major early events 1

• What is depicted in the provided images?

  Folding of embryonic tissues during development

  
• What role does tissue folding play in embryonic development?

  • Creates complex organ structures
  • Shapes and positions tissues
  • Establishes boundaries between germ layers

  
• What is the process shown in image (1b) called?

  Folding

  
• How might tissue folding be affected by genetic mutations in embryonic developmental genes?

  • Incorrect folding leading to malformed organs
  • Disrupted positioning of tissues
  • Altered boundaries between germ layers

  
• What are the two main structures involved in folding of embryonic tissues?

  • Notochord
  • MHP (Main Hinge Point)

  
• How does the interaction between the notochord and the MHP contribute to folding?

  • The notochord acts as a signal center, inducing MHP formation.
  • MHP serves as a hinge point around which tissues bend.
  • The notochord’s position relative to the MHP directs the direction and extent of folding.

  
• What is the initial epithelium layer in primary neurulation?

  • Single layer of epithelial cells

  
• What process occurs in the second step of primary neurulation?

  Columnarization

  
• What occurs during the third step of primary neurulation?

  Rolling/folding

  
• What happens during the fourth step of primary neurulation?

  Closure

  
• What is the final result of primary neurulation?

  Neural tube complete

  
• What is the initial state of the mesenchyme in secondary neurulation?

  • Dispersed mesenchyme

  
• What process occurs in the second step of secondary neurulation?

  Mesenchymal condensation

  
• What structure is formed during the third step of secondary neurulation?

  Medullary cord/neural rod

  
• What is the final result of secondary neurulation?

  Neural tube complete

  
• What occurs during the fourth step of secondary neurulation?

  Epithelial transition/cavitation

  
• What are $Foxi3$ and $Slug?$


  • $Foxi3$ and $Slug$ are transcription factors involved in cell fate determination during embryonic development.

  
• What role do $Foxi3$ and $Slug$ play in embryonic development?


  • They regulate the expression of genes that determine the identity and function of cells in the embryo.

  
• What is $Wnt6?$


  • $Wnt6$ is a signaling molecule involved in cell fate determination and pattern formation during embryonic development.

  
• What is the function of $Wnt6$ in embryonic development?


  • It acts through the $Wnt$ signaling pathway to influence cell behavior and differentiation.

  
• How do $BMPs$ contribute to embryonic development?


  • They regulate cell proliferation, differentiation, and apoptosis, shaping the form and structure of the embryo.

  
• What are $BMPs?$


  • $BMPs$ (Bone Morphogenetic Proteins) are signaling molecules that play essential roles in embryonic development, particularly in patterning and differentiation.

  
• What is the primary role of a sensory receptor in the nervous system?

  • Detects stimuli from the environment or internal body
  • Converts stimuli into nerve impulses
  • Initiates sensory perception

  
• Why are sensory receptors important for an organism's survival?

  They allow the organism to perceive and respond to changes in its internal and external environments, which is crucial for adapting to different conditions.

  
• What type of stimuli does a sensory receptor that detects touch specialize in?

  Mechanical pressure or movement against the skin

  
• How does a sensory receptor initiate nerve impulses?

  Sensory receptors generate graded potentials in response to stimuli. If the graded potentials reach the threshold potential, they trigger action potentials that are transmitted along sensory neurons.

  
• What is the primary function of an interneuron in the neural pathway?

  To relay nerve impulses between sensory and motor neurons.

  
• How do interneurons facilitate communication between sensory and motor neurons?

  They create connections that allow sensory neurons to communicate with motor neurons.

  
• What is the main role of a sensory neuron in the reflex arc?

  To transmit nerve impulses from sensory receptors to the central nervous system.

  
• How do sensory neurons convey information to the central nervous system?

  They transmit action potentials along their axons to the central nervous system.

  
• What is the function of a motor neuron in a reflex arc?

  • Carries nerve impulses from the central nervous system to muscles or glands
  • Causes muscles to contract or glands to secrete
  • Responsible for movement and responses

  
• How do motor neurons cause muscle contraction?

  They release neurotransmitters at neuromuscular junctions that trigger depolarization and contraction of muscle fibers.

  
• What is the main function of muscles in the reflex arc?

  To execute motor responses, such as muscle contractions, as directed by motor neurons.

  
• What are the key steps in a simple neural pathway?

  1. Detection of stimulus by sensory receptor
  2. Transmission of nerve impulses by sensory neuron to the central nervous system
  3. Relay of impulses by interneuron to motor neuron
  4. Transmission of impulses by motor neuron to effector (muscle or gland)
  5. Response by effector (muscle contraction or gland secretion)

  
• What component detects touch in the neural pathway shown?

  Sensory receptor detecting touch

  
• What type of microscopic image is shown in the provided images?

  Microscopic images of cellular structures and tissue types

  
• What are the main components being visualized in the microscopic images?

  • Cellular structures
  • Tissue types

  
• What are the main components of the Central Nervous System (CNS)?

  The CNS consists of the brain and spinal cord.
• What are the divisions of the Peripheral Nervous System (PNS)?

  • Sensory
  • Enteric
  • Sympathetic
  • Parasympathetic
• From which embryonic layer are the CNS and PNS formed?

  They are formed from the neural tube.