Transcript BCH 450 Nervous Tissues

BCH 450
Specialized
Tissues(Nervous Tissue)
Dr. Samina Hyder Haq
Dept of Biochemistry
King saud university
Nervous Tissue is one of 4 major Class
of Tissue
CNS: Consist of Brain, spinal cord
PNS: Peripheral nervous system consist of cranial
and spinal nerves contain both motor and sensory
neurons. It connect CNS to muscles, glands and
all sensory receptors
Major Structures of the Nervous System

Brain, cranial nerves, spinal cord, spinal nerves,
ganglia, enteric plexuses and sensory receptors
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Organization of the Nervous System
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CNS is brain and spinal cord
PNS is everything else
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Subdivision of PNS
SNS:Somatic(Voluntary) system
Neurons from cutaneus regions
Motor neurons to skeleta system
 ANS: autonomic(Involuntary) Nervous system
Sensory Neurons from visceral organs
Motor Neurons to smooth and Cardiac muscles.
Sympathetic( speeds up heart rate)
Parasympathetic (slows down heart rate)
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ENS: Enteric nervous system(Involuntry neurons
to GI
Parts of Human Brain
The brain of all vertebrates develops from three
swellings at the anterior end of the neural canal of
the embryo. From front to back these develop into
the
forebrain (also known as the prosencephalon)
midbrain (mesencephalon)
hindbrain (rhombencephalon)
The brain receives nerve impulses from
the spinal cord and
12 pairs of cranial nerves
Forebrain
Cerebral Hemisphere
Largest part of the human brain.
Controls thinking, speech, vision,
hearing and all voluntary acts
Mid Brain mesencephalon
occupies only a small region in humans (it is
relatively much larger in "lower"
vertebrates
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Controls balance and muscle coordination
Hind Brain
The main structures of the hindbrain are
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medulla oblongata Controls all involuntary acts
(breathing, heart beat, digestion, reflexes)
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pons (The pons seems to serve as a relay station
carrying signals from various parts of the
cerebral cortex to the cerebellum
cerebellum Its most clearly-understood function
is to coordinate body movements. So the
cerebellum appears to be a center for learning
motor skills.
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Parts of Brain
Grey matter and white matter
Both the spinal cord and the brain consist of
 white matter = bundles of axons each coated with
a sheath of myelin
 gray matter = masses of the cell bodies and
dendrites — each covered with synapses
The Meninges
Both the spinal cord and brain are covered in three continuous
sheets of connective tissue, the meninges. From outside in,
these are the
 dura mater — pressed against the bony surface of the
interior of the vertebrae and the cranium
 the arachnoid
 the pia mater
 The region between the arachnoid and pia mater is filled
with cerebrospinal fluid (CSF). The fluid that leaves the capillaries in
the brain contains far less protein than "normal" because of the blood-brain barrier, a
system of tight junctions between the endothelial cells of the capillaries. This barrier creates
problems in medicine as it prevents many therapeutic drugs from reaching the brain.
Nervous system
Cells of the Nervous system
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Neurons
Neuroglial cells have
4 cell types in CNS
 Atrocytes.oligodentrocytes,microglia and
ependymal
2. 2 cell types in PNS that is Schwann and
satellite cells
1.
Neurons
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Functional unit of Nervous system
Have capacity to produce Action potential
Cell Body containing large Nucleus and
Nuclelous, neurofilament and neurotubules.
Contain RER and free ribosomes called Nissl
bodies.
Types of neurons
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Functional Classification: Sensory. Motor and
unipolar
inter-neurons
Bipolar
Structural classification:
Multipolar
Astrocytes
Star shaped cells
 Form Blood brain
Barrier by covering blood capillaries
 Metabolize neurotransmitter
 Regulates K+ balance
 Provide structural support.
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