Body Environment and Exchange

Question 1

How do our bodies interact with the environment?

Answer 1

Our bodies interact with the environment to exchange gases, fluids, and nutrients, extracting useful substances and eliminating waste.

Question 2

Which systems are key for the exchange of materials in the body?

Answer 2

The urinary, digestive, and respiratory systems are key for exchange, while the cardiovascular system serves as the transport network.

Question 3

What is the basic structure of the cell membrane?

Answer 3

The cell membrane is composed of a lipid bilayer that allows hydrophobic molecules to cross easily, while hydrophilic molecules can also pass through, albeit with some assistance.

Question 4

What are the three types of passive transport mechanisms?

Answer 4

The three types of passive transport mechanisms are simple diffusion, facilitated diffusion, and osmosis. These processes do not require energy and move particles from high to low concentration.

Question 5

What distinguishes active transport mechanisms from passive transport?

Answer 5

Active transport mechanisms require energy to move particles from low to high concentration, unlike passive transport which relies on concentration gradients.

Question 6

What are some examples of active transport mechanisms?

Answer 6

Examples of active transport mechanisms include active transport itself, endocytosis, and exocytosis.

Question 7

How do particles move across epithelial tissue?

Answer 7

Particles must cross the apical and basolateral membranes to move from the external environment to the bloodstream and vice versa, utilizing specific transport mechanisms on each membrane.

Question 8

What role does the cytoskeleton play in intracellular transport?

Answer 8

The cytoskeleton provides a framework for motor proteins such as kinesin and dynein, facilitating the transport of vesicles within the cell.

Question 9

What are extracellular vesicles used for?

Answer 9

Extracellular vesicles are involved in transporting materials around the body.

Question 10

How do SNARE proteins function in cellular transport?

Answer 10

NARE proteins identify cargo and bind with complementary SNAREs on target membranes to facilitate the fusion of vesicles with their intended destinations.

Question 11

What does SNARE stand for?

Answer 11

Soluble N-ethylmaleimide-sensitive factor activating protein receptor

Question 12

What is the primary function of the immune system?

Answer 12

The immune system distinguishes between self and non-self, protecting the body from foreign bodies, pathogens, and toxins through various defences.

Question 13

What are some examples of physical defences in the immune system?

Answer 13

Physical defences can include cellular mechanisms that deny entry, mechanical barriers that remove pathogens, and the microbiome that competes with harmful microorganisms.

Question 14

What are the chemical defences employed by the body?

Answer 14

Chemical defences include stomach acid to break down substances, enzymes for digestion, and mucus to trap pathogens.

Question 15

How do white blood cells function in the immune response?

Answer 15

White blood cells recognize antigens on foreign substances and engulf and destroy these invaders.

Question 16

What occurs during inflammation?

Answer 16

Inflammation occurs following injury or infection, leading to the release of inflammatory mediators (e.g., histamine) that help prevent further damage and promote healing by recruiting additional immune cells.

Question 17

What is the role of the liver in detoxification?

Answer 17

The liver plays a crucial role in inactivating and removing harmful substances, containing many enzymes that break down and neutralize toxins.

Question 18

What is the difference between hydrophobic and hydrophilic molecules in relation to the cell membrane?

Answer 18

Hydrophobic molecules can easily cross the lipid bilayer of the cell membrane, while hydrophilic molecules require specific transport mechanisms to pass through.

Question 19

How does osmosis differ from diffusion?

Answer 19

Osmosis is the movement of water across a selectively permeable membrane, specifically from an area of lower solute concentration to an area of higher solute concentration, while diffusion refers to the movement of any solute from high to low concentration.

Question 20

What are the two types of endocytosis?

Answer 20

The two types of endocytosis are phagocytosis (cell eating) and pinocytosis (cell drinking), both of which involve the engulfing of materials into the cell.

Question 21

What is the primary function of exocytosis?

Answer 21

Exocytosis is the process by which cells expel materials, such as hormones or neurotransmitters, by fusing vesicles with the cell membrane.

Question 22

How do epithelial cells facilitate transport?

Answer 22

Epithelial cells facilitate transport by having specialized structures and mechanisms, including tight junctions that control permeability and the presence of transport proteins for selective movement of substances.

Question 23

What is the role of the immune system’s physical barriers?

Answer 23

Physical barriers, such as skin and mucous membranes, act as the first line of defence by preventing the entry of pathogens into the body.

Question 24

How does the microbiome contribute to immune defence?

Answer 24

The microbiome competes with pathogens for resources and space, helping to prevent infections and maintain a balanced immune response.

Question 25

What are inflammatory mediators, and why are they important?

Answer 25

Inflammatory mediators, such as histamine, are substances released during inflammation that help recruit immune cells to the site of injury or infection and promote healing.

Question 26

How do enzymes function as chemical defences?

Answer 26

Enzymes break down harmful substances and pathogens, aiding in digestion and contributing to the body’s chemical defences against infection.

Question 27

What triggers the release of white blood cells to an infection site?

Answer 27

The recognition of antigens on pathogens triggers the immune response, leading to the release and recruitment of white blood cells to the infection site.

Question 28

What is the significance of the liver’s detoxification processes?

Answer 28

The liver’s detoxification processes are vital for metabolizing and neutralizing toxins, preventing their accumulation in the body, and maintaining overall health.

Question 29

How does the body maintain homeostasis during transport processes?

Answer 29

The body maintains homeostasis by regulating transport mechanisms to ensure balanced concentrations of nutrients, gases, and waste products in cells and fluids.

Question 30

What is the function of the cytoskeleton in cellular transport?

Answer 30

The cytoskeleton provides structural support and facilitates the movement of vesicles and organelles within the cell through the action of motor proteins.

Question 31

What are some examples of substances that might be transported via facilitated diffusion?

Answer 31

Examples of substances transported via facilitated diffusion include glucose and amino acids, which require specific transport proteins to cross the cell membrane.