Neurobiology
Week 1 The nervous system, a general view
Nervous tissue
Characteristics
- Different types of cells
- Very little extracellular matrix, only around blood vessels.
- Soft tissue
- Cytoskeleton made of intermediate filament provides firmness.
- Specialized cellular connections.
- Function: transmission of signals.
Neurons
The function of neurons is signal transmission.
Morphology
- perikaryon/soma: cellbody.
- Dendrites: Dendrites receive the signals, signals come IN.
- Axon: the neuron receives signals with the dendrite, the signal
proceeds through the axon. The signal goes OUT.
There can be multiple dendrites but only one axon.
The axon hillock: the place where the axon is connected to the
perikaryon.
Glial cells
The function of glial cells is to nourish and support neurons.
The central nervous system (CNS) and peripheral nervous system (PNS) have different
glial cells. Glial cells support the function of the neurons, signal transmission or signal
transduction.
,Central Nervous System (CNS)
- Ependymal cells: Neuronal support cells that form the epithelial lining of the
ventricles (cavities) in the brain and central canal in the spinal cord. These cells
make cerebrospinal fluid (CSF). The cilia of the cells move the CSF in a directional
flow. Bringing nutrients and other substances to the neurons and filtering harmful
molecules. The ventricles containing the CSF can serve as a protective cushion. It
can also take waste material.
- Astrocytes: Cells with many extensions. These extensions are attached to the
neurons (dendrites) They provide nutrition and structural support. Astrocytes are part
of the blood brain barrier (BBB).
- Oligodendrocytes: Glial cells wrapped around the axon. The oligodendrocytes are
the myelinating cells of the CNS. By insulating the axon with the myelin protein signal
transduction is faster. Schwann cells have the same function in the PNS.
- Microglia: The brain immune cells. They are responsible for the elimination of
microbes, dead cells, redundant synapses, protein aggregates, and other particulate
and soluble antigens that may endanger the CNS.
Central and Peripheral nervous system
The central nervous system is the part of the nervous system where signal integration
occurs.
- The brain.
- Spinal cord.
The peripheral nervous system are the sensory and motor neurons that connect to the CNS.
- All the nerves that go to the different body parts.
CNS: The brain
- Gray matter: neuron cell bodies. OUTSIDE.
- White matter: bundled axons. INSIDE.
- Ventricles: cavities with cerebrospinal fluid
CNS: The spinal cord
The spinal cord runs within the spine
- Linking the CNS to the sensory and motor neurons of the PNS. The spinal cord
sends motor commands from the brain to the body and sensory information from the
body to the brain. It also coordinates reflexes.
- Conveys information to and from the brain.
- Generates basic patterns of locomotion. The ability to generate coordinated and
rhythmic movements of the body without direct input from the brain. This relies on the
inherent neural circuits and reflexes present within the spinal cord itself.
,Peripheral nervous system
Afferent neurons to CNS to Efferent neurons!!
Autonomic nervous system
The autonomic nervous system is part of the peripheral nervous system that regulates
involuntary processes including heart rate, blood pressure, respiration, digestion, and sexual
arousal. It can be divided into two divisions.
- Sympathetic division: corresponds
arousal and energy generation:
accelerates heart rate. Triggers fight
or flight. Releases the
neurotransmitter/hormone
norepinephrine.
- Parasympathetic division: Calming
and self maintenance functions. Uses
acetylcholine as a neurotransmitter.
, Regional specialization of the vertebrate brain
- Forebrain: contains olfactory bulb, cerebrum,
diencephalon. Smell, regulation of sleep, learning
complex processing.
- Midbrain: contains part of the brainstem,
coordinates routing of sensory input.
- Hindbrain: contains cerebellum and part of the
brainstem. Controls involuntary activities e.g.:
blood circulation and coordinates motor activities: locomotion
Study the case of Phineas Gage. He had damage in his prefrontal cortex which is
responsible for decision making and temperament. This damage caused him to be
emotionally detached, impatient and erratic.
The cerebrum: part of the forebrain.
- Controls skeletal muscle contraction.
- Centre for learning, emotion, memory and perception.
Corpus callosum is meant for the communication between our brain hemispheres (left
and right part of the brain).The corpus callosum is a large bundle of more than 200 million
myelinated nerve fibers that connect the two brain hemispheres, permitting communication
between the right and left sides of the brain.
Regional specialization of the brain: The limbic system.
The primary limbic system function is to process and regulate emotion and memory while
also dealing with sexual stimulation and learning. Behavior, motivation, long-term memory,
and our sense of smell also relate to the limbic system
Week 1 The nervous system, a general view
Nervous tissue
Characteristics
- Different types of cells
- Very little extracellular matrix, only around blood vessels.
