Anatomy- Ch 13 Spinal Cord/Spinal Nerves & Somatic Reflexes

The denticulate ligaments are extensions of which meninx?

Pia mater

Which meninx is closly associated w/ contorus of vertebrae?

Pia mater

Which ramus of a spinal nerve innervates the local muscles, joints, & skin of the back?

Posterior

What is an afferent fiber?

Sensory Nerve Fiber

What are 4 possible effectors of a reflex?

cardiac muscle gland smooth muscle skeletal

What rami of spinal nerves T1-L2 connect to the sympathetic chain ganglia?

communicates rami

Which rami connects the anterior rami to the sympathetic chain?

communicating

The anterior horns of the spinal cord contain somas of what neurons?

somatic motor neurons

Whta effect does severing a sensory root that innervartes a drmatome have?

some sensation remains

What is the subarachnoid space?

space b/t arachnoid mater & pia mater

Which are properties of a reflex?

stimulationn stereotyped quick involuntary

Where does CSF circulate?

subarachnoid space

What is a muscle spindle?

type of stretch receptor embeded in the skeletal muscle

In descending pathways, which motor neurons have their somas in the cerebral cortex or brain stem?

upper

What neurosn have their somas in the cerebral cortex or brainstem?

upper motor

Somatic Receptors

use receptros locarted in the skin, muscle , & tendon

# of neurons in a descending pathway?

2

How many neurons are in an ascending pathway b/t receptor & brain?

3

How many spinal nerves there in order from superior to inferior?

8 cervical 12 thoracic 5lumbar 5 sacral 1 coccygeal

First cervical spinal nerve emerge above vertebrae?

C1

What nerve is a peripheral nerve carrying nerve signals to CNS?

Sensory Nerve

First cervical spinal nerve emerges b/t which 2 structures?

Skull & vertebrae C1

Which is a somatosensory stimulus?

TOuch stretch Temp pain pressure

In CNS, bundles of axons that make up white matter are called what?

Tracts

Which ramus of a spinal nerve innervates & lateral skin & muscles of the truck

anterior

What rami & spinal nerves arise from the intercoastal?

anterior; thoracic

What is the dural sheath around the spinal cord formed from?

dura mater

The DICT eclosing an entire nerve

epineurium

In desdending tracts, which motor neuron innervates the target organ?

lower

In descending pathways, the upper motor neurons synapse with whidh neurons in the brainstorm or spinal cord?

lower motor

Ascending tract in the spinal cord will carry what info to the brain?

sensory

The somas of which neurons are found within the posterior root ganglion?

sensory

What type of a neuron has the soma located in the posterior root ganglion?

sensory neuron

Meninges

series of fibrous CT covering the CNS

Arachnoid Layer

several layers of squamos cuboidal cells with loose mesh fibers in space below

What disease results from herpes virus residing in a posterior root ganglian?

shingles

How manyn pair of spinal nerves are there?

31 pairs

The _____ horsw of the spinal cord contain the cell bodies of outgoing somatic motor neurons.

Anterior

Where does the spinal cord arsise from the medulla oblongata?

At the foramen magnum

Which is the name of a plexus?

Brachial Cervical Lumbar Sacral

Regions of the spinal cord?

Cervical Thoracic Lumbar Sacral

Spinal cord region in order

Cervical Thoracic Lumbar Sacral

The anterior rami of spinal nerves form which nerve plexuses?

Cervical, lumbar, sacreal

Functions of the spinal cord?

Condcution Locomotion Reflexes

Which tract will have orgigin & destination on opposite sides of bod?

Contralateral

What is an area of skin innervated by a spinal nerve called?

Dermatome

Within the spinal cord. which tracts carry motor signals down from the brain?

Descending

T/F: Severing a sensory nerve root will completely deaden sensation from a dermatome.

False

What is a cluster of a neuron cell bodies located outside of the CNS called?

Ganglion

Where are the neurons cell bodies, dendrites, & synapsese found in the CNS?

Gray mater

What is the site of synaptic integration in the spinal cord?

Gray matter

In an adult where does the spinal cord end?

