ANATOMY



The Brain




Structures and Divisions



  • Basal Ganglia
  • Controls Cognition , Movement Coordination and Voluntary Movement
  • Location:
  • The basal ganglia is located deep within the cerebral hemispheres in the telencephalon region of the brain. It consists of the corpus stratium, subthalamic nucleus and the substantia nigra.
  • Brainstem :
  • Alertness , Arousal ,Breathing , Blood Pressure , Contains Most of the Crainal Nerves , Digestion , Heart Rate , Other Autonomic Functions Relays Information Between the Peripheral Nerves and Spinal Cord to the Upper Parts of the Brain
  • Location:
  • The brainstem is located at the juncture of the cerebrum and the spinal column. It consists of the midbrain, medulla oblongata, and the pons.
  • Broca's Area
  • Controls Facial Neurons , Controls Speech Production , Understanding Language
  • Location:
  • Broca's area is located in the left frontal lobe, around the opercular and triangular sections of the inferior frontal gyrus.
  • Central Sulcus (Fissure of Rolando)
  • The central sulcus is the large deep groove or indentation that separates the parietal and frontal lobes.
  • Cerebellum
  • Controls Fine Movement Coordination Balance and Equilibrium Muscle Tone
  • Location:
  • The cerebellum is located just above the brainstem, beneath the occipital lobes at the base of the skull.
  • Cerebral Cortex
  • Determines Intelligence , Determines Personality , Interpretation of Sensory Impulses , Motor Function , Planning and Organization , Touch Sensation
  • Location:
  • The cerebral cortex is the outer portion (1.5mm to 5mm) of the cerebrum. It is divided into lobes: frontal, parietal, temporal and occipital. The insula is also found in this region of the brain.

Cerebral Cortex Lobes



  • Frontal Lobes
  • Motor Functions , Higher Order Functions ,Planning , Reasoning , Judgement , Impulse Control, Memory
  • Location:
  • The frontal lobes are the anterior portion of the cerebral cortex.
  • Insula
  • Associated With Visceral Functions , Integrates Autonomic Information
  • Location:
  • The insula is located within the cerebral cortex, beneath the frontal, parietal and temporal opercula.
  • Occipital Lobes
  • Controls Vision , Color Recognition
  • Location:
  • The occipital lobes are the most caudal portion of the cerebral cortex.
  • Parietal Lobes
  • Cognition , Information Processing , Pain and Touch Sensation , Spatial Orientation , Speech ,Visual Perception
  • Location:
  • The parietal lobes are superior to the occipital lobes and posterior to the central sulcus (fissure) and frontal lobes
  • Temporal Lobes
  • Emotional Responses , Hearing , Memory , Speech
  • Location:
  • The temporal lobes are anterior to the occipital lobes and lateral to the Fissure of Sylvius.
  • Cerebrum
  • Determines Intelligence , Personality , Interpretation of Sensory Impulses , Motor Function , Planning and Organization , Touch Sensation
  • Location:
  • The cerebrum is located in the anterior portion of the forebrain. It is divided into two hemispheres that are connected by the corpus callosum.
  • Corpus Callosum
  • Connects the Left and Right Hemispheres
  • Location:
  • The corpus callosum is a thick band of fibers located between the cerebral hemispheres.
  • Cranial Nerves
  • Directs Sense Impulses Throughout the Body , Chewing , Equilibrium , Eye Movement , Vision , Facial Sensation , Hearing , Phonation , Respiration , Salivation , Swallowing , Smell , Taste
  • Location:
  • The olfactory, optic, oculomotor and trochlear cranial nerves are located in the anterior portion of the brain. The trigeminal, abducens, and facial nerves arise in the pons. The vestibulocochlear nerve arises in the inner ear and goes to the pons. The glossopharyngeal, vagus, accessory and hypoglossal nerves are attached to the medulla oblongata.
  • Fissure of Sylvius (Lateral Sulcus)
  • The fissure of sylvius is the large deep groove or indentation that separates the parietal and temporal lobes.
  • Limbic System
  • Controls Emotions , Emotional Responses ,Hormonal Secretions , Mood , Motivation , Pain and Pleasure Sensations

