Physiology Flow and Gradients Concepts

Flow, gradients, resistances and conductances.

Fluid flow

By the amount of a substance that moves over time.

<p>Between point A and point B.</p> Signup and view all the answers

<p>The greater the gradient, the greater the flow.</p> Signup and view all the answers

<p>Channels and transporters increase the permeability of the membrane, allowing substances to cross that otherwise would not due to their solubility.</p> Signup and view all the answers

<p>These cells develop more transporters and features that enhance the surface area-to-volume ratio to facilitate efficient solute transport.</p> Signup and view all the answers

<p>Metabolism and transporters that increase gradients contribute to the manipulation of concentration gradients within the body.</p> Signup and view all the answers

<p>Saturation of protein transporters can reduce flux, and Fick's law is primarily accurate for gases, with exceptions for other substances.</p> Signup and view all the answers

<p>Diffusion 'failure' can lead to inadequate solute transport, resulting in various physiological issues and diseases.</p> Signup and view all the answers

<p>The Nernst potential equation accounts for the charge of the particle, the ratio of its concentration intracellular to extracellular, and the distribution of ions near the membrane.</p> Signup and view all the answers

<p>The Nernst potential defines the membrane voltage at which a specific ion moves into and out of the cell at equal rates, achieving equilibrium.</p> Signup and view all the answers

<p>The charge of an ion, represented by $Z_p$, directly affects the Nernst potential, as it determines whether the membrane voltage will pull the particle into or out of the cell.</p> Signup and view all the answers

<p>Unequal concentrations of sodium and potassium create a voltage difference across the membrane, known as the membrane potential, which influences cell excitability.</p> Signup and view all the answers

<p>The uneven distribution of ions like sodium, potassium, and anions results in a charge imbalance, where the net charge inside the cell differs from outside.</p> Signup and view all the answers

<p>To transport substances to and from tissues.</p> Signup and view all the answers

<p>Hydrostatic pressure drives water out of the capillaries into the interstitial space.</p> Signup and view all the answers

<p>It refers to the permeability of the capillary wall to water, inversely related to resistance.</p> Signup and view all the answers

<p>Flow refers to the volume of fluid movement, while flux is flow per unit area across a membrane.</p> Signup and view all the answers

<p>Flux = Lp Pcap - PISF - σ πcap - πISF.</p> Signup and view all the answers

<p>Electrostatic forces influence the movement of charged particles, dictated by their concentration and electrochemical gradients.</p> Signup and view all the answers

<p>The Nernst equation calculates the electrical potential needed to balance the concentration gradient for a specific ion.</p> Signup and view all the answers

<p>Inflammation, infection, or alterations in vascular pressure can lead to tissue swelling.</p> Signup and view all the answers

<p>Poiseuille’s law describes the flow of a fluid through a tube, calculated with the formula $F = \frac{\pi r^4 (P_1 - P_2)}{8\mu l}$. It relates to bodily fluids by quantifying how factors like pressure difference, tube radius, and fluid viscosity affect flow rates.</p> Signup and view all the answers

<p>An example is the movement of oxygen from the alveoli into the blood, where it moves down a concentration gradient. This process ensures efficient oxygen uptake during respiration.</p> Signup and view all the answers

<p>Hydrostatic pressure generates the force needed for fluids to flow from one point to another, such as blood flow from the heart through arteries. It is a driving factor for circulation.</p> Signup and view all the answers

<p>Viscosity inversely affects flow rate; higher viscosity results in slower flow rates due to increased resistance in the tube. Less viscous fluids flow more easily.</p> Signup and view all the answers

<p>Glucose absorption in the intestines is a key process where diffusion allows glucose to move into the bloodstream. This typically occurs from areas of higher to lower concentration.</p> Signup and view all the answers

<p>The dimensions of the tube, specifically its radius and length, directly affect resistance; narrower or longer tubes increase resistance to fluid flow. Additionally, factors like the roughness of the interior can also contribute.</p> Signup and view all the answers

<p>Fick’s law describes the diffusion process, stating that the rate of diffusion is proportional to the concentration gradient and the surface area involved. It is essential for understanding gas exchange in lungs and nutrient transfer in cells.</p> Signup and view all the answers

<p>Both pressure gradients and viscosity affect flow rates and resistance, which are crucial for proper functioning of organs and overall homeostasis. Neglecting either factor can lead to misunderstandings of physiological processes.</p> Signup and view all the answers

<p>The charge of the particle, the voltage difference across the membrane, and the membrane's permeability to the charged particle.</p> Signup and view all the answers

<p>The formula is $I = \frac{V}{R}$.</p> Signup and view all the answers

<p>Current is defined as the number of charged particles moving across the membrane per unit time.</p> Signup and view all the answers

<p>Current decreases when resistance increases.</p> Signup and view all the answers

<p>Voltage is the energy generated by separating charges across a membrane.</p> Signup and view all the answers

<p>Increasing the number of channels decreases resistance.</p> Signup and view all the answers

<p>Particles move down a voltage gradient according to their charge.</p> Signup and view all the answers

<p>The electric field of a charged particle is responsible for establishing voltage.</p> Signup and view all the answers

<p>Ohm’s law is useful for understanding unequal distributions of charges near membranes.</p> Signup and view all the answers

<p>Opposites attract while like charges repel.</p> Signup and view all the answers

<p>Current increases when voltage increases.</p> Signup and view all the answers

<p>The electric field declines very rapidly as charges are separated by distance.</p> Signup and view all the answers

<p>Current refers to the flow of charges across a membrane.</p> Signup and view all the answers

<p>Resistance impedes the movement of charged particles.</p> Signup and view all the answers