Transcript The Big Picture File

THE BIG PICTURE:
THE ORGANISATION OF THE
NERVOUS SYSTEM
Pedro Amarante Andrade, PhD
LCSC06
BIOSCIENCES
FOR SPEECH AND LANGUAGE THERAPY
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DISORDERS AFFECTING NERVES,
MUSCLE CELLS AND THE FUNCTION
OF THE NEUROMUSCULAR JUNCTION
•
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•
•
•
•
Multiple Sclerosis
Motor neurone disease
Myasthenia gravis
Muscular dystrophies
Guillain-Barre´ syndrome
Parkinson’s disease
Alzheimer’s disease
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CNS
GREY VS WHITE MATTER
PNS
Grey
matter
White
matter
Cerebromente.org.uk.
Histology.leeds.ac.uk
(From Patton K, Thibodeau G:
Anatomy and physiology,
ed 7, St Louis, 2010, Mosby.)
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GREY VS WHITE MATTER
CNS
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GREY VS WHITE MATTER
Multiple Sclerosis
M.S.
Radiology Assistant
http://www.radiologyassistant.nl/en/p4556dea65db
62/multiple-sclerosis.html
MedicineNet.com
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WHITE MATTER
PATHWAYS
• Consist of bundles of axons
• Connect different parts of the CNS together
• Go by a number of names:
Tracts
Fasciculi
Peduncles
Lemniscus
Capsule
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GRAY MATTER
GANGLIA AND NUCLEI
Cell bodies grouped together are mainly called:
NUCLEI
GANGLIA
Central Nervous
System
Peripheral Nervous
System
One exception in CNS  BASAL GANGLIA
Wikicommons. Author: Leevanjackson
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ANATOMICAL AND FUNCTIONAL
DIVISIONS OF THE NERVOUS SYSTEM
Central Nervous System
CNS
Peripheral Nervous System
PNS
Sensory
Division
Brain
Somatic
Spinal
Cord
Autonomic
(visceral)
Motor
Division
Somatic
Autonomic (visceral)
Sympathetic
Division
Parasympathetic
Division
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ANATOMICAL AND FUNCTIONAL
DIVISIONS OF THE NERVOUS SYSTEM
Anatomically:
• Central nervous system:
• Brain and spinal cord
• Peripheral nervous system:
• Cranial nerves
• Spinal nerves
Functionally:
• Somatic
• Motor and sensory
• Autonomic
• General visceral sensory (afferent)
• General visceral motor (efferent)
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ANATOMICAL DIVISIONS OF THE
NERVOUS SYSTEM
http://lensoftheeye.ga/
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THE PERIPHERAL NERVOUS
SYSTEM (PNS)
Consists of cranial and spinal nerves - connected to
the central nervous system
12 pairs of cranial nerves arising from the base of the
brain (I, II, III, IV… XII)
31 pairs of spinal nerves, numbered according to the
level of the spinal cord from which it arises
Cranial and spinal nerves form a network that covers all
parts of the body
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CRANIAL NERVES
Wikicommons. Brain human normal inferior view.
Author: Patrick J. Lynch
Wikicommons.
Public Domain.
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CRANIAL NERVES
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SPINAL NERVES
 Each SN is attached to the
spinal cord by two roots
 Dorsal root provides the
input for sensory nerves.
 Ventral root provides the
output for motor nerves
supplying glands and
muscles.
 In some places the nerve
branches interlace to form
nerve plexuses.
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TRANSVERSE SECTION OF
THE SPINAL CORD
Netter, 2006, plate 169.
https://ittcs.wordpress.com/2010/04/04/notes-on-anatomy-and-physiology-howthe-nervous-system-is-designed-for-movement/
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TRANSVERSE SECTION OF
THE SPINAL CORD
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SOMATIC NERVOUS SYSTEM
Somatic motor
efferent nerves
leave CNS and carry
info to striated
voluntary muscles
• Motor aspects are under our conscious
and voluntary control
• CNS control of somatic muscles: arises in
pre-central region of the cortex
• Then via cranial nerves and spinal nerves
to all skeletal muscles
Somatic sensory
afferents
• Sensory aspects monitor incoming
information from sensory receptors in skin,
mucosa, muscles, deep organs (viscera).
Travel via thalamus to sensory cortex in
parietal lobe of cortex.
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SOMATIC NERVOUS SYSTEM
• Sensors (receptors): means by which the NS
translates info about the internal and external
environment into a form of information that is
usable by the brain
• Effectors: means by which the body responds
to changing internal and external conditions
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AUTONOMIC NERVOUS SYSTEM
Regulates the activity of smooth muscle, cardiac muscle and
some glands
Operates outside of our conscious control
Is regulated by brain centres: The Hypothalamus and Medulla
Sensory input = general visceral sensory (afferent) neurons
Motor output = general visceral motor (efferent) neurons
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GENERAL VISCERAL SENSORY
AFFERENT (Sensory input)
Receptors inside organs or blood vessels
(called interoreceptors)
Relay information regarding: CO2 levels, stretch
or pressure on organs/blood vessels
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GENERAL VISCERAL MOTOR
EFFERENT (Motor output)
• Regulate visceral activities by either exciting or
inhibiting
• The effector tissues are cardiac muscle, smooth
muscle, and glands.
