Transcript Biol 203 Lab Week 10 Nervous System Histology

Lab 9
The Nervous System:
Histology and The Brain
Objective 1
Neuron Structure
Main parts of a neuron
Dendrites (receive)  Cell Body (process)  Axon (send)  Axon Terminals (transfer)
Multipolar Neuron model
Axon
Terminals
Dendrites
(receptive
regions)
Cell body
(biosynthetic center
and receptive region)
Neuron
cell
body
Nissl bodies
(rough ER)
Dendrite
Neurofibrils
Nucleus
Nucleolus
Axon
(impulse generating
and conducting region)
Impulse
direction
Axon hillock
Impulse
direction
Axon
Neurilemma
(sheath of Schwann)
Schwann cell
(one internode)
Node of Ranvier
Impulse
direction
Terminal branches
(Telodendria)
Axon terminals
(secretory component)
What you need to draw and label
Cell Body
Spinal Cord Smear – Motor Neuron
Schwann cells - supporting cells of the PNS that myelinate axons.
• Myelin sheath – whitish lipoprotein that surrounds and insulates
the axon (nerve fiber)
• Neurilemma - external layer containing bulk of cytoplasm with
nucleus and organelles
Schwann cell
myelin sheath
nucleus
axon
neurilemma
Node of
Ranvier
Nodes of Ranvier - Gaps between successive Schwann cells along
the length of the axon
What you need to draw and label
Axon
Node of
Ranvier
Neurilemma
Objective 2
Neuron Classification
Objective 2
Neuron Classification
Pseudounipolar:
-
a short process emerges from the cell body and divides
into proximal and distal branches
-
most sensory neurons
soma
Distal process (toward periphery)
Proximal process (toward CNS)
Pseudounipolar Cell Bodies in the Dorsal Root
ganglion of a Spinal Nerve
Centrally located nuclei
Dorsal Root
Ganglion
Spinal
Cord
Pseudounipolar cell bodies
Bipolar neuron
Human retina
-a single axon and a single
dendrite attached to opposite sides
of the cell body
-found in special sense organs
(eye, ear, etc.)
Bipolar
neurons
Bipolar neurons in the human retina
Bipolar
neurons
Multipolar:
-
multiple dendrites and a single axon
-
includes most neurons; all motor neurons
and most CNS neurons
Purkinje cell of the
Cerebellum
Neuron from the
cerebral cortex
Pyramidal cell of
the hippocampus
Multipolar neurons have diverse morphologies
Silver Stained Neuron In Gray Matter
Spinal Cord - Anterior Horn
Multipolar neurons
Multipolar neurons you will be drawing
Pyramidal cell
Purkinje cell
Pyramidal cell
(Low Power – Cerebrum)
Purkinje cell
(Low Power - Cerebellum)
Objective 3
Nerves
Nerves are structures of the PNS that
consist of axons and dendrites bundled
together by connective tissues
Fascicle: a bundle of axons or dendrites
Epineurium: tough, fibrous connective
tissue sheath surrounding
a nerve
Perineurium: loose, areolar connective
tissue sheath surrounding
fascicles
Endoneurium: delicate connective tissue
wrapping around each nerve
fiber
a = epineurium
b= perineurium
perineurium
endoneurium
axon
LAB ACTIVITY
Draw and label the components of the nerve cross section
Nervous System
The Brain
H
u
m
a
n
B
r
a
i
n
Sheep
Brain
OBJECTIVES
• Identify the components of the
human brain using models and
diagrams
• Identify the structures of the
sheep brain
Objective 4:
Anatomy of the human brain
Cerebrum
(gold area)
Diencephalon
(Violet area)
Brain stem
(green area)
Cerebellum
(pink area)
Cerebrum
Structures of the Cerebrum
Cerebral Hemispheres
Left Hemisphere
Right Hemisphere
Fissure
Gyrus
Sulcus
Frontal cut
Gray Matter – Cerebral cortex & Basal nuclei
White Matter – Myelinated fiber tracts (axons)
Ventricles
Structures of the Cerebrum
Human Brain, Lateral View
Central
sulcus
Parieto-occipital
Sulcus
Gyrus
Parietal
lobe
Occipital
lobe
Transverse
Fissure
Frontal
lobe
Temporal
lobe
Lateral
sulcus
Structures of the Cerebrum
Human Brain, Superior View
Postcentral
gyrus
Longitudinal
fissure
Occipital
pole
Central sulcus
Precentral
gyrus
Frontal
pole
Midsagittal Section of Human Brain
Corpus
Callosum
Frontal
lobe
Parietal
lobe
Fornix
Septum
pellucidum
Occipital
lobe
Internal Structures of the Cerebrum
Frontal Section
Longitudinal fissure
Corpus
callosum
Septum
pellucidum
Lateral
Ventricles
Fornix
Diencephalon
Functions of the Diencephalon
Endocrine System
Relay Stations
Thalamus
Structures of & related to the Diencephalon
Midsagittal Section
Pineal
body/ gland
Intermediate
mass
Hypothalamus
Mammillary body
Hypothalamus
Infundibulum
Pituitary gland
Sella Turcica
Brainstem
Midbrain:
Corpora quadrigemina
Superior colliculi
Inferior colliculi
Cerebral peduncle
Pons
Medulla
oblongata
Spinal
cord
Brainstem
Posterior
Pineal
body/ gland
Corpora
quadrigemina
Superior
colliculus
Inferior
colliculus
Structures of the Brainstem
Inferior View
Optic chiasma
Infundibulum
Mammilary Bodies
Midbrain
(Cerebral peduncle)
Pons
Medulla
oblongata
Spinal
cord
Cerebellum
“Little Brain”
Structures of the Cerebellum
Midsagittal Section
Cerebellar Peduncles
Fourth
ventricle
Arbor
Vitae
Meninges of the Brain
Meninges of the Brain
A mnemonic
PAD from deep to superficial the layers of the meninges
are pia, arachnoid, dura (they pad the brain)
Ventricles of the Brain
Third
Ventricle
Cerebral
Aqueduct
Fourth
Ventricle
The spaces within the brain through which
cerebrospinal fluid flows
Cerebrospinal fluid is continually produced by the
choroid plexus found in the ventricles
Die-cast model
Objective 5:
Sheep Brain Dissection
Identify the
external structures
Inferior
Sheep brain structures are
the same as the human brain,
only slightly different sizes
Remove Dura mater (w/ pituitary gland)
Identify the external structures
Superior
Identify the external structures
Inferior
Pull back the cerebellum to reveal
Corpora Quadrigemina & Pineal Gland
Make a midsagittal cut through the brain
Identify the internal structures
Midsagittal
Identify the internal structures
Midsagittal
Lateral Ventricle
Fourth Ventricle
Cerebral Aqueduct
Third Ventricle