Transcript Unit #1 Case Studies Degenerative Diseases of The

Unit #1 Case Studies
Diseases of The Central &
Peripheral Nervous Systems
ANATOMY & PHYSIOLOGY 2013-2014
The Nervous System
• The nervous system is the part of an animal’s body
that coordinates voluntary and involuntary actions of
the animal and transmits signals between the
different parts of its body.
Central v. Peripheral Divisions
Central (CNS)
o Form: Brain, Spinal Cord, Optic
Nerve
o Form: Protected by bone and/or
blood-brain barrier
o Function: Integrates messages
received from extremities, sensory
organs and internal organs
Peripheral (PNS):
 Form: Nerves and Ganglia outside of CNS.
Includes 10 of 12 cranial nerves
 Form: Not protected by bone or bloodbrain barrier
 Function: Relays messages between CNS
and extremities.
Autonomic v. Somatic Divisions of PNS
• Autonomic Divison (ANS)
o Function: Involuntary control
over heart rate, breathing,
perspiration, salivation,
pupillary dilation and digestion
o Form: Afferent (sensory) &
Efferent (motor) neurons
o Subdivided in Sympathetic and
Parasympathetic Divisions
• Somatic Division (SoNS)
 Function: Voluntary control of body
via efferent motor neurons
 SoNS also encompasses reflex arcs,
which do NOT travel to brain but
instead rely on association neurons
 Form: Comprised of three types of
nerves
 Spinal
 Cranial
 Association
Somatic Division (SoNS)
• The SoNS is responsible for controlling voluntary
movements, using efferent (motor) neurons, and
reflex arcs, using association (inter-) neurons.
• Three types of nerves:
• Spinal: Innervate much of the body, and connect through
the spinal column to the spinal cord. (letter-number
designations according to the vertebra through which they
connect to the spinal column)
• Cranial: Innervate the head, and connect directly to the
brain (especially the brainstem). (Roman Numerals 1-12 +
descriptive names).
• Association: Connects other neurons (not “projection”
neurons)
Somatic Reflex Arcs
• A reflex arc is a neural pathway that controls action
reflexes (ex: patellar reaction) by synapsing in the
spinal cord (not the brain).
• This allows for faster response time. Sensory
information is still relayed to your brain, as the reflex
action
occurs.
Autonomic Division (ANS)
• The ANS is responsible for controlling involuntary
movements, such as heart rate, breathing,
perspiration, salivation, pupillary dilation, and
digestion.
• It is composed of afferent (sensory) and efferent
(motor) neurons.
• The ANS is further subdivided two divisions:
• The Sympathetic Division (“Fight or Flight”)
• The Parasympathetic Division (“Feed & Breed”)
Sympathetic and Parasympathetic Divisions of the ANS
• Sympathetic (Fight or Flight)
• Elevates blood pressure via
vasoconstriction
• Increases respiratory volume via
dilation of bronchioles
• Inhibition of peristalsis
• Dilation of pupil
• Parasympathetic (Feed & Breed)
• Decreased blood pressure via
vasodilation
• Decreased respiratory rate
• Increased digestion, urination and
defecation
Parasympathetic Shock?
Lower Sodium Conductance
Botox
• Protein derived from Clostridium botulinum bacteria
• Prevents the release of acetylcholine (ACH), the neurotransmitter
than stimulates the contraction of skeletal muscle at the synapse
• By preventing contraction of the pretarsal, preseptal and orbital
muscles of the face, glabellar lines do not form
Five Major Diseases of the CNS & PNS
• Amyolateral Sclerosis (ALS)
• Multiple Sclerosis (MS)
• Muscular Dystrophy (MD)
• Parkinson’s Disease (PD)
• Tay-Sachs Disease
• All show similar physical manifestations.
• All have very different causes and treatments