Overview of animal systems

Question 1

What is the main function of the circulatory system?

Answer 1

The transport of materials within the internal environment for exchange with all cells. Nutrients and gases are exchanged for wastes.

Question 2

What are the main parts of the circulatory system?

Answer 2

• Fluid such as blood or haemolymph
• Blood vessels or spaces throughout the body
• A muscular pump, usually a heart

Question 3

What is an open circulatory system?

Answer 3

The transportation fluid circulates freely in the body cavity, bathing the cells. The fluid is called haemolymph.

Question 4

How does the muscular heart function in an open circulatory system?

Answer 4

It pumps haemolymph through open areas into spaces surrounding organs, enabling substance exchange.

Question 5

What is a closed circulatory system?

Answer 5

The fluid flows through enclosed vessels called arteries, veins, and capillaries.

Question 6

What is the fluid in a closed circulatory system called?

Answer 6

Blood

Question 7

Which animals have an open circulatory system?

Answer 7

• Arthropods (e.g., insects, spiders)
• Some molluscs (e.g., snails, slugs)

Question 8

Which animals have a closed circulatory system?

Answer 8

• Annelids (e.g., earthworms)
• Cnidaria (e.g., squids)
• All vertebrates (e.g., mammals, birds, fish, reptiles, amphibians)

Question 9

What is a gastrovascular cavity?

Answer 9

A central cavity with a single opening that functions in transport and digestion of simple organisms.

Question 10

What distinguishes single and double closed circulatory systems?

Answer 10

Single has 1 circuit( travels through heart once); double has 2 circuits (travels through heart twice) (pulmonary and systemic).

pulmonary circulation is a short loop from the heart to the lungs and back again. The systemic circulation carries blood from the heart to all the other parts of the body and back again.

Question 11

What is the blood pressure like in a single closed circulatory system? (aquatic)

Answer 11

Blood loses pressure at the gills and flows under low pressure.

Question 12

What is the primary function of the mammalian circulatory system?

Answer 12

• Transportation of water, oxygen, and carbon dioxide
• Distribution of nutrients and removal of wastes
• Maintenance of body temperature
• Circulation of hormones

Question 13

How do red blood cells facilitate gas transport?

Answer 13

They lack a nucleus allowing more space to carry oxygen and also transport carbon dioxide away from body cells.

Question 14

What structural differences exist between arteries and veins?

Answer 14

Arteries have thicker walls with more muscle to withstand higher blood pressure; veins have thinner walls.

Question 15

What aids in the return of blood to the heart in veins?

Answer 15

The contraction of skeletal muscles and the presence of valves in the veins.

Question 17

What is the main function of respiratory systems?

Answer 17

Gas exchange for a steady supply of oxygen to cells and release of carbon dioxide.

Question 18

What are some examples of gas exchange surfaces in animals?

Answer 18

• Spiracles in insects
• Gills in fish and juvenile amphibians
• Alveoli in birds and mammals
• Skin in adult amphibians

Question 19

What is the process of cellular respiration summarized in a word equation?

Answer 19

Glucose + oxygen → water + carbon dioxide + energy (ATP)

Question 20

What are the essential features of gas exchange surfaces?

Answer 20

• Must be moist
• Thin and permeable
• Large surface area
• Greater concentration gradient
• Highly vascularized

Question 21

How do amphibians exchange gases?

Answer 21

Through skin and lungs; juvenile tadpoles use gills.

Question 22

What is the gas exchange mechanism in fish?

Answer 22

Water flows over gills increasing s/a where oxygen diffuses into blood and carbon dioxide diffuses out.

Question 23

What is countercurrent flow in fish gills?

Answer 23

Water flows over gill filaments in the opposite direction from blood flowing inside, maximizing oxygen transfer.

Question 24

What is the primary function of the digestive system?

Answer 24

Breaking down complex organic molecules into simpler molecules for use by the animal.

Question 25

What are the main types of digestive systems?

Answer 25

* Gastrovascular cavity in simple animals * Alimentary canal in complex animals

Question 26

What are the four main roles of the digestive system?

Answer 26

* Ingestion * Digestion * Absorption * Egestion

Question 27

What is mechanical digestion?

Answer 27

The physical breakdown of food into smaller pieces to increase surface area.

Question 28

What is chemical digestion?

Answer 28

The breakdown of complex substances into their simplest forms by enzymes.

Question 29

What are the four main roles of the digestive system?

Answer 29

* Ingestion * Digestion * Absorption * Egestion

Question 30

What is ingestion in the context of the digestive system?

Answer 30

The acquisition (taking in) of nutrients ## Footnote Ingestion is the first step in the digestive process.

Question 31

Define digestion.

Answer 31

The breakdown of complex organic molecules into smaller components by mechanical and chemical means ## Footnote Digestion occurs after ingestion.

Question 32

What is absorption in the digestive process?

Answer 32

The taking up of digested molecules into the internal environment of the cells of the digestive tract ## Footnote This occurs primarily in the small intestine.

Question 33

What does egestion refer to?

Answer 33

The removal (elimination) of undigested waste food materials from the body ## Footnote Egestion is the final step in the digestive process.

Question 34

Which animals do not have a digestive system?

Answer 34

Microscopic animals and simple animals such as sponges ## Footnote These organisms rely on diffusion for nutrient acquisition.

Question 35

What is a gastrovascular cavity?

Answer 35

central cavity with one opening transpoting and digesting food ## Footnote Found in simple animals like Cnidaria and Platyhelminths.

Question 36

How do omnivores, such as humans, digest their food?

Answer 36

They break down large packages of energy and nutrients from plant and animal sources into simpler forms ## Footnote This allows nutrients to cross cell membranes.

Question 37

What role does mechanical digestion play?

Answer 37

It increases the surface area to volume ratio across which digestive enzymes may act ## Footnote This process is important for effective chemical digestion.

Question 38

What is chemical digestion?

Answer 38

break down of complex substance into simplest form by enzymes so they can be absorbed by cells | Bile in liver assists

Question 39

Where does most nutrient absorption occur?

Answer 39

Along the length of the small intestine ## Footnote The small intestine's structure facilitates efficient absorption.

Question 40

What is the function of the large intestine?

Answer 40

* Compact undigested food material * Absorb water and some salts * Site for bacteria to act on undigested matter * Transport waste material to rectum for elimination ## Footnote The large intestine plays a crucial role in egestion.

Question 41

How do the dentition of herbivores differ from that of carnivores?

Answer 41

Herbivores have molars with broad, ridged surfaces for grinding, while carnivores have pointed inscicors and jaggad molars for killing and ripping flesh ## Footnote Dentition reflects dietary needs.

Question 42

What is a ruminant mammal?

Answer 42

A cud-chewing mammal with an enlarged stomach divided into four chambers ## Footnote Example: cows.

Question 43

How do the alimentary canals of herbivores compare to those of carnivores?

Answer 43

Herbivores have longer alimentary canals, while carnivores have shorter and simpler canals ## Footnote This reflects the difficulty of digesting cellulose in plant materials.

Question 44

What is excretion?

Answer 44

The removal of nitrogen-related or other metabolic wastes ## Footnote It is a key function of the excretory system.