Transcript introduction to the nervous system

LECTURE NOTES IN ANATOMY
PHARMACY STUDENTS; NOVEMBER 24TH 2011
REV. PROF. SETH AYETTEY
OBJECTIVES
• KNOW THE ROLE AND FUNCTIONAL SIGNIFICANCE OF
THE NERVOUS SYSTEM
• KNOW THE ORGANIZATION OF THE NERVOUS SYSTEM
– THE PERIPHERAL NERVOUS SYSTEM
–
–
SOMATIC
VISCERAL (AUTONOMIC)
– THE CENTRAL NERVOUS SYSTEM
–
–
BRAIN
SPINAL CORD
• KNOW ABOUT MAJOR RECEPTORS
• KNOW ABOUT NEURONS AND NEUROGLIA
• KNOW THE CLINICAL SIGNIFICANCE OF THE NERVOUS
SYSTEM
ROLE OF NERVOUS SYSTEM
 PERCEIVE & RESPOND TO CHANGES IN
 EXTERNAL ENVIRONMENT
 INTERNAL ENVIRONMENT
 TRANSPORT INFORMATION FROM PERIPHERY
TO THE SPINAL CORD AND BRAIN
 PROCESS INFORMATION FOR LEARNING
 RESPOND TO INFORMATION TO PROTECT
THE ORGANISM
 FUNCTION WITHIN NORMAL PHYSIOLOGIC LIMITS
 NORMAL GROWTH
 SURVIVAL
MAJOR PARTS OF THE NERVOUS
SYSTEM 1
 CENTRAL NERVOUS SYSTEM (CNS)
 BRAIN (FORE; MID; HIND)
 SPINAL CORD





CERVICAL SEGMENTS (C1-C8)
THORACIC SEGMENTS (T1-12)
LUMBAR SEGMENTS (L1-5)
SACRAL SEGMENTS (S1-5)
COCCYGEAL (1)
MAJOR PARTS OF THE NERVOUS
SYSTEM 2
 PERIPHERAL NERVOUS SYSTEM (PNS)
 SOMATIC


12 CRANIAL NERVES (PAIRS)
31 SPINAL NERVES (PAIRS)
 VISCERAL (AUTONOMIC)


SYMPATHETIC
PARASYMPATHETIC
 RECEPTORS
THE NEURON
 BASIC UNIT OF NERVOUS SYSTEM
 TYPES (FUNCTIONAL)
 SENSORY
 MOTOR
 INTEGRATIVE
 TYPES (MORPHOLOGY)
 UNIPOLAR
 BIPOLAR
 MULTIPOLAR
NEURONAL PARTS
 BODY; AXONAL HILLOCK
 DENDRITES
 RECEPTIVE FIELD
 PERIPHERAL PROCESS
 AXONS
 CONDUCTS IMPULSE AWAY
 CENTRAL PROCESS
 COLLATERALS
AXON - CONTINUED
 MYELINATION
 MYELINATED
 SCHWANN SHEATH (PNS)
 OLIGODENDROCYTES
 UNMYELINATED
 SIZE (DIAMETER)
 0.2u – 20u
 SPEED OF CONDUCTION
 (M/SEC) 5X DIAMETER
 GROWTH RATE - 1 mm/day
THE NEUROGLIA: OLIGODENDROCYTES
 LOCATED IN BOTH GREY AND WHITE
MATTER
 RESPONSIBLE FOR MYELIN SHEATH
FORMATION
 CONTRIBUTE TO IMPULSE PROPAGATION
 EQUIVALENT TO SCHWANN CELLS IN PNS
SUPPORTING CELLS
(NEUROGLIA)
 CNS
 ASTROCYTES
 OLIGODENDROCYTES
 MICROGLIA
 EPENDYMAL CELLS
 PNS
 SCHAWNN CELLS
CELLS OF THE CNS: NEUROGLIA
 ASTROCYTES
 OLIGODENDROCYTES
 MICROGLIA
 EPENDYMAL CELLS
RECEPTORS 1
 EXTEROCEPTORS (SUPERFICIALLY LOCATED)
 PAIN (FREE NERVE ENDINGS)
 TEMPERATURE (ENCAPSULATED RECEPTORS)
 PRESSURE (ENCAPSULATED)
 VISION (RETINA)
 OLFACTION (OLFACTORY CELLS)
 HEARING (COCHLEA)
 TASTE (TASTE BUDS)
RECEPTORS 2
 PROPRIOCEPTORS (LOCOMOTOR SYSTEM)
 POSITION/BALANCE/MOVEMENT (VESTIBULAR
APPARATUS)
 STRETCH (MUSCLE SPINDLES)
 TENSION (TENDON ORGANS)
 PRESSURE/VIBRATION (PACINIAN CORPUSCLES)
RECEPTORS 3
 INTEROCEPTORS
 ASSOCIATED WITH VISCERA (INTERNAL ORGANS)
 CONNECTED TO THE AUTONOMIC NERVOUS
SYSTEM
 LOCATED IN



