chapter 14 the spinal cord and spinal nerves
Order by
133 terms
Terms | Definitions |
|---|---|
 although spinal cord and brain connected they still have some | -functional independence |
| integrates and processes information on its own and relays info to and from the brain | -spinal cord |
| the adult spine has a | -posterior median sulcus and -anterior median fissure |
| shallow | -posterior median sulcus |
| wide | -anterior median fissure |
| cervical and lumbar | -enlargements |
| expanded localized regions where there is increased gray matter to provide innervation of the limbs on the spinal cord | -enlargements |
| adult spinal cord extends from the | -foramen magnum to L1 |
| the spinal cord tapers to a conical tip | -conus medullaris |
| strand of fibrous tissue that originates at the tip and extends through the vertebral canal to the second sacral vertebra, ultimately becoming part of the coccygeal ligament | -filum terminale |
| becomes part of coccygeal ligament | -filum terminale |
| how many segments in spinal cord | -31 segments |
| each segment of the spinal cord associated with a pair of a) ____ ___ _____ and pairs of b) _____ ____ and c)_____ ____ | -dorsal root ganglia -dorsal roots -ventral roots |
| what represents exceptions in that the dorsal roots are absent in many individuals | -the first cervical and first coccygeal nerves |
| sensory and motor fibers unite as a single _____ _____ distal to each dorsal root ganglion | -spinal nerve |
| spinal nerves emerge from | -intervertebral foramina |
| spinal nerves are ____ ____ | mixed nerves |
| mixed nerves since contain both | -sensory fibers and -motor fibers |
| largest nerve in the body | -sciatic nerve |
| inferior extension of the ventral and dorsal roots and the filum terminale in the vertebral canal | -caudal equina |
| spinal meninges | -series of specialized membranes that provide physical stability and shock absorption for neural tissues of the spinal cord |
| membranes that surround the brain | -cranial meninges |
| 3 spinal meningeal layers | -dura mater -arachnoid mater -pia mater |
| the tough, fibrous outermost layer that covers the spinal cord | -dura mater |
| caudally the dura mater forms the _____ ______ with the filum terminale | -coccygeal ligament |
| what separates the dura mater from the inner walls of the vertebral canal | -epidural space |
| internal to the inner surface of the dura mater | -subdural space |
| when present it separates the dura mater from the middle meningeal layer | -arachnoid mater |
| internal to the arachnoid mater | -subarachnoid space |
| space that contains cerebrospinal fluid (csf) | -subarachnoid space |
| acts as a shock absorber and used for spinal tap | -cerebrospinal fluid |
| innermost meningeal layer | -pia mater |
| layer bound firmly to the underlying neural tissue | -pia mater |
| paired supporting fibers extending laterally from the spinal cord surface | -dendiculate ligaments |
| paired supporting fibers binding the spinal pia mater and arachnoid mater to prevent side-to-side or inferior movement of the spinal cord | -dendiculate ligaments |
| surrounds the central canal and contains cell bodies of neurons and glial cells | -central gray mater |
| gray matter projections toward the outer suface of the spinal cord | -horns |
| contains myelinated and unmyelinated axons in tracts and columns | -peripheral white matter |
| neuron cell bodies in the the spinal cord gray matter are organized into groups termed, | -nuclei |
| sensory nuclei | -dorsal -touch receptors |
| motor nuclei | -ventral -issue motor commands to peripheral effectors,muscles |
| separates the sensory nuclei from the motor nuclei | -frontal section along the axis of the central canal |
| horn that contain somatic and visceral sensory nuclei | -posterior gray horn |
| horn that contain nuclei involved with somatic motor control | -anterior gray horn |
| horn that contain visceral motor neurons | -lateral gray horn -found between t1 and l2 |
| posterior and anterior to the central canal | -gray commissures |
| contain the axons of interneurons that cross from one side of the cord to the other | -gray commissures |
| white matter can be divided into six | -columns |
| columns aka | -funiculi |
| each column or funiculi contains | -tracts or fasiculi |
| tracts aka | -fasiculi |
| tract that relays information from the spinal cord to the brain | -ascending tracts |
| tract that carry information from the brain to the spinal cord | -descending tracts |
| how many pairs of spinal nerves? | -31 pairs |
| each spinal nerves is identified through its | -association with an adjacent vertebra |
| vertebra | -cervical, thoracic, lumbar, sacral |
| each spinal nerve is ensheated by a series of connective tissue layers | -epineurium -perinuerium -endoneurium |
| outermost layer of spinal nerve, dense network of collagen fibers | -epineurium |
| middle layer of spinal nerve that partitions the nerve into a series of bundles (fascicles) and conveys blood vessels into each individual fiber | -perineurium |
| inner layer of spinal nerve that is composed of delicate connective tissue fibers that surround individual axons | -endoneurium |
| first branch of spinal nerve in the thoracic and upper lumbar regions | -white ramus |
| contains myelinated axons going to an autonomic ganglion | -white ramus |
| what 2 groups of unmyelinated fibers exit the autonomic ganglion | -gray ramous -autonomic nerve |
| gray ramous | -carry axons that innervate glands and smooth muscles in the body wall or limbs back to the spinal nerve |
| autonomic nerve | -carry fibers to internal organs |
| rami communicantes | -white and gray rami |
| each spinal nerves has both a ____ ____ and a ____ _____ | -dorsal ramus -ventral ramus |
| each pair of spinal nerves monitors a region of the body surface called | -dermatome |
| dorsal ramus | -provides sensory/motor innervation to the skin and muscles of the back |
