Organismal Bio. IV

• Nervous Control


  Has a direct relation to the nervous system, fast-acting (can happen in milliseconds or seconds), but has a short-term effect
• Chemical Control

  Includes endocrine system, has a variety of hormones (controls how our body responds to the different stimuli present in our environment), slow-acting compared to Nervous Control (can happen in minutes, hours, or days), but has a long-term effect
• Plants do not have a nervous system, they can't feel pain (they don't have pain receptors) and can't think (they don't have a brain)
• But plants can recognize their environment and coordinate their behavior, they can respond against these environmental changes with the help of hormones
• Nervous System

  Responsible for coordinating the functions of our body (chewing, digestion, etc.)
• Endocrine System


  Responsible for the attainment of homeostasis or internal balance
• Brain


  • Is the main organ used by vertebrates for nervous control
• Nerve Nets


  • Simple kind of nervous system that some invertebrates have, scattered throughout the body of the animal, allows for simple behavior or movements like contractions
• Animals have nerves that carry information from the brain and spinal cord to the muscles and glands, the transmission of nerve cells just happens in milliseconds
• Dendrites


  Branches of Soma (cell body), main function is to receive electrochemical signals from the neighboring nerve cells
• Axon


  The longest part of the nerve cell, main goal is to transmit the electrochemical signals to the other neighboring nerve cells
• Axon Terminals


  Its main goal is to pass these signals to the other nerve cells until the message will reach the brain
• Human Nervous System


  • Has 2 parts: Central nervous system and Peripheral nervous system, the Central Nervous System has 2 parts: The Brain and Spinal Cord, the Peripheral Nervous System has 2 parts: The Cranial nerves and Spinal nerves

  
• Plants also process information from their environment and change their growth based on that information, they can identify if there's an increase in the temperature or change in the season
• Action Potentials


  Although they don't have nerves, plants cells are capable of generating electrical impulses called action potentials just as nerve cells in animals do
• Circadian Rhythms


  Plants have all kinds of movement based on their circadian rhythms (these are the physical, mental, or behavioral changes that an organism experiences over a 24-hour cycle or a
• Endocrine System Glands and Organs

  • Hypothalamus
  • Pituitary gland
  • Pineal gland
  • Thymus
  • Thyroid and Parathyroid glands
  • Pancreas
  • Adrenal glands
  • Testicle (in male)
  • Ovary (in female)
  • Placenta (during pregnancy)

  
• Hypothalamus


  Called the "Master gland" as it can control the other glands present in the body
• Pituitary Gland


  Controls the growth or development of a person, and releases oxytocin (love hormone), which is a human hormone that stimulate uterine contractions and is important for females during labor
• Pineal Gland


  Controls the production of melatonin
• Some Human Hormones

  • Growth Hormone (Stimulates cell division and growth)
  • Oxytocin (Stimulate uterine contractions)
  • Insulin (Stimulates decrease in blood sugar levels)
  • Estrogen (Stimulates development of female reproductive system)
  • Testosterone (Stimulates development of male reproductive system)
• Plant Hormones


  Auxin (Builds up on the shaded side of the plant & stimulates growth beneath the tip), Gibberellin (Promotes fruit growth, elongation of shoots, and breaking the dormancy in seeds and buds), Cytokinin (Stimulates cell division to grow roots, fruits, and branches)
• Stages of The Sensory & Motor Mechanism


  1. Stimulus

  2. Receptor

  3. Sensory Neurons

  4. Control Center

  5. Effector
• Tropism


  A change in a plant's growth in response to external stimuli
• Auxin


  Plant hormone that causes the cells on the shaded side to grow more than the side exposed to light
• Gibberellin


  Plant hormone that promotes fruit growth, elongation of shoots, and breaking the dormancy in seeds and buds
• Gibberellin


  Present during the early stages of plants
• Cytokinin


  Plant hormone that stimulates cell division to grow roots, fruits, and branches
• Cytokinin


  Produced in the middle to the adult stage of plants
• Sensory & Motor Mechanism

  1. Stimulus

  2. Receptor

  3. Sensory Neurons

  4. Control Center

  5. Effector
• Tropism


  Change in a plant's growth in response to external factors, like towards light
• Positive Tropism

  • Growth is towards the stimulus/the growth of the plant follows the stimulus
• Negative Tropism

  • Growth is away from the stimulus/the growth of the plant will be opposite from the direction of the stimulus
• Phototropism


  Movement of the plant in response to light, usually in the direction toward the light
• Geotropism


  Movement of the plant in response to gravitational force
• Positive Geotropism


  • Growth follows the direction of the gravitational force (downward)
• Negative Geotropism


  • Growth is in contrast with the direction of the gravitational force
• Hydrotropism


  Movement of the plant in response to water
• Positive Hydrotropism


  • The root grows towards water
• Negative Hydrotropism


  • Exhibited by the shoots, because they don't need to collect water, they need to collect light