homeostasis and excretion

Question 1

What is homeostasis?

Answer 1

Homeostasis is the process of keeping conditions inside the body relatively constant.

Question 2

what is the excretory product of the kidneys

Answer 2

urea

Question 3

What are the main sources of water gain for the body?

Answer 3

Water gain comes from:
* drinking
* food
* cell respiration.

Question 4

What are the main ways the body loses water?

Answer 4

Water loss occurs through:
* urine
* sweat
* faeces
* exhaled air.

Question 5

Define tissue fluid.

Answer 5

Tissue fluid is a watery solution of salts, glucose, and other solutes that surrounds all the cells of the body.

Question 6

What is the function of tissue fluid?

Answer 6

Tissue fluid forms a pathway for the transfer of nutrients between the blood and the cells.

Question 7

What happens if tissue fluid contains too many solutes?

Answer 7

Cells lose water by osmosis and become dehydrated.

Question 8

What is excretion?

Answer 8

Excretion is the process by which waste products of metabolism are removed from the body.

Question 9

What is the main nitrogenous excretory substance in humans?

Answer 9

The main nitrogenous excretory substance is urea.

Question 10

What are some examples of nitrogenous waste?

Answer 10

Examples of nitrogenous waste include:
* urea
* ammonia.

Question 11

What is the role of the liver in protein metabolism?

Answer 11

The liver breaks down excess amino acids and converts them into carbohydrates and urea.

Question 12

What is the body temperature of homeothermic animals?

Answer 12

Homeothermic animals maintain a constant body temperature, typically around 37 °C for humans.

Question 13

What is the physiological term for ‘warm-blooded’ animals?

Answer 13

The term is homeothermic.

Question 14

What part of the brain monitors body temperature?

Answer 14

The hypothalamus monitors body temperature.

Question 15

What are the physiological responses to increased body temperature?

Answer 15

Responses include:
* increased sweat production
* vasodilation.

Question 16

What is vasodilation?

Answer 16

Vasodilation is the widening of arterioles to allow more blood flows to the skin surface
(more) heat is taken to the surface and heat (energy ) is lost (from the skin)

Question 17

What is vasoconstriction?

Answer 17

Vasoconstriction is the narrowing of blood vessels to reduce blood flow to the skin’s surface.

Question 18

How does sweating cool the body?

Answer 18

sweat secreted on skin surface. evaporates due to latent heat of evaporation. energy supplied is body’s heat, cooling body down.

Question 19

What is the role of the epidermis?

Answer 19

The epidermis forms a tough outer layer that prevents water loss and protects against pathogens.

Question 20

What is the function of the dermis?

Answer 20

The dermis contains sensory receptors, sweat glands, blood vessels, and hair follicles.

Question 21

What happens to hairs on the skin in cold conditions?

Answer 21

Hairs stand upright to trap a layer of air for insulation.

Question 22

how does shivering generate heat

Answer 22

Shivering generates heat through rapid muscle contractions.

Question 23

how does hair play a part in insulation

Answer 23

in cold conditions hair erector muscles contract pulling hair upright. this traps a layer of air next to the skin . air is a poor conductor of heat so this acts as a insulator.

Question 24

Fill in the blank: The average body temperature of a human is ______.

Answer 24

37 °C

Question 25

What is the core function of the hypothalamus related to temperature control?

Answer 25

It acts as the body's thermostat.

Question 26

What is the latent heat of vaporisation?

Answer 26

It is the energy required for a liquid to turn into gas during evaporation.

Question 27

What is the main function of the hypodermis?

Answer 27

The hypodermis insulates the body and serves as an energy store.

Question 28

What happens to the body's metabolism during conditions that require heat generation?

Answer 28

The body's metabolism speeds up, generating more heat. ## Footnote The liver plays a significant role in producing metabolic heat.

Question 29

Which hormone stimulates an increase in metabolism?

Answer 29

Adrenaline. ## Footnote This is discussed in Chapter 7.

Question 30

What physiological response occurs when the body shivers?

Answer 30

Muscles contract and relax rapidly, generating a large amount of heat. ## Footnote Shivering is an important mechanism for thermoregulation.

Question 31

List some mechanisms the body uses to maintain its temperature around 37 °C.

Answer 31

* Sweating * Vasodilation * Vasoconstriction * Hair erection * Shivering * Changes to metabolism * Behavioral actions ## Footnote These mechanisms work together to keep body temperature stable.

Question 32

What indicates that something is wrong with the body's temperature regulation?

Answer 32

A temperature difference greater than a few tenths of a degree from the normal 37 °C. ## Footnote For example, a temperature of 39 °C might indicate an illness.

Question 33

Fill in the blank: The hormone _______ stimulates the increase in metabolism.

Answer 33

adrenaline

Question 34

True or False: Shivering is a response that helps generate heat in the body.

Answer 34

True

Question 35

What is the normal body temperature in degrees Celsius?

Answer 35

37 °C

Question 36

thermoregulation

Answer 36

the process by which living organisms maintain a constant internal body temperature despite changes in environment.