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Introduction
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Structure of brain
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Human brain development
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Parts of brain
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functions
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The brain is one of the largest and most complex
organs in the human body.
It is made up of more than 100 billion nerves
that communicate in trillions of connections
called synapses.
Interconnecting these brain cells are circuits
complex than those most powerful
supercomputers.
The adult human brain weighs on average about
1.3–1.4 kg , or about 2% of total body weight.
 It is located in the head, protected by the skull.
 The human brain is composed of neurons, glial
cells, and blood vessels.
 The living brain is very soft, having a consistency
similar to soft gelatin or soft tofu.
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During the first three weeks of gestation, the
human embryo's ectoderm forms a thickened strip
called the neural plate.
The neural plate then folds and closes to form the
neural tube.
This tube flexes as it grows, forming the crescentshaped cerebral hemispheres at the head, and the
cerebellum and pons towards the tail.
Our brain is our most powerful organ.
 It has a texture similar to firm jelly.
 It has three main parts:
i. CEREBRUM
ii. CEREBELLUM
iii. BRAIN STEM
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cerebrum, the largest and uppermost portion of the
brain.
 The cerebrum consists of the cerebral hemispheres and
accounts for two-thirds of the total weight of the brain.
 One
hemisphere, usually the left, is functionally
dominant, controlling language and speech.
 The other hemisphere interprets visual and spatial
information.
 The cerebral hemispheres consist of an inner core of
myelinated nerve fibres, the white matter, and an outer
cortex of gray matter.
 The cerebral cortex is responsible for integrating sensory
impulses, directing motor activity, and controlling higher
intellectual functions.
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The cerebral cortex is divided into four sections, called
"lobes": the frontal lobe, parietal lobe, occipital lobe,
and temporal lobe.
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Frontal Lobe- associated with reasoning, planning,
parts of speech, movement, emotions, and problem
solving
Parietal Lobe- associated with movement,
orientation, recognition, perception of stimuli
Occipital Lobe- associated with visual processing
Temporal Lobe- associated with perception and
recognition of auditory stimuli, memory, and
speech.
cerebellum (“little brain”) is a structure that is located at the back of the
brain, underlying the occipital and temporal lobes of the cerebral cortex
 This structure is associated with regulation and coordination of movement,
posture, and balance.
 This structure is associated with regulation and coordination of movement,
posture, and balance.
 Limbic System: The limbic system, often referred to as the "emotional brain",
is found buried within the cerebrum. Like the cerebellum, evolutionarily the
structure is rather old.
 This system contains the thalamus, hypothalamus, amygdala, and
hippocampus.
 The
 The
cerebellum receives information from the sensory systems,
the spinal cord, and other parts of the brain and then regulates
motor movements.
 The cerebellum coordinates voluntary movements such as posture.
-balance.
-coordination.
-speech.
 It is also important for learning motor behaviors.
The brainstem (or brain stem) is the posterior
part of the brain.
 In humans it is usually described as including the
medulla oblongata , pons and midbrain.
 The brainstem also plays an important role in the
regulation of cardiac and respiratory function.
 all information relayed from the body to the
cerebrum and cerebellum and vice versa must
traverse the brainstem.
 It plays an important role in conduction.
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medulla
The lower half of the brainstem that contains the
cardiac, respiratory, vomiting, and vasomotor centers
and deals with autonomic, involuntary functions such
as breathing, heart rate, and blood pressure.
 pons
Contains nuclei that relay signals from the forebrain to
the cerebellum, along with nuclei that deal primarily
with sleep, respiration, swallowing, bladder control,
hearing, equilibrium, taste, eye movement, facial
expressions, facial sensation, and posture.
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