Exam (elaborations)
NUR 612 Exam 1 Questions And Answers With Verified Solutions
- Course
- Institution
NUR 612 Exam 1 Questions And Answers With Verified Solutions
[Show more]
Content preview
NUR 612 Exam 1 Questions And Answers WithVerified Solutions
Endocrine System ANS System composed of various glands that can synthesize and release
special chemical messengers called hormones.
System works closely with the Nervous System and the Immune system to regulate and integrate
body functions.
Functions:
Growth and development
Sexual differentiation
Metabolism
Adaptation to an ever-changing environment
Regulation of digestion
Use and storage of nutrients
Electrolyte and water metabolism
Reproductive functions
Hormones ANS Endocrine system uses chemical substances called hormones as a means of
regulating and integrating body functions.
Hormones are thought of as chemical messengers produced to target a specific cell. They do NOT
initiate reactions but function as a modulator of cellular and systemic responses.
Function as chemical messengers
Move through the blood to distant target sites of action
Or, act more locally as paracrine or autocrine messengers that incite more local effects
Most are present in body fluids at all times in greater or lesser amounts as needed.
Characteristics
A single hormone can exert various effects in different tissues.
,A single function can be regulated by several hormones.
Types of Hormone Actions ANS Hormones are released in one location but can have the biologic
effect either in that location of release or somewhere else
Endocrine
Paracrine
Autocrine
Intracrine
Endocrine ANS Hormones are released in the circulation to act on a target organ (between
remote cells)
Paracrine ANS Hormones acts locally in cells other than that produced the hormones Ex: sex
steroids in ovary (between local cells)
Hormones acting locally on cells other than those that produced the hormone
For example, the action of sex steroids on the ovary
Autocrine ANS Hormones exert action on the cells from which they are produced ex: insulin (on
the cell that produced them)
Hormones exerting action on the cells from which they were produced
For example, the release of insulin from pancreatic beta cells can inhibit its release from the same
cells
Intracrine ANS Hormone action is within the cell that produced the hormone
Mechanisms of Hormone Action ANS Hormones interact with high-affinity receptors.
These are linked to one or more effector system in the cell.
Hormone receptors may be located in the plasma membrane of the cell (surface of the cell) or in the
intracellular compartment (inside the cell) of the target cell.
,The vesicle mediated pathway ANS Protein and polypeptide hormones are synthesized and
stored in vesicles in the cytoplasm of the endocrine cell until secretion is required. Stimulation of the
endocrine cell causes the vesicles to move to the cell membrane and release their hormones.
Non-vesicle mediated pathway ANS Hormones are synthesized in the smooth endoplasmic
reticulum and released upon synthesis. Ex.: Steroid hormones
Actions of Hormones Released
into the Bloodstream ANS Circulate as free, unbound molecules
Peptide hormones and protein hormones usually circulate unbound in the blood.
Circulate as hormones attached to transport carriers
Steroid hormones and thyroid hormone are carried by specific carrier proteins synthesized in the
liver.
Intracellular and extracellular mechanisms participate in the termination of hormone function.
Only free hormones can signal a target cell.
Important Thoughts on Transport
Carrier Hormones ANS The extent of hormone binding to it's transport carrier influences the rate
at which hormones leave the blood and enter the cells.
Pause and read Transport at the bottom of page 1265 through mid-page 1267. Understand the
correlation between hormone binding and half-life.
Metabolism and Elimination ANS Hormones secreted by endocrine cells must be inactivated
continuously to prevent their accumulation.
Some hormones are degraded by enzymes in the blood or tissue and excreted by the kidneys and liver
Major mechanism of degradation is through hormone binding to cell-surface receptors, with
subsequent uptake and degradation by enzymes in the cell membrane or inside the cell.
Hormones Receptors ANS Complex molecular structures located either on the surface or inside
the target cells.
, The function of these receptors is to recognize a specific hormone and translate the hormonal signal
into a cellular response. The receptor is structured in such a way that they respond to specific
hormones. (Think "lock and key".)
The response of a target cell to a hormone varies with the NUMBER of receptors present and with
the AFFINITY of these receptors for hormone binding.
A variety of factors influence the number of receptors that are present on target cells and their affinity
for hormone.
Factors Affecting Response of a Target Cell to a Hormone ANS Number of receptors present:
Increased or decreased hormone levels often induce changes in the activity of the genes that regulate
receptor synthesis.
Up-regulation: decreased hormone levels increase receptor numbers
Increased hormone sensitivity results
Down-regulation: increased hormone levels decrease receptor numbers
Decreased hormone sensitivity results
Affinity of receptors for hormones
Affected by a number of conditions
pH
For example, pH of the body fluids plays an important role in the affinity of insulin receptors
Temperature
Diet
Presence of other chemicals such as medications
Relationship between Hormones
and Target Cell Receptors ANS Hormones are either Lipid Soluble or Non-Lipid (Water) Soluble
(Cell membranes are made up of a lipid layer)
Lipid Soluble Hormones pass freely through cell membrane, attach to intracellular receptors and
form a hormone-receptor complex and travel to the cell nucleus to activate or suppress intracellular
mechanisms
Non-Lipid (Water) Soluble Hormones cannot cross the cell membrane readily. These hormones (first
messenger) interact with surface receptors to incite intracellular signal system or message (second
messenger) to the presence of a hormone.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Labtech. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $17.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
78462 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now