MUCOUS MEMBRANES
WALLS OF VESSELS/TUBULAR STRUCTURES
CONNECTIVE TISSUE OF VISCERA
 TYPES
 FREE NERVE ENDINGS
 ENCAPSULATED
 MODIFIED EPITHELIAL CELLS
PERIPHERAL NERVOUS SYSTEM
 RECEPTORS
 AFFERENT NEURONS
 SPINAL CORD
 EFFERENT NEURON
 EFFECTOR ORGAN
 CONNECTION WITH THE CNS
ORGANIZATION OF CNS 1
 FOREBRAIN
 CEREBRAL HEMISPHERES (THE TELENCEPHALON)
 RECOGNITION
 PROCESSING
 INTEPRETATION
 STORAGE OF INFORMATION
 MODIFICATION OF INFORMATION
 RECALL
 UTILIZATION
ORGANIZATION OF CNS 2
 DIENCEPHALON
 THALAMUS

FINAL RELAY STATION TO CEREBRAL HEMISPHERE
 HYPOTHALAMUS

REGULATION OF
 AUTONOMIC NERVOUS SYSTEM
 ENDOCRINE SYSTEM
ORGANIZATION OF CNS 3
 MID BRAIN
 SITUATED BETWEEN FORE AND HIND BRAINS
 CONNECTS FORE AND HIND BRAINS
FUNCTIONALLY
 HIND BRAIN
 PONS
 MEDULLA
 CEREBELLUM
ORGANIZATION OF CNS 4
 SPINAL CORD
 SIMPLEST FORM OF CNS
 INNER GREY MATTER
 DORSAL HORN (SENSORY)
 VENTRAL HORN (MOTOR)
 LATERAL HORN (T1-L1-2) SYMPATHETIC OUTFLOW
 OUTER WHITE MATTER


DESCENDING TRACTS
ASCENDING TRACTS
DIVISIONS OF THE CENTRAL NERVOUS
SYSTEM – SPINAL CORD
 SPINAL CORD
 SEGMENTS
 CERVICAL C1-8
 THORACIC T1-T12
 LUMBAR L1-5
 SACRAL S1-S5
 COCCYGEAL 1
ORGANIZATION OF PNS
 CRANIAL (12 PAIRS OF CRANIAL NERVES)
 SPINAL
 DORSAL ROOTS (SENSORY)
 VENTRAL ROOTS (MOTOR)
 SPINAL NERVES (MIXED)
 DORSAL RAMI
 VENTRAL RAMIDORSAL HORN (SENSORY)
 VENTRAL HORN (MOTOR)
 LATERAL HORN (T1-L1-2) SYMPATHETIC OUTFLOW
 PLEXUSES

CERVICAL; BRACHIAL; LUMBAR; SACRAL