Related Concept Videos

Drug Elimination by Renal Route: Tubular Reabsorption01:22

Drug Elimination by Renal Route: Tubular Reabsorption

During the process of renal excretion, as the glomerular filtrate progresses to the distal convoluted tubule (DCT), drugs that are highly permeable, lipophilic, and nonionized undergo passive reabsorption from the tubular fluid into the surrounding peritubular capillaries. This reabsorption process restricts their elimination through the kidneys. However, the majority of drugs are either weak acids or weak bases, and their ionization level is dependent on pH. By altering the pH of urine, the...
Hormones and Bone Tissue01:17

Hormones and Bone Tissue

The endocrine system produces and secretes hormones, which interact with the skeletal system. These hormones control bone growth, maintain bone once it is formed, and remodel it.
Hormones That Influence Osteoblasts and/or Maintain the Matrix
Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth. This happens in several ways: first, it triggers chondrocyte...
Drug Elimination by Renal Route: Tubular Secretion01:15

Drug Elimination by Renal Route: Tubular Secretion

Once the process of glomerular filtration is completed, blood carrying unfiltered drug molecules traverses through efferent arterioles and makes its way into the peritubular capillaries in the proximal tubule. A variety of carriers play a pivotal role in actively secreting drugs from these peritubular capillaries into the tubular fluid. The organic anion transporter transfers acidic drugs, against an electrochemical gradient, from the peritubular capillaries into the renal tubule cells and...
Renal Drug Excretion: Tubular Secretion01:28

Renal Drug Excretion: Tubular Secretion

Active tubular secretion is a robust, energy-demanding process that utilizes carrier systems to transport drugs into renal tubules. The active renal secretion systems include the organic anion transporter (OAT) for weak acids and the organic cation transporter (OCT) for weak bases. Structurally similar drugs can compete for the same transporter, potentially leading to drug accumulation and toxicity. However, this principle can be exploited therapeutically. One example is probenecid (Probalan),...
Phosphate Buffer01:22

Phosphate Buffer

The phosphate buffer system is a critical biological mechanism for maintaining pH stability in the body. This system operates primarily through two components: sodium dihydrogen phosphate (NaH2PO4), which acts as a weak acid, and sodium hydrogen phosphate (Na2HPO4), which serves as a weak base.
Sodium dihydrogen phosphate does not fully dissociate in neutral or acidic solutions. When a strong base, such as sodium hydroxide (NaOH), is introduced into the solution, sodium dihydrogen phosphate...
Roles of Electrolytes: Calcium and Phosphate01:27

Roles of Electrolytes: Calcium and Phosphate

Calcium and phosphate are essential electrolytes in the human body, with calcium being the most abundant mineral. Around 99% of the body's calcium is stored in the skeleton and teeth, forming a crystal lattice of mineral salts in combination with phosphates. Calcium plays crucial roles in various bodily functions such as blood clotting, neurotransmitter release, muscle tone maintenance, and nervous and muscle tissue excitability.
The calcium concentration in blood plasma is primarily regulated...