PCBI101: NERVOUS (3)

• Cells of the central and peripheral nervous systems


  • They have functions and locales of residence distinctive of each of them
  • They all can secrete exosomes and receive exosomes from the others

  
• Brain sections

  • Forebrain
  • Hindbrain
  • Midbrain

  
• Forebrain


  • The biggest part of the brain
  • Major parts: thalamus, hypothalamus, limbic system (hippocampus, amygdala, and septum), and the cerebrum

  
• Hindbrain


  • The most primitive and basic of the brain regions
  • Deals with basic bodily coordination and fine motor skills
  • Major parts: medulla, cerebellum, pons

  
• The main functions of the meninges include: protecting the brain and spinal cord from mechanical injury, providing blood supply to the skull and to the hemispheres, and providing a space for the flow of cerebrospinal fluid
• Meninges


  The layer of protective tissues composed of the Dura mater, the Arachnoid layer, and the Pia mater
• Hypothalamus


  • Involved in different daily activities like eating or drinking, in the control of the body's temperature and energy maintenance, and in the process of memorizing and in stress control
  • Modulates the endocrine system through its connections with the pituitary gland
• Autonomic nervous system divisions

  • Parasympathetic
  • Sympathetic

  
• Parasympathetic


  Concerned with keeping body energy use as low as possible, and SLUDD: salivation, lacrimation, urination digestion, defecation
• Sympathetic


  The "fight or flight" system, excites body in emergency or threatening situations
• Autonomic neurotransmitters

  • Acetylcholine
  • Norepinephrine (Noradrenaline)
• Parasympathetic preganglionic neurons


  • Have cell body in the nuclei of the oculomotor, facial, glossopharyngeal, and vagus cranial nerves and in the lateral gray horns of the second through fourth sacral segments
  • Their axons pass to terminal ganglia near or within the visceral receptor

  
• Parasympathetic postganglionic neurons


  • Cell bodies are found in the terminal ganglia and their axons synapse with single visceral effectors

  
• Sympathetic preganglionic neurons


  • Have cell bodies in the lateral gray horns of the 12 thoracic segments and the first 2-3 lumbar segments
  • Their axons synapse in the ganglia of the sympathetic trunk (paravertebral ganglia) located in parallel rows on both sides of the vertebral column or prevertebral ganglia which are located close to large abdominal cavities

  
• Nicotinic receptors


  Found on the postganglionic cell bodies in all autonomic ganglia and cause depolarization by opening both Na+ and K+ channels

  
• Muscarinic receptors


  Found on smooth, cardiac muscle and glands, bind with acetylcholine released from parasympathetic postganglionic fibers and are linked to G proteins that activate 2nd messenger systems that lead to the target cell response