Human Biology Chapter 11 Part 2

What is the juxtaglomerular apparatus?

• Secretes ,renin, which causes the release of aldosterone by the adrenal cortex

Water reabsorption in nephron loops / Loop of Henle (2)

• Sodium (Na+) is reabsorbed from the ascending limb of the loop of Henle making filtrate less concentrated.

Water reabsorption in nephron loops / Loop of Henle (3)

• This is the countercurrent-multiplier.

H+ means

hydrogen ion

How is the acid-base balance maintained? • Ultimately, the ____________ are responsible for maintaining blood pH.

kidneys

What is the main buffer of blood?

kidneys

Tubular Secretion occurs when molecules/substances ___________ the blood and enter the tubular nephron at a location other than the __________ corpuscle.

leave, renal

Water reabsorption in nephron loops / Loop of Henle(1)

• Water (H2O) is reabsorbed from the descending limb of the loop of Henle making filtrate more concentrated.

How do the kidneys maintain homeostasis?(2)

• Water-salt balance of blood Helps regulate blood volume and pressure

What is the juxtaglomerular apparatus?

• Where the afferent arteriole and the distal convoluted tubule touch

• What is the juxtamedullary apparatus?

• Where the afferent arteriole and the distal convoluted tubule touch • Secretes ,renin, which causes the release of aldosterone by the adrenal cortex.

How is blood volume and pressure maintained by the kidneys?(step 2)

•Establishment of solute gradient - a greater concentration is towards the inner medulla

Tubular reabsorption- Many molecules and ions are reabsorbed from the __________ __________ into the blood.

tubular nephron

How do the kidneys maintain homeostasis?(3)

• Acid-base balance of blood Helps regulate pH

What role does alcohol play in this process?

• Alcohol inhibits ADH secretion and thus increases the amount of urine produced which can lead to dehydration.

How do the kidneys maintain homeostasis?(4)

• Assistance to other systems Endocrine, cardiovascular, skeletal, muscular, nervous, and digestive

How do the kidneys maintain homeostasis?(1)

• Excrete wastes Urea, creatinine, and uric acid

What are the three processes in the formation of urine?

• Glomerular Filtration, Tubular Reabsorption, Tubular Secretion

• List the components of the (glomerular) filtrate. (See Fig 11.6)

• Glomerular Filtration, Tubular Reabsorption, Tubular Secretion

Tubular reabsorption

• Many molecules and ions are reabsorbed from the tubular nephron into the blood.

How is blood volume and pressure maintained by the kidneys?

• Reabsorption of salt - increases the blood volume aldosterone promotes the excretion of K+ and the reabsorption of Na+.

How is blood volume and pressure maintained by the kidneys?(step 3)

• Reabsorption of water - due to the solute gradient, water leaves the descending limb of the loop of the nephron; then antidiuretic hormone (ADH) from the pituitary plays a role in water reabsorption at the collecting duct

How is the acid-base balance maintained?

Buffers, respiratory center, but ultimately the Kidney's are responsible for mainting blood pH

How does the nephron form urine?

?

• What substances can be found in urine?

??

• Trace the formation of urine through the tubular nephron.

ADD PIC

How does aldosterone work?

Aldosterone promotes ion exchange at the distal convoluted tubules. Potassium ions (K+)are excreted and sodium ions (Na+) are reabsorbed into the blood. The release of aldosterone is set into motion by kidneys. The juxtaglomerular apparatus is a region in contact between the afferent arteriole and the distal convoluted tubule.

• How do these hormones work

Aldosterone promotes ion exchange at the distal convoluted tubules. Potassium ions (K+)are excreted and sodium ions (Na+) are reabsorbed into the blood. The release of aldosterone is set into motion by kidneys. The juxtaglomerular apparatus is a region in contact between the afferent arteriole and the distal convoluted tubule. When blood volume falls too low fir filtration occurs, the juxtaglomerular apparatus can respond by secreting renin. Renin is an enzyme that ultimately leads to secretion of aldosterone by the adrenal glands. Atrial natriuretic hormone (ANH) is secreted by the atria of the heart when cardiac cells are stretched due to increased blood volume. ANH inhibits the secretion of renin by the juxtaglomerular apparatus and the secretion of aldosterone by the adrenal glands. It's effect therefore is to promote excretion of sodium ion (Na+), called natriuresis. Normally, salt reabsorption creates osmotic gradient that causes water to be absorbed. Thus by causing salt excretion, ANH causes water excretion, too. If ANH is present, less water will be absorbed, even if ADH is also present.

How does Atrial natriuretic hormone (ANH) work?

