8.3 The brain Flashcards
Cerebral hemisphere
The forebrain is divided
into a right and a left cerebral hemisphere. Each
cerebral hemisphere consists of four lobes: the
frontal, parietal, occipital and temporal lobes,
which are responsible for interpreting different
sensory inputs. The two cerebral hemispheres
are linked to each other by a band of nerve cell
axons called the corpus callosum.
Grey matter
Grey matter describes any area of
the central nervous system that consists mainly
of nerve cell bodies, synapses and dendrites. It
contrasts with white matter, which consists
mainly of axons. The myelin sheath surrounding
many axons gives tissue containing these
structures its characteristic white colour.
Frontal lobe
One of the four regions into which
the cerebral hemispheres of the brain are
divided. The frontal lobe is concerned with
processes such as decision making, reasoning
and planning. It is also concerned with forming
associations and with ideas.
Parietal lobe
One of the four regions into which
the cerebral hemispheres of the brain are
divided. The parietal lobe is concerned with
orientation and movement as well as some types
of recognition and memory.
Occipital lobe
One of the four regions into which
the cerebral hemispheres of the brain are
divided. The occipital lobe is concerned with
processing information from the eyes.
Temporal lobe
One of the four regions into
which the cerebral hemispheres of the brain are
divided. The temporal lobe is concerned with
processing auditory information. This is
information about hearing, sound recognition
and speech. It is also involved with memory.
White matter
White matter describes any area of
the central nervous system which consists
mainly of axons. The myelin sheath surrounding
many axons gives tissue containing these
structures its characteristic white colour. It
contrasts with grey matter which consists of
nerve cell bodies, synapses and dendrites.
Thalamus
Part of the brain which acts as a relay
station for incoming sensory information,
passing it on to the appropriate part of the brain
where it will be processed.
Cerebellum
Part of the hindbrain which is
responsible for posture and balance. It also
coordinates movement as it is being carried out.
Hypothalamus
A part of the brain responsible
for monitoring and helping to regulate a number
of physiological states including temperature,
thirst and hunger.
Hippocampus
A region of the brain involved in
laying down long-term memory.
Basal ganglia
A group of neurones within each
cerebral hemisphere of the brain responsible
for selecting and initiating stored programmes
for movement.
Medulla oblongata
Part of the hindbrain or brain
stem which is responsible for controlling body
processes that we do not consciously have to
control. These include heart rate, breathing and
blood pressure.
Pituitary gland
An endocrine gland situated at
the base of brain. It releases a number of
hormones. These include growth hormone,
follicle stimulating hormone and antidiuretic
hormone.
Corpus callosum
white matter composed mainly of axons, whose white myelin sheaths give it its characteristic appearance. It provides connections between the cortex and the brain structures. It also forms connections between the two hemispheres of the cortex.
Midbrain
relays information to the cerebral hemispheres, including auditory information to the temporal lobe and visual information the the occipital lobe
Neural plasticity
The ability of nerve cells to
change in structure and function. Because of
neural plasticity, some patients are able to
recover their ability after a stroke.
CT, CAT scan, Computerised Axial
Tomography
CAT scans use large numbers of
narrow beam X-rays which are rotated around a
patient to pass through tissue at different angles.
Each beam is reduced in strength according to
the density of the tissue through which it passes.
The X-rays are then detected and used to
produce an image of the tissue on a computer
screen.
Magnetic Resonance Imaging, MRI
A method
of imaging soft tissues using a magnetic field
and radio waves. The technique produces an
image of thin slices through a tissue from which
a computer can produce a 3D image.
Functional Magnetic Resonance Imaging, fMRI
A method of obtaining information about brain
activity. It depends on using radio waves to
determine oxygen uptake by distinguishing
between haemoglobin and oxyhaemoglobin.
This enables active areas of the brain to be
identified and associated with the performance
of particular tasks such as those involving
memory, language and emotion.
