Tubular Reabsorption and Secretion

These flashcards cover key vocabulary and concepts related to kidney function, tubular reabsorption, secretion, and diabetes mellitus.

Proximal Convoluted Tubule (PCT)

The part of the nephron responsible for reabsorbing 60-70% of filtered water and 99-100% of organic substrates.

Glucosuria

The presence of glucose in urine, often associated with diabetes mellitus.

Polyuria

Increased urine production, a common symptom of diabetes.

Transport Proteins

Proteins that facilitate the movement of substances across cell membranes, crucial for reabsorption and secretion in renal tubules.

Osmotic Reabsorption

The process by which water is reabsorbed in response to the reabsorption of solutes, especially in the PCT.

Carbonic Anhydrase

An enzyme that facilitates the conversion of CO2 to H2CO3, playing an essential role in acid-base balance in the kidneys.

Epithelial Cell Characteristics

PCT epithelial cells have a 'leaky' cuboidal structure with microvilli that increase surface area for absorption.

Diabetes Insipidus

A condition characterized by frequent urination and excessive thirst due to inadequate secretion of vasopressin (ADH).

Co-Transport

A mechanism that allows the coupled transport of one solute (e.g., sodium) alongside another solute (e.g., glucose) across a membrane.

Transmembrane Transport

The movement of substances across a cellular membrane, involving various transport proteins and mechanisms.

Sodium-Potassium Pump (Na+/K+ ATPase)

A primary active transporter that maintains sodium and potassium gradients across the cellular membrane.

Fluid Filtration Rate

The rate of fluid filtered through the glomeruli, typically around 120 mL/min.

Peritubular Capillaries

Capillaries that surround the nephron, facilitating the exchange of nutrients and waste.

Hypoglycemia

Low blood sugar levels, which can lead to symptoms like fatigue and increased appetite.