Long Term Control Of Blood Pressure Flashcards
Describe the experiment conducted in dogs regarding baroreflex and blood regulation.
The experiment involved comparing mean arterial pressure regulation in healthy dogs versus dogs with sinoaortic-denervation, showing that dogs without input from arterial baroreceptors struggled to regulate blood pressure.
Define the role of the kidney in regulating mean arterial pressure.
The kidney plays a crucial role in regulating mean arterial pressure by controlling plasma volume, which directly impacts blood pressure.
How does the kidney regulate plasma volume to influence mean arterial pressure?
The kidney regulates plasma volume by processes such as filtration, reabsorption, and secretion along the nephron, ultimately impacting blood pressure.
Describe the pathway of filtrate through the kidney, starting from Bowman’s capsule.
Filtrate enters the proximal tubule, then moves through the loop of Henle (descending and ascending limbs), before reaching the collecting duct and eventually being excreted as urine.
What is the significance of the efferent arteriole in kidney function?
The efferent arteriole closely follows the path of filtrate, allowing for reabsorption (from filtrate to blood) and secretion (from blood to filtrate) processes to occur, aiding in kidney function.
Explain the concept of the counter-current system in the kidney.
The kidney utilizes a counter-current system to create a concentration gradient that facilitates reabsorption and secretion processes, crucial for maintaining fluid balance and regulating blood pressure.
Describe the process of building up a sodium gradient in the loop of Henle.
Sodium is transported out as the filtrate moves down the loop of Henle, creating a higher concentration of sodium in the extracellular fluid, leading to a significant osmotic gradient.
How does controlling the permeability of the collecting duct affect water reabsorption?
By controlling permeability, the collecting duct can either allow water to follow the osmotic gradient, leading to water reabsorption, or prevent water reabsorption, resulting in more water being lost in urine.
Define diuresis in the context of the urinary system.
Diuresis refers to the process of producing a large volume of very dilute urine due to the collecting duct being very impermeable, leading to little water reabsorption.
Explain the significance of retaining lots of water in the body.
Retaining lots of water leads to an increase in plasma volume and mean arterial pressure.
What is the role of the renin-angiotensin-aldosterone system in regulating water reabsorption?
The renin-angiotensin-aldosterone system senses disturbances in plasma volume and mean arterial pressure, producing hormones like renin to elicit an appropriate response.
How does modulating sodium transport impact the osmotic gradient in the kidney?
Modulating sodium transport can change the size of the osmotic gradient in the kidney, affecting the reabsorption of water in the collecting duct.
Describe the three triggers for renin production.
Activation of sympathetic nerves to the juxtaglomerular apparatus, decreased distension of the afferent arterioles (renal baroreflex), and decreased delivery of sodium and chloride through the tubule.
What is the role of the juxtaglomerular cells in the process of renin release?
Juxtaglomerular cells release renin in response to stimuli like sympathetic innervation, decreased distension of afferent arterioles, and reduced delivery of sodium and chloride to the Macula densa.
How does sympathetic activation contribute to the release of renin?
Sympathetic activation increases contractility in the heart, heart rate, stroke volume, cardiac output, and mean arterial pressure, which in turn activates juxtaglomerular cells to release renin.