| ventral ramus | -supplies ventrolateral body surface, body wall structures, and limbs |
| complex, interwoven network of nerves | -nerve plexus |
| four major nerve plexuses are the | -cervical plexus -brachial plexus -lumbar plexus -sacral plexus |
| plexus that consists of the ventral rami of c1-c4 and some fibers from c5 | -cervical plexus |
| plexus in which muscles of the neck are innervated, and some branches extend into the thoracic cavity to the diaphragm | -cervical plexus |
| which nerve is the major nerve in the cervical plexus | -phrenic nerve |
| plexus that innervates the pectoral girdle and upper limbs by the c5-t1. | -brachial plexus |
| nerves in this plexus originate from cords or trunks | -brachial plexus |
| superior, middle, and inferior trunks give rise to the | -lateral cord, medial cord, and posterior cord |
| what 2 plexuses collectively originate from the posterior abdominal wall and ventral rami of nerves supply the pelvic girdle and lower limb | -lumbar plexus -sacral plexus |
| plexus that contains fibers from spinal segments t12-l4 | -lumbar plexus |
| plexus that contains fibers from spinal segments l4-s4 | -sacral plexus |
| rapid, automatic, involuntary motor response to stimuli | -neural reflex |
| help preserve homeostasis by rapidly adjusting the functions of organs or organ systems | -reflexes |
| the neural 'wiring' of a single reflex | -reflex arc |
| a ______ is a specialized cell that monitors condition in the body or external environment | -receptor |
| each receptor has a characteristic range of _________ | -sensitivity |
| there are _ steps involved in the neural reflex | -5 |
| neural reflex steps | -1) arrival of a stimulus and activation of a receptor -2) relay of information to the cns -3) information processing -4) activation of a motor neuron -5) response by a peripheral effectors |
| what step of neural reflex information processing | 3 |
| what step of neural reflex -4) activation of a motor neuron | 4 |
| what step of neural reflex response by a peripheral effectors | 5 |
| what step of neural reflex relay of information to the cns | 2 |
| what step of neural reflex arrival of a stimulus and activation of a receptor | 1 |
| reflexes classified by | 1) their development (innate, acquired) 2) where information is processed (spinal, cranial) 3) motor response (somatic, visceral) 4) complexity of the neural circuit (monosynaptic, polysynaptic) |
| innate reflexes are determined _______ | -genetically |
| acquired reflexes are | -learned following repeated exposure to a stimulus |
| reflexes processed in the brain | -cranial reflexes |
| reflex where the important interconnections and processing occur inside the spinal cord | -spinal reflex |
| reflex that control skeletal muscle contractions | -somatic reflex |
| visceral (autonomic) reflex | -control the activities of smooth and cardiac muscles and glands |
| simplest reflex arc | -monosynaptic reflex |
| which neuron synapses direct on a motor neuron that acts as the processing center | -sensory neuron |
| polysynaptic reflexes | -have at least one interneuron places between the sensory afferent and the motor efferent |
| which reflex have a longer delay between stimulus and response? | -polysynaptic reflexes |
| spinal reflexes range from simple a)______reflexes to more complex b)_______reflexes | a) monosynaptic b) polysynaptic |
| simple monosynaptic reflexes | -involving only one segment of the cord |
| complex polysynaptic reflexes | -many segments of the cord interact to produce a coordinated motor response |
| stretch reflex | -a monosynaptic reflex that automatically regulates skeletal muscle length and muscle tone. |
| reflex that includes patellar, bicep, triceps, and ankle jerk reflex | -stretch reflex |
| reflex the familiar knee jerk, where in a rap on the patellar ligament stretches the muscle spindles in the quadriceps muscles. | -patellar reflex |
| stretch reflex that maintains normal upright posture | -postural reflex |
| what can enhance or inhibit reflex motor patterns based in the spinal cord | -higher centers in the brain |
| loss of sensation and motor control of the upper and lower limbs | -quadriplegia |
| ventral root | -motor neuron axons |
| epidural space | -loose connective tissue, adipose tissue |
| white matter | -tracts and columns |
| fascicle | -single bundle of axons |
| dermatome | -specific region of body surface |
| phrenic nerve | -cervical plexus |
| brachial plexus | -pectoral girdle/upper extremity |
| obturator nerve | -lumbar plexus |
| reflex | -involuntary motor response |
| pudendal nerve | -sacral plexus |
| the _____ ______ is a strand of fibrous tissue that provides longitudinal support as a component of the coccygeal ligament | -filum terminale |
| axons crossing from one side of the spinal cord to the other within the gray matter are found in the | -gray commissures |
| the paired structures that contain cell bodies of sensory neurons and are associated with each segment of the spinal cord are the | -dorsal root ganglia |
| the deep crease on the ventral surface of the spinal cord is the | -anterior median fissure |
| sensory and motor innervations of the skin of the lateral and ventral surfaces of the body are provided by the | -ventral ramus |
| brachial plexus | -innervates the shoulder girdle and the upper extremity, is formed from the ventral rami of spinal nerves c5-t1, and is the source of the musculocutaneous, radial, median, and ulnar nerves |
| the middle layer of connective tissue that surrounds each peripheral nerve is the | -perineurium |
| the expanded area of the spinal cord that supplies nerves to the pectoral girdle and upper limbs is the | -cervical enlargement |
| spinal nerves are called mixed nerves because | -they contain sensory and motor fibers |
| the gray matter of the spinal cord is dominated by | -cell bodies of neurons and glial cells |
First Time Here?
Welcome to Quizlet, a fun, free place to study. Try these flashcards, find others to study, or make your own.