Darkthorn’s Blog

Organization of the Nervous System

- one of the two control systems of the body (endocrine system)

- maintains homeostatis through control of the other body systems (first communication system, responsible for higher function)

PNS – nervous system outside the brain/spinal cord

- somatic – innervates skin, muscle, joints

- visceral – innervates internal organs, blood vessels, glands

- Dorsal root ganglia – clusters of neurosn outside spinal cord contain SS axons

Protection of the CNS

- bone – cranium and vertebral column

- meninges – outer dura matter, middle arachanoid matter, innermost pia matter

- cerebrospinal fluid and blood brain barrier

- blood brain barrier – series of capillaries regulating exchange, limiting number of substances allowed into brain, brain damage if brain lacks oxygen or glucose

- ventricles and CSF – cavities inside brain that produce fluid that surrounds and floats the brain

The Brain

- brain stem and cerebellum

- cerebral hemispheres and diencephalon

Cerebral Cortex

- two hemispheres with bilateral symmetry

- language on left side, mental activities well distributed

- grey matter – contains cell bodies and dendrites, reticular formation

- white matter – collections of nerve cell fibres or axons

- corpus callosum, internal capsule, corticle white matter,

- information superhighway, 300+ neuronal axons

- prefrontal association cortex – decision making, creativity, personality

- parietal/occipital/temporal or limbic association cortexes

Dienchephalon – hypothalamus – homeostatic function

- thalamus – primitive sensory processing, relay station

Brain Stem – midbrain/pons/medulla – controls breathing/digestion

Spinal Cord – conducts from skin/joints/muscle

Cerebellum – maintains balance, muscle tone, coordinates voluntary movement

- several parts of the brain are always working together

- ventricular system and CNS – CNS forms the walls of a fluid-filled neural tube, inside of that tube becomes ventricular system, formation of neural tube from ectoderm (tube = CNS, crest = PNS)

- telencephalon – cerebral hemispheres, olfactory bulbs, basal telencephalon

- diencephalon – thalamus, hypothalamus

- forebrain – telencephalon, diencephalon, retina

- cerebral cortex – analyse sensory input and command motor output

- thalamus – axons from thalamus to cortex, carry information from body

- hypothalamus – connected to ANS, brainstem, telencephalon, pituitary gland à control of autonomic nervous system, motivation, neuroendocrine

- midbrain – information conduit from spinal cord to forebrain

- tectum – superior colliocus (information from eyes) vs inferior colliocus (information from ears)

- tegmentum – substancia nigra to control voluntary movement

- hindbrain – cerebellum – movement control

- pons – massive switchboard connecting cerebral cortex to cerebellum

- cochlear nuclei – project axons, auditory nerve terminal

- taste and touch motor neurons

- pyramidal decussation – crossing of axons from one side to another

- brain maturation in adults

- reduction in grey matter

- reflects increased myelination to improve cognitive processing (response inhibition, emotional regulation, planning and organization

- frontal cortex projects to striatal areas involved in learning