lesson 7 (1)

• Nervous system


  Complex network of nerves and cells (neurons) that carry messages to and from the brain and spinal cord to various parts of the body

  
• Functions of the nervous system

  • Sensory function
  • Integrative function
  • Motor function

  
• Central Nervous System (CNS)


  Comprises the brain and the spinal cord

  
• Brain


  Control center of the body, responsible for processing sensory information, regulating bodily functions, and enabling consciousness, thoughts, and emotions
• Spinal cord


  Main pathway for information connecting the brain and peripheral nervous system

  
• Lobes of the cerebrum

  • Frontal
  • Parietal
  • Temporal
  • Occipital

  
• Frontal lobe


  • Associated with reasoning, planning, parts of speech, movement, emotions, and problem-solving

  
• Parietal lobe


  • Associated with movement, orientation, recognition, and perception of stimuli

  
• Occipital lobe


  • Associated with visual processing

  
• Temporal lobe


  • Associated with perception and recognition of auditory stimuli, memory, and speech

  
• Cerebellum


  Located under the cerebrum, its functions include coordinating muscle movements and maintaining posture and balance
• Functions of the cerebellum

  • Coordination of voluntary movements
  • Maintenance of balance and posture
  • Motor learning
  • Timing and precision
• Brainstem


  Acts as a relay center connecting the cerebrum and cerebellum to the spinal cord, controls vital functions such as breathing, heart rate, and blood pressure
• Components of the brainstem

  • Midbrain
  • Pons
  • Medulla oblongata

  
• Midbrain


  • Involved in functions such as vision, hearing, eye movement, and body movement
• Pons


  • Acts as a major pathway for signals passing between the cerebrum and the medulla or cerebellum, plays a critical role in controlling breathing
• Medulla oblongata


  • Continuous with the spinal cord and controls vital body functions such as heart rate, blood pressure, and digestion
• Limbic system


  Complex set of structures located within the brain that plays a key role in controlling emotional responses, behaviors, motivation, and long-term memory

  
• Major components of the limbic system

  • Amygdala
  • Hippocampus
  • Thalamus
  • Hypothalamus
  • Cingulate cortex
• Amygdala


  • Critical for emotional processing, plays a key role in detecting fear and preparing for emergency events, helps store memories of events and emotions
• Hippocampus


  • Primarily involved in memory formation, helps convert short-term memory to long-term memory, important in spatial navigation
• Thalamus


  • Primarily a relay station for sensory information, plays a role in controlling sleep and awake states, functionally connected to the limbic system, contributing to emotional regulation
• Hypothalamus


  • Responsible for releasing hormones and regulating bodily functions, including temperature, hunger, thirst, fatigue, sleep, and circadian cycles, plays a crucial role in the emotional aspect of sexual arousal and aggression
• Cingulate cortex


  • Involved in processing emotions and behavior regulation, helps regulate autonomic motor function
• Functions of the limbic system

  • Emotion
  • Memory
  • Behavior
• Spinal cord


  Long, cylindrical structure, encased within the vertebral column (spine) for protection, surrounded by cerebrospinal fluid (CSF) which provides cushioning
• Gray matter


  Located in the center, shaped like a butterfly or an H, contains neuron cell bodies, dendrites, and axon terminals
• White matter


  Surrounds the gray matter, contains myelinated and unmyelinated axons that form ascending (sensory) and descending (motor) tracts
• Regions of the spinal cord

  • Cervical
  • Thoracic
  • Lumbar
  • Sacral
• Spinal nerves


  Each spinal cord segment is connected to a pair of spinal nerves, which branch out to the body and convey sensory and motor information
• Functions of the spinal cord

  • Conduction
  • Locomotion
  • Reflexes
• Blood-brain barrier (BBB)


  A selective barrier that protects the brain from harmful substances and pathogens while allowing essential nutrients to pass through
• Peripheral Nervous System (PNS)

  Crucial component of the nervous system outside of the brain and spinal cord, consists of the nerves and ganglia that lie outside the brain and spinal cord

  
• Components of the Peripheral Nervous System

  • Somatic nervous system (SNS)
  • Autonomic nervous system (ANS)

  
• Somatic Nervous System (SNS)


  Controls voluntary movements and transmits sensory information to the CNS

  
• Autonomic Nervous System (ANS)


  Regulates involuntary body functions, such as blood flow, heartbeat, digestion, and breathing
• Divisions of the Autonomic Nervous System

  • Sympathetic
  • Parasympathetic

  
• Sympathetic Nervous System


  • Prepares the body for intense physical activity and is often referred to as the fight-or-flight response
• Parasympathetic Nervous System


  • Relaxes the body and slows many high energy functions, often referred to as the rest-and-digest or feed-and-breed system
• Functions of the Peripheral Nervous System

  • Transmission of sensory information
  • Regulation of motor functions
  • Regulation of autonomic functions
  • Neuromodulation