Urinary System and Kidney Function

Flashcards covering key concepts and functions of the urinary system and kidney physiology.

Tubular Reabsorption

The process by which essential substances are reabsorbed from filtrate back into the bloodstream during urine formation.

Proximal Convoluted Tubule (PCT)

The initial segment of the nephron where 65-70% of filtered water and sodium, nearly 100% of glucose, amino acids and vitamins, 90% of bicarbonate, and passive urea are reabsorbed.

Loop of Henle

A U-shaped part of the nephron consisting of a descending limb that is permeable to water and an ascending limb that is impermeable to water and actively transports sodium, potassium, and chloride.

Distal Convoluted Tubule (DCT)

A part of the nephron where sodium and calcium reabsorption is regulated by hormones such as aldosterone and parathyroid hormone.

Collecting Duct

The final segment of the nephron responsible for water reabsorption regulated by antidiuretic hormone and sodium reabsorption regulated by aldosterone.

Tubular Secretion

The process of moving substances from peritubular capillaries into the tubular lumen, which eliminates waste products, regulates blood pH, and removes excess potassium.

Glomerular Filtration Rate (GFR)

The rate at which blood is filtered through the glomeruli of the kidneys, typically around 120-125 mL/min.

Juxtaglomerular Apparatus (JGA)

A specialized structure in the kidney that regulates blood pressure and glomerular filtration rate through the renin-angiotensin-aldosterone system.

Renal Capsule

A tough fibrous layer directly surrounding the kidney.

Perirenal Fat

A fatty layer that cushions the kidney.

Renal Fascia

An outer connective tissue layer that anchors the kidney to surrounding structures.

Renal Cortex

The outer region of the kidney that contains renal corpuscles.

Renal Medulla

The inner region of the kidney that contains cone-shaped structures known as renal pyramids.

Renal colum

Extension of cortical tissue between the pyramids

Renal Sinuses

Contains renal pelvis, called, blood vessels, and fat

Papilla

Tip of each pyramid

Minor Calyx

A cup-like structure that receives urine from the renal papilla.

Major Calyx

A structure formed by the union of several minor calyces, leading to the renal pelvis.

Nephron

Functional unit of the kidney

Nephron

Filter blood and produce urine

Each Nephrin

Contains Renal Corpuscle and Renal Tubule

Renal corpuscle contains

Glomerulus- Specialized capillaries network

Bowman’s capsule: cup like structure surrounding the glomerulus

Juxtaglomerular Apparatus

Specialized structure involved with regulating blood presssure and glomerulst filtration rate through angiotensin system

Glomerular Filtration

First step in urine formations

Fluid filtered from blood into bowman’s capsule glomerular filtrate

Tubular reabsorption

Essential substance transported back into the blood stream

Proximal convoluted tubule

Loop of Henley

Collecting Ducts

Proximal tubules

Reabsorb and filter bicarbonate

Homeostasis

The process by which the urinary system maintains a stable internal environment by regulating waste removal, water, and electrolyte balance.

Urinary System

The system that includes the kidneys, ureters, urinary bladder, and urethra, functioning to filter blood and produce, store, and eliminate urine.

Aldosterone

A hormone that regulates sodium reabsorption in the kidneys.

Antidiuretic Hormone (ADH)

A hormone that regulates water reabsorption in the kidneys.

High ADH levels

Increase water permeability, leading to concentrated urine

Low ADH levels

Decrease water permeability leading to dilute urine

Bladder (Trigone)

Stores urine until eliminating.

Destructor

Muscle of bladder wall

Bladder hold

300-500 ml of urine

Urge begins at 150-200ml

Urtheral

Urine from bladder to outside the body

Females short than males

Urination ( Micturition)

Urinating

Kidney

Regulate bp

Renin Angiotensin Aldo system

Response to decreased blood flow to renin

Decreased NaCl delivery

Sympathetic nervous system stimulation

Renin

Converts angotensinogen to angiotensin ll

Angiotensin ll cause

Vasoconstriction ( increase bp)

Stimulate Aldo to secrete from adrenal cortex

Stimulate ADH to release

Increase thirst

Aldosterone

Increase sodium and water reabsorption in distal tubules and collecting ducts