CNS/PNS I

Cranial vs Spinal Nerves

-Cranial nerves: exit the cranial cavity through foramina in the cranium, ID'd by a name or numeral (CN 11 arises from superior part of the spinal chord) -Spinal (segmental) nerves: exit the vertebral column through the intervertebral foramina, Arise in bilateral pairs from a spinal cord segment

Sensory Ganglia (2)

-Spinal ganglia (dorsal or posterior root ganglia- SENSORY PSEUDOUNIPOLAR DRG) -Cranial ganglia (V, VII, VIII, IX, X- PSEUDOUNIPOLAR except vestibular ganglion CN VIII)

somatic

A subdivision of the peripheral nervous system. Enables voluntary actions to be undertaken due to its control of skeletal muscles

Which of the following structures contains visceral motor nerve cell bodies? Autonomic ganglion Dorsal root Dorsal root ganglion Ventral root More than one of the above (A - D) None of the above (A - D)

Autonomic ganglion

CNS components

Cerebral hemisphere (1) Cerebrum (2) Diencephalon (thalamus, hypothalamus, epithalamus, subthalamus) b. Cerebellum- coordination c. Brain stem (most cranial nerves come from here) (1) Midbrain (2) Pons (3) Medulla d. Spinal cord in vertebral canal

Which of the following ganglia contain sensory nerve cell bodies? Autonomic ganglia Cranial nerve ganglia Cranial nerve and dorsal root ganglia Dorsal root ganglia Dorsal root and parasympathetic ganglia Dorsal root and sympathetic ganglia

Cranial nerve and dorsal root ganglia

Where are the cell bodies of multipolar neurons located? Dorsal or posterior column (funiculus) Dorsal or posterior horn Lateral column (funiculus) Ventral or anterior column (funiculus) None of the above (A - D)

Dorsal or posterior horn

Dorsal ramus

Dorsal ramus: Supplies muscular and cutaneous branches to the deep muscles and skin of the back and posterior head. Ventral Ramus: Supplies muscular and cutaneous branches to the skin and skeletal muscles of the lateral and anterior aspects of the trunk, and the skin and muscles of the limbs.

Where are the cell bodies of axons found in the dorsal column located? Dorsal or posterior horn Dorsal root ganglion Lateral horn Ventral or anterior column (funiculus) Ventral or anterior horn

Dorsal root ganglion

Which of the following structures contains somatic sensory nerve cell bodies? Autonomic ganglion Dorsal root Dorsal root ganglion Ventral root More than one of the above (A - D) None of the above (A - D)

Dorsal root ganglion

Which of the following structures contains visceral sensory nerve cell bodies? Autonomic ganglion Dorsal root Dorsal root ganglion Ventral root More than one of the above (A - D) None of the above (A - D)

Dorsal root ganglion

Gray v white matter

Gray Matter contains the Nerve Cell Bodies and Synapses. White Matter consists of Axons which form Tracts.

Where are the cell bodies of preganglionic neurons located in the spinal cord? Dorsal or posterior column (funiculus) Dorsal or posterior horn Dorsal root ganglion Intermediolateral cell column Ventral or anterior column (funiculus) Ventral or anterior horn

Intermediolateral cell column In the autonomic nervous system, fibers from the CNS to the ganglion are known as preganglionic fibers. All preganglionic fibers, whether they are in the sympathetic division or in the parasympathetic division, are cholinergic (that is, these fibers use acetylcholine as their neurotransmitter) and can be either unmyelinated or myelinated.

Lower Vs Upper motor neurons

LOWER MOTOR NEURON (alpha) start in CNS and end on peripheral structure. Cell body is in CNS, axon terminates on some other structure (ganglion, muscle cell) UPPER MOTOR NEURON (gamma) starts in the CNS and ends in the CNS

Where are the sympathetic preganglionic cell bodies located in the spinal cord? Dorsal or posterior cell column Dorsal root ganglion Lateral horn Ventral or anterior column (funiculus) Ventral or anterior horn

Lateral horn

Which of the following structures contains somatic and visceral motor nerve cell structures? Autonomic ganglion Dorsal root Dorsal root ganglion Ventral root More than one of the above None of the above (A - E)

More than one of the above

Which of the following structures contains somatic and visceral sensory nerve cell structures? Autonomic ganglion Dorsal root Dorsal root ganglion Ventral root More than one of the above None of the above (A - E)

More than one of the above

Ventral Horn

Motor neruon (multipolar). Alpha multipolar neurons that innervate extrafusal skeletal muscle fibers/cells (lower motor neurons) and Gamma motor neurons that innervate intrafusal muscle fibers/cells of neuromuscular spindle

Sensory Ganglion Cells

Nerve cell bodies associated with cranial and spinal nerves Ganglion cells are located outside the CNS

Spinal nerves

PNS- but originates from spinal cord. The anterior horn consists of gray matter and contains the multipolar cell bodies of motor neurons. The posterior horn contains multipolar neurons that give rise to sensory tracts that ascend in the white matter of the spinal cord to higher levels of the CNS. The spinal nerve is formed by the union of the dorsal and ventral roots. Each spinal cord segment has numerous rootlets that join together to form the dorsal and ventral roots.

