human physiology human physiology human physiology human physiology human physio
ID: 3519490 • Letter: H
Question
human physiology human physiology human physiology human physiology human physiology Describe the at-rest respiratory cycle including both the neural stimuli and the resulting mechanical action that causes inspiration and expiration. 1. Describe how the kidney creates concentrated and dilute urine, and the role of hormones in the process. 2. Describe factors affecting O, hemoglobin saturation, including the factors that increase and decrease hemoglobin's affinity, and how 02 and CO2 interact with hemoglobin to associate and 3. dissociate at the lungs and tissues. 4. Describe how the stomach and duodenum interact to regulate stomach acidity. 5. Describe the 4 stages of the female menstrual cycle and: a. How pituitary hormones affect the ovarian cycle b. How the ovarian cycle affects end-hormone levels c. How end-hormone levels affect endometrial changesExplanation / Answer
1). Breathing or pulmonary ventilation is a process during which the oxygen and carbon dioxide are exchanged between the alveoli and the blood.
During normal quiet inspiration, the diaphragm contracts and thus, causing the chest cavity enlargement (increase in volume) from above downwards. The contraction of intercostals muscles causes elevation of ribs and sternum. This is an active process, which requires energy.
The lungs expand in this stage; the pressure in the lungs is less than atmospheric pressure, so air enters into the lungs.
During normal quiet exhalation (passive process), the diaphragm and the intercostal muscles relax. The size of the chest cavity decreases (lung volume decreases) and the pressure in the lungs increases which allows the air out. During forced exhalation, the contraction of abdominal muscles is also involved, and the process is active.
2). The mechanism of a countercurrent multiplier system operates to create a concentration gradient, we can observe this mechanism widely in the nature, and one of the examples is formation of concentrated urine by the kidneys.
Formation of concentrated urine by countercurrent multiplier system: Upon the influence of vasopressin (antidiuretic hormone), the permeability of water increases, the water present in the hypoosmotic fluid of distal tubule and thick ascending limb is lost by osmotic equilibration with the interstitial fluid along the cortical collecting duct.
As the fluid travels through the distial tubule (DT) and T-connecting tubule (CNT), cortical collecting duct (CCD), the NaCl is lost, and the osmotic pressure of the fluid becomes equal to that of the plasma.
This isoosmotic fluid flows into the medullary collecting ducts and further loses more water because the medullary and papillary interstitial are hyperosmotic, The urine, eventually becomes hyperosmotic and is excreted as a concentrated urine.
The ADH (anti-diuretic hormone) or vasopressin is a peptide hormone. It increases the water reabsorption from the collecting ducts by binding to the vasopressin receptors V1 and V2, which are a type of G-protein coupled receptors. So, the addition of ADH reduces the volume of urine output and concentrate the urine.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.