CENTRAL NERVOUS
SYSTEM
Brain Dominance
• Right Brain
–
–
–
–
–
non-verbal
Concrete
Holistic (big pic)
Intuitive
spontaneous
• Left Brain
–
–
–
–
–
–
Logical
Language
Verbal
Sequential/linear (Math)
Abstract…math/science
Planner
http://www.web-us.com/BRAIN/braindominance.htm
Objectives
• To learn protective parts/features of CNS
• To learn structure and function of the Spinal
Cord
• To understand the brain structure and
function as well as development.
Protection of the CNS
• Bones
• Meninges
Protection of the CNS
• The brain & spinal cord are protected by
bones, membranes, and fluid
A. Bones
–*8 skull bones encase the brain
–*30 vertebrae encase the spinal cord
Can you name the bones?
– B.) Meninges - Membranes surrounding CNS
• 3 Layers encasing the brain
–a.) Dura mater
»outermost membrane: attached to
periosteum of the skull
»contains many blood vessels & nerves
»tough, white fibrous connective tissue
–b.) Arachnoid Mater
»middle layer
»thin net-like membrane
»No blood vessels
»Sub-arachnoid space lies deep to this
layer and is filled with CSF which serves
as a cushion for brain
–c.) Pia Mater
»inner layer that clings to brain surface
»very thin delicate connective tissue
»many nerves & blood vessels =
nourishment
»dips into grooves and contours inner layer
that clings to brain surface
Meningitis
• What does the word Mean?
• Caused by:
– Bacteria or virus
• Affects:
– Mainly arachnoid and pia maters
– Younger or older generations
– People with suppressed immune systems
• Complications of disease:
– Loss of vision, hearing paralysis, mental
retardation…death
C. Ventricles
– Interconnected cavities within the cerebral hemispheres
and brain stem
– Continuous with central canal of spinal cord
– Filled with CSF cerebral spinal fluid
– D. Cerebrospinal Fluid (CSF)
– Secreted by Choroid Plexus
– Circulation: Ventricles 1&2 --> 3rd --> 4th --> central
canal --> reabsorbed into bloodstream
– Approx. 1 liter is secreted daily: Secreted and reabsorbed
continuously
– Functions: cushion & circulation of
nutrients/wastes
The Brain
Structures and Functions
Brain Lobes
Forebrain
prosencepahlon
• Includes hypothalamus, thalamus and
cerebrum
Midbrain
mesencephalon
• Connects cerebrum to
spinal cord
• Reflex center for eye
and some head
movements
Hindbrain
rhombencephalon
• Cerebellum
• Medulla oblongata
• Pons
Cerebrum
• Largest part of brain
• Contains many folds and
bumbs
– Sulci vs. gyri
• Corpus callosum is found b/t
the L and R
• Responsible for reasoning,
intellectual fxn and critical
thinking
Brain Dominance
• Right Brain
–
–
–
–
–
non-verbal
Concrete
Holistic (big pic)
Intuitive
spontaneous
• Left Brain
–
–
–
–
–
Verbal
Sequential/linear
Abstract…math/science
Logical
Planner
http://www.web-us.com/BRAIN/braindominance.htm
Cerebral Cortex
• Thin layer (2-5mm);
largest and most
anterior structure of
brain
• Contains 75% of
neuron cell bodies in
NS
• Memory, attn, thought
processes, language
cerebellum
•
•
•
•
Regulates balance
body position
Posture
Muscle coordination
Medulla oblongata
• Vital Reflex center
– Visceral activities:
– blood pressure, respiratory
– cardiac
• Part of the brain stem
• Injuries often fatal
Corpus callosum
• Deep bridge of
nerve fibers
• Connects L and R
brain
• Intercommunication
b/t hemispheres is
not completely
understood
Optic chiasma
Limbic System
Limbic
• Includes the hypothalamus, hippocampus,
amygdala
• Important in emotions and formation of
memories
Limbic
• Hypothalamus
• Part of diencephalon
• Secretes hormones
– Dopamine, oxytocin, growth
hormones
• Regulates body temp, heart
rate, hunger/weight,
alertness
• Center involved with
emotion
Thalamus
• Part of diencephalon
• Motor control
• Receives visual and
auditory senses
Pineal gland
• Produces melatonin;
controls circadian rhythm
• Size of a pea; 8mm
• Think about it…
– Stimulated by dark
– Inhibited by light
c
Pineal body
Pituitary
gland
• Endocrine gland; secretes
hormones
• Examples
– growth hormones;
– regulate breast milk
production; sexual hormones
– possibly blood pressure
Pons
• b/t midbrain and
medulla oblongata
• Regulates rate and
depth of breathing
• Homeostatic
mechanisms
Mammillary body
• Named for
resemblance of 2
breast
• Associated with
memory
• Damaged by alcoholic
intoxication
Hippocampus
• Part of limbic system
• Emotions, inhibition
• Long term memory
• Alzheimer’s disease
– First to be damaged
If damaged, what do you predict
would be the results?
Reticular formation
• Brainstem and diencephalon
• Alertness, arousal, sensory integration,
motivation
• connects to areas in the thalamus,
hypothalamus, cortex and cerebellum
http://www.web-us.com/BRAIN/braindominance.htm