L8 Plant & Animal Endocrine System & Nervous Control

• In animals, this control is primarily achieved through the endocrine system, which consists of glands that secrete hormones into the bloodstream.
• Plants, on the other hand, lack a circulatory system but have a similar mechanism called the plant endocrine system.
• Hormones: Plants produce hormones that regulate growth, development, and responses to environmental stimuli.
• These hormones in plants are chemical messengers that are synthesized in one part of the plant and transported to target cells in another part.
• Major Plant Hormones: Auxins, Gibberellins, Cytokinins, Abscisic Acid, and Ethylene
• Auxins: Promote cell elongation, root development, and apical dominance.
• Gibberellins: Stimulate stem elongation, seed germination, and flowering.
• Cytokinins: Promote cell division, delay senescence, and regulate nutrient distribution.
• Abscisic Acid: Inhibits growth, promotes seed dormancy, and regulates stomatal closure.
• Ethylene: Regulates fruit ripening, leaf senescence, and abscission.
• Plant, Mode of Transport: plant hormones are transported through the vascular tissues, such as xylem and phloem.
• Xylem carries hormones upwards from the roots to the shoots, while phloem transports hormones in both.
• Plant, Target Cells: Plant hormones can act on cells in close proximity or at a distance from their site of synthesis.
• Plant, Target Cells: They can also act on the same cells that produce them (autocrine) or on neighboring cells (paracrine).
• The target cells of plant hormones have specific receptors that bind to the hormones and initiate a response.
• Animals, Hormones: The animal endocrine system consists of various glands, such as the pituitary gland, thyroid gland, adrenal glands, and reproductive glands, that secrete hormones into the bloodstream.
• ,Animals, Hormones: These hormones regulate growth, metabolism, reproduction, and other physiological processes.
• Hormones in Animals: Insulin, Thyroxine, Adrenaline, Estrogen and Testosterone
• Insulin: regulates blood sugar levels by promoting glucose uptake by cells.
• Thyroxine: controls metabolism and growth.
• Adrenaline: triggers the "fight or flight" response in situations.
• Estrogen and Testosterone: regulate reproductive functions and secondary sexual characters.
• Animals, Mode of Transport: Animal hormones are transported through the bloodstream to reach their target cells.
• Animals, Mode of Transport: They are released by endocrine glands into the bloodstream and then carried to specific tissues or organs where they exert their effects.
• Animals, Target Cells: Animal hormones act on specific target cells that have receptors for the hormones.
• Animals, target cells: These receptors are usually located on the surface or inside the target cells.
• Animals, Target Cells: When a hormone binds to its receptor, it triggers a series of biochemical reactions that lead to a physiological response.
• Chemical Control: endocrine systems rely on this to regulate physiological processes.
• Hormones act as chemical messengers that coordinate and integrate various functions within the organism.
• Hormones can be produced in response to internal or external stimuli and can have long-lasting effects on the target cells.
• Nervous Control: animals have a well-developed nervous system that allows for rapid and precise control of physiological processes.
• Nervous Control: involves the transmission of electrical signals, called nerve impulses, through specialized cells called neurons. These impulses travel along nerve fibers and allow for quick responses to stimuli.
• Nervous Control: While the endocrine system regulates long-term processes, the nervous system is responsible for immediate responses.
• Nervous Control: For example, if you touch a hot object, your nervous system will quickly send a signal to your muscles to withdraw your hand
• Plants have a unique endocrine system that relies on hormones transported through vascular tissues, while animals have a well-developed endocrine system that uses hormones transported through the bloodstream. Additionally, animals have a nervous system that allows for rapid and precise control of physiological processes.