Week 6 - Study Guide - Part 1 Flashcards
Nervous and endocrine systems:
what kind of systems?
Both are control systems:
Help to regulate and coordinate the body processes
But are not the same
Differences in Nervous and Endocrine
Nervous is Fast and ends suddenly
Endocrine is slow but long-lasting
Hormone producers are:
specific glands and some organs
The pancreas and gonads have both endocrine and exocrine function
Endocrine means you are releasing
releasing the substance into the bloodstream
Pancreas
Exocrine means production
production of something that goes into a hollow tube.
Gonads
example: digestive system, urinary, respiratory, reproductive
Tissues can release their own hormones
adipose tissue
intestines
stoach
kidneys
heart
What is the Master Gland
the Hypothalamus
What gland is homeostasis central?
Hypothalamus
Tons of neural and endocrine influence
- Does nervous system function
- Also aids in a lot of endocrine function
- It is the interconnection between regulatory systems
Endocrine - means -
- you are releasing the substance into the bloodstream
- blood has to pump around the body
- The reactions at the body tissue are varied and complete
- Process is long term
- Slower regulation
- But has long-lasting impacts
Exocrine - means -
Production of something that goes into a hollow tube.
AND - very quick and ends suddenly
EX - digestive, urinary, respiratory, and reproductive systems
What Tissues release their own hormones?
- Adipose
- Intestines
- Stomach,
- Kidneys
- Heart
What is the master gland?
Hypothalamus
Homeostasis central
Neural and endocrine functions
Somatostatin inhibits -
GH
TSH
Vasopressin AKA -
Antidiuretic Hormone
Hormone Mechanisms include:
Change Membrane Permeability - meaning
- A hormone could bind to a receptor
- and Cause the permeability or potential of that cell to change
Potential = Action Potentials
1. Gate opens or closes
2. Depolarization
3. Substance entering or leaving
4. Permeability changes
Hormone Mechanisms include:
Stimulate molecule synthesis -
- to influence the metabolic activity of the cell by causing protein synthesis of molecules
Hormone Mechanisms include:
Activate/deactivate enzymes -
- To have deactivation or activation of enzymes associated with the cell membrane.
- If you change the behavior of an enzyme (increase or decrease) you will change the action of that cell.
Hormone Mechanisms include:
Induce secretory activity
Cause the cell to produce new chemicals.
- Hormone comes in
- binds to receptor
- causing the cell with that receptor to start secreting something new
- it may be a cascade effect
Hormone Mechanisms include:
Stimulate Mitosis
(Growth and Development)
(Growth Hormone)
Specificity Matters anytime you have a receptor–
- Receptor
- It needs to be specific to the signal being sent out
LOCK and KEY
- Receptors are proteins
- Proteins have one shape
- One job
- so when a hormone is released
- and binds to a receptor
- It means that the target cell is specific
Insulin helps regulate what kind of metabolism?
Cellular metabolisms
Where we store our energy
When we store it
Hormone ACTH released from the pituitary gland reacts with –>
certain cells of ADRENAL CORTEX ONLY
Target Cell Behavior:
Target cells have specificity
Activation depends on
- Concentration of hormones in the blood.
- Number of receptors - do we have enough receptors for the hormone and the correct receptors for the hormone?
- Affinity receptor-hormone -
how much affinity the hormone has for a given receptor
Target Cell Behavior:
Two influences at the target cell can be…
Up or Down regulation
(Where the number of hormone receptors increase or decrease.)
Up-Regulation
The hormone will increase the number of receptors available.
Meaning - you can increase the sensitivity of the target cell to that given hormone
Down-Regulation
Hormone gets sent out but, over time, the body stops responding - in part because the receptor numbers are going down and down.
Example of Down-Regulation
Diabetes Type 2
Person may have normal insulin l evels or even high insulin - BUT-
-It is as if the body has stopped responding.
-Amount of hormone may be normal or high, but receptors themselves are not listening.
