Neuroscience Semester 2

• The Nervous System - detects environmental changes, responds to such events, divided into CNS and PNS, coordinates actions by transmitting signals to and from different parts of its body
• Peripheral Nervous System - The nervous system outside the brain and spinal cord. Separated into the somatic and autonomic nervous system
• Autonomic nervous system - Has the sympathetic division (fight or flight response) and the parasympathetic division (rest and digest)
• Cranial Nerves - Afferent functions (sensation to eyes, ears, mouth and nose) information coming in from the outside world. Efferent functions (motor control over facial muscles, tongue and eyes), information outgoing, generally a motor action. - connects the brain and the internal organs (influenced by autonomic responses)
• Spinal Nerves - functionally equivalent to the cranial nerves of the head; control and carry information about the body, trunk and limbs
• Spinal - Nerve Connection - dorsal fibres (afferent - sensory functions), ventral fibres (efferent - motor functions), collection of fibres entering/exiting spinal-cord segment is called a root
• Law of Bell and Magendie: dorsal spinal cord is sensory and ventral side is motor, allows interferences about location of spinal-cord damage on the basis of changes in sensation or movement that a patient experiences.
• Sympathetic Division - fight or flight, connected to thoracic and lumbar spinal-cord regions, spinal cord connects to autonomic control centre, made up of ganglia
• Parasympathetic Division - rest and digest, connects through cranial nerves 3, 7 and 10, also connected to sacral region of spinal cord
• CNS - Spinal Cord - Vertebrae -> segments of the spinal cord, divided into 5 anatomical regions (from top to bottom: cranial, cervical, thoracic, lumbar and sacral)
• CNS - Spinal Cord - Dermatomes -> segments of the body, each dermatome contains sensory nerve and motor nerves (spinal nerves)
• The spinal cord controls most body movements, cannot move a limb unless u get a motor instruction that is sent from the nerves
• Series of vertebrae - Cervical (C1-C8), Thoracic (T1-T12), Lumbar (L1-L5), Sacral (S1-S5)
• The Meninges - Dura Mater - tough, double layered fibrous tissue that covers the brain and spinal cord
• The Meninges - Arachnoid Layer - thin sheet of delicate connective tissue, follows the brain's contour
• The Meninges - Pia Mater - Moderately tough membrane of connective tissue, clings to brain surface
• Meningitis - inflammation of the meninges, bacterial infection (particularly the Pia mater and arachnoid space, CSF is implicated as well) - Intra Cranial Pressure - inflammation puts pressure on the brain, leads to drowsiness, delirium, coma (swelling happens because cells are rushing to that area
• Frontal Lobe - Executive function, decision making, planning, impulse control
• Occipital lobe - vision, 1 degree, 2 degree visual cortices
• Parietal Lobe - tactile function, sensory and motor information processing
• Temporal Lobe - auditory, visual, gustatory, emotion, memory, language comprehension
• Cerebrum - Forebrain structure, two identical hemispheres, responsible for most conscious behaviour
• Cerebellum - control and coordination of fine motor skills, does not initiate movements, but coordinates the timing, precision and accuracy of movements
• Brainstem - Responsible for unconscious behaviours, structurally continuous with the spinal cord
• Gyri (convoluted brain) - bumps and ridges of the cerebral cortex
• Sulci (convoluted brain) - cracks and valleys of the cerebral cortex, fissures are deep sulci
• Gray Matter (coronal section) - largely composed of cell bodies and capillary blood vessels, process information and supports behaviour
• White Matter (coronal section) - nerve fibres with fatty coverings, form connections between cells
• Ventricles (coronal section) - 4 cavities filled with cerebral spinal fluid, derived from blood plasma, NaCl and other salts, serves as a cushion and immunological support for the brain, cells that line the walls of the ventricles are called ependymal cells that produce CSF
• Corpus Callosum (saggital section) - over 200 million nerve fibres that connect the 2 hemispheres, divides brain into cortical and subcortical system
• Brainstem - receives afferent nerves from all body senses, sends efferent nerves to the spinal cord, divided into 3; hindbrain (lowest part), midbrain (middle of the stem), diencephalon (between brain, transition from brainstem to the rest of the brain
• Cerebellum (hindbrain) - increases with physical speech and dexterity (athlete, piano player), controls fine motor skills
• Reticular formation (hindbrain) - located at the core of brainstem, mixture of grey and white matter, alert and aware would lead to extra movement
• pons (hindbrain) - connects the cerebellum to the rest of the brain
• Medulla (hindbrain) - controls breathing and cardiovascular system
• Tectum (midbrain) - dorsal side of the midbrain, receives sensory information from the eyes and ears, allows production of oriented movements (reflexive)
• Tegmentum (midbrain) - red nuclei (motor coordinations of the limbs), substantial nigra (initiates voluntary movements, Parkinson's disease), Periaqueductal grey matter (sexual behaviour and mediating pain)
• Hypothalamus (diencephalon) - controls hormone production, influences feeding, sexual behaviour, sleeping, thermoregulation, emotions, hormone functions, movements and more, 22 different functional regions
• Thalamus (diencephalon) - relay station for sensory information travelling to the cortex, all sensory systems send input to the thalamus, visual information -> occipital lobe, decides where the sensory information goes, olfactory information is processed before reaching the thalamus but gets reprocessed through the thalamus
• Basal ganglia (forebrain) - caudate nucleus, putamen, globus pallidus, substantia nigra, controls certain aspects of involuntary movements