Biology Pre-Lecture on Urinary System

Pre-Lecture Urinary

• Kidneys are fist-sized organs located near the lower ribs, in the back.
• They are held in place by structures like the peritoneum and psoas major muscle.
• The left kidney is usually slightly higher than the right due to the liver's position.
• Kidneys filter blood, creating urine, and maintaining homeostasis (pH and fluid balance).
• Renal arteries carry blood to the kidneys for filtration.
• Renal veins carry filtered blood away from the kidneys.
• The kidneys reabsorb important substances from the blood, like proteins.
• The outer cortex of the kidney contains structures like glomeruli, part of the nephron.
• Renal pyramids are areas where nephrons and loops of Henle are located.
• Blood vessels that filter the blood are located around the renal pyramids.
• Renal pelvis is the base of the kidneys connecting to the ureters.
• The kidneys and ureters connect to each other, and to other parts of the body.

Pre-Lecture Gastrointestinal

• The gastrointestinal tract starts with the mouth and breaks down food.
• The esophagus is a stretchy tube carrying food to the stomach.
• The stomach has four tissue layers – serosa, longitudinal, circular, and oblique.
• The stomach has a mucus layer (tunica mucosa) protecting it from stomach acid.
• The duodenum is the first part of the small intestine.
• The duodenum is where ulcers commonly occur.
• Ulcers can be caused by problems with the digestive enzymes and stomach acid.
• Ulcers can be treated and prevented by managing the enzymes and acid levels.

Vesicouretheral Reflux

• Ureter may be outside normal position.
• This can cause backflow of urine.
• Urine flowing backward from the ureters to the bladder is a potential issue.

Renal Calculi

• Kidney stones.
• Stones form in the urinary tract from high salt concentrations, uric acid, and calcium salts.
• Pain from stones is due to ureter/kidney spasms, as stones move through the urethra.
• Kidney stones can cause blockage of the ureters.
• Lithotripsy can break down kidney stones.

Chronic Renal Disease

• Renal function failure occurs.
• Normal functioning nephrons decrease to 30%.
• Chronic inflammation causes chronic renal disease.
• End-stage renal disease (ESRD) requires treatment, which may include dialysis or a transplant.

Congenital Abnormalities

• Kidney may be missing or not develop correctly.
• Congenital kidney problems tend to be bilateral (both kidneys).
• Kidney problems are rarer when only one kidney does not develop.

Nephropathies/Glomerulonephritis

• Inflammation of the glomeruli.
• This is often caused by an antibody reaction.
• This can cause immune complex glomerulonephritis, which can cause the protein to leak out in the urine.

Acute Renal Tubular Injury

• Impaired renal blood flow and toxic chemicals damage the kidneys.
• Tissue death.
• Tubular necrosis, which can be caused by toxins and other damage.
• Can lead to acute renal failure. (Kidney failure)

Renal Tumours

• Cortical tumors are epithelial cell in origin.
• They are largely benign, but some can be cancerous.
• Adenomas are typically small, asymptomatic and white in appearance.
• Carcinomas are more common and can have blood in the urine as a symptom.
• Nephroblastoma is a highly malignant tumour affecting mainly children.

Vesicoureteral Reflux

• Ureters are located outside the normal position in the trigone preventing backflow to the bladder.
• Backflow of urine increases pressure, leading to ureter damage and potential infections.

Cardiovascular, Cardiac Sphincter, Conditions and Treatment

• Problems with the valve at the beginning of the stomach (cardiac sphincter) such as cardiospasm can create difficult swallowing.
• Ulcer are very common in the mucous lining and is due to damage from acids.
• Cancer can potentially arise at any part of the esophagus.
• The issue of the esophagus may get worse over time due to problems with the cardiac sphincter.

Diverticulosis and Diverticulitis

• Outpouches called diverticula occur due to weak spot in the lining of the colon.
• Diverticulitis is the inflammation of the diverticula, caused by fecal matter getting trapped in the pouches.
• This can result in serious complications such as chronic constipation, perforations, bleeding, and scar tissue formation in the colon.
• Hemorrhoids cause pain and discomfort to the rectum and anus and can be internal or external.

Tumours of the Colon

• Benign tumours such as polyps.
• Carcinoma is a cancerous tumour
• Polyps often can be removed through colonoscopy.
• The tumour may ulcerate, causing iron deficiency and lower gastrointestinal issues.