Transport Systems in Living Organisms

Vocabulary flashcards covering the necessity of transport systems, surface area to volume ratios, transported substances, and the components of the human circulatory system.

Transport systems

Systems that provide a means by which substances are moved between the exchange surfaces and body cells.

Surface area to volume ratio in unicellular organisms

A large ratio found in very small organisms (such as an amoeba) that allows simple diffusion across their body surface to adequately supply requirements and remove waste.

Surface area to volume ratio in large multicellular organisms

A small ratio resulting in diffusion across the body surface being inadequate to reach deep cells, necessitating dedicated transport systems.

Useful substances transported in animals

Materials delivered to body cells, including oxygen, water, digested food (glucose and amino acids), vitamins, minerals, hormones, antibodies, plasma proteins, and heat.

Useful substances transported in plants

Materials moved throughout the plant, including manufactured food, water, and mineral salts.

Waste substances transported in animals

Excretory materials carried away from body cells, specifically carbon dioxide and nitrogenous waste such as urea.

Circulatory system

A system in humans consisting of blood as the transport medium, blood vessels as pathways, and the heart as the pump.

Blood

A bodily fluid that serves as the transport medium, consisting of red blood cells, white blood cells, and platelets suspended in plasma.

Blood vessels

Tubes through which blood flows to and from all parts of the body.

Heart

An organ that pumps blood through the blood vessels.

Plasma

The fluid portion of the blood in which blood cells are suspended, making up about $55\%$ by volume of the blood.

Cellular component of blood

The red blood cells, white blood cells, and platelets that collectively make up about $45\%$ by volume of the blood.