Lateral horn

Preganglionic cell bodies (multipolar neurons) of the sympathetic nervous system- intermediolateral cell column. T1-L2

Ganglia Types/locations

Sensory nerve fibers have their cell bodies located in dorsal or posterior root ganglia, while sensory fibers associated with cranial nerves have their cell bodies located in ganglia associated with the cranial nerve. Cranial nerves do not have a dorsal or ventral root. Autonomic (motor) ganglia are associated with both spinal and cranial nerves.

somatic sensory fibers of PNS

Sensory nerves to and from skin, skeletal muscle, and joints. Located in cranial and spinal sensory ganglia (DRG)

Dorsal horn

Sensory. Multipolar neurons send axons to higher levels in CNS OR ventral or anterior horn cells

parasympathetic autonomic nervous system

The parasympathetic ganglia are located near the organ or structure of innervation and are derived from four cranial nerves (III, VII, IX, X) and three spinal cord segments (S2,3,4). The labeled celiac ganglion and superior mesenteric ganglion are sympathetic ganglia and are not part of the parasympathetic component of the visceral motor or autonomic nervous system.

CN with motor ganglia

Three cranial nerves have motor ganglia (parasympathetic ganglia): the oculomotor, facial, and glossopharyngeal nerves. The vagus nerve has parasympathetic ganglia nears its organs of innervation in the thorax and abdomen. Only parasympathetic ganglia are associated with cranial nerves. Parasympathetic ganglia, as well as sympathetic ganglia, contain multipolar neurons.

CN with (sensory ganglia)

Trigeminal (semilunar, Gasserian, or Trigeminal), facial (geniculate), vestibulocochlear (spiral/cochlear, vestibular/scarpa's), glossopharyngeal (superior, inferior/petrosal), Vagus (superior/jugular, inferior/nodose)

Which of the following structures contains somatic motor neurons? Autonomic ganglion Dorsal root Dorsal root ganglion Ventral root More than one of the above (A - D) None of the above (A - D)

Ventral root

Ganglia

a collection of nerve cell bodies (or in some cases, a single nerve cell body) associated with peripheral nerves and located outside the CNS. Sensory or Autonomic

dorsal funiculus

ascending nerve cell processes whose cell bodies are in the DRG. Carries touch and proprioceptive sensory tracts + descending neurons carrying motor information to the gray matter of the spinal cord.

lateral funiculus

ascending sensory tracts (origin in gray matter of dorsal horn) and descending motor tracts (origin in brain stem or cerebrum) carrying motor information to the gray matter of the spinal cord.

Visceral motor fibers/ autonomic nervous system

innervates smooth muscle, cardiac muscle, and glands. 2 Efferents (one in CNS, one in visceral ganglion). Sympathetic or parasympathetic

ANS

innervates smooth muscle, cardiac muscle, and glands. 2 efferent neurons (one in CNS, one in autonomic ganglion)

Anterior (ventral) root

motor fibers from nerve cell bodies in the anterior horn of spinal cord gray matter to effector organs located peripherally MULTIPOLAR

Ventral root of spinal nerve

motor/efferent. The cell bodies that send their axons through the ventral roots are located in the ventral and lateral horns (gray matter) of the spinal cord. The ventral root joins the dorsal root to form the spinal nerve.

sympathetic autonomic nervous system

paravertebral ganglia or the sympathetic chain ganglia.

Posterior (dorsal) nerve root

sensory afferent fibers from cell bodies in spinal (sensory) or dorsal root ganglion that extend peripherally to sensory endings and centrally to the posterior horn of the spinal cord gray matter. PSEUDOUNIPOLAR

Visceral sensory fibers

sensory nerves from viscera. Cell bodies of afferents in cranial and spinal sensory ganlgia

Dorsal root of spinal nerve

sensory or afferent. No C1. DRG or spinal ganglion on each root. SENSORY. PSEUDOUNIPOLAR (central process to SC, peripheral process makes spinal nerve)

Cranial nerves

sensory, motor, or mixed. Do not have dorsal/ ventral roots or rami. Cranial nerves only have sensory and parasympathetic ganglia. There are NO sympathetic ganglia associated with the cranial nerves. Originate from cerebral hemisphere or brain stem/spinal cord

Autonomic Ganglia

visceral or motor. MULTIPOLAR (sympathetic in sympathetic chain and parasympathetic associated with cranial and sacral nerves)

somatic motor fibers of PNS

voluntary control of skeletal muscle. Motor nerve cell bodies located in CNS- 1 efferent axon for each cell body