What is the Central Nervous system (CNS)? What structures are included?
The Brain and the Spinal Cord
*Integrative and control centers
What is the Peripheral Nervous system? What is included in this category?
12 pairs of Cranial Nerves
31 pairs of Spinal Nerves
Communication lines between CNS and the rest of the body
What are the various protective aspects of the CNS? What are the
meninges, cerebrospinal fluid, bloodbrain barrier?
Bones: Skull protects the brain. Vertebrae protect the spinal cord.
Meninges: Connective tissues that are wrapped around the brain and the spinal cord.
Dura meninges: outermost, most fibrous, double layered, closest
to the skull.
Arachnoid: middle tissue.
Pia: very fine, attached very closely to brain tissue and is difficult
to separate the two.
Cerebrospinal fluid: cushioning fluid, filtrates from the blood, but doesn’t have blood cells or the
same amount of protein as blood. It is produced by structures in the arachnoid area of tissue. It is a
shock absorber so that vibrations of the body do not jar the brain. Also buoys/bags the brain so it
doesn’t collapse on itself. Nourishes the brain and removes waste products. Circulates and is
BloodBrain barrier: a physical barrier to chemicals and certain microorganisms. It has the structure
of the capillaries. The capillaries have very tight walls so that very little can cross from capillary into
brain tissue. Also fairly strong basement membrane that prevents certain molecules from moving to
*certain drugs can’t cross barrier, so need to be manufactured accordingly if meant to
affect nervous system.
What are the structural features of the Cerebral Hemispheres and how are
the left and right connected?
They are connected by the Corpus Callosum, which is a network of nerves that communicate from
side to side.
Left: Language, analytical thought, fine motor control Right: Musical aptitude, intuitive thought, emotional expression
What is the brain stem? What are the structures and what are their
Structure that connects the Brain and the Spinal Cord. It is involved in receiving, processing, and
relaying sensory information and then relaying and processing motor information. It consists of:
Midbrain: contains nuclei that are involved in visual reflexes and auditory information. Contains
gray matter that is involved in the suppression of pain.
Pons: important in relaying information and communicating between the Motor Cortex and
Cerebellum (essential for balance/smooth movements)
Medulla: contains nuclei that are involved in (autonomic functions) respiration, cardiovascular
functions, swallowing, and reflexes.
What are the locations and significance (functionally) of:
The Periaqueductal gray, The Substantia nigra, The Superior and Inferior
colliculi, The middle and Inferior Cerebellar peduncles, The Pyramids and
their discussation, The Medial Lemniscus, The Olivary and Vestibular
Periaqueductal Gray Matter: in the Midbrain. Involved in the suppression of pain. Serves as a link
between the Amygdala and the Autonomic NS.
Substantia Nigra: in the Midbrain. Made of dopaminergic neurons. Their deterioration is said to
lead to Parkinson’s Disease. Controls voluntary movement, produces dopamine (neurotransmitter),
Superior colliculi: In the Midbrain. Contains nuclei (Corpora quadrigemina). Involved in visual
reflexessee input from eye and put out motor information that allows for visual eye movement.
Inferior colliculi: In the Midbrain. Contains Corpora quadrigemina. Involved in relayed auditory
information from the inner ear to the cerebrum.
Middle Cerebellar Peduncles: in the Medulla.
Inferior Cerebellar Peduncles: in the Medulla. They connect the Medulla and Cerebellum
(dorsally/on the back).
Pyramids: In the Medulla. Consists of nerve tracts that carry information both down from the motor
cortex and the cerebellum to the muscles.
Discussation of pyramids: where the nerve fibers cross (why the right side of the brain controls the
left side of body)
Medial Lemniscus: in the Medulla. Fiber tracts (bundles of neurons) that bring up input from
general sensory areas (like skin; not eyes, ears…)
Olivary Nuclei: in the Medulla. Maintain balance by relaying sensory information from the stretch
receptors to cerebellum.
Vestibular Nuclei: Relay auditory and balance information from inner ear to cerebellum (to maintain
equilibrium). What are some of the structural and functional characteristics of the
cerebellum? What would be one of the major functions affected by
Motor control, paying attention, language, regulating fear and language responses.
What are the important functions of the Thalamus and Hypothalamus?
Both involved in emotional interpretation of sensory reception.
Thalamus: directs sensory input to correct place in cerebral cortex.
Hypothalamus: regulates hormones and body temp, etc. (if thirsty)
What are the various brain (cerebral cortex) regions and what are some of
the functions that are associated with each?
Prefrontal Cortex: Complex learning and intellect. Production of abstract ideas. Discernment,
reasoning, planning, concern for others, conscience. Mood and emotions (linked to limbic system).
*Meditators have thick areas of this region.
Frontal Lobe: Motor control. Contains Broca’s area – translation of thought to speech.
Parietal/Posterior Lobe: General sensory. Gustation (taste).
Temporal/Lateral Lobe: Auditory. Olfaction (smell) on the medial side of the uncus.
Insula: Visceral sensory (digestive system/internal body) and V