NURS 612 Unit 1 Exam 2025/2026 – Verified
Comprehensive Questions & Correct
Answers And Explanations Detailed
Endocrine System - CORRECT ANSWER=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 - CORRECT ANSWER=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.
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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 - CORRECT ANSWER=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 - CORRECT ANSWER=Hormones are released in the circulation to act
on a target organ (between remote cells)
Paracrine - CORRECT ANSWER=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
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Autocrine - CORRECT ANSWER=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 - CORRECT ANSWER=Hormone action is within the cell that
produced the hormone
Mechanisms of Hormone Action - CORRECT ANSWER=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 - CORRECT ANSWER=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 - CORRECT ANSWER=Hormones are
synthesized in the smooth endoplasmic reticulum and released upon synthesis. Ex.:
Steroid hormones
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Actions of Hormones Released
into the Bloodstream - CORRECT ANSWER=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 - CORRECT ANSWER=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 - CORRECT ANSWER=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 - CORRECT ANSWER=Complex molecular structures
located either on the surface or inside the target cells.