Lecture 4: nervous tissue and digestive system
Able to recognize and name different types of nervous tissue and neural cells
Able to explain the relation between shape and function of different cell types of nervous tissue
Able to explain the mechanism of synaptic communication
Able to name the characteristics and functions of different types of glia cells
Derived from ectoderm
Central nervous system
– Brain
– Spinal cord
Peripheral nervous system: the rest,
e.g. in limbs, gut, etc
Afferent system (sensory information)
Efferent system (motor commands)
Neurons have many different morphologies,
more complex morphology, more complex
function/ more info needs to be processed.
Neuronal Neurons communicate:
communication With chemical messengers via synapses: Chemical messengers (neurotransmitters)
– Acetylcholine
– Amino acids (glutamate, GABA (gamma-Aminobutyric acid))
– Biogenic amines (serotonin, dopamine, adrenaline)
These substances are in de axons (presynaptic) in vesicles and released after an
electric stimulus via exocytose
Results in activation of neurotransmitter receptors on the postsynaptic membrane
Via gap junctions (electrical synapses)
Skeletal muscle
, innervation: the
neuromuscular
junction
Glial cells in the
nervous system
Glial cell are
present in high
diversity in the
brain. They are
about equal
numbers of glia
as neuronal
cells.
Ependymal cells:
are not epithelial
cells
Schwann cells • Unsheathe axons in the PNS
• Make the myelin sheath (plasma membrane), which enhances conduction velocity of
Myeline = white action potentials in axons
• Nodes of Ranvier: for saltatory conduction (spaces between myelin sheaths.
Schematic Representation of the reflex-
representation of arc: sensory information (e.g.
the peripheral heat) is from the skin
nerve transferred via sensory
axons to neurons in the
Connective dorsal root ganglia. There,
tissue: the neurons conduct the
endoneurium, signal to motor neurons, that
perineurium, on their turn conduct the
epineurium. signal via their axons to the
muscle. As a consequence,
Axon not pars of the muscle contracts.
Schwann cell.
There are two types of
Schwann cells: 1)
Myelinating Schwann cells;
these interact with 1 large
axon, and synthesize a myelin membrane around it,
2) nonmyelinating Schwann cells; these interacts
with a number of small axons, ensheath those, but
do not synthesize myelin around it.
Able to recognize and name different types of nervous tissue and neural cells
Able to explain the relation between shape and function of different cell types of nervous tissue
Able to explain the mechanism of synaptic communication
Able to name the characteristics and functions of different types of glia cells
Derived from ectoderm
Central nervous system
– Brain
– Spinal cord
Peripheral nervous system: the rest,
e.g. in limbs, gut, etc
Afferent system (sensory information)
Efferent system (motor commands)
Neurons have many different morphologies,
more complex morphology, more complex
function/ more info needs to be processed.
Neuronal Neurons communicate:
communication With chemical messengers via synapses: Chemical messengers (neurotransmitters)
– Acetylcholine
– Amino acids (glutamate, GABA (gamma-Aminobutyric acid))
– Biogenic amines (serotonin, dopamine, adrenaline)
These substances are in de axons (presynaptic) in vesicles and released after an
electric stimulus via exocytose
Results in activation of neurotransmitter receptors on the postsynaptic membrane
Via gap junctions (electrical synapses)
Skeletal muscle
, innervation: the
neuromuscular
junction
Glial cells in the
nervous system
Glial cell are
present in high
diversity in the
brain. They are
about equal
numbers of glia
as neuronal
cells.
Ependymal cells:
are not epithelial
cells
Schwann cells • Unsheathe axons in the PNS
• Make the myelin sheath (plasma membrane), which enhances conduction velocity of
Myeline = white action potentials in axons
• Nodes of Ranvier: for saltatory conduction (spaces between myelin sheaths.
Schematic Representation of the reflex-
representation of arc: sensory information (e.g.
the peripheral heat) is from the skin
nerve transferred via sensory
axons to neurons in the
Connective dorsal root ganglia. There,
tissue: the neurons conduct the
endoneurium, signal to motor neurons, that
perineurium, on their turn conduct the
epineurium. signal via their axons to the
muscle. As a consequence,
Axon not pars of the muscle contracts.
Schwann cell.
There are two types of
Schwann cells: 1)
Myelinating Schwann cells;
these interact with 1 large
axon, and synthesize a myelin membrane around it,
2) nonmyelinating Schwann cells; these interacts
with a number of small axons, ensheath those, but
do not synthesize myelin around it.
