CNS and brain functions

• Cerebral cortex is responsible for higher cognitive functions such as perception, memory, language, and consciousness.
• Limbic system includes structures involved in emotion, motivation, learning, and memory.
• The brainstem connects the spinal cord to the forebrain and controls vital functions like breathing, heart rate, blood pressure, and swallowing.
• The hypothalamus regulates body temperature, hunger, thirst, sleep-wake cycles, and emotional responses.
• The nervous system consists of two main parts - central (brain and spinal cord) and peripheral (nerves).
• The hippocampus plays a role in forming new memories and spatial navigation.
• The amygdala processes emotions related to fear and aggression.
• Neurons are specialized cells that transmit electrical signals throughout the nervous system.
• Sensory neurons carry information from sensory receptors to the CNS.
• Motor neurons carry information from the CNS to effectors (muscles or glands).
• Central nervous system (CNS)

  Made up of the spinal cord and the brain
• Nervous system


  • Specialised and complex network of cells in the human body
  • Primary internal communication system
  • Collects, processes and responds to information in the environment
  • Coordinates the working of different organs and cells in the body
• Spinal cord


  • Tube-like extension of the brain, connected to the brain via the brain stem
  • Responsible for reflex actions
  • Passes messages to and from the brain, linking it to the peripheral nervous system
• Brain


  • Source of our conscious awareness and where decision-making takes place
  • Divided into two near-symmetrical hemispheres, connected by the corpus callosum
  • Control of the body is generally contralateral
• Cerebral cortex


  • Highly developed in humans
  • About 3 mm thick and covers the "inner" parts of the brain
  • Divided into cortical (belonging to the cortex) and subcortical (below the cortex) structures
• Thalamus


  • Brain's relay station
  • Receives information from various senses and passes it on to the cerebral cortex
  • Carries out some initial processing of its own
  • Acts as a 'gate' or filter of information
  • Plays a role in sleep, wakefulness and obsessive compulsive disorder (OCD)
• Hypothalamus


  • Tiny structure with involvement in a variety of behaviours
  • Controls motivational behaviours such as hunger, thirst and sex
  • Key role in the body's stress response
  • Maintains balance in many bodily functions such as temperature (homeostasis)
  • Regulates the activity of the endocrine system via its connection with the pituitary gland
• Limbic system


  • Consists of several structures such as the amygdala
  • Plays a large role in regulating emotional responses
  • Has a role in memory and learning
  • Highly interconnected with areas of the cortex, integrating cortical and subcortical parts of the brain
• Cerebellum


  • Primary role is to coordinate posture, balance and movement
  • Receives and integrates information from the spinal cord and other areas such as the motor cortex
  • Contains almost 50% of the brain's neurons despite being only about 10% of the brain's entire weight
• Corpus callosum


  • Dense collection of nerve cells that physically connects the two hemispheres below the cerebral cortex
  • Allows communication between the hemispheres by passing signals back and forth
  • Critical for integrating the activities of both sides of the body
• Lateralisation


  • The two hemispheres have different functions (e.g. language is associated with the left hemisphere)
• Localisation


  • Certain areas within each hemisphere are responsible for specific functions and behaviours
• Frontal lobes


  • Control high-level cognitive functions such as thinking, planning, problem-solving and decision-making
  • Contain the motor cortex which controls voluntary movements on the opposite side of the body
  • Left frontal lobe includes Broca's area
• Parietal lobes


  • Contain the somatosensory cortex which processes sensory information from the skin (e.g. touch, temperature, pressure)
  • Somatosensory cortex area devoted to a particular body part reflects that part's sensitivity to touch
• Temporal lobes


  • Contain the auditory cortex which deals with sound information
  • Process the location, volume and pitch of sounds, and therefore have a role in understanding language
  • Left temporal lobe is the location of Wernicke's area
• Occipital lobes


  • Contain the primary visual cortex and several secondary areas
  • Everything we see to the right of our field of vision is initially processed by the left visual cortex before being shared with the right visual cortex (and vice versa)
• Broca's area


  • Small area in the left frontal lobe responsible for speech production
  • Damage to this area causes Broca's aphasia, the main feature of which is slow, laborious speech lacking in fluency
• Wernicke's area


  • Located in the left temporal lobe
  • Damage to this area causes Wernicke's aphasia, which is characterized by fluent but meaningless speech