Ch. 5 The Central Nervous System Flashcards
What are the three protections of the CNS
Cranium, meninges, CSF
Explain what meninges are
- Inside the bones, covering surface of brain + spinal chord= three layers of connective tissue forming membranes = meninges
What are the three layers of the meninges
o Outer layer= tough, fibrous, sticks closely to bones on skull, but on inside of vertebral canal= not close fitting
o Middle= loose mesh of fibres
o Inner= delicate, contains blood vessels and sticks closely to surface of brain + spinal chord
What are the three functions of the CSF
- 3 functions (protect, support, transport)
o acts as shock absorber
o also supports brain (brain suspended + floats in CSF)
o CSF= formed in blood> circulates CNS (taking nutrients to cells of brain + sp.c. and carries away wastes)> re enters blood capillaries
What is the General Function of the cerebral cortex
Higher order functions
What is the General Function of the corpus callosum
communication b/w two hemispheres
What is the General Function of the cerebellum
coordination of fine movements and maintenance of balance and posture
What is the General Function of the hypothalams
homeostasis
What is the General Function of the medulla oblongata
(under influence of hypo) regulates heart, breathing, diameter of blood vessels
What is the General Function of the spinal chord
pathway for communication b/w effector and brain
reflexes
What is the layers of the cerebrum
o Cerebral Cortex (outer grey matter)
o White matter
o Inner basal ganglia (grey matter)
What are convolutions, sulci and fissures
- Contains convolutions (gyri; singular gyrus) > increase SA
- Separated by either:
o Sulci= shallow down folds
o Fissures= deep down folds
What is the corpus colosseum composed of
o White matter consisting of a large bundle of transverse fibres
What is the white matter between grey layers of the cerebrum composed of
o Composed of bundles of nerve fibres (tracts, nerves outside CNS)= with myelin sheath,
What are the three types of tracts in the cns
- Tracts that connect various areas of the cortex within same hemisphere
- Tracts that carry impulses b/w left/right
- Tracts that connect cortex to other parts of brain/spinal chord
What are the three functional areas of the cerebrum
o Sensory areas- receive + process/interpret nerve impulses from receptors
o Motor areas- send impulses/controls for muscular movement (i.e. voluntary)
o Association areas- concerned with intellectual and emotional processes, interpret info from the senses and make it useful
what is basal ganglia
- Basal ganglia (grey matter in each hemisphere)
o Consists of groups of nerve cell bodies= associated with control of skeletal muscles
How does cerebrum control memory
o Association areas involved in memory
o Memories not stored in individual memory cells, they are pathways of nerve cells
o When memory is stored= new links are made b/w neurons, or existing link= modified
what are the two areas of the cerebellum
o Outer (folded part)= grey matter o Inner= white matter, branches to all parts of the cerebellum
if damaged occurred in the cerebellum what would be a consequence
- impulses don’t originate from cerebellum // would still move if didn’t have though would be sporadic, uncontrolled
What re the three centres of the medulla oblongata
o Cardiac Centre ♣ Regulates rate + force of heartbeat o Respiratory Centre ♣ Control rate + depth of breathing o Vasomotor Centre ♣ Regulates diameter of blood vessels
what are reflexes controlled by the medulla oblongata
swallowing, sneezing, coughing, vomiting,
what allows the spinal chord to bend
Outermost layer= does not join to bone= space containing fat, connective tissue + blood
what is the spinal chord composed of
o grey (H) (nerve cell bodies + unmyelinated) o white matter (myelinated fibres)
