Lec Exam 4: Focused Urinary system

What is a nephron?

Functional unit of the kidney

What is the main job of the nephron?

Filters blood and forms urine

How many nephrons are there per kidney?

About 1.25 million

What are the three main processes of the nephron?

Filtration, reabsorption, secretion

What is filtration?

Movement of fluid and small particles from blood into nephron

Where does filtration occur?

Renal corpuscle

What two structures make up the renal corpuscle?

Glomerulus and Bowman's capsule

What is the glomerulus?

Tiny capillary network inside renal corpuscle

What is the function of the glomerulus?

Filters blood

What does the glomerulus keep in the blood?

Blood cells and large proteins

What is Bowman's capsule?

Cup-like structure surrounding glomerulus

What is the function of Bowman's capsule?

Collects filtrate from blood

What is reabsorption?

Useful substances move from filtrate back into blood

Where does reabsorption happen?

Renal tubules

What percent of filtrate is reabsorbed?

About 70%

What is secretion?

Wastes move from blood into urine

Where does secretion happen?

Renal tubules

How much urine is made per day?

About 2 liters

What are the three parts of the renal tubule?

Proximal convoluted tubule, loop of Henle, distal convoluted tubule

What is the function of the proximal convoluted tubule?

Major reabsorption

What is the function of the loop of Henle?

Reabsorbs water and salts

What is the function of the distal convoluted tubule?

Secretion and final adjustment of filtrate

What are kidney stones?

Solid crystal deposits from urinary minerals

What is another name for kidney stones?

Renal calculi

What is the medical term for stones in the kidney?

Nephrolithiasis

What is the medical term for stones in the ureter?

Ureterolithiasis

What is the most common type of kidney stone?

Calcium oxalate

What is lithiasis?

Formation of stones

What are the main causes of kidney stones?

Low fluid intake, high protein, sodium, sugar, oxalate

Why can low water intake cause stones?

Urine becomes too concentrated

What diet factors are linked to kidney stones?

Animal protein, sodium, refined sugar, cola, some juices

What are the treatments for kidney stones?

Lithotripsy, endoscopy, catheter, rarely surgery

What is lithotripsy?

Shock waves used to break stones

What is the lower kidney urine pathway?

Minor calyx → major calyx → renal pelvis → ureter

What is the function of the minor calyx?

Collects urine from renal pyramids

What is the function of the major calyx?

Collects urine from minor calyces

What is the function of the renal pelvis?

Funnels urine into ureter

What are ureters?

Muscular tubes carrying urine to bladder

What epithelium lines the ureters?

Transitional epithelium

Why do ureters have smooth muscle?

To squeeze urine toward bladder

What prevents urine backflow into ureters?

Slit-like openings at bladder wall

What is the function of the urinary bladder?

Temporary storage of urine

What muscle empties the bladder?

Detrusor muscle

What epithelium lines the bladder?

Transitional epithelium

What is the function of the urethra?

Carries urine out of body

What is the function of the female urethra?

Urine transport only

What is the function of the male urethra?

Urine and semen transport

What is the prostate gland?

Male gland surrounding part of urethra

What is the function of the prostate gland?

Secretes slightly alkaline fluid for sperm survival

What is benign prostatic hypertrophy?

Enlarged prostate

How does BPH affect urination?

Compresses urethra and slows urine flow

Why can BPH cause urinary problems?

Prostate squeezes the urethra