Excretion

Question 1

What is excretion?

Answer 1

Removal of metabolic waste products from the body, e.g. sweat, urea

Excretion is crucial for maintaining homeostasis.

Question 2

How does excretion contribute to homeostasis?

Answer 2

Helps maintain body temperature, fluid balance, and removes poisonous wastes

Homeostasis is the body’s ability to maintain stable internal conditions.

Question 3

What are the waste management strategies of plants?

Answer 3

Produce little waste, store wastes, lose more when dead structures fall off

Plants lose waste gases through stomata and lenticels.

Question 4

Define ectotherms.

Answer 4

Animals that obtain heat from external sources

Examples include reptiles and amphibians.

Question 5

Define endotherms.

Answer 5

Animals that generate their own body heat by internal reactions

Examples include mammals and birds.

Question 6

What are the excretory functions of the lungs?

Answer 6

Excrete water and carbon dioxide through exhaled air

This process is part of respiratory excretion.

Question 7

What is the role of the skin in excretion?

Answer 7

Excretes water and salts through sweat

The skin plays a vital role in thermoregulation and waste removal.

Question 8

What substances are excreted by the kidneys?

Answer 8

Water, urea, salts, and toxins in urine

Kidneys are essential for filtering blood and maintaining fluid balance.

Question 9

What is egestion?

Answer 9

Removal of unabsorbed waste products from the body

Unlike excretion, egestion involves solid waste.

Question 10

What is the outer layer of the skin composed of?

Answer 10

Dead, cornified cells full of waterproof keratin

This layer provides a protective barrier against environmental damage.

Question 11

What is found in the inner layer of the skin?

Answer 11

Living granular cells

The inner layer is responsible for growth and repair of the skin.

Question 12

What is the function of sweat glands?

Answer 12

Produce sweat to help cool the body and excrete waste

Sweat is primarily composed of water and salts.

Question 13

Fill in the blank: The _______ is involved in the removal of unabsorbed waste products.

Answer 13

intestines

Egestion occurs in the intestines.

Question 14

What role do capillaries play in the skin?

Answer 14

Supply nutrients and aid in thermoregulation

Capillaries are small blood vessels that facilitate exchange.

Question 15

True or False: Egestion and excretion refer to the same process.

Answer 15

False

Egestion involves solid waste, while excretion involves metabolic waste.

Question 17

What is the granular layer at the base of the skin called?

Answer 17

Malpighian layer

The Malpighian layer is responsible for making new cells and contains many melanin cells.

Question 18

What strong protein is found in the dermis?

Answer 18

Collagen

Collagen provides strength and structure to the skin.

Question 19

What components are found in the dermis?

Answer 19

• Blood vessels
• Sweat glands
• Hairs
• Sebaceous glands
• Nerve receptors

These components contribute to the skin’s functions and sensation.

Question 20

What tissue is found in the subcutaneous layer?

Answer 20

Adipose tissue

Adipose tissue contains fat, which serves as an energy store.

Question 21

What is one function of the epidermis?

Answer 21

Protection

The epidermis protects against damage, water loss, and pathogen entry.

Question 22

How does melanin protect the skin?

Answer 22

Against UV radiation

Melanin absorbs harmful UV rays from the sun.

Question 23

What does sebum do for the epidermis?

Answer 23

Keeps it intact

Sebum is an oily substance that helps to maintain skin hydration.

Question 24

What vitamin is produced in the skin?

Answer 24

Vitamin D

Vitamin D is essential for various bodily functions, including calcium absorption.

Question 25

What is the skin's role as a sense organ?

Answer 25

Organ of touch ## Footnote The skin contains sensory receptors that detect touch, pressure, and temperature.

Question 26

What does sweat remove from the body?

Answer 26

Water and salts ## Footnote Sweating is a crucial process for maintaining fluid balance and temperature regulation.

Question 27

What happens to blood vessels in cold conditions?

Answer 27

Constrict (vasoconstriction) ## Footnote This process helps retain heat in the body.

