Respiratory Surfaces and Skin System in Animals Quiz

Characteristics of Respiratory Surfaces

• Respiratory surfaces must be moist, thin, and large enough to supply oxygen to the entire body.
• Skin System (Integumentary System): found in animals like worms and amphibians living in moist environments.
• Oxygen is absorbed directly through the moist skin surface, and capillaries beneath the skin facilitate gas exchange with the circulatory system.

Respiratory Systems

• Gills System: used by fish and aquatic animals to extract dissolved oxygen from water.
• Gills are thin tissue filaments highly branched and folded, increasing surface area.
• Dissolved oxygen in water diffuses across gill membranes into the bloodstream.
• Carbon dioxide from the bloodstream leaves through the gills.
• Tracheal System: found in insects like grasshoppers and spiders.
• Consists of a network of air tubes called tracheae.
• Spiracles on the body surface connect to tracheae.
• Oxygen enters through spiracles and diffuses into tissues, and carbon dioxide and water vapor exit.
• Lung System: found in land animals like humans.
• Lungs are paired organs with chambers filled with capillaries.
• Air is inhaled through the nose/mouth, passing through the trachea, bronchi, and bronchioles to reach alveoli where gas exchange occurs.

Gas Exchange in Plants

• Plants exchange gases with the environment primarily through diffusion.
• They require carbon dioxide for photosynthesis and release oxygen as a byproduct.
• Unlike animals, plants lack specialized organs for gas exchange.
• In aquatic plants, gases diffuse through water among tissues, while in terrestrial plants, gases diffuse into the moisture surrounding internal cells.

Plant Organs for Gas Exchange

• Leaves
• Stomata: tiny openings on leaves that let in carbon dioxide (CO2) for photosynthesis and release oxygen (O2).
• Mesophyll: inside the leaf, there's a middle layer called the mesophyll, where photosynthesis happens.
• Palisade Mesophyll: where most of the photosynthesis happens.
• Spongy Mesophyll: below the palisade mesophyll is the spongy mesophyll, with looser cells with lots of air spaces that help with gas exchange.
• Air Spaces: throughout the mesophyll, there are spaces filled with air.

Transport of Substances in Plants

• Absorption: plants take water and nutrients from the soil through their roots.
• Transport: water and nutrients move up through the plant in tubes called xylem.
• Photosynthesis: in the leaves, water and carbon dioxide from the air are used to make food for the plant in a process called photosynthesis.
• Energy Source: glucose is like fuel for the plant, broken down to release energy, which the plant uses to grow, reproduce, and stay healthy.
• Transport of Water and Minerals: roots and root hairs absorb water and minerals from the soil, and vascular tissues transport water and nutrients throughout the plant.

Transport of Water and Minerals

• Xylem: transports water and nutrients from the roots to the rest of the plant, just like pipes in a water supply system.
• Phloem: transports sugars produced in the leaves (through photosynthesis) to other parts of the plant, providing energy for growth and other activities.

Transpiration

• Plants release water vapor into the air through tiny openings on their leaves called stomata.
• Water Absorption: plants absorb mineral nutrients and water from the soil through their roots.
• Evaporation from Leaves: the excess water is evaporated from the leaves through transpiration.
• Suction Pull: as water evaporates from the leaves, it creates a suction pull, similar to sucking water through a straw.
• Cooling Effect: transpiration also helps cool the plant, similar to how sweating cools our bodies.