Atrial natriuretic hormone (ANH) is secreted by the atria of the heart when cardiac cells are stretched due to increased blood volume. ANH inhibits the secretion of renin by the juxtaglomerular apparatus and the secretion of aldosterone by the adrenal glands. It's effect therefore is to promote excretion of sodium ion (Na+), called natriuresis. Normally, salt reabsorption creates osmotic gradient that causes water to be absorbed. Thus by causing salt excretion, ANH causes water excretion, too. If ANH is present, less water will be absorbed, even if ADH is also present.

___________ ________________ __________ ___________ (ANH or ANP) is secreted by the heart when blood volume increases and inhibits the secretion of aldosterone which promotes the excretion of Na+. • Establishment of solute gradient - a greater concentration is towards the inner medulla • Reabsorption of water - due to the solute gradient, water leaves the __________________ limb of the loop of the nephron; then antidiuretic hormone (ADH) from the pituitary plays a role in water reabsorption at the collecting duct.

Atrial natriuretic peptide hormone, descending (this is used for water)

How is the acid-base balance maintained? _____________ are a chemical that maintain the pH of a solution by adding or removing H+ to/from the solution.

Buffers

What is a buffer and how does it work?

Buffers are a chemical that maintain the pH of a solution by adding or removing H+ to/from the solution.

-Describe tubular secretion.

Certain ions and molecules (e.g., H+ and penicillin) are actively secreted from the peritubular capillary network into the convoluted tubules

Water Nitrogenous wastes Nutrients Salts (ions) are all examples of:

Filterable Blood Components

Nonfilterable Blood Components:

Formed elements (blood cells and platelets) Plasma proteins

• What can't be filtered from the blood?

Formed elements (blood cells and platelets) Plasma proteins

• List and describe the three processes in urine formation.

Glomerular Filtration-Water and small molecules move from the glomerulus to the glomerular capsule, while large molecules and formed elements remain in the glomerular blood. Tubular Reabsorption-Nutrient and salt molecules are activity reabsorbed from the convoluted tubules into the peritubular capillary network, and water flows passively. Tubular Secretion-Certain ions and molecules (e.g., H+ and penicillin) are actively secreted from the peritubular capillary network into the convoluted tubules

When H+ are added to blood: H + HCO3 --->

H2CO3

When OH- are added to blood: OH- + H2CO3-----> HCO3- +

H2O

What parts of the tubular nephron produce the countercurrent-multiplier?

Loop of Henle

Which two organs regulate the pH of the blood?

Lungs, Kidneys

Reabsorbed Filtrate Components:

Most water, Nutrients, Required salts-(ions)

Formed elements (blood cells and platelets) Plasma proteins are all examples of:

NONfilterable blood components

Describe tubular reabsorption:

Nutrient and salt molecules are activity reabsorbed from the convoluted tubules into the peritubular capillary network, and water flows passively

Nonreabsorbed Filtrate Components:

Some water, Much nitrogenous waste, Excess salts (ions)

Filterable Blood Components

Water, Nitrogenous wastes, Nutrients, Salts (ions)

• What can be filtered from the blood?

Water, Nitrogenous wastes, Nutrients, Salts (ions)

Glomerular filtration • ___________ and small molecules move from the glomerulus to the glomerular capsule, while large molecules and _________ elements remain in the glomerular blood.

Water, formed

How does renin work?

When blood volume falls too low fir filtration occurs, the juxtaglomerular apparatus can respond by secreting renin. Renin is an enzyme that ultimately leads to secretion of aldosterone by the adrenal glands.

The juxtaglomerular apparatus is where the _____________ arteriole and the distal convoluted tubule touch. It secretes ,_______, which causes the release of aldosterone by the adrenal cortex.

afferent, renin

• List three hormones that regulate blood volume and pressure.

aldosterone, renin, atrial natriuretic hormone (ANH)

Tubular reabsorption: Nutrient and salt molecules are activity reabsorbed from the ___________ tubules into the peritubular capillary network, and water flows ___________.

convoluted, passively

Tubular secretion is a second way to remove substances such as:

drugs, H+ and creatinine from the blood.

As an aid to all the systems, the kidneys excrete nitrogenous wastes and ____________ the water-salt balance and the acid-base balance of the blood. The urinary system also specifically helps the _______ systems.

maintain, other

How is the acid-base balance maintained? • The _____________ center in the brain can increase breathing rate if the buffers cannot maintain the pH.

respiratory

How is blood volume and pressure maintained by the kidneys? (step 1)

•Reabsorption of salt - increases the blood volume- aldosterone promotes the excretion of K+ and the reabsorption of Na+. Atrial natriuretic peptide hormone (ANH or ______) is secreted by the heart when blood volume increases and inhibits the secretion of aldosterone which promotes the excretion of Na+.