Quiz 8

Where are the renal tubules of the cortical nephrons?

They are mostly in the cortex and have a small segment in the renal medulla

Where do the efferent arterioles of nephrons drain into?

peritubular capillaries

What do peritubular capillaries surround?

Renal tubules

What characterizes Juxtamedullary nephrons?

Having long loops that extend into the medulla

What surrounds the loop of henle

Vasa recta

What is the vasa recta connected to?

Peritubular capillaries

What is the vasa recta

Capillaries that run parallel to the loop of Henle (nephron loop)

What do Juxtamedullary nephrons allow for?

They allow for the kidneys to produce concentrated urine

What are the 3 processes involved in the formation of urine?

Glomerular filtration, Tubular reabsorption, Tubular secretion

Where does Glomerular filtration occur

The renal corpuscle

What produces cell and protein free fluid?

Glomerular filtration

What occurs in the renal tubules and collecting ducts that allows for selective movement of substances in filtrate and blood?

Tubular reabsorption and secretion

What happens during tubular reabsorption?

Selective movement of substance from filtrate to blood

What can be reabsorbed during tubular reabsorption?

Reclaims almost everything filtered (glucose, amino acids, 99% water and salt)

What allows for selective movement of substances from blood into filtrate?

Tubular secretion

What composes the Renal Corpuscle?

Glomerulus, and Glomerular capsule (Bowman’s capsule)

What is the renal corpuscle?

The initial, blood-filtering component of a kidney nephron

What is the glomerulus composed of?

Capillaries

What Surrounds glomerulus and is continuous with the renal tubules?

Glomerular capsule

What are the components of the glomerular capsule?

An outer parietal layer and an inner visceral layer

Where is the visceral layer of the glomerular capsule?

It surrounds the glomerular capillaries

What is the name of the highly branching epithelial cell that composes the visceral layer of the glomerular capsule?

Podocyte

What is the structure that podocytes produce that allow for fluid to be filtered out of the capillaries?

Filtration slits

What type of capillary forms the glomerular capillaries?

fenestrated

What forms the filtration membrane of the renal corpuscle?

Fenestrated endothelium, basement membrane and filtration slits

What forces water and dissolved solutes out of the capillaries in the glomerular capsule?

Blood pressure

What doesn’t get filtered out of the capillary at the glomerular capsule?

Large proteins

What is the name of the protein-free solution that is produced by filtration?

Filtrate

What is filtrate similar to?

Blood plasma without proteins

Where does filtrate go after being filtered out in the glomerular capsule?

The renal tubules

What are the functions of the renal tubules?

To secrete waste products into the tubule, reabsorb useful organic nutrients, and 90% of water from filtrate

What are the three segments of the renal tubule in order?

Proximal convoluted tubule, Loop of Henle (nephron loop), distal convoluted tubule

What separates the proximal and distal convoluted tubules?

The loop of Henle

Where are the convoluted tubules?

In the cortex

Where is the majority of the nephron loop?

Medulla

Where do the renal tubules drain into?

Collecting ducts

What is the major function of the proximal convoluted tubule?

Reabsorption of NaCl and water

What precent of filtered water, NaCl, K, and other solutes reabsorbed in the proximal convoluted tubule?

65%

What precent of filtered HCO₃^- is reabsorbed in the proximal convoluted tubule?

80%

What precent of glucose and amino acids are reabsorbed in the proximal convoluted tubule?

100%

What is secreted into the proximal convoluted tubule?

H⁺ and ammonium ions
bile and creatinine
Drugs like penicillin, aspirin, and morphine

What are the two sections of the loop of Henle?

Descending limb and ascending limb

What are the segments of both the descending and ascending limb of the loop of Henle?

A thick and thin segment

What is the thick descending limb of the loop of Henle similar to?

proximal convoluted tubule

What is the thick descending limb of the loop of Henle involved in?

reabsorption

What is the thin segment of the descending limb of the loop of Henle permeable to?

Water

Does water move in or out of the descending loop of Henle?

Out

What is caused by water leaving the tubule in the descending loop of Henle?

Tubular fluid is concentrated

What precent of water is reabsorbed in the loop of henle?

15%

What is secreted into the thin ascending limb of the loop of Henle?

Urea

What is the thick ascending limb of the loop of Henle permeable to?

Solutes

What happens to the concentration of the tubular fluid as solutes move out of it in the thick ascending limb of the loop of Henle?