Question 28

What is the effect of warm conditions on the body?

Answer 28

* Sweating * Vasodilation ## Footnote Sweating cools the body through evaporation, while vasodilation helps lose heat.

Question 29

What are the main components of the urinary system?

Answer 29

* Two kidneys * Two ureters * Bladder * Urethra ## Footnote These components work together to manage waste and fluid balance in the body.

Question 30

What is one function of the kidneys?

Answer 30

Excretion of water, salts, and urea ## Footnote This function is vital for maintaining homeostasis in the body.

Question 31

What is osmoregulation?

Answer 31

The process of maintaining water and salt balance in the body ## Footnote It is a key function of the kidneys to ensure proper hydration and electrolyte levels.

Question 32

What is the primary role of the nephron?

Answer 32

Carries out the functions of the kidneys ## Footnote Nephrons are the functional units of the kidneys, essential for urine formation.

Question 33

Where are nephrons located within the kidney?

Answer 33

In the cortex and medulla of the kidney ## Footnote The cortex is the outer region, while the medulla is the inner region of the kidney.

Question 34

What is the first step in urine formation by the nephron?

Answer 34

Filtration ## Footnote This process begins when blood enters the nephron at the afferent arteriole.

Question 35

What structure within the nephron is responsible for filtration?

Answer 35

Glomerulus ## Footnote The glomerulus is a network of capillaries that filters blood under high pressure.

Question 36

What happens to red blood cells and proteins during filtration in the glomerulus?

Answer 36

They do not enter the glomerular filtrate ## Footnote Red blood cells and larger molecules like proteins are too large to pass through the filtration barrier.

Question 37

What does glomerular filtrate consist of?

Answer 37

A dilute solution of waste and useful molecules ## Footnote The filtrate includes substances that can be either reabsorbed or excreted.

Question 38

What is the second step in the urine formation process?

Answer 38

Reabsorption ## Footnote This step involves reclaiming water and useful molecules from the filtrate.

Question 39

Which part of the nephron reabsorbs water by osmosis?

Answer 39

Proximal tubule ## Footnote The proximal tubule is crucial for reabsorbing water and salts.

Question 40

How are salts reabsorbed in the proximal tubule?

Answer 40

By diffusion and active transport ## Footnote This ensures essential electrolytes are retained in the body.

Question 41

What is the role of the loop of Henle in reabsorption?

Answer 41

Reabsorbs water by osmosis in the descending loop and salts by diffusion ## Footnote The loop of Henle plays a key role in concentrating urine.

Question 42

What occurs in the distal tubule regarding reabsorption?

Answer 42

Absorbs water by osmosis and some salts by active transport ## Footnote This final step of reabsorption helps regulate body fluid balance.

Question 43

Fill in the blank: Blood enters the nephron at the _______.

Answer 43

afferent arteriole ## Footnote The afferent arteriole brings blood to the nephron for filtration.

Question 44

What do the collecting ducts absorb?

Answer 44

Water by osmosis

Question 45

Where is ADH produced?

Answer 45

Hypothalamus

Question 46

Where is ADH released into?

Answer 46

The blood from the pituitary gland

Question 47

What does ADH control?

Answer 47

The volume of urine formed

Question 48

What substances can be secreted into the nephron?

Answer 48

Hormones and ions

Question 49

Which ions are secreted in the distal convoluted tubule for pH control?

Answer 49

Potassium and hydrogen ions

Question 50

What is the pathway of urine after it leaves the collecting ducts?

Answer 50

To the ureters and then to the bladder

Question 51

What stimulates the production of ADH?

Answer 51

Lack of water in the plasma

Question 52

What effect does ADH have on the distal tubule and collecting ducts?

Answer 52

Increases reabsorption of water

Question 53

Fill in the blank: Water is returned to the plasma and less urine is _______.

Answer 53

Released

Question 54

List the key components of the kidney anatomy mentioned.

Answer 54

* Cortex * Medulla * Renal artery * Renal vein * Pelvis