INTRODUCTION TO THE NERVOUS AND VASCULAR SYSTEMS NERVOUS

INTRODUCTION TO THE NERVOUS AND VASCULAR SYSTEMS

NERVOUS SYSTEM

GENERAL ORGANIZATION

BY LOCATION: • CENTRAL NERVOUS SYSTEM – BRAIN – SPINAL CORD • PERIPHERAL NERVOUS SYSTEM – NERVOUS TISSUE OUTSIDE THE CENTRAL NERVOUS SYSTEM – SPINAL NERVES – CRANIAL NERVES – AUTONOMIC NERVOUS SYSTEM

GANGLIA • A GROUP OF NERVE CELL BODIES OUTSIDE OF THE CNS • TYPES OF GANGLIA – DORSAL ROOT – CRANIAL NERVE GANGLIA – AUTONOMIC GANGLIA

AUTONOMIC GANGLIA • PARASYMPATHETIC – HEAD GANGLIA – NEAR ORGAN (EPICARDIUM) – WITHIN ORGAN (INTRAMURAL) • SYMPATHETIC – PARAVERTEBRAL – PREVERTEBRAL – ADRENAL MEDULLA

CRANIAL NERVES • ORIGIN: BRAIN • EACH ONE IS NAMED AND NUMBERED – ROMAN NUMERALS USED FOR NUMBERS • MAY BE SENSORY NERVES, MOTOR NERVES OR CARRY BOTH SENSORY AND MOTOR INFORMATION.

CRANIAL NERVES (Cont. ) I. III. IV. V. VIII. IX. X. XII. OLFACTORY OPTIC OCULOMOTOR TROCHLEAR TRIGEMINAL ABDUCENS FACIAL VESTIBULOCOCHLEAR GLOSSOPHARYNGEAL VAGUS ACCESSORY HYPOGLOSSAL ON OLD OLYMPUS’ TOWERING TOP A FAT VULGAR GERMAN VIEWED A HOP

CRANIAL NERVES (Cont. ) I. III. IV. V. VIII. IX. X. XII. OLFACTORY OPTIC OCULOMOTOR TROCHLEAR TRIGEMINAL ABDUCENS FACIAL VESTIBULOCOCHLEAR GLOSSOPHARYNGEAL VAGUS ACCESSORY HYPOGLOSSAL SOME (SENSORY) SAY MARRY (MOTOR) MONEY BUT (BOTH SEN. & MOT. ) MY BROTHER SAYS BETTER BORROW MORE MONEY

BY FUNCTION: • MOTOR/EFFERENT – SOMATIC MOTOR • MOTOR/EFFERENT – VISCERAL MOTOR • SENSORY/AFFERENT – GENERAL SENSORY – SPECIAL SENSORY

SPINAL NERVES • ORIGIN: SPINAL CORD • EXIT VERTEBRAL COLUMN BETWEEN VERTEBRAE • NAMED FOR REGION – CERVICAL (C 1 -8) – THORACIC (T 1 -12) – LUMBAR (L 1 -5) – SACRAL (S 1 -5) – COCCYGEAL • ALL BOTH SENSORY AND MOTOR

SEGMENTAL INNERVATION • SPINAL NERVES LEAVE THE SPINAL CORD AT REGULAR INTERVALS • EACH SUPPLIES A SPECIFIC AREA OR SEGMENT OF THE BODY

CROSS SECTION OF THE CORD • • • WHITE MATER CENTRAL GRAY CENTRAL CANAL DORSAL ROOT GANGLION • VENTRAL ROOT • SPINAL NERVE

MENINGES • • DURA ARACHNOID PIA SUBDURAL SPACE • SUBARACHNOID SPACE • EPIDURAL SPACE

SPECIALIZATIONS • ENLARGEMENTS • CONUS MEDULLARIS • CAUDA EQUINA • FILUM TERMINALE

TYPICAL SPINAL NERVE • EXITS INTERVERTEBRAL FORAMEN • DIVIDES – POSTERIOR PRIMARY RAMUS – ANTERIOR PRIMARY RAMUS

AUTONOMIC NERVOUS SYSTEM • 2 NEURON CHAIN • PREGANGLIONIC CELL BODY IN CNS • POSTGANGLIONIC CELL BODY IN GANGLION (PERIPHERY) GANGLION 1 2

