brain

• Central Nervous System (CNS)


  Brain and spinal cord
• Peripheral Nervous System (PNS)


  Other nerves that are not controlled by will
• Central Nervous System (CNS)


  • Brain and spinal cord
  • Transmits electrical signals between the brain and the rest of the body
• Brain

  • Most complex organ in the body
  • Accounts for 2% of body mass
  • 15cm long in adults
  • Weighs 400g at birth, doubles in childhood, reaches 1.3kg in adulthood
• What the brain does

  • Gathers information from sensory organs and receptors
  • Sends messages (electrical and chemical signals) to muscles and glands
  • Control centre of all conscious awareness
• What the brain is responsible for

  • Thoughts and decisions
  • Memories and emotions
  • Movements, balance and coordination
  • Perception of various sensations including pain
  • Automatic behavior such as breathing, heart rate, sleep and temperature control
  • Regulation of organ function
  • Speech and language functions
  • Fight or flight response
• Brain composition


  • 60% fat
  • 40% water, protein, carbohydrates and salts
  • Not a muscle, contains blood vessels and nerves, including neurons and glial cells
• Grey matter


  • Darker, outer portion of the CNS
  • Made up of the round central cell bodies of neurons
• White matter


  • Lighter, inner section underneath grey matter
  • Made of axons (long stems that connect neurons) wrapped in myelin
• Meninges


  Three membrane layers that cover and protect the brain and spinal cord
• Meninges layers


  • Dura mater
  • Arachnoid mater
  • Pia mater
• Spaces between meninges


  • Epidural space
  • Subdural space
  • Subarachnoid space
• Importance of meninges


  • Protect CNS from trauma
  • Help protect spinal cord
  • Anchor CNS and keep brain stable
  • Provide support system for blood vessels
• Main parts of the brain

  • Cerebrum
  • Cerebellum
  • Brainstem
• Cerebrum


  • Largest part of the brain (85% of total mass)
  • Most recently developed part
  • Initiates and coordinates movement
  • Regulates temperature
  • Responsible for higher functioning roles
• Functions originating in cerebral cortex

  • Consciousness
  • Higher-order thinking
  • Imagination
  • Information processing
  • Language
  • Memory
  • Perception
  • Reasoning
  • Sensation
  • Voluntary physical action
• Cerebral cortex


  • Outer grey matter covering of the cerebrum
  • Has a large surface area due to folds (gyri and sulci)
• Cerebral hemispheres


  • Two symmetrical parts of the cerebrum
  • Connected by the corpus callosum
• Corpus callosum


  Thick layer of neural fibres that connects the two cerebral hemispheres
• Cerebral hemispheres


  Left hemisphere controls right side of body, right hemisphere controls left side of body
• Four brain lobes


  • Frontal
  • Parietal
  • Temporal
  • Occipital
• Frontal lobe


  • Largest lobe
  • Associated with higher cognitive functions
  • Contains motor cortex and prefrontal cortex
  • Contains Broca's area for language production
• Parietal lobe


  • Processes tactile sensory information
  • Contains somatosensory cortex
• Temporal lobe


  • Involved in short-term memory, speech, facial and object recognition, emotional interpretation, musical rhythm and smell recognition
  • Contains primary auditory cortex and Wernicke's area for language
• Broca's and Wernicke's areas

  Language centres in the brain
• Occipital lobe


  • Receives sensory information from the eyes' retinas and encodes visual data
• Left temporal lobe


  Associated with language, learning, memorizing, forming words, and remembering verbal information
• Wernicke's area


  Vital language center in the left temporal lobe, essential for language development and coherent language
• Right temporal lobe


  Associated with learning and memorizing non-verbal information and determining facial expressions
• Wernicke and Broca worked on fully developed adults when they came up with their findings
• Children might not necessarily have similar difficulties if they suffer damage in these parts of their brains
• Occipital lobe


  Receives sensory information from the eyes' retinas, which is then encoded into different visual data. Functions include assessing size, depth, and distance, determining color information, object and facial recognition, and mapping the visual world
• Primary visual cortex


  Receives sensory information from the retinas, transmitting this information relating to location, spatial data, motion, and the colors of objects in the field of vision
• Main parts of the brain

  • Cerebrum
  • Cerebellum
  • Brainstem
• Cerebellum


  Fist-sized portion of the brain located at the back of the head, below the temporal and occipital lobes and above the brainstem. Functions include coordinating voluntary and automatic muscle movements, maintaining posture, balance and equilibrium. Also involved in thought, learning, attention, emotions and social behavior, as well as conditions like addiction, autism and schizophrenia
• Brainstem


  Connects the cerebrum and the cerebellum to the spinal cord, regulating automatic/reflex activities such as sleep cycles, heart rate, blood sugar levels, breathing, body temperature, digestion, coughing, and sneezing
• Midbrain


  Relay station for auditory and visual information, controls visual and auditory systems as well as eye movement. Portions involved in control of body movement
• Pons


  Connection between the midbrain and the medulla, carries information to and from the brain, controls muscle activity and autonomic processes like breathing and sleep cycles
• Medulla


  Essential to survival, controls vital autonomic bodily functions like heart rate, breathing, and blood flow, as well as reflexive activities like sneezing, vomiting, coughing and swallowing
• Limbic system


  Set of brain structures involved in behavioural and emotional responses, especially those related to survival: feeding, reproduction, fight or flight, long-term memory, and sense of smell