机能实验题（Functional experiment）

1、机能实验题（Functional experiment）7 Why does the increase in CO2 concentration in inhaled gas increase respiratory activity?CO2 is the most important physiological humoral factor regulating respiratory movement. It not only has a strong stimulating effect on respiration, but also is essential for maintain

2、ing the normal activity of the respiratory center of the medulla oblongata. Whenever the increase of P and CO2 in arterial blood, the respiration rate increased, the pulmonary ventilation increased, and reached the peak in about one minute. Due to the concentration of CO2 in gas inhalation increased

3、, the increase in blood CO2, CO2 through the blood-brain barrier to the concentration of CO2 in CSF increased, CO2+H2OH2CO3HCO3-+H+, CO2 through its H+ produced by stimulation of the medullary chemoreceptor and indirect effect on the respiratory center, through respiratory muscle function make respi

4、ratory movement strengthen. In addition, when the PC O2 is increased, but also stimulate the aortic body and carotid body peripheral chemoreceptor reflex, the dyspnea, but because of the stimulation threshold C O2 peripheral receptors than the central chemoreceptor is high, so the latter interaction

5、.8. does any inhalation of pure nitrogen affect respiratory movement?Inhalation of pure nitrogen, due to inhalation of gas in the lack of O2, P in alveolar air O2 decreased, resulting in arterial blood P and O2 decreased, PC O2 was basically unchanged (because C O2 diffusion speed), with the decline

6、 in arterial blood P O2, aortic and carotid body by stimulating peripheral chemoreceptor to the respiratory center extension cord excited, diaphragm and external intercostal muscle activity strengthened, cause of respiratory motion enhanced reflex.In addition, the direct effect of O2 deficiency on t

7、he respiratory center was inhibited and gradually increased with the extent of O2 deficiency. Therefore, the lack of O2 is different, and its performance is different. When mild O2 is absent, the afferent impulses of the peripheral chemoreceptor through the carotid body are more exciting to the resp

8、iratory center than the direct inhibition of the respiratory center by the absence of O2, which is manifested by increased respiration. In severe absence of O2, the inhibitory effect on respiratory center is greater than that of peripheral chemoreceptor to respiratory center, so the inhibition of re

9、spiration is manifested.9., increase the void cavity, respiratory movement will change, why?Long tube breathing, respiratory movement will be accelerated, because artificially increased void cavity, reduce alveolar ventilation, reduce the rate of gas regeneration, resulting in increased blood PC, O2

10、, P, O2 decreased. At the same time, the airway lengthened, so that the respiratory airway resistance increased, so as to deepen the deepening of respiration, the mechanism of action is as follows:The increase in PC O2 affects the fall of P O2 (see above)10. does lactic acid affect respiratory movem

11、ent?After intravenous injection of lactic acid, respiratory movement accelerated. Because the change of blood lactic acid pH value, improve the blood concentration of H+, H+ is an effective stimulus chemoreceptor, H+ can regulate respiratory movement through peripheral chemoreceptor, also can direct

12、ly stimulate the central chemoreceptor. But because the blood H+ is not easy to pass through the blood-brain barrier, it acts directly on the central chemoreceptor. Therefore, the direct stimulatory effect of H+ in the blood on the central chemoreceptor is not large, and it is also slow.11 Whats the

13、 effect on breathing after cutting off the vagus nerve on both sides? Why?When the vagus nerves were severed, the respiratory movement of the animals showed a slow and deep change.The vagus nerve contains afferent fibers that stretch the lungs. Pulmonary stretch reflex in a pulmonary dilation reflex

14、 (also called inspiratory inhibition reflex) physiological role is to prevent the air too deep too long, breathe in a timely to exhale, thus accelerating the alternation of inspiratory and expiratory movements. The frequency and depth of respiration regulation. When the vagus nerve was cut off, the

15、afferent pathway of the pulmonary stretch reflex was interrupted, and the physiological effects of the pulmonary stretch reflex were eliminated, thus showing a slow and deep breathing movement to prolong the inspiratory activity.14 how does the blood pressure change with the occlusion of the common

16、carotid artery? Why?Occlusion of common carotid artery, carotid sinus decreased blood pressure, carotid sinus baroreceptor stimulation to sinus nerve afferent impulses.Vagal vagal efferent impulses (inhibition), to reduce heart rate, cardiac output increased to strengthen the generalThe up arrowTo r

17、educe the cardiac sympathetic center (excited) general small vein contraction, increased blood pressure, increased blood volumeSympathetic efferent impulses increaseA general central sympathetic vasoconstrictor (excitement), general arteriolar constriction increase of peripheral resistance15 stimula

18、te the complete decompression of the nerve and the central end and the peripheral end of the artery Why?Rabbit depressor nerve is afferent nerve, its function is to send the impulse that aorta arch sensor sends into medullary cardiovascular center, reflex causes blood pressure to drop.Thus, stimulat

19、ion of the intact decompression nerve or the central end of the nerve may increase the impulse of the afferent center, which results in a marked decrease in blood pressure, while stimulating the peripheral end of the nerveIt travels outward, but does not cause blood pressure changes.16 stimulation o

20、f the peripheral end of the vagus nerve leads to a decrease in blood pressureIn experiments, multiple stimuli were used to stimulate the peripheral end of the right vagus nerve, where the parasympathetic nerve fibers were excited, releasing acetylcholine, acetylcholine, and the myocardial cell membr

21、aneThe M receptor binding produces negative chronotropic, inotropic, chronotropic, slowing heart rate, decreased cardiac output, and decreased blood pressure.17 intravenous injection of norepinephrine, elevated blood pressureNorepinephrine is mainly associated with the alpha receptor and may also bi

