Unit 4

Question 1

What is the purpose of the excretory system?

Answer 1

Rids the body of metabolic wastes

The excretory system is crucial for maintaining homeostasis by removing waste products generated by cellular metabolism.

Question 2

Name three examples of wastes produced by body cells that must be removed.

Answer 2

• Nitrogenous wastes
• Ammonia
• Urea
• Bile Pigments
• CO2
• HCO3- (Bicarbonate)
• Ions - Sodium, Potassium, Calcium, Magnesium, Iron
• Water

These wastes are by-products of metabolic processes and can be toxic if accumulated in the body.

Question 3

What are the three major organs of the excretory system and what do they excrete?

Answer 3

• Kidneys - excretes urine
• Skin - excretes perspiration (water, salt, small amounts of urea)
• Liver - excretes bile
• Lungs - excretes CO2 and some water

Each organ plays a specific role in the excretion process, contributing to the overall function of the excretory system.

Question 4

What is ‘the main’ organ of the excretory system?

Answer 4

The Kidney

The kidneys are essential for filtering blood and forming urine, thus playing a central role in waste removal.

Question 5

Fill in the blank: The main organ of the excretory system is the _______.

Answer 5

Kidney

Question 6

True or False: The skin is part of the excretory system.

Answer 6

True

Question 7

What does the liver excrete as part of the excretory system?

Answer 7

Bile

Bile is important for the digestion of fats and also plays a role in the elimination of certain waste products.

Question 8

What waste product is excreted by the lungs?

Answer 8

CO2 and some water

The excretion of carbon dioxide is a vital process for maintaining the body’s acid-base balance.

Question 9

Define homeostasis

Answer 9

Maintaining internal balance of water and salt and other waste products

Homeostasis is crucial for the proper functioning of cells and organs.

Question 10

What is urea?

Answer 10

Ammonia converted to urea in the liver, excreted by the kidney in urine and through the skin in perspiration

Urea is less toxic than ammonia and is a key component of urine.

Question 11

What is the function of the ureter?

Answer 11

A muscular tube that moves urine from the kidneys to the bladder via peristalsis

Peristalsis is a series of wave-like muscle contractions.

Question 12

What is the urinary bladder?

Answer 12

The part of the body that stores urine until it is released, can hold between 300 and 1000 ml

The bladder has stretch receptors that signal when it is full.

Question 13

What is a nephron?

Answer 13

The functional unit of the kidney that filters wastes from the blood and retains water and other needed materials

Each kidney contains approximately one million nephrons.

Question 14

Define glomerulus

Answer 14

A cluster of capillaries where wastes are filtered from the blood

The glomerulus is the first step in the filtration process of the nephron.

Question 15

What is Bowman’s capsule?

Answer 15

The cup-like end of the nephron that surrounds the glomerulus to catch filtrate and send it into the proximal convoluted tubule

Bowman’s capsule is crucial for the filtration of blood.

Question 16

What is the loop of Henle?

Answer 16

A part of the nephron where urine becomes concentrated before going into the distal convoluted tubule

The loop of Henle plays a key role in the reabsorption of water.

Question 17

What is urine?

Answer 17

A liquid by-product of the body secreted by the kidneys through urination, containing many nitrogen-rich byproducts

Urine is a primary means of excreting waste from the body.

Question 18

Define dialysis

Answer 18

The artificial process of eliminating waste and unwanted water from the blood when kidneys cannot perform these functions

Dialysis is essential for individuals with kidney failure.

Question 19

Where in the nephron does FILTRATION take place?

Answer 19

In the glomerulus

Filtration is driven by high blood pressure that forces small molecules into Bowman’s capsule.

Question 20

What happens during the FILTRATION process?

Answer 20

Small molecules such as water, nitrogenous wastes, nutrients, and ions are forced from the glomerulus into Bowman’s capsule

Large molecules are filtered out via the efferent arteriole.

Question 21

Where in the nephron does REABSORPTION take place?

Answer 21

In the peritubular capillaries

This occurs after the filtrate has passed through the Proximal Convoluted Tubule.

Question 22

What happens during the REABSORPTION process?

Answer 22

Molecules needed by the body are reabsorbed from the filtrate into the blood

Water and salt are also reabsorbed in the Loop of Henle.

Question 23

What is the role of the Loop of Henle in urine concentration?

Answer 23

Urine becomes concentrated as water is reabsorbed; salt is actively and passively reabsorbed

Not all materials are reabsorbed and continue through the nephron.

Question 24

Where in the nephron does SECRETION take place?

Answer 24

In the distal convoluted tubule

This process adds non-filterable wastes to the tubular fluid.

Question 25

What happens during the SECRETION process?

Answer 25

Non-filterable wastes are added to the tubular fluid for secretion out in the urine ## Footnote The fluid then enters the collecting duct and proceeds through the urinary tract.

Question 26

Fill in the blank: The process of _______ occurs in the glomerulus.

Answer 26

FILTRATION

Question 27

Fill in the blank: The process of _______ occurs in the peritubular capillaries.

Answer 27

REABSORPTION

Question 28

True or False: Secretion occurs in the Loop of Henle.

Answer 28

False ## Footnote Secretion occurs in the distal convoluted tubule.

