L6 Plant & Animal Circulatory System & Transport Mechanism

• Plants have a unique circulatory system known as the vascular system.
• Vascular System: consists of two main components, xylem and phloem
• Xylem: responsible for the transport of water and minerals from the roots to the rest of the plant.
• Xylem: one-way (upward) flow
• Xylem: transports water and minerals
• Xylem: transport is bulk flow due to negative pressure
• Xylem: hollow dead cells
• Xylem: form the center of the vascular bundle
• Xylem: no end walls
• Xylem: rich in lignin, which supports the plant
• Xylem: composed of specialized cells called tracheids and vessel elements
• Tracheids & Vessel Elements: are interconnected, forming long tubes that allow for the upward movement of water through capillary action.
• Xylem: also provides structural support to the plant
• Phloem: is responsible for the transport of organic compounds, such as sugars, from the leaves to other parts of the plant.
• Phloem: transports food in the form of sugars
• Phloem: two-way flow
• Phloem: transport is by osmosis/turgor pressure
• Phloem: perforated end walls
• Phloem: outside edge of the vascular bundle
• Phloem: also transports amino acids, mRNA, and hormones
• Phloem: consists of sieve tube elements and companion cells
• Sieve tube elements: form long tubes that allow for the movement of sugars through pressure flow
• Companion Cells: provide metabolic support to the sieve tube elements
• Animals have a closed circulatory system, which consists of a heart, blood vessels, and blood.
• Animal Circulatory System: heart, blood vessels, and blood
• Heart: a muscular organ that pumps blood throughout the body.
• Heart: consists of four chambers: two atria and two ventricles.
• Atria: receive blood from the body and lungs
• Ventricles: pump blood out to the body and lungs.
• Blood Vessels: are responsible for carrying blood to and from the heart and various organs.
• Blood Vessels: Arteries, Veins, and Capillaries
• Arteries: carry oxygenated blood away from the heart
• Veins: carry deoxygenated blood back to the heart.
• Capillaries: are tiny, thin-walled vessels that allow for the exchange of nutrients, gases, and waste products between the blood and body tissues.
• Blood: a fluid connective tissue that carries oxygen, nutrients, hormones, and waste products throughout the body.
• Transport Mechanism in Plant: Transpiration and Translocation
• Transpiration: Water is absorbed by the roots and transported through the xylem to the leaves.
• Transpiration (cont.): It then evaporates from the leaf surface through small openings called stomata.
• Transpiration: This process creates a suction force that pulls water up through the xylem.
• Translocation: Sugars produced in the leaves through photosynthesis are transported through the phloem to other parts of the plant.