Biology

• Nephron


  The functional unit of the kidney, responsible for the actual process of filtration and reabsorption
• Each kidney contains about a million nephrons
• Bowman's Capsule


  • A cup-like sac at the beginning of the tubular component of a nephron
  • Surrounds the glomerulus and collects the filtrate that the glomerulus filters from the blood
• Glomerulus


  • A network of capillaries that performs the first step of filtering blood
• Proximal Convoluted Tubule (PCT)


  • The first segment of a nephron
  • Primarily allows the reabsorption of ions, water, and nutrients from the filtrate into the blood, while allowing waste products to remain in the filtrate
• Loop of Henle


  • A U-shaped tube that extends from the PCT
  • Has a descending limb and an ascending limb
  • The main function is to concentrate the urine, as it allows for the reabsorption of water and ions
• Urine formation


  1. Glomerular Filtration

  2. Tubular Reabsorption

  3. Tubular Secretion
• Distal Convoluted Tubule (DCT)


  • The portion of the nephron that lies between the Loop of Henle and the collecting duct
  • Responsible for the selective reabsorption and secretion of ions to adjust the urine pH and electrolyte balance
• Collecting Duct


  • The final part of the nephron
  • Carries the urine from the nephrons to the renal pelvis, from where it is transported to the bladder
• Glomerular Filtration


  The first step in urine formation where blood enters the kidneys, is filtered by the glomerulus, and the filtered fluid (glomerular filtrate) moves into the Bowman's capsule
• Each part of the nephron has a specific role in the process of urine formation, ensuring that waste products are efficiently removed from the body while necessary nutrients and water are reabsorbed
• Glomerulus


  • Acts as a filtering unit and filters out waste products, ions, glucose, and other small molecules from the blood, while larger molecules like proteins and blood cells are retained
• Tubular Reabsorption


  The glomerular filtrate moves into the proximal convoluted tubule, where most of the water, glucose, and ions are reabsorbed back into the blood, leaving only waste products and excess ions in the filtrate
• Tubular Secretion


  The final step in urine formation where the filtrate, now called urine, passes through the distal convoluted tubule and the collecting duct, and the kidneys secrete additional waste products from the blood into the urine, including hydrogen ions, potassium ions, and certain drugs
• The urine is then passed into the renal pelvis, from where it moves into the ureter and is stored in the urinary bladder until it is excreted from the body
• Urine formation involves the filtration of blood, reabsorption of necessary substances, and secretion of waste products
• Hemodialysis


  A process that uses a machine to clean the blood when the kidneys are not able to do so
• Hemodialysis process


  1. Access

  2. Blood Pump

  3. Dialyzer

  4. Removal of Waste

  5. Return of Blood

  6. Monitoring
• Access


  • A surgeon connects an artery to a vein, usually in your arm, to create a vascular access. Blood flows out of the access to the dialysis machine.
• Blood Pump


  • The dialysis machine has a pump that controls the flow of blood. The pump pulls blood from your body and returns it, allowing it to flow through the machine at a controlled rate.
• Dialyzer


  • The dialyzer, or artificial kidney, is a part of the machine where your blood is cleaned. The blood flows on one side of a semi-permeable membrane, and a dialysate, or special cleaning fluid, flows on the other side. The waste products in your blood pass through the membrane into the dialysate.
• Removal of Waste


  • The dialysate now carries the waste products from your blood. The dialysate is discarded, and the clean blood is returned to your body.
• Return of Blood


  • The cleaned blood is returned to your body through another tube in your vascular access.
• Monitoring


  • Throughout the process, the machine monitors your blood pressure and the rate at which your blood is being cleaned.
• Hemodialysis is a complex process and should always be performed under the supervision of a healthcare professional.
• Asthma


  A chronic disease that inflames and narrows the bronchial tubes in the lungs
• Asthma


  • Can be managed with medication and by avoiding triggers like allergens and irritants
• Chronic Obstructive Pulmonary Disease (COPD)


  A term used to describe progressive lung diseases including emphysema, chronic bronchitis, and refractory asthma
• Pneumonia


  An infection that inflames the air sacs in one or both lungs
• Pneumonia can range in seriousness from mild to life-threatening
• Tuberculosis


  A highly infectious disease caused by the bacterium Mycobacterium tuberculosis
• Lung Cancer


  A type of cancer that begins in the lungs
• Cystic Fibrosis


  A genetic disorder that causes severe damage to the lungs, digestive system, and other organs in the body
• If you're experiencing persistent respiratory symptoms, it's important to seek medical attention
• What is the main purpose of life processes in living organisms?

  To maintain the functioning of the body even when not physically active.
• What does the term 'nutrition' refer to in living organisms?

  The process of obtaining energy through consumption of food.
• What is respiration in the context of life processes?

  The process of acquiring oxygen through breathing for breaking down organic substances.
• How does transportation function in living organisms?

  It carries food and oxygen from one organ to other organs in the body.
• What is excretion in living organisms?

  The process of removing metabolic waste by-products from the body.
• Why is diffusion insufficient for multicellular organisms like humans?

  Because they have complex body designs and specialized cells that are not in direct contact with the environment.