Download Chapter 1 Introduction 一、名词解释 1.Human Physiology Physiology

Chapter 1 Introduction
一、名词解释
1.Human Physiology
Physiology is one of the biological sciences dealing with normal life phenomena of all living
organisms.
2.Internal Environment
Extracellular fluid directly baths body cells
Internal environment = Extracellular fluid
3.Homeostasis
Homeostasis means a condition in which physical and chemical properties of internal
environment is kept at a “dynamic constancy”.
4.Regulation- the ability of an organism to maintain a stable internal conditions in a constantly
changing environment
5.Nervous Regulation
a process in which body functions are controlled by the nerve system.
Pathway:
nerve reflex
Structure basis: reflex arc
Types: unconditioned reflex and conditioned reflex
6.Hormonal Regulation
a regulatory process performed by hormones or active chemical substances in blood or
tissue.
7.Auto-regulation
direct response of the organ to stimulus, independent of nervous and hormonal control.
8.Feedback Control System 反馈控制系统
a process in which a part of output (feedback signal) from controlled organ returns to affect
or modify the action of the control system.
closed loop system very important control
system
9.Negative feedback
If the feedback signals produce effect opposite to action of control system, this type of feedback is
called negative feedback.
10.Positive feedbackIf
the feedback signals from controlled system increase the action of the control system, this
type of feedback is called positive feedback.
Feed-Forward Control
a direct effect of stimulus (interference or disturbance signal) on control system before action
of the feedback signal occurs
二、选择题
Instructions:
Select the single best answer to the numbered question.
1.Which of the following statements about the responses to depleted extracellular fluid volume is
NOT true?
A. Increased activity in renal sympathetic nerves will result in decreased GFR and increased NaCl
reabsorption in proximal tubule.
B. If the volume depletion is large, ADH release will be decreased.
C. Renin will be released due to decreased pressure in afferent arterioles and decreased delivery of
NaCl to the macula densa.
D. Angiotensin II levels will rise, enhancing thirst and increasing NaCl reabsorption in the
proximal tubule.
E. Level of atrial natriuretic peptide will decrease.
-------------------------------------------------------------------------------2.Which of the following statements about the responses to expanded extracellular volume is NOT
true?
A. Decreased activity in renal sympathetic nerves will result in increased GFR and decreased
reabsorption of NaCl in proximal tubule.
B. Increased levels of atrial natriuretic peptide will stimulate reabsorption of NaCl in collecting
ducts.
C. Decreased levels renin will be released, leading to diminished levels of angiotensin II.
D. Decreased release of aldosterone from the adrenal cortex will result in less reabsorption of
NaCl in distal tubule and collecting duct.
E. The diminished angiotensin II levels will contribute to less reabsorption of NaCl by the
proximal tubule.
-------------------------------------------------------------------------------3.Which of the following statements about regulation of plasma osmolality is NOT true?
A. Urine volume can vary from about 0.5 to 20 liters/day, while urine osmolality can vary from
about 50 mosmolal to 2500 mosmolal.
B. Total solute excretion (mosmoles/unit time) tends to remain constant in the face of large
changes in volume and osmolality.
C. ADH release is much more sensitive to changes in the osmolality of extracellular fluid than to
changes in extracellular fluid volume.
D. In a patient with expanded extracellular volume, ADH release in response to an increase in
osmolality is decreased (relative to an individual with normal ECF volume).
E. In a volume-expanded individual the release of ADH is suppressed via neural reflexes.
-------------------------------------------------------------------------------4.Which of the following statements about the renal regulation of extracellular fluid (ECF) volume
is NOT correct?
A. In a volume depleted individual, increased reabsorption of Na+ in Henle's loop is brought about
by increased levels of aldosterone and ADH.
B. In response to decreased extracellular fluid volume, more NaCl is reabsorbed in the collecting
ducts. This effect is promoted by elevated levels of aldosterone.
C. In response to expansion of the extracellular fluid volume, levels of renin and ADH in the
circulation decrease.
D. In response to expansion of the extracellular fluid volume, impulse traffic in sympathetic
nerves to the kidney increases.
E. In response to expansion of extracellular fluid volume, less reabsorption of Na+ occurs in the
proximal tubule.
-------------------------------------------------------------------------------5.Which of the following statements about responses to decreased extracellular volume is NOT
correct?
A. There are decreased levels of ANP, hence increased reabsorption of Na+ in the collecting duct.
B. There is increased impulse traffic in renal sympathetic nerves and hence decreased GFR.
C. There are increased levels of aldosterone and hence increased reabsorption of Na+ in the
proximal tubule.
D. There is an increase in ADH and hence production of a small volume of urine with high
osmolality.
E. There will be increased levels of angiotensin II and hence increased reabsorption of Na+ in the
proximal tubule.
-------------------------------------------------------------------------------6.Which of the following statements control of the osmolality of body fluids NOT correct?
A. ADH is the only major regulator of urine osmolality.
B. The maximal osmolality of urine is about 1200 mosmolal.
C. ADH is released in response to increased osmolality of extracellular fluid.
D. ADH is released in response to depletion of the volume of the extracellular fluid.
E. The release of ADH is about as sensitive to changes in ECF osmolality as to changes in ECF
volume.
-------------------------------------------------------------------------------7.Which of the following statements about regulation of salt and water reabsorption in the
proximal tubule is NOT correct?
A. When GFR in a single nephron increases at constant plasma flow, the oncotic pressure in the
peritubular capillary increases. This promotes increased reabsorption of salt and water from the
proximal tubule of that same nephron.
B. When GFR in a single nephron increases at constant plasma flow, the hydrostatic pressure in
the peritubular capillary increases. This promotes increased reabsorption of salt and water from
the proximal tubule of that same nephron.
