Neuroanatomy Chapter 1 Organization of the Nervous System

Neurons are supported by specialized tissue called _______.

neuroglia

________ matter consists of nerve cells embedded in neuroglia.

________ matter consists of nerve fibers embedded in neuroglia and is this color because of the presence of lipid material in nerve fiber myelin sheaths.

Gray (cells and do not have myelin or lipid)
White (myelinated fibers)

The ______ are relatively unprotected and commonly damaged by trauma due to lack of bony protection

PNS

The ___________ is the part of the nervous system that innervates the body's involuntary structures, such as the heart, smooth muscle, and glands.

autonomic nervous system (ANS)

The ANS is divided into two parts, the ________ and _______, both containing afferent and efferent nerve fibers.

sympathetic and the parasympathetic

Forebrain consist of (2)

Midbrain (1)

Hindbrain consist of (3)

Cerebrum and Dicephalon

Mesencephelon

Medulla oblongata, Pons, Cerebellum

The spinal cord is situated within the ______ ______ of the vertebral column and is surrounded by three meninges

vertebral canal

3 meninges (dura (outermost), arachnoid, pia (innermost))

CSF is in subarachnoid space

Protection is provided by the ________ which surrounds the spinal cord in the subarachnoid space.

CSF,

The spinal cord is roughly cylindrical and begins superiorly at the foramen magnum in the skull, where it is continuous with the ______ ______ of the brain.

Below, the spinal cord tapers off into the ______ _____, from the apex of which the filum terminale (a prolongation of the _____ mater) descends to attach to the coccyx.

medulla oblongata

conus medullaris

pia

Along the entire length of the spinal cord, 31 pairs of spinal nerves are attached by the anterior or ______ roots and the posterior or _______ roots

motor (efferent)
sensory (afferent)

Each posterior nerve root possesses a posterior root ________, the cells of which give rise to peripheral and central nerve fibers.

ganglion

There are _____ pairs of ganglia from the cranial nerves.

12

There are ___ total ganglia from the spinal nerves.
_____ - Cervical
_____ - Thoracic
_____ - Lumbar
_____ - Sacral
_____ - Coccygeal

31 total
8
12
5
5
1

The spinal cord is composed of an inner core of _____ matter, which is surrounded by an outer covering of ____ matter.

gray
white

The brain is conventionally divided into three major divisions: the _____,_______, and ______ in ascending order from the spinal cord

hindbrain, the midbrain, and the forebrain

The hindbrain comprises the ______ ______, the ______, and the ______.

medulla oblongata, pons, and cerebellum

The ______, or bridge, derives its name from the large number of transverse fibers on its anterior aspect connecting the two cerebellar hemispheres.

pons

(situated on anterior surface of cerebellum below midbrain and superior to medulla oblongata)

The cerebellum is connected to the

______ by the superior cerebellar peduncles,

______ by the middle cerebellar peduncles,

______ by the inferior cerebellar peduncles

midbrain

pons

medulla

The ________ are composed of large bundles of nerve fibers connecting the cerebellum to the remainder of the nervous system.

peduncles

The surface layer of each cerebellar hemisphere is called the ______ and is composed of gray matter

cortex

Certain masses of gray matter are found in the interior of the cerebellum, embedded in the white matter; the largest of these is known as the ________ ______.

dentate nucleus

The medulla oblongata, the pons, and the cerebellum surround a cavity filled with CSF, called the _________ ventricle. This is connected superiorly to the third ventricle by the cerebral aqueduct; inferiorly, it is continuous with the central canal of the spinal cord. It communicates with the subarachnoid space

fourth

The _______ comprises the diencephalon (between brain), which is the central part of the forebrain, and the cerebrum.

forebrain

The _________ is almost completely hidden from the surface of the brain. It consists of a dorsal thalamus and a ventral hypothalamus

diencephalon

The cerebrum, the largest part of the brain, consists of two cerebral hemispheres, which are connected by a mass of white matter called the ______ ______.

corpus callosum

The hemispheres are separated by a deep cleft, the _________ fissure, into which projects the falx cerebri

longitudinal

Within the hemisphere is a central core of white matter containing several large masses of gray matter, the _________.

basal nuclei or ganglia.

The lateral ventricles communicate with the third ventricle through the _________ foramina.

interventricular

The spinal nerve roots pass from the spinal cord to the level of their respective intervertebral foramina, where they unite to form a ______ nerve

spinal (combined afferent and efferent.)