• These activities lie beyond conscious control
• This output part has 2 divisions: the sympathetic
and parasympathetic nervous systems
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SYMPATHETIC AND PARASYMPATHETIC
NERVOUS SYSTEMS
• The autonomic nervous system controls bodily
functions that are beyond our conscious
control
• The efferent portions are divided into the
sympathetic and parasympathetic divisions
• Some organs receive input from both parts of
the Autonomic Nervous System
• Branches usually act antagonistically but
sometimes work synergistically
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SYMPATHETIC AND PARASYMPATHETIC
NERVOUS SYSTEMS
http://zaccupples.files.wordpress.com/2013/04/autonomic-nervous-system.gif
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ACTIONS OF SYMP. & PARASYMP. NERVES
Organs
SYMPATHETIC
“FIGHT OR FLIGHT”
PARASYMPATHETIC
“REST – RELAXATION”
Pupils
Dilation
Constriction
Heart
Increased rate
Decreased rate
Bronchi of Lungs
Dilation
Constriction
Digestive muscles
Decreased activity
Increase activity
Bladder
Relaxation
Contraction &
emptying
Kidneys
Decrease activity
None
Liver
Increase glucose
release
none
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AUTONOMIC PATHWAYS
The actions of the sympathetic and
parasympathetic divisions are usually antagonistic
in any tissue that is supplied by both divisions (i.e.
one division stimulates whilst the other inhibits)
Example: Heart
• sympathetic activity __________
accelerates heart rate and
slow heart rate.
• parasympathetic activity ______
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TRANSVERSE SECTION OF
THE SPINAL CORD
Antranik.org
http://antranik.org/peripheral-nervous-system-spinal-nerves-and-plexuses/
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TRANSVERSE SECTION OF
THE SPINAL CORD
The diagram shows
the arrangement of
sympathetic
neurons and the
involvement of the
sympathetic chain of
ganglia
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SPECIFICITY OF ACTIVITY OF THE
AUTONOMIC NERVOUS SYSTEM
Sympathetic activity is very generalised
Preganglionic n. branch  multiple postganglionic n.
Ganglia at a distance from specific structures
Parasympathetic activity is very discrete
Ganglia lies close to structure
(preganglionic n. make connections with individual
structures)
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PARASYMPATHETIC
PREGANGLIONIC NERVES
• Travel with CN III, VII, IX and X, and the sacral spinal
nerves
• CNs III, VII and IX supply head and neck structures
and sacral supplies pubic organs
(The ‘gap’ in the middle is filled by the wanderer –
the Vagus or CN X)
Travels down thorax and abdomen and supplies
viscera in these regions
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www.med.umich.edu
PARASYMPATHETIC
PREGANGLIONIC NERVES
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PARASYMPATHETIC GANGLIA
Lie in or near
• e.g. the parotid salivary gland
the target organ
synapse with the
post-ganglionic
nerve
• (short and either branch (ramify) or
spread out over the organ, or join a
somatic nerve as it enters the structure
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NEUROTRANSMITTERS FOR THE
SYMP. & PARASYM. SYS.
In both (SS & PS),
acetylcholine acts at the
ganglia and at synapses
between autonomic
nerves and targets
SS also uses
norepinephrine and
epinephrine (noradrenalin
and adrenalin) operates at
four major receptor types,
collectively called
adrenoreceptors
http://pharmacology-notes-free.blogspot.co.uk/2012/01/neurotransmitters-associated-with.html
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N
N
A
A
N
N
M
N = Nicotinic acetylcholine receptor; M= Muscarinic Ach
receptor; A= unspecified adrenergic receptor
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ACETYLCHOLINE
• A key neurotransmitter in the PNS and also found in
the CNS
• Drugs to treat a number of the conditions which we
are interested in as SLT have their action on Ach
• If they reduce the action of Ach they are called
anticholinergics (PD, Chron. Pulm. Obstruc. Dise.)
PD = inhibit tremor; CPOD = inhibit muscles spasm/contraction
• If they prevent the breakdown of Ach they are called
cholinesterase inhibitors (Mya. Gra., Alz.D)
e.g.Donezipyl hydrochloride (Aricept); Galantamine/Rivastimine (Reminyl)
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THE BRAIN
http://futurism.com/scientists-take-big-step-toward-using-light-instead-wires-inside-computers/
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THE BRAIN
http://science.nationalgeographic.com/science/photos/brain/
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THE BRAIN
General anatomy
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THE BRAIN
General
anatomy
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LISSENCEPHALY
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THE BRAIN VIEWED FROM THE LEFT SIDE
Question:
why is the left
side of the
brain of such
interest to
SLTs?