C. When GFR increases, the filtered load of glucose and amino acids increases. This tends to
promote increased reabsorption of salt and water in the proximal tubule.
D. Angiotensin II increases NaCl reabsorption in the proximal tubule.
E. Activity in sympathetic nerves stimulates NaCl reabsorption in the proximal tubule.
--------------------------------------------------------------------------------
8.Which of the following statements about ADH is NOT true?
A. Hyperosmolality in the supraoptic nuclei causes ADH release from the posterior pituitary.
B. Increased pulse pressure causes decreased ADH release from the posterior pituitary.
C. Stretch of the left atrium causes decreased release of ADH.
D. Increased ADH induces the sensation of thirst.
E. ADH increases the permeability of the collecting ducts to water and Na+.
-------------------------------------------------------------------------------9.A patient has urinary osmolality of 50 mOsm/L, a urine flow rate of 15 ml/min, and a plasma
osmolality of 300 mOsm/L. Which of the following statements about this patient is NOT true?
A. The patient is in pronounced diuresis.
B. The patient's osmolar clearance is 2.5 ml/min.
C. The patient's free water clearance is 12.5 ml/min.
D. The osmotically active solute in the patient's urine each minute is equal to that in 2.5 ml of
plasma.
E. The patient is excreting 750 mosmoles of solute each minute.
-------------------------------------------------------------------------------10.Which of the following statements about regulation of osmolality is NOT true?
A. Osmolar clearance is equal to urine osmolality times urine flow rate divided by plasma
osmolality.
B. Free water clearance is equal to urine flow rate minus osmolar clearance.
C. Osmolar clearance tends to remain constant in the face of changes in urine flow rate.
D. In the absence of ADH, free water clearance tends to be positive and large.
E. A free water clearance of negative 1.5 ml/min means that the effect on total body osmolality is
equivalent to the addition to the extracellular space of 1.5 ml of isotonic saline per minute.
-------------------------------------------------------------------------------11.A patient complains of several days of vomiting and diarrhea and is found to have a reduced
effective circulating volume that activates the sympathetic nervous system. In this case, activation
of the sympathetic nervous system reduces sodium excretion by the following mechanisms
EXCEPT:
A. Decreases glomerular hydrostatic pressure by increasing afferent arteriolar constriction.
B. Increases renin secretion leading to an increase in plasma angiotensin II and aldosterone levels.
C. Indirectly increases proximal tubule sodium reabsorption through the action of aldosterone on
proximal tubule cells.
D. Directly increases reabsorption of sodium by the proximal tubule and loop of Henle.
-------------------------------------------------------------------------------12.In response to an expanded effective circulating volume, atrial natriuretic peptide is released
from the cardiac atria to promote sodium excretion by the following mechanisms EXCEPT:
A. Increased glomerular filtration rate by dilating afferent arterioles.
B. Decreased sodium reabsorption by the collecting duct cells.
C. Decreased aldosterone secretion by the adrenal cortex.
D. Decreased NaCl transport by the thick ascending limb.
-------------------------------------------------------------------------------13.Which of the following statements about regulation of plasma osmolality is NOT true:
A. ADH release is influenced by nonosmotic stimuli including blood volume and certain
medications.
B. ADH release is more sensitive to changes in plasma osmolality than to changes in effective
circulating volume
C. Urine volume can vary between 0.5 to 20 L/day in a normal individual.
D. Regulation of ADH release and perception of thirst work together to maintain plasma
osmolality.
E. Total solute excretion is highly dependent on the urine flow rate.
-------------------------------------------------------------------------------Answer：
1.B 2.B 3.A 4.D 5.C 6.E 7.B 8.E 9.E 10.E
11.C 12.D 13.E
三、问答题
1. Difference between extracellular and intracellular fluid
The extracellular fluid contains large amount of sodium, chloride and nutrients for the cells, such
as oxygen, glucose, fatty acids and amino acids .
The intracellular fluid contains large amount of potassium, magnesium and phosphate ions.
alveolar fluid.
2. What is the walk-along theary of contraction?
Walk-along theory is a generally accepted model for the way in which contraction occurs in the
sarcomere of striated muscle, by the sliding of the thick filaments relative to the thin filaments.
As soon as the actin filament becomes activated by the calcium ions, the heads of the
cross-bridges from the myosin filaments become attracted to the active sites of the actin filament,
and this, in some way, causes contraction to occur.
3. What is the importance of active transport?
a. To the cells, Active Transport is more important than other modes of transport.Only in this
way,the live cell can selectively absorb the substances which are necessary for its live,and excrete
the wastes which are toxiferous to the cell.
b. Active Transport contains Primary Active Transport and Secondary Active Transport.
c. In primary active transport,energy is directly coupled to the movement of desired substances
across a membrane, independent of any other species. Such as Sodium-Potassium pump, Calcium
pump and Hydrogen pump,they are important to controll the cell volume,and they can maintain
the resting potential and are the base of Co-Transport and Counter-Transport.
d. Secondary active transport concerns the diffusion of one species across a membrane to drive the
transport of another. Secondary Active Transport contains Co-Transport and
Counter-Transport,such as Co-Transport of Glucose and Amino Acids along with Sodium Ions in
the small intestinal epidermal cell,and Sodium Counter-Transport of Calcium and Hydrogen Ions
in the proximal tubules of the kidneys.
e. Active Transport Through Cellular Sheets,it is also called transmembrane transport,it can
provide a precise transport through the cell sheet for some more important substances in some
special tissues.
f. They are important because they help to establish and maintain gradients, move substances
against their gradients or move substances to different compartments in the cell or out of cells.