Question 29

Fill in the blank: After secretion, fluid enters the _______.

Answer 29

collecting duct

Question 30

List the three processes that occur in the nephron.

Answer 30

* Filtration * Reabsorption * Secretion

Question 31

What role do the kidneys play in maintaining homeostasis?

Answer 31

They perform the following functions: * Regulate the volume of blood (water volume) * Help maintain blood pH * Excrete urine * Regulate the volume of salts ## Footnote These functions are crucial for the body's internal balance.

Question 32

What is a negative feedback system?

Answer 32

A system that controls homeostasis by regulating the levels of almost every substance in the blood ## Footnote It involves receptors, control centers, and effectors to maintain stability.

Question 33

What hormone is secreted by the pituitary gland to control blood water levels?

Answer 33

Antidiuretic hormone (ADH) ## Footnote ADH plays a key role in regulating water balance in the body.

Question 34

What triggers the release of ADH from the pituitary gland?

Answer 34

Messages from osmoreceptors in the hypothalamus ## Footnote Osmoreceptors detect changes in blood osmolarity.

Question 35

What happens to water concentration in the bloodstream when ADH is released?

Answer 35

Water concentration in the bloodstream is lowered ## Footnote This occurs as water is reabsorbed in the kidneys.

Question 36

What is the effect of intense physical activity without fluid intake on the body?

Answer 36

It causes a decrease in blood water levels ## Footnote This triggers the negative feedback response to restore balance.

Question 37

What is the normal condition after ADH acts on the kidneys?

Answer 37

Water concentration is restored in the bloodstream ## Footnote This helps maintain homeostasis.

Question 38

Fill in the blank: The hypothalamus sends a message to the _______ to regulate water levels.

Answer 38

pituitary gland ## Footnote The pituitary gland is the control center in this feedback loop.

Question 39

True or False: The kidneys help maintain blood pH.

Answer 39

True ## Footnote This is one of the essential functions of the kidneys.

Question 40

What are the components of the negative feedback system involving ADH?

Answer 40

The components include: * Hypothalamus * Pituitary gland * ADH * Blood * Kidney tubules * Blood water levels ## Footnote These components interact to regulate hydration in the body.

Question 41

What type of receptors are involved in the process described?

Answer 41

Osmoreceptors in the adrenal glands ## Footnote These receptors monitor the osmotic pressure of body fluids.

Question 42

What is the role of the adrenal cortex in this process?

Answer 42

It acts as the control center that receives messages from the osmoreceptors ## Footnote The adrenal cortex is responsible for producing hormones, including aldosterone.

Question 43

What happens to sodium (Na+) and potassium (K+) during intense physical activity without fluid intake?

Answer 43

Na+ is lost and K+ is retained ## Footnote This imbalance can lead to dehydration and other physiological effects.

Question 44

What is the effector response in this hormonal regulation?

Answer 44

Release of Aldosterone ## Footnote Aldosterone helps to regulate sodium and potassium levels in the body.

Question 45

What change occurs as a result of aldosterone release?

Answer 45

Na+ is retained and K+ is excreted ## Footnote This helps to restore normal electrolyte balance.

Question 46

What is the normal condition after the physiological response?

Answer 46

Na+ and K+ concentrations return to normal ## Footnote This restoration is crucial for maintaining homeostasis.

Question 47

True or False: The adrenal cortex releases aldosterone when Na+ is retained.

Answer 47

False ## Footnote Aldosterone is released to retain Na+ and excrete K+ when there is a deficiency of Na+.

Question 48

Fill in the blank: The control center in this hormonal regulation is the _______.

Answer 48

Adrenal Cortex ## Footnote The adrenal cortex is crucial for producing hormones that regulate electrolyte balance.

Question 49

What effect does caffeine have on glomerular blood pressure?

Answer 49

Caffeine increases glomerular blood pressure ## Footnote This increase in pressure enhances the filtration process in the kidneys.

Question 50

How does caffeine affect sodium reabsorption?

Answer 50

Caffeine decreases the reabsorption of sodium ## Footnote This leads to increased sodium and water excretion.

Question 51

What is the expected effect of caffeine on urination?

Answer 51

You will urinate more often and your urine will be highly concentrated ## Footnote This is due to increased filtration and decreased sodium reabsorption.

Question 52

What happens when you drink a large pop at the beginning of a movie?

Answer 52

You would probably have to urinate before the end of the movie ## Footnote The large volume of liquid and caffeine content contribute to this need.

Question 53

What effect does eating salty popcorn have when consuming a large pop?

Answer 53

Increased sodium can be reabsorbed with excess water from the pop ## Footnote This may reduce the need to urinate during the movie.

Question 54

True or False: Caffeine acts as a diuretic.

Answer 54

True ## Footnote Diuretics increase urine production.

Question 55

Fill in the blank: Caffeine inhibits the reabsorption of _______.

Answer 55

sodium ## Footnote This inhibition leads to increased sodium in urine.

Question 56

What is the relationship between sodium reabsorption and water excretion?

Answer 56

Water follows the salt being reabsorbed ## Footnote This relationship impacts urine concentration.

Question 57

What should you always study from in preparation for tests?

Answer 57

Slide shows and notes ## Footnote These materials contain important information relevant to the tests.