- Soft tissue
- Cytoskeleton made of intermediate filament provides firmness.
- Specialized cellular connections.
- Function: transmission of signals.
Neurons
The function of neurons is signal transmission.
Morphology
- perikaryon/soma: cellbody.
- Dendrites: Dendrites receive the signals, signals come IN.
- Axon: the neuron receives signals with the dendrite, the signal
proceeds through the axon. The signal goes OUT.
There can be multiple dendrites but only one axon.
The axon hillock: the place where the axon is connected to the
perikaryon.
Glial cells
The function of glial cells is to nourish and support neurons.
The central nervous system (CNS) and peripheral nervous system (PNS) have different
glial cells. Glial cells support the function of the neurons, signal transmission or signal
transduction.
,Central Nervous System (CNS)
- Ependymal cells: Neuronal support cells that form the epithelial lining of the
ventricles (cavities) in the brain and central canal in the spinal cord. These cells
make cerebrospinal fluid (CSF). The cilia of the cells move the CSF in a directional
flow. Bringing nutrients and other substances to the neurons and filtering harmful
molecules. The ventricles containing the CSF can serve as a protective cushion. It
can also take waste material.
- Astrocytes: Cells with many extensions. These extensions are attached to the
neurons (dendrites) They provide nutrition and structural support. Astrocytes are part
of the blood brain barrier (BBB).
- Oligodendrocytes: Glial cells wrapped around the axon. The oligodendrocytes are
the myelinating cells of the CNS. By insulating the axon with the myelin protein signal
transduction is faster. Schwann cells have the same function in the PNS.
- Microglia: The brain immune cells. They are responsible for the elimination of
microbes, dead cells, redundant synapses, protein aggregates, and other particulate
and soluble antigens that may endanger the CNS.
Central and Peripheral nervous system
The central nervous system is the part of the nervous system where signal integration
occurs.
- The brain.
- Spinal cord.
The peripheral nervous system are the sensory and motor neurons that connect to the CNS.
- All the nerves that go to the different body parts.
CNS: The brain
- Gray matter: neuron cell bodies. OUTSIDE.
- White matter: bundled axons. INSIDE.
- Ventricles: cavities with cerebrospinal fluid
CNS: The spinal cord
The spinal cord runs within the spine
- Linking the CNS to the sensory and motor neurons of the PNS. The spinal cord
sends motor commands from the brain to the body and sensory information from the
body to the brain. It also coordinates reflexes.
- Conveys information to and from the brain.
- Generates basic patterns of locomotion. The ability to generate coordinated and
rhythmic movements of the body without direct input from the brain. This relies on the
inherent neural circuits and reflexes present within the spinal cord itself.
,Peripheral nervous system
Afferent neurons to CNS to Efferent neurons!!
Autonomic nervous system
The autonomic nervous system is part of the peripheral nervous system that regulates
involuntary processes including heart rate, blood pressure, respiration, digestion, and sexual
arousal. It can be divided into two divisions.
- Sympathetic division: corresponds
arousal and energy generation:
accelerates heart rate. Triggers fight
or flight. Releases the
neurotransmitter/hormone
norepinephrine.
- Parasympathetic division: Calming
and self maintenance functions. Uses
acetylcholine as a neurotransmitter.
, Regional specialization of the vertebrate brain
- Forebrain: contains olfactory bulb, cerebrum,
diencephalon. Smell, regulation of sleep, learning
complex processing.
- Midbrain: contains part of the brainstem,
coordinates routing of sensory input.
- Hindbrain: contains cerebellum and part of the
brainstem. Controls involuntary activities e.g.:
blood circulation and coordinates motor activities: locomotion
Study the case of Phineas Gage. He had damage in his prefrontal cortex which is
responsible for decision making and temperament. This damage caused him to be
emotionally detached, impatient and erratic.
The cerebrum: part of the forebrain.
- Controls skeletal muscle contraction.
- Centre for learning, emotion, memory and perception.
Corpus callosum is meant for the communication between our brain hemispheres (left
and right part of the brain).The corpus callosum is a large bundle of more than 200 million
myelinated nerve fibers that connect the two brain hemispheres, permitting communication
between the right and left sides of the brain.
Regional specialization of the brain: The limbic system.
The primary limbic system function is to process and regulate emotion and memory while
also dealing with sexual stimulation and learning. Behavior, motivation, long-term memory,
and our sense of smell also relate to the limbic system
