The Urinary System

A set of flashcards designed to cover key concepts related to the urinary system and kidney function as per the lecture notes.

What are the main anatomical structures of the urinary system?

The kidneys, urinary bladder, ureters, and urethra.

What are the primary regulatory functions of the urinary system? (Very clever pigeons migrate east)

• V: volume — maintains fluid volume/BP

• C: concentration — ions = chloride, sodium, magnesium etc

• P: pH — regulate long term acid base balance

  • hydrogen and bicarbonate ions released to neutralise acid

• M: metabolic — glucogenesis, glycogenesis, vitD synthesis

• E: excretory — metabolic waste, drugs and toxins

• E: endocrine — renin, when released tells kidneys to hold onto salt = pulls water back in = maintains BP

  • Kidneys = play a role in controlling how many RBC are produced

what are the two main regions of the kidneys and where does blood filtration take place?

• renal cortex (cortex means outer) and renal medulla

  • Filtration takes place in renal medulla as it contains nephrons

how is the filtered blood collected and transported to the bladder?

• by the calyxes

  • Urine exits down the ureter, through to the bladder

Structure of the bladder

• stretchy — transitional epithelium = cells can change shape as the bladder expands

what specific structure marks the beginning of the nephron where filtration first takes place?

Bowman’s capsule

What is selective reabsorption, and where does it primarily occur?

The process by which the nephron reabsorbs necessary substances back into the blood, primarily occurring in the proximal convoluted tubule.

What are the effects of aging on the urinary system?

• Decline in the number of nephrons and less effective tubules, resulting in difficulties with blood pressure management and increased frequency of incontinence.

What is the filtrate?

The term used for when the fluid (blood plasma) enters the bowman’s capsule

describe what is happening in the descending and ascending nephrons

• Descending nephron:

  • Medulla is salty — salt attracts water = water diffuses out of nephron loop, back into bloodstream.

• Ascending nephron:

  • SODIUM and CHLORIDE ions actively transported out of = making medulla salty

Where does the actual regulation of water take place (conservation of water/release of urine)?

Distal convoluted tubule (DCT) and collecting ducts

If the body is dehydrated how does ADH work to conserve water?

• pituitary glad releases ADH hormone

  • Causes collecting ducts and DCT to become permeable — water leaks = allowing water to diffuse back into bloodstream.