Tubular fluid becomes less concentrated

What is reabsorbed in the ascending loop of henle?

Na, Cl, K

What precent of filtered Na, Cl, and K are reabsorbed in the thick ascending loop of Henle?

25%

What is reabsorbed in the distal convoluted tubules?

Selectively reabsorbs NaCl, calcium ions, and Water from the tubular fluid

What is secreted into the distal convoluted tubules?

Secretes ions, acids, drugs and toxins into the tubules

What is reabsorbed from the collecting duct?

Selectively reabsorb sodium ions, water, HCO3- and urea from tubular fluid

What is secreted into the collecting duct?

K, H, and HCO₃

What is the juxtaglomerular complex?

Formed by cells of the distal convoluted tubule and afferent arterioles, they monitor blood pressure.

Where is the juxtaglomerular complex?

between the distal convoluted tubule and the afferent arterioles

What hormone is released by the justaglomerular complex when blood pressure is low?

Renin

What does renin do?

increase blood pressure

What does the juxtaglomerular complex monitor?

Blood pressure

What is the function of the Renin-Angiotensin-Aldosterone System?

This hormone system regulates blood pressure, volume, and sodium/potassium balance.

What is the order of hormones in the hormone system initiated by Renin?

Renin → angiotensinogen → angiotensin I → angiotensin II → aldosterone

What converts angiotensinogen to angiotensin I?

Renin

What converts angiotensin I to angiotensin II

Angiotensin converting enzyme (ACE)

What does renin do within the Renin-Angiotensin-Aldosterone System?

Renin converts angiotensinogen to angiotensin I

What does Angiotensin converting enzyme (ACE) do within the Renin-Angiotensin-Aldosterone System?

Converts angiotensin I to angiotensin II

What’s the role of Angiotensin II in the Renin-Angiotensin-Aldosterone System?

Stimulates adrenal cortex to release aldosterone

What are all of the effects of angiotensin II on the body?

Stimulates the release of aldosterone, Vasoconstriction, Release of ADH, and Increased thirst

What is the basic function of aldosterone in the urinary system?

It reabsorbs salt, which causes water to also be reabsorbed, which then raises blood pressure and gets rid of a K.

What does aldosterone do with Na and K?

It stimulates placing Na/k channels into the apical membrane which causes the Na/K ATPase transporters in the basolateral membrane within the Distal convoluted tubule and the collecting duct which increases the reabsorption of Na

What does the increased reabsorption of Na by aldosterone cause?

The reabsorption of water

What does an increase in Na reabsorption cause for K?

Increased secretion of K in the opposite direction of Na

What causes lipids to be insoluble in the aqueous solution of the digestive tract?

They are hydrophobic

How do lipids arrange themselves in the digestive tract?

Large fat droplets

What breaks down (emulsifies) large fat droplets?

Bile salts

What digest fat?

Lipase

What are small spherical aggregates of bile salts and phospholipids that surround brokendown fats?

Micelles

What is the product of lipid digestion?

free fatty acids and monoglycerides

Where do micelles bring fatty acids and mono glycerides?

To the apical membrane of brush boarder cells

What do fatty acids and monoglycerides do at the brush border cells?

Diffuse into the brush border cells

What is transported into the brush border cells alongside the absorption of fatty acids and Monoglycerides?

Cholesterol

What is formed by fatty acids, monoglycerides, cholesterol, and proteins?

Chylomicrons

What is the function of the chylomicrons during the digestion of fats?

Transport fat to the lacteal.

Where do chylomicrons leave the membrane of the brush border cell?

The basolateral membrane

What are the components of the urinary system?

Kidney, ureter, urinary bladder, and Urethra.

Function of the kidneys

Form urine

Function of the ureters

Transport urine from kidneys to urinary bladder

Function of Urinary bladder

Temporary storage of urine

Function of urethra

Drains urine from bladder

What do the ureter, renal blood vessels, lymphatics and nerves enter the kidney?

Renal hilum

What is on the superior surface of the kidneys?

Adrenal glands

What regulates the volume and osmolarity of blood (broadly)?

The kidneys

What regulates the concentration of ions in blood (broadly)?

Kidneys

What excretes waste and toxins from the blood (broadly)?

The Kidneys

What regulates the acid base balance of blood (broadly)?

The kidneys

What converts vitamin d to its active form (broadly)?

The kidneys

Where does the production of erythropoietin and renin happen (broadly)?

Kidneys