SYMPATHETIC SHORT PREGANGLIONIC AXON GANGLION LONG POSTGANGLIONIC AXON

SYMPATHETIC • THORACOLUMBAR OUTFLOW – PREGANGLIONIC FIBERS EXIT WITH THORACIC AND LUMBAR SPINAL NERVES

PARAVERTEBRAL (CHAIN) GANGLIA • ONE GANGLION/ SPINAL NERVE – WHITE RAMI – GRAY RAMI • THREE CERVICAL GANGLIA

FATE OF PREGANGLIONIC FIBER • PREGANG. NEURON IN LAT. HORN • AXON EXITS IN VENTRAL ROOT • SYNAPSE IN GANGLION • POSTGANG. AXON REJOINS SPINAL NERVE

FATE OF PREGANGLIONIC FIBER • PASS THROUGH GANGLION WITHOUT SYNAPSE – ASCEND OR DESCEND IN CHAIN TO DIFFERENT LEVEL

FATE OF PREGANGLIONIC FIBER • EXIT THE CHAIN VIA THE SPLANCHNIC NERVE (VISCERAL RAMUS) – PASS TO THE PREVERTEBRAL GANGLIA PREVERTEBRAL GANGLION SPLANCHNIC NERVE

PREVERTEBRAL GANGLIA • THREE GANGLIA – CELIAC – SUPERIOR MESENTERIC – INFERIOR MESENTERIC • PREGANGLIONIC FIBERS FROM SPLANCHNIC NERVES • POSTGANGLIONIC FIBERS DISTRIBUTE WITH ARTERY

PARASYMPATHETIC

PARASYMPATHETIC SYSTEM LONG PREGANGLIONIC AXON SHORT POSTGANGLIONIC AXON GANGLION

CRANIAL-SACRAL OUTFLOW • CRANIAL NERVES III, VII, IX, X – OCULOMOTOR (III): NUCLEUS OF EDINGER-WESTPHAL – FACIAL (VII) • SUPERIOR SALIVATORY NUCLEUS – GLOSSOPHARYNGEAL (IX) • INFERIOR SALIVATORY NUCLEUS – VAGUS (X) • MOTOR NUCLEUS OF VAGUS

CRANIAL-SACRAL OUTFLOW (Cont. ) • SACRAL SPINAL CORD – PREGANGLIONIC NEURONS IN THE SACRAL REGION OF THE CORD • AXONS EXIT THE ANTERIOR (VENTRAL) ROOT – PELVIC SPLANCHNIC NERVES

GANGLIA • HEAD GANGLIA – CILIARY – PTERYGOPALATINE – OTIC – SUBMANDIBULAR • GANGLIA AT THE ORGAN BEING INNERVATED – EPICARDIUM – INTRAMURAL GANGLIA

AUTONOMIC FIBERS • WHITE RAMUS – PREGANGLIONIC FIBERS • CHAIN GANGLION • GRAY RAMUS – POSTGANGLIONIC FIBERS

DERMATOMES • SENSORY AREA SUPPLIED BY ONE SPECIFIC SPINAL NERVE.

MYOTOMES • MOTOR AREA SUPPLIED BY ONE SPECIFIC SPINAL NERVE. – SIMILAR TO DERMATOMES IN THE TRUNK

REFERRED PAIN • CONVERGENCE OF SENSORY INFORMATION. • BRAIN MISIDENTIFIES SOURCE OF PAIN IMPULSE.

BLOOD VASCULAR SYSTEM

ARTERY • EFFERENT VESSELS • HIGH PRESSURE – THICK WALL – ROUND

CAPILLARIES • MICROSCOPIC VESSELS • WHERE NUTRIENTS AND WASTE EXCHANGED BETWEEN BLOOD AND TISSUES

VEIN • AFFERENT VESSEL • LOW PRESSURE SYSTEM – THIN WALL – FLATTENED IN APPEARANCE

PORTAL VESSELS • CONNECT TWO CAPILLARY BEDS • THREE PORTAL SYSTEMS – HEPATIC PORTAL SYSTEM (LIVER) – HYPOTHALAMO-HYPOPHYSEAL PORTAL SYSTEM – KIDNEY

LYMPHATIC VESSELS • FUNCTION • STRUCTURE