PNB 2250 EXAM 4 (final exam review)
Questions and Answers 100% Pass
stimulus - ✔✔detection by interaction with cellular proteins
a change in cellular properties that generates a signal to other cells
(chemical and electrical)
causes a change in physiological state
Control Systems - ✔✔(1) measure
(2) compare to desired values
(3) compute what changes need to be made
(4) correct and carry out
negative feedback process - ✔✔limited the change in physiological process
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,most common
postive feedback - ✔✔Accelerates the change in a physiological process
Inherently uncontrollable
Found in clotting and reproduction
feedback systems - ✔✔either on or off
there is no in between
homeostasis is based on 2 types of cells - ✔✔Neurons -- capable of electrical current
flows across membrane
Endocrine cells - Release of chemical messengers into the blood
differences between neurons and endocrine cells in homeostasis - ✔✔(1) signal speed
(2) number of cells affect
(3) precision
(4) extensive overlap
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,what is regulated? - ✔✔critical factors that can cause rapid death (T, pH, amount of O2,
etc)
less critical yet still improtant (blood levels of nutrients)
endocrine signaling - ✔✔Regulated secretion of extracellular signal
Diffusion of signal into blood & circulation throughout body
Diffusion of signal into extracellular space
Binding (interacting) with target cell
slower time frame, longer lasting effects
diffusion towards target cells, recognition effect
endocrine vs exocrine secretion - ✔✔endocrine (inner secretion)
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, exocrine (outer secretion)
sensory cells --> afferent (into) CNS input --> efferent (out of) response
paracrine vs autocrine - ✔✔paracrine (secretion to neighbors)
autocrine (secretion to oneself)
endocrine tissue - ✔✔Cells or glands (Derived from epithelium but also nervous tissue)
hormones (chemical messengers) very low concentrations
movement via diffusion (why circulation is so important)
target cells recognize message
endocrine glands - ✔✔Pancreas
parathyroid
pituitary
Katelyn Whitman, All Rights Reserved © 2025 4
Questions and Answers 100% Pass
stimulus - ✔✔detection by interaction with cellular proteins
a change in cellular properties that generates a signal to other cells
(chemical and electrical)
causes a change in physiological state
Control Systems - ✔✔(1) measure
(2) compare to desired values
(3) compute what changes need to be made
(4) correct and carry out
negative feedback process - ✔✔limited the change in physiological process
Katelyn Whitman, All Rights Reserved © 2025 1
,most common
postive feedback - ✔✔Accelerates the change in a physiological process
Inherently uncontrollable
Found in clotting and reproduction
feedback systems - ✔✔either on or off
there is no in between
homeostasis is based on 2 types of cells - ✔✔Neurons -- capable of electrical current
flows across membrane
Endocrine cells - Release of chemical messengers into the blood
differences between neurons and endocrine cells in homeostasis - ✔✔(1) signal speed
(2) number of cells affect
(3) precision
(4) extensive overlap
Katelyn Whitman, All Rights Reserved © 2025 2
,what is regulated? - ✔✔critical factors that can cause rapid death (T, pH, amount of O2,
etc)
less critical yet still improtant (blood levels of nutrients)
endocrine signaling - ✔✔Regulated secretion of extracellular signal
Diffusion of signal into blood & circulation throughout body
Diffusion of signal into extracellular space
Binding (interacting) with target cell
slower time frame, longer lasting effects
diffusion towards target cells, recognition effect
endocrine vs exocrine secretion - ✔✔endocrine (inner secretion)
Katelyn Whitman, All Rights Reserved © 2025 3
, exocrine (outer secretion)
sensory cells --> afferent (into) CNS input --> efferent (out of) response
paracrine vs autocrine - ✔✔paracrine (secretion to neighbors)
autocrine (secretion to oneself)
endocrine tissue - ✔✔Cells or glands (Derived from epithelium but also nervous tissue)
hormones (chemical messengers) very low concentrations
movement via diffusion (why circulation is so important)
target cells recognize message
endocrine glands - ✔✔Pancreas
parathyroid
pituitary
Katelyn Whitman, All Rights Reserved © 2025 4
