are trophic hormones
- Target other endocrine gland
Sex hormones
Target reproductive tissues
Anabolic hormones
Bring about anabolism in their target cells
Chemical classification of hormones - based on hormone structure
- Steroid hormones ———> steroid hormones
- Protein / polypeptide hormones
- Modified amino-acid hormones. —————-> non steroid hormones
What is the solubility of hormones
Steroid hormones are lipid-soluble
• Protein/polypeptide hormones are water-soluble
• Majority of modified amino-acid hormones are water-
soluble. Exceptions: thyroid hormones – lipid soluble
Receptor location depends on the solubility of the hormone
Where are receptors located for hormones
Either inside or on the surface of the target cell
Receptor location depends on the solubility of the hormone
How do water soluable hormones work
As they are unable to bund to phospholipid belayer.
They bund to the receptor on the surface of the target cell
As they cannot pass the plasma membrane, water soluable hormones do not affect gene transcription
How do lipid soluable hormone work
• Are able to cross the phospholipid bilayer and so …
• Bind to receptors inside the target cell
• As they can pass the plasma membrane, lipid-soluble
hormones are able to alter gene transcription
• They are therefore able to cause alteration of cellular
What are steroid hormones
Steroid hormones are lipid-soluble
• Secreted by, e.g. adrenal cortex, ovaries and testes
Steroid hormones are transported through the blood
by specialised carrier proteins
• They are mostly derived from cholesterol
Two main classifications of steroid hormones
Corticosteroids
Sex steroids
Examples of corticosteroids
Cortisol
Aldosterone
Non steroid hormones- protein/ polypeptide hormones
Protein/polypeptide hormones are water-soluble
• Secreted by, e.g. pituitary, pancreas