Brain and behavior
Chapter 2: What is the nervous system’s functional anatomy? This chapter concerns structure and function of the brain
Gyrus (γύρος ≈ round, curve): bumps
Sulcus: cracks. Some of them
are so deep that they are
called fissures
Although the brain has structure, that does not imply that the brain is a static organ, or that we are born with a brain that remains
unchanged for the rest of our lives.
Flexibility – neural plasticity
The brain is plastic: neural tissue has the capacity to adapt to the world by changing how its functions are organized. Ability to
compensate for injury. This characteristic is part of a larger biological capacity called phenotypic plasticity: the individual’s capacity to
develop more than one phenotype. Epigenetic factors do not change genes but rather influence how genes express specific traits.
Phylogenetic development of structure
Key functions of the brain (overly simplified):
1. perception (sensing)
2. integration of information (create a perceptual world)
3. action (behavior)
Neuroanatomy and spatial orientation
,
,The brain is vulnerable, so it is well packed
Meninges: 3 layers of protective tissue that encase the brain
and spinal cord.
1. Dura mater: double layer of fibrous tissue that
encloses the brain and spinal cord in a kind of loose
sac
2. Arachnoid layer: ultrathin sheet of delicate
connective tissue that follows the brain’s contours
3. Pia mater, inner layer, is a moderately tough
membrane of connective tissue fibers that cling the
brain’s surface.
The brain from the outside
The outer forebrain consists of a thin, folded film of nerve tissue, the cerebral cortex
Components:
Cerebrum
Cerebellum
Brain stem
(Too) general principle: The higher a structure is located physically in the brain, the ‘higher’ its function
Blood supply of the brain
Cerebral circulation
The brain’s surface appears to be covered with blood vessels. As with the rest of the body, the arteries feed blood to the brain and
send it back thorugh veins to the kidneys and lungs for cleaning and oxygenation.
Three major arteries that send blood to the cerebrum:
, A blockage or break in the cerebral artery (stroke) is likely to lead to death of the affected region. Because the brain’s connection are
crossed, stroke in the left hemisphere affects sensation and movement on the right side of the body.
Inside the brain
White matter: nerve fibers, mostly with fatty coverings that produce the white appearance (insulating layer). White matter fibers
form connections between and among the brain’s vells.
Grey matter: nerve cells (no insulating layer). Largely composed by cell bodies and capillary blood vessels. Gray matter neurons
either collect and modify information or support this activity.
Reticular matter: net-shaped (fibers and cells)
Ventricle system – cerebrospinal fluid
Ventricles: 2 wing shaped cavities that contain cerebrospinal fluid. All 4 are connected. Their function is not well understood, but
researchers think they play a role in maintaining brain metabolism.
with a vertical cut (above) we produce a sagittal section where we can see the corpus callosum, containing nerves that connect the 2
hemispheres and allow them to communicate
The brain has 2 of nearly every structure. an only structure is for example the pineal gland.
Microscopic inspection: Cells and fibers
Chapter 2: What is the nervous system’s functional anatomy? This chapter concerns structure and function of the brain
Gyrus (γύρος ≈ round, curve): bumps
Sulcus: cracks. Some of them
are so deep that they are
called fissures
Although the brain has structure, that does not imply that the brain is a static organ, or that we are born with a brain that remains
unchanged for the rest of our lives.
Flexibility – neural plasticity
The brain is plastic: neural tissue has the capacity to adapt to the world by changing how its functions are organized. Ability to
compensate for injury. This characteristic is part of a larger biological capacity called phenotypic plasticity: the individual’s capacity to
develop more than one phenotype. Epigenetic factors do not change genes but rather influence how genes express specific traits.
Phylogenetic development of structure
Key functions of the brain (overly simplified):
1. perception (sensing)
2. integration of information (create a perceptual world)
3. action (behavior)
Neuroanatomy and spatial orientation
,
,The brain is vulnerable, so it is well packed
Meninges: 3 layers of protective tissue that encase the brain
and spinal cord.
1. Dura mater: double layer of fibrous tissue that
encloses the brain and spinal cord in a kind of loose
sac
2. Arachnoid layer: ultrathin sheet of delicate
connective tissue that follows the brain’s contours
3. Pia mater, inner layer, is a moderately tough
membrane of connective tissue fibers that cling the
brain’s surface.
The brain from the outside
The outer forebrain consists of a thin, folded film of nerve tissue, the cerebral cortex
Components:
Cerebrum
Cerebellum
Brain stem
(Too) general principle: The higher a structure is located physically in the brain, the ‘higher’ its function
Blood supply of the brain
Cerebral circulation
The brain’s surface appears to be covered with blood vessels. As with the rest of the body, the arteries feed blood to the brain and
send it back thorugh veins to the kidneys and lungs for cleaning and oxygenation.
Three major arteries that send blood to the cerebrum:
, A blockage or break in the cerebral artery (stroke) is likely to lead to death of the affected region. Because the brain’s connection are
crossed, stroke in the left hemisphere affects sensation and movement on the right side of the body.
Inside the brain
White matter: nerve fibers, mostly with fatty coverings that produce the white appearance (insulating layer). White matter fibers
form connections between and among the brain’s vells.
Grey matter: nerve cells (no insulating layer). Largely composed by cell bodies and capillary blood vessels. Gray matter neurons
either collect and modify information or support this activity.
Reticular matter: net-shaped (fibers and cells)
Ventricle system – cerebrospinal fluid
Ventricles: 2 wing shaped cavities that contain cerebrospinal fluid. All 4 are connected. Their function is not well understood, but
researchers think they play a role in maintaining brain metabolism.
with a vertical cut (above) we produce a sagittal section where we can see the corpus callosum, containing nerves that connect the 2
hemispheres and allow them to communicate
The brain has 2 of nearly every structure. an only structure is for example the pineal gland.
Microscopic inspection: Cells and fibers