L1

A special fiber innervates what in the body?

Lcalized organs in te head (eyes, eaar, olfactory, tase receptors)

What indicatese the end of the spinal cord?

Medullary Cone

The anterior root of a spinal nerve contain axons of which neurons?

Motor

Visceral Fibers

Nerve fibers that innervate BV, glands, & internal organs

What are 3 columns of what matter found in the spinal cord?

Posterior column Anterior column Lateral column

Components of a reflex arc in order

Receptor Afferent Nerve Fiber Integration center Efferent Nerve Fiber Effector

Which of these structures is closest to the spinal cord?

Rootlet

Nerve fibers of periphereal nerves are encased in which cells?

Schwann

The coccygela ligament is formed from the fusion of which 2 structers?

Terminal filum & dura mater

A generla fiber innervates what?

Widespread organs such as muscles, skin, glands, visceria, BV

Nerve fiber refers to what of a neuron?

axon

What is the gray commissure of the spinal cord?

band of gray matter connecting the gray matter of the L side to the R

What is the cauda equina?

bundle of nerve roots occupying the vertebral canal L2 - S5

What enlargement of thspinal cord gives rise to the nerves of the upper limbs

cervical enlargement

What area of skin is innervated by spinal nerve?

dermatome

Mater of brain in order from superficial layer

dura mater arachnoid mater pia mater

external to the neurilemma of a nerve fiber is a loose layer of CT surrounding a nerve fiber is called what?

endoneurium

With in a nerve, nerve fibers are gathered into bundles called?

fascicles

Which stimulus causes a muscle to reflexively contract?

increased strech

Which spinal cord areas are composed of gray matter?

lateral horn anterior horn posterior horn

Central Canal

lined w ependymal cells & contains cerebrospinal fluid (CSF)

posterior median sulcas

longitudinal groove on the dorsal surface of the spinal cord

What is the anterior median fissure of the spinal cord?

longitudinal groove on the ventral surface of the spinal cord

What branch of the spinal nerve innervates the meninges?

meningeal branch

The pollipvirus destroys which neurons in the brain steam & anterior horn of the spinal cord?

motor

Which of the following desrcibes a sensory nerve?

nerve containing only fibers carrying incoming nerve signals to the CNS

Monosynaptic

reflex containing only 1 synapse b/t neurons

What tract carries signals that control muscles of the upper and lower limbs for posture and balance?

reticulospinal tract

Moving peripherally from the spinal cord, which anterior & posterior structures form a spinal nerve?

roots

Somatic nerve fiber innervates which of the following?

skin, skelteal muscles, bones & joints

, where is the white matter in relation to the gray matter?

superficial

Intercoastal arise from the anterior rami of the _______ spinal nerves.

thoracic

Which are considered a distal branch of a spinal nerve?

Anterior ramus Posterior ramus

All spinal nerves except C1 pass through what structure to emerge from vertebral column?

Intervertebral foramen

_______ muscle fibers are modified muscle fibers with in a muscle spindle.

Intrafusal

Which tract will have its origin & destination on the same side of body?

Ipsilateral

The communicating rami connect to the anterior rami to which of the following?

The sympathetic chain

Nerve

a cordlike organ composed of numerous nerve fibers (axons) bound together by connective tissue

Posterior root of a spinal nerve carries _______ nerve fibers

afferent

What is the lumbar enlargement of the spinal cord?

area of spinal cord that gives rise to nerves of the lower limbs + pelvis

What factor accounts for the fact that the R side of brain communicates with the left side of body?

decussation

What is the epineurium, composed of?

dense irregular connective tissue

What happens to motor neurons of the lateral regios of the spinal cord when amyotrophic lateral sclerosis?

destroyed sclerosis

Which describes a motor nerve?

nerve containing only fibers carrying outgoing nerve signals from the CNS

Within a nerve, each fascicle is wrapped in a layer called a ________

perineurium

Which spinal nerve roots carry sensory nerve signals?

posteior

Reflex

quick, involunatry, stereotped responses to a stimulus

Fasciculus

tract of nerve fibers with in a column of the spinal cord.