Introduction of
neuroanatomy
Syed abdul basit
Mphil anatomy
What is neuro anatomy
• Study of the nervous system
• The nervous system is made up of vast neural networks; signalling
within these circuits enables thinking, language, feeling, learning,
memory, and all function and sensation. It is well-established that
through plasticity of existing cells our nervous systems can adapt to
situations not previously encountered, but it also has been shown
that cells (NSCs) are plastic and involved in creating new connections
in adaptation and response to injury.
The Nervous System has three specific
functions:
• Sensory Input - Sensory receptors present in the skin and organs
respond to external & internal stimuli by generating nerve impulses
that to the central nervous system
• Integration - The brain and spinal cord of the Central Nervous System
combine and sum up all the data received from the body and send
out nerve impulses.
• Motor Output - The nerve impulses from the Central Nervous System
go to the effectors (muscles and glands). Muscle contractions and
gland secretions are responses to stimuli received by sensory
receptors.
The Nervous System is divided into two main
divisions
1.Central Nervous System (CNS)
2.Peripheral Nervous System (PNS)
Cns divided into two parts
brain and spinalcord
• The Brain is divided into four main parts[1]:
• Brain stem, consisting of the medulla, pons, and midbrain
• Cerebellum
• Diencephalon, with the thalamus and hypothalamus
• Cerebral hemispheres (comprised of the cerebral cortex, basal
ganglia, white matter, hippocampi and amygdalae). The right and left
hemisphere are connected by the corpus callosum which facilitates
communication between both sides of the brain. The Hemispheres
are then further divided into four lobes.
NEURONS
• Neurons are cells of the nervous system, located within the grey
matter, and responsible for all neurological functions of the brain.
• They are any of the impulse-conducting cells that constitute the brain,
spinal column, and nerves in vertebrates, consisting of a nucleated
cell body with one or more dendrites and a single axon. See Neurone
link for more detailed information
Neurological conditions
• Neurological Conditions: many neurological conditions affect the CNS.
They range dramatically in scope, impact, and nature of the effect.
Some conditions lead to progressively impaired movement eg
Parkinson disease. Huntington chorea. The demyelination in multiple
sclerosis can cause acute attacks, and over time, chronic degradation
of function. Others may impact cognition such as the various
dementias. Epilepsy can cause uncontrolled excitation. Headaches
often impair the daily function of patients. Traumatic injuries can
cause plegia or paresis and may result a wide range of deficits
depending on the location and extent of the lesion
The cerebrum consists of two cerebral hemispheres, the right and left
hemisphere are connected by the corpus callosum which facilitates
communication between both sides of the brain, with each hemisphere
in the main connection to the contralateral side of the body i.e. the left
hemisphere of the cerebrum receives information from the right side of
the body resulting in motor control of the right side of the body and vice
versa.
The hemispheres are then further divided into four lobes;
Occipital
Parietal
Temporal (medial part of which are a series of structures including the
Hippocampus)
Frontal
Cerebral cortex
• The outer layer of the cerebral hemisphere is termed the cerebral
cortex. This is inter-connected via pathways that run sub-cortically. It
is these connections as well as the connections from the cerebral
cortex to the brainstem, spinal cord and nuclei deep within the
cerebral hemisphere that form the white matter of the cerebral
hemisphere. The deep nuclei include structures such as the basal
ganglia and the thalamus.
Basal ganglia
• The “basal ganglia” refers to a group of subcortical nuclei within the
brain responsible primarily for motor control, as well as other roles
such as motor learning, executive functions, emotional behaviours,
and play an important role in reward and reinforcement, addictive
behaviours and habit formation.
hypothalamus
• The hypothalamus is an organ central to many autonomous functions
of the human body, notably the regulation of homeostasis. It has a
significantly large efferent output to the ANS and has a highly
significant role in the control of pituitary endocrine function.
• The hypothalamus lies on either side of the 3rd ventricle, below the
thalamus and between the optic chiasm and the midbrain. It receives
a large input from limbic structures. See link for detailed description.
Meningis
• The CNS is enclosed within the skull and vertebral column. These
structures are separated by a series of membranes known as the
Meninges. The Pia Mater is separated from the delicate arachnoid
membrane by the subarachnoid space, which is then in turn
separated from the Dura mater by the Sub-dural space