Osmoregulation and Excretion Flashcards

Vocabulary flashcards covering key terms and concepts from the osmoregulation and excretion lecture.

Osmolarity

The amount of dissolved substance in water.

Sodium (Na+)

Plays the largest role in determining blood osmolarity, typically accounting for 90–95% of effective plasma osmolarity.

Other Substances (Glucose, Urea, Blood proteins)

Substances that contribute minimally to blood osmolarity; includes glucose, urea and blood proteins.

Hyperosmotic/Hypertonic Solution

A solution with higher dissolved substances than the cell, leading to water loss from the cell (cell shrinks).

Hypoosmotic/Hypotonic Solution

A solution with lower dissolved substances than the cell, causing water to move into the cell (cell swells or might burst).

Iso-osmotic/Isotonic Solutions

Solutions that have equal concentrations, resulting in no net water movement (no change in cell size or shape).

Osmoconformers

Organisms whose internal osmolarity is equal to that of their external environment, typically restricted to stable environments.

Osmoregulators

Organisms that actively regulate (or control) their internal osmolarity, keeping it constant despite changes in the environment's osmolarity.

Ammonotelism

The process of removing ammonia from the body.

Nephron

The structural and functional unit of the kidney, responsible for osmoregulation and removal of nitrogenous waste.

Glomerulus

A ball of capillaries in the nephron that filters blood under pressure.

Bowman’s Capsule

Surrounds the glomerulus and collects the generated filtrate.

Proximal Convoluted Tubule (PCT)

Part of the nephron where reabsorption of 100% of glucose and amino acids and 65% of Na⁺ (and other ions) and water occurs.

Descending Limb of Henle’s Loop

Permeable to water, impermeable to salts; responsible for water reabsorption in the nephron.

Ascending Limb of Henle’s Loop

Impermeable to water, permeable to salts; responsible for Na+ reabsorption in the nephron.

Distal Convoluted Tubule (DCT)

Part of the nephron responsible for fine-tuning of salt and pH balance of the blood.

Collecting Duct

Part of the nephron where final water reabsorption occurs, controlled by ADH.

Anti-Diuretic Hormone (ADH)

Hormone that promotes reabsorption of water back into the blood from the distal convoluted tubule and collecting duct.

Desmopressin (DDAVP)

A synthetic form of ADH used to treat central diabetes insipidus.

Bowman's Capsule

A double-walled structure that encases the glomerulus, collecting filtrate.

Fenestrated endothelium of glomerular capillaries

Pores of the fenestrated capillaries are enough to block Red Blood Cells and other blood cells from passing but will not be enough to block the passage of proteins.

Basement membrane

Blocks the passage of proteins.

Podocytes

Blocks blood cells and Proteins

Glomerulonephritis

Inflammation of the glomeruli, leading to impaired kidney filtration.

Hematuria

Blood in urine, a symptom of glomerulonephritis.

Proteinuria

Foamy urine due to protein loss, a symptom of glomerulonephritis.

Edema

Swelling in legs, ankles, or around eyes, a symptom of glomerulonephritis.

Hypertension

Elevated blood pressure, a symptom of glomerulonephritis and kidney stones .

Kidney Stones

Hard objects formed of substances found in the urine.

Calcium Oxalate Stones

Kidney stones are hard crystals formed when calcium combines with oxalate in the urine.

Uric Acid Stones

Kidney stones formed from uric acid, a waste product that results from the breakdown of purines.

Renal Colic

Severe flank or back pain caused by kidney stones.

Lithotripsy

A non-invasive procedure to break kidney stones into smaller pieces using shock waves.

Renal Failure

A medical condition in which the kidneys lose their ability to adequately filter waste products, excess fluids, and electrolytes from the blood.

Dialysis

Medical treatment that performs the function of the kidneys when they can no longer work properly.

Malpighian tubules

Absorb water, salts and ions and wastes (e.g. Uric Acid) from the insect’s hemolymph (insect’s blood)

Osmolarity

The amount of dissolved substance in water.

Sodium (Na+)

Plays the largest role in determining blood osmolarity, typically accounting for 90–95% of effective plasma osmolarity.

Other Substances (Glucose, Urea, Blood proteins)

Substances that contribute minimally to blood osmolarity; includes glucose, urea and blood proteins.

Hyperosmotic/Hypertonic Solution

A solution with higher dissolved substances than the cell, leading to water loss from the cell (cell shrinks).

Hypoosmotic/Hypotonic Solution

A solution with lower dissolved substances than the cell, causing water to move into the cell (cell swells or might burst).

