Neuroendocrine- musculoskeletal system

• Levels of organization and the related fields of study

  • System
  • Organ
  • Tissue
  • Cell
• Cardiovascular system


  • Heart
  • Myocardium (Muscle Cell)
• Integration between systems of the body

  Function: Convey sensations to the brain and motor impulses to organs and muscles

  
• Nervous tissue


  • Neurons
  • Sensory
  • Motor
  • Interneuron

  
• Glial cells/glia


  Part of nervous tissue
• Nervous system


  • Master controlling and communicating system of the body
  • Responsible for all behavior
  • Along with endocrine system, responsible for regulating and maintaining body homeostasis
  • Cells communicate by means of electrical signals
• Functions of the nervous system

  1. Sensory input

  2. Integration

  3. Motor output

  
• Functional classification of neurons

  • Sensory neurons
  • Motor neurons
  • Interneurons

  
• Sensory neurons


  Transmit information about external and internal stimuli

  
• Interneurons


  Form local circuits connecting neurons in the brain or ganglia, responsible for integration of sensory input

  
• Motor neurons


  Transmit signals to muscle cells, causing them to contract

  
• Resting potential


  Condition where the outside of the membrane is positively charged compared to the inside which is negatively charged

  
• Action potential

  1. Depolarization

  2. Repolarization
• Depolarization


  Inflow of Na+, reduction in electrical gradient, cell becomes less negative
• Hyperpolarization


  Outflow of K+, increase in electrical gradient, cell becomes more negative
• Sequence of events during action potential

  1. Sodium ions rush into the axon, neutralizing negative ions inside

  2. Nearby sodium channels open to continue depolarization

  3. Potassium channels open, potassium floods out, generating positive charge on outside of membrane

  4. Sodium channels close, sodium-potassium pump moves sodium out of cell
• Electrical synapses


  Allow electrical current to flow directly from one neuron to another

  
• Chemical synapses


  Rely on release of a chemical neurotransmitter by the presynaptic neuron to transfer information to the target cell

  
• Parts of the nervous system

  • Central nervous system (brain and spinal cord)
  • Peripheral nervous system (spinal and cranial nerves)
• Endocrine system


  • Produces, stores, and secretes hormones
  • Hormones transfer information and instructions from cell to cell, regulate growth and development, control function of various tissues, support pregnancy and other reproductive functions, regulate metabolism
• Chemical categories of hormones

  • Peptides, proteins
  • Amino acid derivatives
  • Steroids
• Pineal gland


  Secretes melatonin, which functions in biological rhythms
• Prolactin


  Stimulates milk production in mammals, has diverse effects in other vertebrates
• Melanocyte-stimulating hormone (MSH)


  Influences fat metabolism in mammals and skin pigmentation in other vertebrates
• Functions of skeletal system

  • Movement
  • Support
  • Protection
  • Form/Maintenance of shape
• Skeletal forms


  • Hardened support structures can be external (exoskeletons), internal (endoskeletons), or absent (fluid-based, hydrostatic skeletons)
• Hydrostatic skeleton

  Consists of fluid held under pressure in a closed body compartment
• Peristalsis

  Rhythmic waves of muscle contractions passing from front to back
• Exoskeleton

  Hard covering deposited on an animal's surface, about 30-50% chitin
• Endoskeleton


  Hardened internal skeleton, osteoblasts secrete bone matrix, osteoclasts resorb bone components
• Each form of locomotion—swimming, movement on land, or flying—presents a particular challenge
• Swimmers need to overcome friction, but face less of a challenge from gravity than do animals that move on land or fly