The Brain

• The frontal lobes control voluntary movements, decision making, planning, judgment, and personality expression.
• No system is a lot more important than the rest.

  Nervous System is a communication network that controls all other systems of your body.

  there are two parts of the nervous system, these are the central Nervous System (LN3) and Peripheral Nervous System

  Central means 'main, or primary, therefore remember the definition of central to think of your brain and spinal cord.

  the nervous system is made of trillions of nerve cells, called neurons that transmit electrical messages through the body.
• The cell body contains the nucleus, which is the cell's control centre
• Dendrites branch out from the cell body and receive messages from other nerve cells, sending them onto the cell body
• The axon sends nerve impulses in only one direction - away from the cell body
• Motor neurons carry messages from the central nervous system to effectors, which are muscles or glands that translate the messages into actions
• Connector neurons transmit messages between neurons in the central nervous system
• Sensory neurons have specialized receptors sensitive to stimuli like heat or light, carrying messages to the brain and spinal cord from cells in sense organs such as eyes, ears, tongue, and skin
• If all neurons in the body touched each other, stimulating one nerve ending would be like turning one switch on in your house and all lights turning on
• When a nerve impulse reaches an axon, a neurotransmitter is released into the space between neurons, called a synapse
• Neurons are covered with an insulating layer called a myelin sheath, which insulates neurons from each other and increases the speed of the nerve impulse
• In the forebrain, emotions, memories, and thinking are attributed
• Adult brain structure includes: spinal cord, hindbrain, midbrain, and a large forebrain
• Basic brain plan includes brainstem, cerebellum, thalamus hypothalamus, and cerebrum
• Brainstem consists of medulla oblongata, pons, and midbrain
• Brainstem functions include controlling basic needs like breathing, circulation, and swallowing, as well as routing sensory and motor information
• Cerebellum is responsible for motor control and motor memory
• Thalamus acts as a router, sorting and sending data where it needs to go
• Hypothalamus is responsible for homeostasis, maintaining body temperature and osmolarity
• Posterior pituitary gland, part of the brain, releases hormones like antidiuretic hormone and oxytocin
• Cerebrum's function is integration, making sense of incoming data through billions of neurons and synapses
• Functional MRI technology helps study brain activity by showing blood flow during different stimuli
• The cerebrum is divided into two hemispheres, right and left, connected by the corpus callosum
• Lateralization occurs in the brain, with certain functions located on the left side (e.g. mathematical reasoning and logic) and others on the right side (e.g. facial recognition)
• Plasticity in the brain allows for the movement of functions between hemispheres, even after a radical hemispherectomy
• Below the corpus callosum is the basal ganglia, made up of nuclei that control motor functions through inhibition and excitatory responses
• The cerebral cortex makes up about 80% of the brain and is divided into four lobes: frontal, parietal, occipital, and temporal
• Frontal lobe: responsible for executive functions and emotional control
• Parietal lobe: involved in sensation and reacting to the environment
• Occipital lobe: primarily responsible for vision
• Temporal lobe: important for language, hearing, and memory
• Inside the parietal lobe is the somatosensory cortex, where sensory information is processed
• Adjacent to the somatosensory cortex is the motor cortex, responsible for sending out motor commands
• The brainstem consists of the medulla oblongata, pons, and midbrain, responsible for maintaining vital functions and sorting information
• The cerebellum, located behind the brainstem, is involved in coordination, motor control, and motor memory
• Above the brainstem is the thalamus, which sorts information to the upper parts of the cerebrum
• Below the thalamus is the hypothalamus, responsible for maintaining internal body state (homeostasis)
• The posterior pituitary hangs off the bottom of the hypothalamus