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Central Nervous system 4/10/2016 G.LUFUKUJA 1 Nervous system • Divided – Central nervous system • Brain & Spinal cord – Peripheral nervous system • Cranial and Spinal nerves • Autonomic nervous system 4/10/2016 G.LUFUKUJA 2 NEUROANATOMY Spinal cord 4/10/2016 G.LUFUKUJA 3 4/10/2016 G.LUFUKUJA 4 4/10/2016 G.LUFUKUJA 5 4/10/2016 G.LUFUKUJA 6 4/10/2016 G.LUFUKUJA 7 • Covered by three meninges namely Dura, Arachnoid and Pia matter 4/10/2016 G.LUFUKUJA 8 Dorsal root ganglion (spinal ganglion) Denticulate ligament Ventral root Dorsal root 4/10/2016 G.LUFUKUJA 9 4/10/2016 G.LUFUKUJA 10 4/10/2016 G.LUFUKUJA 11 4/10/2016 G.LUFUKUJA 12 4/10/2016 G.LUFUKUJA 13 4/10/2016 G.LUFUKUJA 14 4/10/2016 G.LUFUKUJA 15 4/10/2016 G.LUFUKUJA 16 4/10/2016 G.LUFUKUJA 17 4/10/2016 G.LUFUKUJA 18 External part of the brain 4/10/2016 G.LUFUKUJA 19 4/10/2016 G.LUFUKUJA 20 4/10/2016 G.LUFUKUJA 21 4/10/2016 G.LUFUKUJA 22 Test your self…… 4/10/2016 G.LUFUKUJA 23 4/10/2016 G.LUFUKUJA 24 4/10/2016 G.LUFUKUJA 25 Test your self…… 4/10/2016 G.LUFUKUJA 26 Test your self…… 4/10/2016 G.LUFUKUJA 27 4/10/2016 G.LUFUKUJA 28 4/10/2016 G.LUFUKUJA 29 4/10/2016 G.LUFUKUJA 30 4/10/2016 G.LUFUKUJA 31 External organization of cerebellum 4/10/2016 G.LUFUKUJA 32 homunculus 4/10/2016 G.LUFUKUJA 33 4/10/2016 G.LUFUKUJA 34 4/10/2016 G.LUFUKUJA 35 4/10/2016 G.LUFUKUJA 36 4/10/2016 G.LUFUKUJA 37 4/10/2016 G.LUFUKUJA 38 4/10/2016 G.LUFUKUJA 39 4/10/2016 G.LUFUKUJA 40 4/10/2016 G.LUFUKUJA 41 4/10/2016 G.LUFUKUJA 42 Stroke Stroke, also known as cerebrovascular accident (CVA), cerebrovascular insult (CVI), or brain attack, is when poor blood flow to the brain results in cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. They result in part of the brain not functioning properly. Signs and symptoms of a stroke may include an inability to move or feel on one side of the body 4/10/2016 G.LUFUKUJA 43 Brodmann areas • More than 100 years ago, Brodman parceled the surface of the cortex out into more than 50 areas, based on the distinctive cellular appearance and function of each • His map, shown here, is used to this day in describing the functional organization of this region b’se many of the areas identified by Broadman correlate fairly well with various functional areas of the cortex 4/10/2016 G.LUFUKUJA 44 4/10/2016 G.LUFUKUJA 45 4/10/2016 G.LUFUKUJA 46 4/10/2016 G.LUFUKUJA 47 The Frontal Lobe • The frontal lobe contains areas that Brodmann identified as involved in cognitive functioning and in speech and language. • Brodmann Area 4 corresponds to the precentral gyrus or primary motor area. • Neurons here send descending axons to the spinal cord and brainstem; activity of these neurons results in movement on the opposite side of the body • Brodmann Area 6 is the premotor or supplementary motor area. 4/10/2016 G.LUFUKUJA 48 The Frontal Lobe… • Brodmann Area 8 is anterior of the premotor cortex. It facilitates eye movements and is involved in visual reflexes as well as pupil dilation and constriction. 4/10/2016 G.LUFUKUJA 49 The Frontal Lobe… • Areas 44 and 45 are Broca's area. These are motor speech areas – Important on the left or dominant hemisphere in majority of individuals – Brings about formation of words by its connections with adjacent primary motor area; muscles of larynx, mouth, tongue, soft palate – Lesion of this area on left hemisphere • Results in loss to produce speech (expressive aphasia) • Patient retains ability to think words they wish to say, can write words and can understand their meaning when they see or hear them! 4/10/2016 G.LUFUKUJA 50 The Frontal Lobe… • Brodmann Areas 9, 10, and 11 are anterior to area 8. • They are involved in cognitive processes like reasoning and judgment which may be collectively called biological intelligence including executive function 4/10/2016 G.LUFUKUJA 51 Parietal Lobe • The Postcentral gyrus (primary sensory gyrus) roughly coincides with Brodmann's areas 3, 1 and 2 - Primary sensory cortex. – Neurons here receive a direct input from ascending somatic sensory pathways from opposite side of the body • These are somatosthetic areas, meaning that they are the primary sensory areas for touch and proprioception including kinesthesia 4/10/2016 G.LUFUKUJA 52 …Parietal Lobe • Areas 5, 7, and 40 are found posterior to the primary sensory strip and are considered presensory association areas where somatosensory processing occurs. 4/10/2016 G.LUFUKUJA 53 …Parietal Lobe • The angular gyrus is Brodman area 39 of the human brain is involved in a number of processes related to language and cognition. 4/10/2016 G.LUFUKUJA 54 Temporal Lobe • Areas involved in the processing of auditory information and semantics as well as the appreciation of smell are found in the Temporal Lobe • Area 41 is Heschl's gyrus, the primary auditory area. 4/10/2016 G.LUFUKUJA 55 …Temporal Lobe • Area 42 immediately inferior to area 41 is the secondary auditory area also involved in the detection and recognition of speech. • The processing done in this area of the cortex provides a more detailed analysis than that done in area 41. 4/10/2016 G.LUFUKUJA 56 …Temporal Lobe • Areas 21 and 22 are the auditory association areas. Both areas are divided into two parts; one half of each area lies on either side of area 42. Collec tively they can be called Wernicke's auditory area. – Involved in language processing to enable particular sequences of sound to be identified and comprehended as meaningful words – Damage Wernicke's area leads to receptive or sensory aphasia which is primarily a difficulty in understanding language 4/10/2016 G.LUFUKUJA 57 …Temporal Lobe • Area 37 is found on the posterior-inferior part of the temporal lobe. Lesions here can cause anomia (Inability to remember words/names) • Anomia is usually caused by brain trauma, such as an accident, stroke, or tumor. • Dysnomia refers to a less severe form of this word-recall dysfunction 4/10/2016 G.LUFUKUJA 58 Occipital Lobe • The Occipital Lobe contains areas that process visual stimuli (visual cortex). • Area 17 is the primary visual area. • Areas 18 and 19 are the secondary visual (association) areas where visual processing occurs. 4/10/2016 G.LUFUKUJA 59 4/10/2016 G.LUFUKUJA 60