Ch 18 The Endocrine System Flashcards
The nervous and endocrine systems coordinate to maintain what
Homeostasis
Define hormone
A chemical messenger released in one area of the body that regulates activities in other areas of the body
The target of the hormone is those other areas of the body
What are exocrine glands
Sweat or oil glands?
That have ducts that can lead to the body’s service or into body cavities or organs
What are endocrine glands?
Ductless glands
They secrete their product directly into interstitial fluid
Which diffuses with the blood?
And then the blood transports the hormones
What is the quantity needed for hormones
Small amounts because it takes very little for them to function properly
Circulating levels of hormones are low
What must hormones bind to
A specific receptor on a Target cell
What are the characteristics of receptors on a hormone as far as their longevity
They are constantly being made and broken down
They have 2,000 to 100,000 receptors on one cell membrane
What is upregulation?
An increase in the number of receptors so the cell is more sensitive to hormones
What is down regulation
A decrease in the number of receptors so the cell is less sensitive to hormones
Example would be type 2 diabetes
What is endocrinology
The study of hormones and diagnosis and treatment of hormonal diseases
How do water soluble hormones travel
They travel the blood by dissolving in the plasma
How do lipid soluble hormones travel?
they are bound to a transport protein made in the liver
What are the three functions of lipid soluble hormones
To make lipid soluble hydrogen temporarily H2O soluble
To prevent the loss of hydrogen from the kidneys( too big to be excreted)
To maintain the level of lipid solubles in the blood
How do The mechanisms of hormone actions function in synthesis
They function in the synthesis of molecules
How do the mechanisms of hormone action function and cell permeability
They changed the permeability of the cell membranes which means allowing things in or out
How do the mechanisms of hormone actions affect metabolic reactions
They alter the rate of metabolic reactions
For example, hyperthyroid or hypothyroid?
How do the mechanisms of hormone action affect contraction of involuntary muscles?
They cause the contraction of involuntary muscles
Uterine cramps from the manufacturer of prostaglandin
Ibuprofen helps. Uterine cramps but only at the beginning if taken later are not helpful
Actions of lipidsoluble versus water-soluble hormones
Receptors are located in the target cells
Versus
These hormones cannot pass through the phospholipid bilayer so receptors are integral proteins in the cell membrane
The receptors located in the target cells are lipid soluble
The hormones that cannot pass through the phospholipid bilayer so have integral proteins as receptors in the cell membrane are water soluble
Lipidsoluble versus water soluble hormones
The hormone enters the cell and binds to activated receptors in the cytosol or nucleus
Lipid soluble
Lipid soluble versus water soluble hormones
The hormone acts as a first messenger and a second messenger is required
Water soluble
Lipidsoluble versus water soluble hormones
Once the hormones are bound together, the receptor hormone complex alters gene expression by turning segments of the DNA on or off, meaning it turns protein synthesis on or off
Lipid soluble proteins
Lipidsoluble versus water soluble hormone actions
After the receptor hormone complex alters gene expression by turning segments of the DNA on and off, the DNA is transcribed into RNA which controls protein synthesis and newly made proteins alter the cell’s activity
Lipid soluble hormone actions
Lipid soluble versus water-soluble hormone actions
The hormone binds to receptor on integral protein activating a g protein in the cell membrane
The g. Protein activates adenylate cyclase
Adenylase cyclase converts ATP into camp and the cytosol
Water-Soluble hormone actions