22、nd to the beta 1 receptor of the myocardium, but it is weak in its ability to bind to the beta 2 receptor of the vascular smooth muscleNorepinephrine can cause extensive contraction of the whole blood vessels, elevated arterial blood pressure, increased blood pressure and enhanced baroreceptor refle

23、x activity, and baroreceptor resistanceThe effect of radiation on the heart is more than the direct effect of norepinephrine on the heart, slowing heart rate.18 intravenous injection of large amounts of physiological saline, urine volume increasedHuman blood weight of 7-8%, that is about 70-80ml per

24、 kilogram of body weight, and rabbit blood volume is 5.5% of weight, that is about 55ml of blood per kilogram of body weight. If the rabbit weighs about 2.5kg, blood 138ml, a rapid injection of 20ml physiological saline, so that the blood volume increased by 15-22%, causing the following situations:

25、The blood is diluted, the plasma colloid osmotic pressure drops, the glomerular effective filtration pressure increases, the glomerular filtration rate increases, the urine volume increasesA lot of saline into the blood vessels, increase blood volume, glomerular plasma flow increased, urine filtrati

26、on fraction decreased around the pipe pressure, and plasma colloid osmotic pressure decreased, the two factors are caused by pipe of water reabsorption reduced set of renal tubules, the urine volume increased; at the same time, glomerular plasma flow increased. The urine filtration increased, also c

27、ontributed to the increase of urineThe blood volume increase, stimulation of the left atrium and thoracic volumereceptor, uploaded to the vagus nerve impulse along the supraoptic nucleus, paraventricular nucleus, the secretion of ADH and the decreased release of the distal tubule, collecting duct wa

28、ter permeability of the reduction of water reabsorption decreased, urine volume increasedIncrease in blood volume, blood pressure, carotid sinus and aortic arch baroreceptor stimuli enhanced by nerve ADH secretion and decreased the release of upload, hydrouria19 intravenous 1:10000 norepinephrine re

29、duced urinary outputNorepinephrine and goals and the combination of alpha receptor arteriole smooth muscle of the renal vasoconstriction, increased resistance, the afferent arteriole contraction, the blood pressure and blood flow in the glomerular capillaries reduced glomerular filtration rate decre

30、ased, thus reducing the amount of urine. Therefore, in the clinical rescue of shock patients, the use of large doses of norepinephrine, we must pay attention to changes in urine volume.20 intravenous injection of 20% glucose solution, urine volume increasedThe increased blood glucose concentration,

31、above the renal glucose threshold (20%GS5ml, increased 1000mg in blood glucose, if the weight of rabbits 2.5kg, the blood volume per kilogram of 55ml is about 130ml, so 100ml in the blood increases when the blood glucose concentration can be as high as 667mg glucose and blood glucose concentration i

32、n rabbits itself is assumed to be 100mg%, at this time, blood glucose the concentration can be as high as 767mg%, this data is far more than the renal glucose threshold 160-180mg%) by a large number of glucose in glomerular filtration of renal tubular epithelial cells cannot be fully absorbed,It res

33、ults in more glucose in the renal tubule, which increases the osmotic pressure in the renal tubule fluid and prevents the reabsorption of water. Thus, the water is discharged with the glucose and the urine volume increases. This phenomenon is called osmotic diuresis.21 interrupted intermittent stimu

34、lation of the peripheral end of the vagus nerve and decreased urine outputStimulation of the vagus nerve, the acetylcholine terminals release and myocardial membrane receptors for M, changes in permeability and myocardial action potential of ion channel, inhibiting the action of the heart, the varia

35、ble force negative chronotropic, dromotropic effect, and decrease in cardiac output, blood pressure, blood pressure decreased more than when the renal autoregulation range. Decreased renal blood flow, glomerular capillary pressure decreased, reduce the effective filtration pressure, reduce urine fil

36、tration, so reduce the amount of urineIn addition, there may be the following reasonsA decrease in blood pressure can cause reflex contraction of the target arteriole, decrease in capillary blood flow in the glomerulus, decrease in blood pressure, decrease in the effective filtration pressure, and d

37、ecrease in urine volumeGlomerular decrease in blood volume and blood pressure drop, causing the afferent arteriole stretch receptors and macula densa receptors, promote juxtaglomerular cell renin secretion increased, the renin angiotensin aldosterone system makes the glomerular artery contraction, r

38、educe the effective filtration pressure, urine filtration decreased with increase in urine water and sodium reabsorption the amount of urine discharge reductionWhen the blood pressure drops, can stimulate the sympathetic center, causes the innervation sympathetic nerve to be excited, the renin secre

39、tion increasesDecreased blood pressure on carotid sinus baroreceptor stimulation decreased, released from the hypothalamus, pituitary ADH secretion of leaves and released after inhibition of the secretion of ADH and the increased release of water reabsorption, the urine volume decreased.22 intraveno

40、us injection of furosemide, urine volume increasedFurosemide is a commonly used a fast strong diuretic, the mechanism of furosemide and mtal luminal membrane on Na+: 2Cl-: K+ transporter binding competition, prevent reabsorption of sodium ions, chloride ions, because this sodium chloride reabsorptio

41、n inhibition, affecting the formation of outer medullary tissue liquid hyperosmolar state interference, urinary concentrating mechanism, decreased urine concentration, the water absorption is greatly reduced, so that the diuretic effect was very significant.23 intravenous injection of pituitrin reduces urinary outputPituitrin contains oxytocin and antidiuretic hormone two components, affecting the amount of urine change is ADH, the mechanism of action: