lecture 5 exam

Urinary system

Removes metabolic wastes produced by the body's cells.

Kidneys

Paired organs that produce urine by removing metabolic wastes from circulation.

Ureters

Paired tubes that transport urine from the kidneys to the urinary bladder.

Urinary bladder

A muscular sac that temporarily stores urine.

Urethra

The exit tube that transports urine out of the body.

Micturition

The process of eliminating urine.

Excretion

The removal of metabolic wastes from body fluids.

Elimination

The discharge of wastes from the body.

Homeostatic regulation

The maintenance of stable internal conditions, including blood volume and solute concentration.

Erythropoietin

Hormone released by the kidneys to stimulate red blood cell formation.

Renin

Hormone released by the kidneys that regulates water and sodium balance.

Hydrogen ions

Ions regulated by the kidneys to help stabilize blood pH.

Calcitriol

Active form of vitamin D synthesized by kidneys to regulate calcium ion levels.

Renal cortex

The superficial region of the kidney in contact with the fibrous capsule.

Renal pyramids

Triangular structures in the renal medulla that contain nephrons.

Renal columns

Bands of tissue that separate adjacent renal pyramids.

Glomerular (Bowman’s) capsule

The spherical structure that encapsulates glomerular capillaries.

Glomerulus

A network of capillaries within the nephron where blood filtration occurs.

Podocytes

Cells of the visceral layer of the glomerular capsule that wrap around capillaries.

Filtration membrane

Structure that allows water and small solutes to pass while restricting larger substances.

Proximal convoluted tubule (PCT)

First segment of the renal tubule responsible for reabsorption of nutrients.

Distal convoluted tubule (DCT)

Third segment of the renal tubule that reabsorbs water and ions.

Juxtaglomerular complex (JGC)

Structure that helps regulate blood pressure and filtrate formation.

Collecting duct

Receives fluid from many nephrons and adjusts its composition.

Cortical nephron

Nephrons primarily located within the cortex of the kidney.

Juxtamedullary nephron

Nephrons with long loops of Henle that extend deep into the medulla.

Glomerular filtration rate (GFR)

The amount of filtrate produced by kidneys each minute.

Autoregulation

Local regulation of GFR despite changes in blood pressure.

Renin-angiotensin-aldosterone system (RAAS)

Hormonal system that regulates blood pressure and fluid balance.

Atrial natriuretic peptide (ANP)

Hormone that promotes loss of sodium and increases GFR.

Transport maximum (Tm)

The maximum rate at which a substance can be reabsorbed by renal tubules.

Renal threshold

Plasma concentration at which a specific solute begins to appear in urine.

Glucosuria

Presence of glucose in the urine, occurring when renal threshold is exceeded.

Sodium ion reabsorption

Critical process in the PCT that influences water reabsorption.

Nephron loop

U-shaped tube responsible for the reabsorption of water and salts.

Secretion at DCT

Process where potassium and hydrogen ions are secreted into the tubular fluid.

Urethra

Tube that carries urine from the urinary bladder to the outside of the body.

Detrusor muscle

Muscle in the bladder wall that contracts to expel urine.

Trigone of urinary bladder

Triangular area that channels urine into the urethra.

External urethral sphincter

Circular band of skeletal muscle that provides voluntary control over urination.

Urine composition

Reflects filtration, reabsorption, and secretion activities of nephrons.

Creatinine clearance

Test that compares creatinine levels in urine and blood to estimate kidney function.

Urinalysis

Analysis of urine sample to assess health and kidney function.

Pyelogram

Image of the urinary system obtained after dye administration for X-ray.

Incontinence

Inability to control urination voluntarily.

Ureters

Muscular tubes that transport urine from the kidneys to the bladder.

Nephron

Microscopic functional unit of the kidney.

Filtrate

Fluid that enters the renal tubule after filtration at the glomerulus.

Calcium ion regulation

Process managed by kidneys to maintain plasma ion concentrations.

Nitrogenous wastes

Waste products from the breakdown of proteins (e.g., urea, creatinine).

Homeostasis

Maintaining stable internal conditions in the body.

Hydrogen ions

Help regulate blood pH through urine secretion.

Filtrations slits

Narrow gaps between podocyte processes that allow filtration.

Basement membrane

Selective barrier in the filtration membrane of the glomerulus.

Filtration pressures

Balances hydrostatic and osmotic pressures to drive glomerular filtration.

Net filtration pressure (NFP)

Overall pressure that pushes water and solutes in the filtration process.

Blood colloid osmotic pressure (BCOP)

Pressure generated by proteins in blood that draws water back into circulation.

Aldosterone

Hormone that increases sodium reabsorption and potassium secretion.

Antidiuretic hormone (ADH)

Hormone that regulates water permeability in the collecting duct.

Urinary bladder

Organ that stores urine prior to elimination.

Muscular layer of bladder

Contains detrusor muscle responsible for urine expulsion.

Fluid balance

Daily balance between the amount of water gained and the amount of water lost to the environment.

Electrolyte balance

When gains and losses for every electrolyte are in balance.

Acid-base balance

Precise balancing of hydrogen ions (H+) production and loss.

Extracellular fluid (ECF)

Fluid outside cells; essential for cytosol composition.

Intracellular fluid (ICF)

Fluid inside cells; reliant on water for cellular operations.

Osmosis

Movement of water across selectively permeable membranes.

Adh (Antidiuretic hormone)

Hormone stimulating water conservation at kidneys.

Aldosterone

Hormone regulating sodium and potassium balance in kidneys.

Natriuretic peptides

Hormones reducing thirst and promoting diuresis in response to heart wall stretching.

Edema

Swelling caused by abnormal movement of water from plasma into interstitial fluid.

Dehydration

Condition resulting from water losses exceeding gains.

Hyperhydration

Condition caused by excess water in the body, affecting cell function.

Hyponatremia

Abnormally low sodium concentration in the blood.

Hypernatremia

Abnormally high sodium concentration in the blood.

Fixed acids

Acids that do not leave solution and remain until eliminated by kidneys.

Volatile acids

Acids that can leave the body through the lungs.

Buffers

Dissolved compounds that stabilize pH by adding or removing H+.

Hemoglobin buffer system

Buffer system that helps stabilize pH during CO2 fluctuations.

Acidosis

Physiological state resulting from abnormally low blood pH.

Alkalosis

Physiological state resulting from abnormally high blood pH.

Phosphate buffer system

Buffer system important in buffering the pH of intracellular fluid and urine.

Protein buffer systems

Buffer systems that rely on amino acids to respond to pH changes.

Sodium concentration role

Plays a crucial role in determining ECF osmotic concentration.

Potassium role in ICF

Primary cation in intracellular fluid with crucial physiological roles.

Calcium's physiological functions

Involved in muscular, neural activities, and blood clotting.

Chloride balance

Chloride ions are the most abundant anions in extracellular fluid.

Magnesium's role

Required as a cofactor for enzymatic reactions and muscle function.

Phosphate in bone mineralization

Phosphate ions are essential for bone mineralization.

Bicarbonate ion

Main component of carbonic acid-bicarbonate buffer system,

Respiratory compensation

Changes in the respiratory rate to stabilize blood pH.

Renal compensation

Kidneys regulate H+ and HCO3− to adjust body pH.

Hydrogen ions gain sources

Gained through the digestive tract and cellular metabolism.

Hydrogen ions elimination sources

Eliminated through kidneys and lungs.

Ion secretion in renal function

Kidneys secrete H+ to maintain acid-base balance.

Osmotic concentration of ECF and ICF

Identical under normal circumstances.

Fluid compartments

Separate regions where fluid is contained in the body.

Lymphatic drainage

System involved in fluid exchange from interstitial spaces back to venous circulation.

Concentration of electrolytes

Directly affects cell function and water balance.

Electrolyte imbalances

Can significantly impact bodily functions and health.