Example of Down-Regulation
Menopause
Body is still releasing certain types of hormones
But cells stop responding
Up-regulation
- Hormone comes into the cell
- Causing cell to synthesize more receptors
- New receptor added to plasma membrane
- Now there are more receptors and more sensors to the hormone
Down-regulation
- Hormone binds to receptor
- Receptor removed from plasma membrane
- Receptor is internalized and degraded
What organ is breaking down
What organ is filtering
Liver is breaking down
Kidneys are filtering
A concentration of hormones reflects…
- Rate of Release
How much you produce (Rate of Release) - Speed of inactivation (at the liver) & Removal (at the kidneys)
How much you inactivate or remove
Inactivation means
- An enzyme comes along and breaks down the hormone.
- Once broken down, it is gone.
- It does not impact the activity of the cell
Removal of stuff…
Kidneys are good at removing nasty things
Liver will break things down, detoxify, and send out into the bloodstream to them be filtered by the kidneys
Two main classes of Hormones (chemically)
- Amino Acid based (protein-based)
- Steroids (cholesterol-based) (lipid-based)
Amino acids (protein-based) - hormones Involve -
Involve 2nd messengers
Amines
thyroxine
peptides
proteins
Steroids - cholesterol (lipid-based) hormones - Involve -
- Intracellular receptors
- Act on genes directly
Gonadal
Adrenocortical
Hormones circulate free or bound -
- Steroids & Thyroid hormones attach to plasma proteins
- Rest circulate without carriers
How do Lipid-based hormones and thyroid hormones (Amino acid-base) travel
- They require a chaperone.
- A carrier protein that helps grab onto a hormone
- Because it does not get along with water
- Steroids are lipid-based - non polar (water is polar) - ton of water in body
- not going to wor well within the body
- However - if we have a carrier protein -
- it can bind to the steroid or thyroid hormone
- through the target cell
- Then the hormone can detach
- and go into the target cell
Hormones that circulate free are everything EXCEPT steroid or thyroid hormones
- these - everything else - can flow around on its own without a carrier
- Because - it gets along well with water
- why it is called a water-soluble hormone
Which form of hormone is slow-acting
Lipid-Soluble hormone
(Steroid)
- Hormone bypasses the plasma membrane
- Binds to an intracellular receptor (intranuclear receptor aka)
- That influences the expression of specific genes in the DNA
- DNA builds the mRNA
- mRNA gets used to build a protein - (Protein synthesis)
Which form of hormone is Fast-acting
Water-Soluble Hormone
Protein based hormone
Amino Acid based
- hormone binds to a surface receptor on the plasma membrane (G-protein)
- Which will cause the activation of an enzyme
- Depicting an enzyme -
- ATP helps create a 2nd messenger (cyclic molecule is always the 2nd messenger)
- this cyclic molecule will have whatever specific effect it has on the cell function
(EFFECT on CELL FUNCTION)
Water Soluble Hormones
ACTIONS
FAST ACTING
1. no entrance.
2. Bind to receptor
3. 2nd messenger system (big reactions from this)
- Fast acting -
due to 2nd messenger - subject to signal amplification - do not need a lot of hormone because of this signal amplification
BIG REACTIONS
Signal Amplification
- one hormone binds to one receptor
- Activates more than one G-protein
- Activates enzymes
- these multiple enzymes can act on many cyclic molecules creating a lot of cAMPs (2nd messengers)
- Those cyclic molecules go off and do even more of whatever their action is
- A bunch of reactions happening
Lipid Hormone Cells
ACTIONS
SLOW - ACTING
1. Enter the cell (pass through the membrane)
2. Bind to the intercellular (intranuclear) receptors
3. Activate the specific gene sequences inside the cell -
4. DNA will allow specific production of mRNA
5. Protein synthesis will occur (increasing or decreasing synthesis - depending on the specific hormone and receptor type)
Are enzymes reusable?
Yes
If a hormone binds to a receptor (does not enter a cell) on the target cell, which of the following deductions would be appropriate for this hormone?
A. it is lipid-soluble
B. it is polar charged
C. It changes the rate of expression of specific genes
D. It relies on a 2nd messenger system
E. Fast acting
F. Slow acting
G. Signal amplification
b. It is polar charged
d. It relies on a 2nd messenger system
e. Fast acting
g. Signal amplification