Iso-osmotic/Isotonic Solutions

Solutions that have equal concentrations, resulting in no net water movement (no change in cell size or shape).

Osmoconformers

Organisms whose internal osmolarity is equal to that of their external environment, typically restricted to stable environments.

Osmoregulators

Organisms that actively regulate (or control) their internal osmolarity, keeping it constant despite changes in the environment's osmolarity.

Ammonotelism

The process of removing ammonia from the body.

Nephron

The structural and functional unit of the kidney, responsible for osmoregulation and removal of nitrogenous waste.

Glomerulus

A ball of capillaries in the nephron that filters blood under pressure.

Bowman’s Capsule

Surrounds the glomerulus and collects the generated filtrate.

Proximal Convoluted Tubule (PCT)

Part of the nephron where reabsorption of 100% of glucose and amino acids and 65% of Na⁺ (and other ions) and water occurs.

Descending Limb of Henle’s Loop

Permeable to water, impermeable to salts; responsible for water reabsorption in the nephron.

Ascending Limb of Henle’s Loop

Impermeable to water, permeable to salts; responsible for Na+ reabsorption in the nephron.

Distal Convoluted Tubule (DCT)

Part of the nephron responsible for fine-tuning of salt and pH balance of the blood.

Collecting Duct

Part of the nephron where final water reabsorption occurs, controlled by ADH.

Anti-Diuretic Hormone (ADH)

Hormone that promotes reabsorption of water back into the blood from the distal convoluted tubule and collecting duct.

Desmopressin (DDAVP)

A synthetic form of ADH used to treat central diabetes insipidus.

Bowman's Capsule

A double-walled structure that encases the glomerulus, collecting filtrate.

Fenestrated endothelium of glomerular capillaries

Pores of the fenestrated capillaries are enough to block Red Blood Cells and other blood cells from passing but will not be enough to block the passage of proteins.

Basement membrane

Blocks the passage of proteins.

Podocytes

Blocks blood cells and Proteins

Glomerulonephritis

Inflammation of the glomeruli, leading to impaired kidney filtration.

Hematuria

Blood in urine, a symptom of glomerulonephritis.

Proteinuria

Foamy urine due to protein loss, a symptom of glomerulonephritis.

Edema

Swelling in legs, ankles, or around eyes, a symptom of glomerulonephritis.

Hypertension

Elevated blood pressure, a symptom of glomerulonephritis and kidney stones .

Kidney Stones

Hard objects formed of substances found in the urine.

Calcium Oxalate Stones

Kidney stones are hard crystals formed when calcium combines with oxalate in the urine.

Uric Acid Stones

Kidney stones formed from uric acid, a waste product that results from the breakdown of purines.

Renal Colic

Severe flank or back pain caused by kidney stones.

Lithotripsy

A non-invasive procedure to break kidney stones into smaller pieces using shock waves.

Renal Failure

A medical condition in which the kidneys lose their ability to adequately filter waste products, excess fluids, and electrolytes from the blood.

Dialysis

Medical treatment that performs the function of the kidneys when they can no longer work properly.

Malpighian tubules

Absorb water, salts and ions and wastes (e

Ureotelism

Excretion of excess nitrogen as urea.

Uricotelism

Excretion of excess nitrogen as uric acid.

Role of ADH in Osmoregulation

Causes the insertion of aquaporins into the collecting duct, increasing its permeability to water, increasing water reabsorption and reducing urine volume.

Diabetes Insipidus

A condition characterized by the excretion of large amounts of dilute urine due to a deficiency in ADH or insensitivity of the kidneys to ADH.

Central Diabetes Insipidus

Caused by a deficiency in the production or release of ADH from the posterior pituitary gland.

Nephrogenic Diabetes Insipidus

Caused by the kidneys' insensitivity to ADH.

Symptoms of Diabetes Insipidus

Include polyuria (frequent urination), polydipsia (excessive thirst), and nocturia (frequent urination at night).

Aquaporins

Water channel proteins that facilitate the movement of water across cell membranes.

Effect of Alcohol on ADH

Alcohol inhibits the release of ADH, leading to increased urine production and dehydration.

Hormonal Regulation of the Nephron

Aldosterone promotes sodium reabsorption and potassium secretion in the distal convoluted tubule; atrial natriuretic peptide (ANP) inhibits sodium reabsorption.

Source and Function of Aldosterone

Produced by the adrenal cortex; increases sodium reabsorption and potassium secretion in the DCT.

Source and Function of Atrial Natriuretic Peptide (ANP)

Released by the heart in response to high blood volume; inhibits sodium reabsorption in the nephron, leading to increased sodium and water excretion.