Biology Chapter: Waste Excretion and Balance

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Questions and Answers

What primarily dictates the filtration process in the glomerulus?

Temperature differences

Chemical properties of solutes

Size of the molecules

Pressure differences (correct)

Which of the following substances is NOT typically filtered into Bowman's capsule?

Amino acids

Glucose

Urea

Platelets (correct)

What role does the active transport mechanism play in reabsorption?

It pumps glucose into the urine

It pumps Na+ ions across the membrane (correct)

It permits unrestricted ion flow

It allows passive diffusion of water

During reabsorption, what happens to glucose when it is present in excess?

It remains in the urine Signup and view all the answers

How does water reabsorption primarily occur in the nephron?

Diffusion following solute concentration Signup and view all the answers

What characterizes the ascending portion of the Loop of Henle?

It pumps out Na+ ions actively Signup and view all the answers

What is the outcome of active transport in the distal tubule?

Transports hydrogen ions into urine Signup and view all the answers

What occurs in the nephron when the solute concentration in the blood is higher than in the nephron?

Water diffuses out of the nephron Signup and view all the answers

What is the process called when excess protein is converted to carbohydrates, resulting in the formation of ammonia?

Deamination Signup and view all the answers

Which waste product is formed by the liver when it combines ammonia with carbon dioxide?

Urea Signup and view all the answers

What is the primary functional unit of the kidney responsible for urine formation?

Nephron Signup and view all the answers

Which layer of the kidney contains the Bowman’s capsule and glomerulus?

Cortex Signup and view all the answers

During the formation of urine, which step involves the transfer of essential solutes and water back into the bloodstream?

Reabsorption Signup and view all the answers

What triggers the urgency for urination when the bladder is full?

Message sent to the brain Signup and view all the answers

Which structures do the renal arteries branch from to supply blood to the kidneys?

Aorta Signup and view all the answers

Which part of the nephron is directly involved in the filtration process?

Bowman’s capsule Signup and view all the answers

What happens to urine after it is formed in the kidneys?

It is stored in the bladder until excretion Signup and view all the answers

What is uric acid a byproduct of?

Nucleic acid breakdown Signup and view all the answers

What is the term used to describe the process of converting excess protein to carbs, forming an amino group in the process?

Deamination Signup and view all the answers

What is the name of the hollow tube that joins the kidney with the ureter?

Renal pelvis Signup and view all the answers

The blood that leaves the glomerulus enters a vein.

False Signup and view all the answers

Which of the following are actively transported across the membrane during reabsorption? (Select all that apply).

Glucose Signup and view all the answers

What is the function of the hormone ADH (Antidiuretic Hormone)?

ADH acts on the collecting duct to increase water reabsorption. Signup and view all the answers

Which gland releases ADH into the bloodstream?

Pituitary gland Signup and view all the answers

What is the name of the hormone that has a similar overall effect to ADH, but acts on the distal tubule and the collecting duct to increase the active transport of Na+ back into the blood?

Aldosterone Signup and view all the answers

Study Notes

Waste Excretion and Internal Equilibrium

Waste products are eliminated from the body, maintaining internal equilibrium.
The liver processes toxins (e.g., alcohol) into less harmful substances and sends them to the kidneys for excretion.
Kidneys receive various waste products, including excess protein, that are metabolized.
Water balance is essential for maintaining internal equilibrium.

Waste Products

Kidneys receive substantial amounts of waste.
Excess protein is converted into carbohydrates through a process called deamination, creating ammonia.
Ammonia, being very toxic, is converted by the liver into urea and sent to the kidneys.
Uric acid is produced during the breakdown of nucleic acids and also sent to the kidneys.
CO2 is also a waste product, combined with ammonia by the liver, to form urea.

Water Balance

Kidneys are essential for maintaining water balance.
Water is more important than food; daily water loss must be replenished.
Improper water balance can be fatal within three days.
Water is critical for blood circulation.

Anatomy of the Urinary System

The kidneys filter waste from the blood.
Blood enters the kidneys through renal arteries.
The kidneys hold up to 25% of the body's blood at any given time.
Filtered waste is sent to the bladder via the ureters.
Urine is stored in the bladder until it becomes full.
A nerve impulse signals the brain when the bladder is full, resulting in urination.
Relaxation of the sphincter allows urine flow.

Anatomy of the Kidney

The outer layer of the kidney is the cortex, followed by the medulla.
A hollow tube connects the kidney to the ureter – the renal pelvis.
Functional units of the kidney are nephrons.
Renal arteries supply blood to the kidney.
Renal veins carry blood away.

Anatomy of the Nephron

The nephron is the functional unit of the kidney.
Blood is supplied by afferent arteries.
Afferent arteries branch into capillary beds called glomeruli.
Blood leaving the glomerulus enters another capillary bed called peritubular capillaries
These then merge with the renal vein.
The glomerulus is surrounded by Bowman's capsule, which becomes the proximal tubule.
The proximal tubule leads to the Loop of Henle, which then leads to the distal tubule.
These tubules eventually lead to the collecting duct.

Formation of Urine

Urine formation has three primary steps: filtration, reabsorption, and secretion.
Filtration involves fluid from blood moving to Bowman's capsule, which has smaller pores compared to capillaries, preventing larger cells, platelets, and proteins from passing.
Reabsorption involves transferring "good" substances (water and solutes) back into the bloodstream to maintain balance.
Secretion is the transport of materials from the blood into the nephron tubules to balance blood conditions.
Components like water, Salt (sodium chloride), Glucose, Amino acids, Hydrogen ions, and urea filter through the glomerulus.

Hormones That Affect Renal Function

ADH (Antidiuretic Hormone):
- Produced by the hypothalamus and released by the pituitary gland.
- Increases water reabsorption in the collecting ducts.
- Controls urine concentration.
- Release is triggered by high blood osmotic pressure.
Aldosterone:
- Released by the adrenal glands.
- Increases active transport of sodium (Na+) in distal and collecting tubules, promoting water retention.
- Regulates fluid volume and blood pressure.

2. Aldosterone

Works similarly to ADH, but has key differences.
Released by adrenal glands.
Acts on distal and collecting ducts.
Increases active transport of sodium (Na+), promoting water retention.
Water follows sodium due to concentration gradients.

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Description

Explore the intricacies of waste excretion and internal equilibrium in this quiz based on biology principles. Learn about the roles of the liver and kidneys in processing toxins and maintaining water balance. Test your knowledge on the anatomy of the urinary system and its importance in human health.