Structures of the Brain



  • Inferior Frontal Gyrus
  • A gyrus is a fold or bump in the brain. The inferior frontal gyrus (gyri pl.) includes an opercular section, orbital section and triangular section.
  • Location:
  • The inferior frontal gyrus is located in the inferior frontal lobe of the cerebral cortex.
  • Amygdala
  • Arousal , Controls Autonomic Responses Associated with Fear , Emotional Responses , Hormonal Secretions
  • Location:
  • The amygdala is an almond shaped mass of nuclei located deep within the temporal lobes, medial to the hypothalamus and adjacent to the hippocampus.
  • Cingulate Gyrus
  • Coordinates Sensory Input With Emotions , Emotional Responses to Pain , Regulates Aggressive , Behavior
  • Location:
  • A gyrus is a fold or bump in the brain. The cingulate gyrus is superior to the corpus callosum, located between the cingulate sulcus and the sulcus (groove or indentation) of the corpus callosum.
  • Fornix
  • Connects the Hippocampus to the Hypothalamus
  • Location:
  • The fornix is an arching, fibrous band of nerve fibers that extend from the hippocampus to the mamillary body of the hypothalamus and forms an arch over the thalamus.
  • Hippocampus
  • Consolidation of New Memories , Emotions , Navigation , Spatial Orientation
  • Location:
  • The hippocampus is a horseshoe shaped sheet of neurons located within the temporal lobes and adjacent to the amygdala.
  • Hypothalamus
  • Controls Autonomic Functions , Emotions , Endocrine Functions , Homeostasis , Motor Functions , Regulates Food and Water Intake , Regulates Sleep Wake Cycle
  • Location:
  • The hypothalamus is located below the thalamus and posterior to the optic chiasma.
  • Olfactory Cortex
  • Conscious Awareness of Odors , Identification of Odors , Receives Sensory Information From the Olfactory Bulb
  • Location:
  • The olfactory cortex is located within the medial temporal lobes.
  • Thalamus
  • Motor Control , Receives Auditory, Somatosensory and Visual Sensory Signals , Relays Sensory Signals to the Cerebral Cortex
  • Location:
  • The thalamus is a large, dual lobed mass of grey matter cells located at the top of the brainstem, superior to the hypothalamus.
  • Medulla Oblongata
  • Controls Autonomic Functions , Relays Nerve Signals Between the Brain and Spinal Cord
  • Location:
  • The medulla oblongata is the lower portion of the brainstem. It is inferior to the pons and anterior to the cerebellum.
  • Meninges
  • Protects Cranial Nerves and Spinal Cord
  • Location:
  • The meninges are membranes that cover and protect the brain and spinal cord. The meninges consist of the pia mater, dura mater and the arachnoid.
  • Olfactory Bulb
  • Relays Sensory Signals to the Olfactory Tract , Sense of Smell
  • Location:
  • The olfactory bulb is located in the limbic region of the brain.
  • Pineal Gland
  • Causes Feeling of Sleepiness , Converts Nervous System Signals to Endocrine Signals , Regulates Endocrine Functions , Secretes the Hormone Melatonin
  • Location:
  • The pineal gland is attached to the posterior wall of the third ventricle.
  • Pituitary Gland
  • Produces Growth Hormone , Produces Hormones That Act on Other Endocrine Glands , Produces Hormones That Act on the Muscles and the Kidneys , Regulates Endocrine Functions , Stores Hormones Produced by the Hypothalamus
  • Location:
  • The pituitary gland is located at the base of the hypothalamus.
  • Pons
  • Arousal , Assists in Controlling Autonomic Functions , Relays Sensory Information Between the Cerebrum and Cerebellum , Sleep
  • Location:
  • The pons is the portion of the brainstem that is superior to the medulla oblongata.
  • Reticular Formation
  • Arousal , Attention , Cardiac Reflexes , Motor Functions , Regulates Awareness , Relays Nerve Signals to the Cerebral Cortex , Sleep
  • Location:
  • The reticular formation is a group of nerve fibers located inside the brainstem.
  • Substantia Nigra
  • Controls Voluntary Movement , Produces the Neurotransmitter Dopamine , Regulates Mood
  • Location:
  • The substantia nigra is located in the mesencephalon (mid brain) region of the brain. It is part of the basal ganglia.
  • Tectum
  • Controls Auditory and Visual Responses
  • Location:
  • The tectum is located in the dorsal region of the mesencephalon (mid brain). It consists of the superior colliculi (visual receptors) and inferior colliculi (auditory receptors).
  • Tegmentum
  • Controls Motor Functions , Regulates Awareness and Attention , Regulates Some Autonomic Functions
  • Location:
  • The tegmentum is located in the ventral region of the mesencephalon (mid brain). It consists of the cerebral aqueduct, periaqueductal gray, reticular formation, substantia nigra and the red nucleus.

Ventricular System



  • Protects the Brain From Trauma and Transports Cerebrospinal Fluid
  • Aqueduct of Sylvius
  • Connects the Third Ventricle and Fourth Ventricle
  • Location:
  • The Aqueduct of Sylvius is a canal that is located between the third ventricle and the fourth ventricle. It contains cerebrospinal fluid.
  • Choroid Plexus
  • Produces Cerebrospinal Fluid Barrier Between Blood and Cerebrospinal Fluid
  • Location:
  • The choroid plexus is located behind the pons and medulla oblongata.
  • Fourth Ventricle
  • Forms the Central Canal of the Spinal Cord and Protects the Brain From Trauma
  • Location:
  • The fourth ventricle is a diamond shaped cavity located behind the pons and medulla oblongata.
  • Lateral Ventricle
  • Protects the Brain From Trauma Provides Pathway for the Circulation of Cerebrospinal Fluid
  • Location:
  • The lateral ventricles are two curved shaped cavities located within the cerebrum.
  • Third Ventricle
  • Protects the Brain From Trauma Provides Pathway for the Circulation of Cerebrospinal Fluid
  • Location:
  • The third ventricle is a narrow cavity located between the two hemispheres of the diencephalon.
  • Wernicke's Area
  • Language Comprehension
  • Location:
  • Wernicke's area is located in the left temporal lobe, posterior to the primary auditory complex.