Chapter 7: Excretion Flashcards

A set of 50 practice flashcards covering the human excretory system, including organ functions, nephron structure, and the process of urine formation.

How is excretion defined in the context of metabolism?

Excretion is the removal of metabolic waste and involves ridding the body of any materials that are in excess supply.

What is the definition of metabolism?

Metabolism refers to all the chemical reactions that occur in a living cell.

Which two excretory products are produced from respiration?

Carbon dioxide and water.

What is the word equation for aerobic respiration?

$$Glucose + Oxygen \rightarrow Carbon\,dioxide + Water + Energy$$

According to the respiration equation, what are the metabolic waste products?

Carbon dioxide and water.

In the process of aerobic respiration, what is considered the main product?

Energy.

Where is urea formed and from what substance?

Urea is formed in the liver from the deamination of excess amino acids.

How is bile produced as an excretory product?

Bile is formed by the breakdown of old red blood cells in the liver.

What is the source of excreted salts?

Salts are produced from nutrient metabolism.

Which organ is responsible for excreting carbon dioxide?

The lungs.

What is the excretory role of the liver?

The liver excretes bile formed by the breakdown of old red blood cells.

What do the sweat glands in the skin produce?

They produce sweat, which consists mostly of water, a small amount of salt, and urea.

What is the primary function of sweat releasing onto the skin surface?

It evaporates and cools the body.

Which organs are described as the main organs of excretion?

The kidneys.

What three substances are removed from the blood when it is filtered by the kidneys?

Urea, excess water, and salts.

What is the liquid waste formed by the kidneys called?

Urine.

Which four structures make up the excretory (urinary) system?

Two kidneys, ureters, the bladder, and the urethra.

What is the function of the renal artery?

The renal artery brings blood to the kidneys to be filtered.

What is the function of the renal vein?

The renal vein carries filtered blood away from the kidneys to the heart.

What are the three main components of urine?

Water, urea, and salt.

What are ureters?

Ureters are tubes that carry urine from the kidneys to the urinary bladder.

What is the urinary bladder?

The urinary bladder is a saclike organ that stores urine.

What is the function of the muscular walls of the bladder?

The muscular walls help push urine out of the body.

What is the urethra?

The urethra is a tube that carries urine from the bladder to the outside of the body.

What is the physical appearance of the kidneys?

They are dark reddish brown in color and bean-shaped.

Where are the kidneys located in the body?

They are found high up on the wall of the abdomen, one on each side of the backbone.

How many nephrons are found in each kidney?

Each kidney has at least $1 \times 10^6$ nephrons (one million).

What are nephrons?

Nephrons are the microscopic filtering units of the kidney.

Name the structures that protect the kidneys.

Bones of the lower ribs and spine, abdominal wall and intestines, bulky back muscles, a layer of fat, and a tough membrane.

What is the specific job of the nephrons?

Filtering the blood and forming urine.

What is a glomerulus?

A glomerulus is a knot of capillaries found in the nephron.

What structure surrounds the glomerulus?

The cup-shaped Bowman's capsule.

What does the Bowman's capsule connect with?

It connects with a tubule.

Where does urine go after it passes through the tubule?

It passes into a larger tube called a collecting duct.

How does urine exit the kidneys from the collecting ducts?

It passes from the collecting ducts into a ureter.

What are the three steps in the formation of urine?

Filtering, Reabsorbing, and Removing.

What occurs during the filtering stage in the nephron?

Small molecules are forced out of the glomerulus under high pressure and into the Bowman's capsule.

List four examples of small molecules forced into the Bowman's capsule during filtering.

Water, urea, salt, and glucose.

Which components of the blood do NOT leave the glomerulus during filtering?

Red blood cells, platelets, and plasma proteins.

Why do red blood cells and plasma proteins stay in the glomerulus?

They are too big to pass through.

What happens during the reabsorbing step of urine formation?

Substances the body needs are absorbed back into the blood.

In which part of the nephron does reabsorption occur?

In the tubules.

Name three substances that are reabsorbed into the blood.

Glucose, some water, and some salt.

What is the final step of the kidney's work in urine formation?

Removing of urine by the collecting duct.

What is kidney failure?

Kidney failure is when one or both kidneys stop working.

What can cause kidney failure?

Infection or injury (such as an accident).

What are the two common treatments for kidney failure?

Dialysis or kidney transplant.

Where is the sphincter muscle located in the excretory system diagram?

At the base of the bladder, leading to the urethra.

Which large blood vessels are connected to the renal system?

The Vena cava and the Aorta.

True or False: The body can function normally with only one kidney.

True.