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FUNCTIONAL ZONES IN THE
CORTEX
http://www.sofiatopia.org/equiaeon/ibrain12.jpg
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MENINGES
http://missinglink.ucsf.edu/lm/ids_104_cns_injury/R
esponse%20_to_Injury/Meninges.htm
www.studyblue.com
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THE DURA MATER
•
•
•
•
Thick, durable membrane, closest to the skull.
composed of dense fibrous tissue
made up of 2 tightly bound layers.
surrounds and supports the large venous
channels (dural sinuses) carrying blood from
the brain toward the heart.
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THE ARACHNOID MATER
• A thin, lacy, spider-like
transparent membrane,
composed of fibrous tissue
• Provides a cushioning effect for
the central nervous system.
• Many blood vessels pass through
it to the brain
• The arachnoid does not follow
the convolutions of the surface
of the brain and so looks like a
loosely fitting sac.
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THE PIA MATER
• A very delicate, thin membrane
• Firmly adheres to the surface of the brain
and spinal cord, following all the minor
contours of the brain (called gyri and sulci)
• The pia is pierced by blood vessels which
travel to the brain and spinal cord, and its
capillaries are responsible for nourishing
the brain
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THE CEREBELLUM
• Balance
• Motor coordination
3 important conditions:
• Bulbar palsy;
• Progressive bulbar palsy;
• Pseudobulbar palsy
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THE VENTRICLES OF THE BRAIN
(a) Lateral view (b) Frontal view
http://justanothersciencenerd.files.wordpress.com/2012/11/ventricles-of-brain.png
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HIPPOCAMPUS
http://www.apsubiology.org/anatomy/2010/2010_
Exam_Reviews/Exam_4_Review/CH_12_Functional_
Areas_of_the_Cerebral_Cortex.htm
Wikicommons
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THE CIRCULATION OF
CEREBROSPINAL FLUID
(a) Pattern of circulation through and
around the brain and spinal cord
(b) Reabsorption of CSF into venous
sinus through arachnoid granulations
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PROSENCEPHALON (Forebrain),
MESENCEPHALON (midbrain) and
RHOMBENCEPHALON (hindbrain)
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www.en.wikipedia.org
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ANATOMICAL
LOCATION
The base of the forebrain, comprising:
• Epithalamus (links limbic system to rest of the
brain)
• Thalamus (Sensory relay) + movement and
emotion
• Hypothalamus “Endocrine engine”
(thermoregulation, appetite, sleep-wake,
autonomic NS)  Pituitary gland  (ACTH, GH,
FSH, LH, TSH, MSH)
• Subthalamus
• Pineal gland
Images: Copyright © 2007 Pearson Education, Inc., publishing as Benjamin
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THE THALAMUS
The thalamus is the final
relay point for ascending
sensory information.
It also plays a major role in
coordinating the activities
of the cerebral cortex,
basal ganglia and
cerebellum
(a) Lateral view of brain from left side
(b) Detail of the various thalamic nuclei
Images: Copyright © 2007 Pearson Education, Inc., publishing as Benjamin
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ANATOMICAL
LOCATION
Images: Copyright © 2007 Pearson Education, Inc., publishing as Benjamin
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THE MESENCEPHALON OR MID-BRAIN
(a) View from above (b) section viewed from anterior surface
Images: Copyright © 2007 Pearson Education, Inc., publishing as Benjamin
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ANATOMICAL
LOCATION
Images: Copyright © 2007 Pearson Education, Inc., publishing as Benjamin
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THE MEDULLA OBLONGATA AND PONS
Images: Copyright © 2007 Pearson Education, Inc., publishing as Benjamin
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THE MEDULLA OBLONGATA AND PONS
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WHAT TO DO NOW:
DIRECTED STUDY
• Read about the embryological origins of the brain, to embed
your understanding of the terms below, and their significance:
• Encephalon
• Prosencephalon
– Telencephalon
• Rhinecephalon
– Diencephalon
• Mesencephalon
• Metencephalon
• Rhombencephalon
https://www.dana.org/uploadedImages/Images/Spotlight_Images/DanaGuid
e_CH05_P065a_spot.jpg
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MAJOR REGIONS OF THE BRAIN AND
THEIR FUNCTIONS
Images: Copyright ©
2007 Pearson Education,
Inc., publishing as
Benjamin
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QUIZ: CHOOSE ONE ANSWER
• Sensory = afferent/efferent
• Motor = afferent/efferent
• Grey matter = cell bodies/axons
• Cranial nerves =12 pairs/31 pairs
• Spinal nerves = 12 pairs/31 pairs
• Cranial nerves = motor/sensory/motor & sensory/all
of the above
• Dorsal root =motor/sensory root
• Ventral root =motor/sensory root
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STUDENT TASK:
• Write short notes on the meninges ie
• The dura mater
• The arachnoid mater
• The pia mater
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SO..YOU ARE GOING INTO THE
BIOSCIENCE EXAM
•
•
•
•
•
Your palms are sticky
Your heart is thumping
Your mouth is dry
Your skin is pale and clammy..
Which division of the nervous system is acting
on your body?
• Which neurotransmitter is at play?
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PARASYMPATHETICOMIMETIC
DRUG…
• What unwelcome effects might such a drug
have?
Excessive saliva production:
Anticholinergic drug
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