AP 4 Nov Lecture 27 Dictation Flashcards
What physiological concepts must be understood to study the kidneys?
Osmosis, fluid shifts, ion shifts, transporters.
What is the primary role of the cardiovascular system?
Transporting nutrients to tissues and waste products away from tissues.
How does the endocrine system interact with the cardiovascular system?
It puts hormones into the cardiovascular system for delivery to target areas.
Define ‘Volume’ in the context of this course.
Volume refers to measures like liters, milliliters, or microliters.
What units are used to express ‘Velocity’?
Meters per second or kilometers per hour.
What does ‘Pressure’ represent in the cardiovascular system?
Pressure is a force typically measured in millimeters of mercury.
Differentiate between cross-sectional area and surface area.
Cross-sectional area is the area within the center of a tube; surface area refers to the walls of the cylinder.
How is ‘Blood Flow’ calculated?
Blood flow is volume divided by time, e.g., mLs/minute or L/minute.
What is the most important factor determining blood flow?
Vascular resistance.
What happens to pressure measurements upstream and downstream of a choke point?
Upstream, pressure is high; downstream, pressure is lower.
Define ‘Vascular Conductance’.
It is how easy it is to drive blood flow through a blood vessel.
What does Poiseuille’s Law help explain?
It helps understand vascular resistance and pressures.
Where is the majority of blood stored in the body?
In systemic veins.
What role do kidneys play in fluid regulation?
Kidneys control body fluid levels tied to blood volume.
What occurs if the kidneys conserve more fluid?
Blood volume increases.
What type of arrangement increases resistance in blood vessels?
Series arrangement.
What type of arrangement decreases resistance in blood vessels?
Parallel arrangement.
What happens to blood pressure as it moves away from the heart?
Blood pressure tends to decrease.
What is the total cross-sectional area in the circulatory system like?
It increases significantly in small arteries and capillaries.
What happens to blood flow velocity as total cross-sectional area increases?
Blood flow velocity decreases.
Which vessels are considered resistance vessels?
Small arteries and arterioles.
How do veins compare to arteries in terms of resistance?
Veins have low resistance due to their thin walls and compliance.
What determines blood pressure in the systemic circulation?
The resistance vessels, specifically small arteries and arterioles
These vessels play a crucial role in regulating blood pressure.
What is the typical pressure in the end of the capillaries to the right atrium (Excluding the right ventricle and pulmonary arteries?
About 10 millimeters of mercury
This is a very small pressure gradient, indicating low resistance in veins.
How does the kidney manage blood flow?
By adjusting its vascular resistance
This regulation helps maintain appropriate blood flow and pressure.
Why is pressure necessary in the circulatory system?
To drive blood flow
Without pressure, blood cannot move through the vessels.
What type of flow is considered efficient in blood vessels?
Laminar flow
This type of flow is orderly and does not cause turbulence.
What is turbulence in blood flow?
Disorderly movement of blood that can lead to inefficiencies
Turbulent flow can cause damage to blood vessels over time.
What can turbulent flow contribute to in blood vessels?
Cholesterol and calcium deposits
These deposits can lead to blockages and other vascular issues.
What causes turbulent flow?
Narrow openings or blockages in blood vessels
These conditions increase the velocity of blood flow, leading to turbulence.
What percentage of cardiac output do the kidneys receive?
About 20%
This translates to approximately one liter per minute.
What law can be applied to understand blood flow in the cardiovascular system?
Ohm’s law
It can be rewritten to relate pressure, blood flow, and vascular resistance.
What is the relationship between blood vessel diameter and flow?
A small change in diameter can result in a large change in flow
This is significant in maintaining proper blood circulation.
How is vascular resistance calculated?
Vascular resistance = Delta P / Blood flow
Delta P is the pressure difference across the vessel.
What is the formula for vascular conductance?
Conductance = 1 / Resistance
Higher resistance leads to lower conductance, and vice versa.
What are Starling forces?
Forces determining fluid movement across capillary walls
These forces are crucial for filtration and reabsorption in the kidney.
What are Starling forces?
Forces that determine fluid movement between capillaries and surrounding tissues
Starling forces include hydrostatic and osmotic pressures that influence filtration and reabsorption in capillaries.
What is the significance of Starling forces in the kidneys?
They regulate the filtration and reabsorption processes
Understanding Starling forces is crucial for comprehending how kidneys filter blood and reabsorb substances.
What is the blood pressure at the beginning of a systemic capillary?
Approximately 30 mmHg
This pressure is essential for driving fluid flow through the capillary.
What is the blood pressure at the end of a capillary?
Typically about 10 mmHg
The difference in pressure between the beginning and end of the capillary drives fluid movement.
What is the delta p that drives flow through a capillary?
About 20 mmHg
This is calculated from the difference between the blood pressure at the beginning and end of the capillary.
Fill in the blank: The capillary hydrostatic pressure at the arterial end is _______.
30 mmHg
Fill in the blank: The capillary hydrostatic pressure at the venous end is _______.
10 mmHg
What do the Starling forces influence in terms of fluid movement?
They can either pull fluid into or push fluid out of the capillary
This dynamic is essential for maintaining fluid balance in tissues.
True or False: The Starling forces are only responsible for fluid movement out of the capillary.
False
Starling forces can both promote filtration (fluid out) and reabsorption (fluid in).
What is the primary focus of the next discussion mentioned in the text?
The four Starling forces
Understanding these forces is critical for the context of kidney function.
Where can one find detailed information about Starling forces in relation to capillaries?
In chapter 16 of Guyton, specifically pages 197 and 199
These pages provide charts and explanations of typical values for Starling forces.
