Xylem are tubes in the stem that transport water and minerals upward, from the roots to the leaves. Phloem are tubes in the stem that move food made in the leaves to other parts of the plant. ... Chlorophyll is a pigment that helps plants use energy from the sun to produce sugars.
Answer: The relationship between blood pressure and heart rate responses to coughing was investigated in 10 healthy subjects in three body positions and compared with the circulatory responses to commonly used autonomic function tests: forced breathing, standing up and the Valsalva manoeuvre. 2. We observed a concomitant intra-cough increase in supine heart rate and blood pressure and a sustained post-cough elevation of heart rate in the absence of arterial hypotension. These findings indicate that the sustained increase in heart rate in response to coughing is not caused by arterial hypotension and that these heart rate changes are not under arterial baroreflex control. 3. The maximal change in heart rate in response to coughing (28 +/- 8 beats/min) was comparable with the response to forced breathing (29 +/- 9 beats/min, P greater than 0.4), with a reasonable correlation (r = 0.67, P less than 0.05), and smaller than the change in response to standing up (41 +/- 9 beats/min, P less than 0.01) and to the Valsalva manoeuvre (39 +/- 13 beats/min, P less than 0.01). 4. Quantifying the initial heart rate response to coughing offers no advantage in measuring cardiac acceleratory capacity; standing up and the Valsalva manoeuvre are superior to coughing in evaluating arterial baroreflex cardiovascular function.
Explanation:
A population cannot continue to increase forever because each population has a carrying capacity, which is the max number of organisms that can live in an environment with the available resources. At some point, each population will hit their carrying capacity when they run out of resources.
abiotic factors.
An abiotic factor is a non-living part of an ecosystem that shapes its environment.
