thigmonastic response

Examples of thigmonastic response in the following topics:

• Plant Responses to Wind and Touch

  • The shoot of a pea plant wraps around a trellis while a tree grows on an angle in response to strong prevailing winds.
  • A tendril is a specialized stem, leaf, or petiole with a threadlike shape that is used by climbing plants for support.The meristematic region of tendrils is very touch sensitive; light touch will evoke a quick coiling response.
  • A thigmonastic response is a touch response independent of the direction of stimulus.
  • Tendrils of a redvine produce auxin in response to touching a support stick and then transfer the auxin to non-touching cells.

• Antigen-presenting Cells: B and T cells

  • The adaptive, or acquired, immune response to an initial infection takes days or even weeks to become established, much longer than the innate response.
  • The adaptive immune response activates when the innate immune response insufficiently controls an infection.
  • There are two types of adaptive responses: the cell-mediated immune response, which is controlled by activated T cells, and the humoral immune response, which is controlled by activated B cells and antibodies.
  • The two types of lymphocytes of the adaptive immune response are B and T cells .
  • B cells are involved in the humoral immune response, which targets pathogens loose in blood and lymph, while T cells are involved in the cell-mediated immune response, which targets infected cells.

• Neural Responses to Food

  • In reaction to the smell, sight, or thought of food, the first hormonal response is that of salivation.
  • The salivary glands secrete more saliva in response to the stimulus presented by food in preparation for digestion.
  • The response to food begins even before food enters the mouth.
  • This phase consists of local, hormonal, and neural responses.
  • These responses stimulate secretions and powerful contractions.

• Immunological Memory

  • During the adaptive immune response to a pathogen that has not been encountered before, known as the primary immune response, plasma cells secreting antibodies and differentiated T cells increase, then plateau over time.
  • This is known as the secondary immune response.
  • This rapid and dramatic antibody response may stop the infection before it can even become established.
  • The immune response to vaccination may not be perceived by the host as illness, but still confers immune memory.
  • In the primary response to infection, antibodies are secreted first from plasma cells.

• Hormonal Responses to Food

  • The endocrine system controls the release of hormones responsible for starting, stopping, slowing, and quickening digestive processes.
  • The endocrine system controls the response of the various glands in the body and the release of hormones at the appropriate times.
  • The endocrine system's effects are slow to initiate, but prolonged in their response, lasting from a few hours up to weeks.
  • During the gastric phase, the hormone gastrin is secreted by G cells in the stomach in response to the presence of proteins.
  • Another level of hormonal control occurs in response to the composition of food.

• Conditioned Behavior

  • In classical conditioning, a response called the conditioned response is associated with a stimulus that it had previously not been associated with, the conditioned stimulus.
  • The response to the original, unconditioned stimulus is called the unconditioned response.
  • In Pavlov's experiments, the unconditioned response was the salivation of dogs in response to the unconditioned stimulus of seeing or smelling their food.
  • The conditioning stimulus that researchers associated with the unconditioned response was the ringing of a bell.
  • Thus, the ringing of the bell became the conditioned stimulus and the salivation became the conditioned response.

• Blue Light Response

  • Phototropins are protein-based receptors responsible for mediating the phototropic response in plants.
  • However, of all responses controlled by phototropins, phototropism has been studied the longest and is the best understood.
  • In 1913, Peter Boysen-Jensen conducted an experiment that demonstrated that a chemical signal produced in the plant tip was responsible for the plant's bending response at the base.
  • Azure bluets (Houstonia caerulea) display a phototropic response by bending toward the light.
  • Phototropism is the growth of plants in response to light.

• Hypersensitivities

  • These chemical mediators then recruit eosinophils which mediate allergic responses .
  • This type of hypersensitivity involves the TH1 cytokine-mediated inflammatory response.
  • Cortisone is typically used to treat such responses as it inhibits cytokine production.
  • Most types of autoimmunity involve the humoral immune response.
  • This image shows an example of an allergic response to ragweed pollen.

• Physical and Chemical Barriers

  • The innate immune response has physical and chemical barriers that exist as the first line of defense against infectious pathogens.
  • The immune system comprises both innate and adaptive immune responses.
  • It is not induced by infection or vaccination, but is constantly available to reduce the workload for the adaptive immune response.
  • The adaptive immune response expands over time, storing information about past infections and mounting pathogen-specific defenses.
  • In the innate immune response, any pathogenic threat triggers a consistent sequence of events that can identify the type of pathogen and either clear the infection independently or mobilize a highly-specialized adaptive immune response.

• Innate Immune Response

  • The immune response that defends against pathogens can be classified as either innate or active.
  • The innate immune response is present in its final state from birth and attempts to defend against all pathogens.
  • Conversely, the adaptive immune response stores information about past infections and mounts pathogen-specific defenses.
  • However, we are born with only innate immunity, developing our adaptive immune response after birth.
  • Eosinophils play a variety of roles in the immune response.