Chemical and nervous control

• chemical messengers - A plant's sensory response to external stimuli relies on (. ) (hormones).
• Plant hormones - affect all aspects of plant life, from flowering to fruit setting and maturation, and from

  phototropism to leaf fall.
• hormones - signaling molecules which are present in very small amounts, transported throughout the plant body, and only elicit in responses in cells which have the

  appropriate hormone receptors.
• (xylem and phloem) - In plants, hormones travel large throughout the body via the vascular tissue
• plasmodesmata - and cell-to-cell via .
• Auxin - the master growth regulator;
• Cytokinin - which is responsible for cell division;
• Gibberellins - responsible for stem, fruit, and seed growth;
• Abscisic Acid (ABA) - that causes dormancy of the plant;
• Ethylene - promotes fruit ripening, flower wil ting, and leaf fall;
• Systemin, anti-herbivory hormone that activates plant responses to wounds from herbivores;
• Methyl Salicylate (MeSa) - hormone for immunity that helps regulate responses to infection by parasites or pathogens
• feedback mechanism - The Endocrine and nervous system coordinate with each other through a series of .
• Feedback mechanism - A mechanism or a signal that tends to initiate (or accelerate) or to inhibit (or slow down) a process. i
• Hypothalamus - the hormones from the hypothalamus govern physiologic functions such as temperature regulation, thirst, hunger, sleep, mood, sex drive, and the release of other hormones within the body.;
• Anterior Pituitary gland

  Growth Hormone (GH) - stimulates growth,
• Adrenocorticotropic hormone (ACTH) - regulates levels of the steroid hormone cortisol, which released from the adrenal gland;
• Parathyroid gland

  Parathyroid Hormone - increases blood Ca 2+;
• Thyroid gland - produces thyroxine that increases metabolic rate and heart rate; promotes growth;
• Adrenal glands

  Epinephrine - produces many effects related to short-term stress response,
• Cortisol - produces many effects related to short-term and long-term responses,
• Aldosterone - increases reabsorption of Na+ by kidneys;
• Pancreas

  Islets of [Langerhans Insulin - decreases blood glucose,
• Glucagon - increases blood glucose

  Kidneys,
• Erythropoietin (EPO) - increases synthesis of red blood cells Vitamin D and decreases blood Ca2+;
• Ovaries

  Estradiol - regulates development and maintenance of secondary sex characteristics in females; other effects;
• Progesterone - prepares uterus for pregnancy;
• Testes

  testosterone - regulates development and maintenance of secondary sex characteristics in males; other effects
• sea sponges - All animals have a true nervous system except
• nerve net - connected neurons
• Echinoderms - such as sea stars, have neurons that are bundled into fibers called nerves.
• Flatworms - of the phylum Platyhelminthes have both a CNS made up of a small brain and two nerve cords, and PNS containing a system of nerves that extend throughout the body.
• insect nervous- is more complex but also fairly decentralized, with a brain, ventral nerve cord, and ganglia (clusters of connected neurons).
• ganglia - can control movements and behaviors without input from the brain.
• cephalopods - such as octopus, may have the most complicated of invertebrate nervous systems, with neurons that are organized in specialized lobes and eyes that are structurally similar to vertebrate species.
• vertibrate nervous - systems are more complex, centralized, and specialized.
• brain and spinal chord - a CNS that contains
• PNS made up - peripheral sensory and motor nerves.
• ventrally - nerve cords of many invertebrates are located
• dorsally - whereas the vertebrate spinal cords are located