Class 2

• Nervous System, cont.• Spinal Cord• Brain

Development of the Brain and Spinal Cord

Development of the Brain and Spinal Cord

Repair of Neurons

PNS• Slow and/or non-existent• Cell body can’t be

damaged• Axon must be able to find

Schwann cellsCNS

• Rare• Non-ideal environment• Some evidence in

laboratories

Protective Coverings of the Central Nervous System

Bone: hard, fibrous tissue

Skull and Spinal Column

Meninges of the brain

Subdural space

Skull

Pia mater

Dura mater

Arachnoid mater

Cerebrum:

Gray matter

White matter

Subarachnoidspace

Cerebrospinal spinal fluid

Protective Coverings of the Central Nervous System

Meninges

Cerebrospinal Fluid

• Clear fluid found in and around the brain and spinal cord

• Formed by choroid plexus in ventricles• Absorbed into bloodstream by arachnoid villi

• CSF provides these functions:– Buoyancy– Protection– Chemical stability

Spinal Cord

Gray Matter and White Matter

The Brain

Cerebrum (The “Higher” Brain)

• Left and Right Hemispheresseparated by the Corpus Callosum

•bridge of neurons that allow hemispheres to communicate.

Surface Convolutions:•Gyrus

•a ridge, ie. Central Gyrus•Sulcus

•a shallow groove•Fissures

•a deep groove, ie. Longitudinal Fissure and Transverse Fissure

Cerebrum

4 Lobes:

Frontal Reasoning, Long-Term Memory,Analysis, Movement,

TemporalSpeech, Memory, Hearing

ParietalIntegration of Sensation

OccipitalVisual processing center

Note: Corpus callosum

Cerebrum

Cross Section(Gross)

Coronal Section(MRI Study)

White matter tracts

Cerebrum

Basal Nuclei (aka. Basal Ganglia)

Functions:•Conscious Awareness•Reasoning•Memory•Interpretation of Senses•Initiates Voluntary Motor Responses

Functionally Divided: •Sensory Areas•Cortex of Parietal Lobe

•Motor Areas•Cortex of Frontal Lobe

•Association Areas•Cortex of all Lobes

Cerebrum

Hemisphere Communication and Lateralization

Basal Nuclei (aka. Basal ganglia)

Basal Nuclei (aka. Basal Ganglia)

Diencephalon

Thalamus• Relay station of sensory input except for sense of smell

Hypothalamus• regulates autonomic function and major link between the nervous and endocrine systems

Epithalamus• CSF is made here. •The Pineal gland

•Creates hormone melatonin.

Limbic System

Limbic System

• Includes centers for both gratification and aversion– gratification – sensations of pleasure or reward– aversion – sensations of fear or sorrow

Corpus callosum

Olfactory bulb

•Hypothalamus

•Cingulate gyrus

•Amygdala•Hippocampus

Thalamic Nuclei

Brain Stem

Brain Stem• Midbrain

– The midbrain connects the diencephalon to the pons

– CN’s III and IV • Pons

– Connects cerebrum to the cerebellum

– Connects midbrain to medulla

– CN’s V, VI, VII• Medulla

– Connects brain to spinal cord

– Regulates basic body functions

– CN’s VIII, IX, X, XI, XII

CerebellumFunction: •Involved with vestibular and eye movement functions•Controls proprioception related to muscle tone•Fine tunes and coordinates movements

Thank goodness!!!