Together, the lower nerve roots are called the ______ ______.

cauda equina

The __________ ramus continues anteriorly to supply the muscles and skin over the anterolateral body wall and all the muscles and skin of the limbs.

The __________ ramus passes posteriorly around the vertebral column to supply the muscles and skin of the back.

anterior
posterior
(each containing both motor and sensory fibers)

Posterior ______ _______ and are fusiform swellings on the posterior root of each spinal nerve just proximal to the root's junction with a corresponding anterior root.

root ganglia

Autonomic ganglia, which are often irregular in shape, are situated along the course of _________ nerve fibers of the ANS.

efferent

The innermost layer, the ________, gives rise to the gastrointestinal tract, the lungs, and the liver. The _________ gives rise to the muscle, connective tissues, and the vascular system. The third and outermost layer, the _________, formed of columnar epithelium, gives rise to the entire nervous system.

endoderm
mesoderm
ectoderm

During the third week of development, the ectoderm on the dorsal surface of the embryo between the primitive knot and the buccopharyngeal membrane thickens to form the _____ ______.

neural plate

The ______ neuropore closes first and the posterior______ 2 days later.

anterior

neuropore

Ultimately, the ______ ______ cells will differentiate into the cells of the posterior root ganglia, the sensory ganglia of the cranial nerves, autonomic ganglia, the cells of the suprarenal medulla, and the melanocytes.

neural crest

In the adult extends down only as far as the level of the lower border of the _____ lumbar vertebra

Large size of the vertebral foramen in lumbar region gives the roots of the _____ _____ ample room

1st

Cauda Equina

These help prevent nerve injury of lumbar

Cervical disc herniations are (more or less) common than herniations in the lumbar region.

less

Herniated Intervertebral Discs is when a mobile part joins a immobile part. For example, posterior part of _____ _____ of disc ruptures and central nucleus pulposus is forced posteriorly like toothpaste out of tube.

Annulus fibrosus

Which herniation is most common and where?

Cervical or Lumbar

Lumbar in L4-L5 and L5-Sacrum

_____ is when herniation causes pain felt down the back and lateral side of the leg, radiating to the sole of the foot

Sciata

Using a careful aseptic technique and local anesthesia, the clinician passes the lumbar puncture needle fitted with a stylet into the vertebral canal above or below the ______ lumbar spine to draw CSF for testing.

4th

A block of the subarachnoid space in the vertebral canal, which may be caused by a tumor of the spinal cord or the meninges, can be detected by compressing the ________ ________ veins in the neck.

A positive Queckenstedt is indicates ______ of CNS

internal jugular

blockage

Anesthetic solutions may be injected into the sacral canal through the sacral hiatus during labor. This is called ______ anesthesia

Cauda

A sudden severe blow to the head, as in an automobile accident, may result in damage to the brain at two sites: at the point of impact and at the pole of the brain opposite the point of impact, where the brain is thrown against the skull wall. This is referred to as __________ injury.

contrecoup

Epidural Hemorrhage results from _______ _______

Subdural Hemorrhage results from _____ ____ ____

Subarachnoid Hemorrhage results from rupture in _____ __ _____

meningeal arteries

superior cerebral veins

circle of willis

With cerebral hemorrhage, spontaneous intracerebral hemorrhage is most common in patients with hypertension. It is generally due to rupture of the thin-walled ____________ artery (a branch of middle cerebral)

lenticulostriate

Shaken baby syndrome is caused by sudden deceleration from shaking or head impact causing brain injuries which causes raised ____ and blood in ____ ____ which indicates what?

ICP (intracranial pressure)

Spinal Tap (blood in CSF)

Space-occupying lesions within the skull should be identified by _____ and _____ and not by _____ _____ due to sudden displacement and can lead to brain herniation.

CT, MRI, Spinal Tap

______ is used for the detection of intracranial lesions. The procedure is quick, safe, and accurate. The total dose of irradiation is no greater than for a conventional skull radiograph.

_____ takes longer and costs two-thirds more than a ____ scan.

CT (method of choice in emergency head trauma)

MRI (more clear and distinguish gray and white matter)

________ uses radioactive isotopes that decay with the emission of positively charged electrons (positrons) to map the biochemical, physiologic, and pharmacologic processes taking place in the brain.

Positron emission tomography (PET)

______ is absolutely safe to the patient, and because it provides better differentiation between gray and white matter, and can be more revealing than CT.

MRI