NEUROSCI_LEC - INTRODUCTION & ORGANIZATION OF THE NERVOUS SYSTEM

2 Main Parts of NS

CNS which consists of the _____ and ________

PNS which consists of the _______ and ______

Final common pathway is ______. It is where upper and lower motor neuron meets ( Start of PNS)

2 Main Parts of NS

CNS which consists of the _____ and ________

PNS which consists of the _______ and ______

Final common pathway is ______. It is where upper and lower motor neuron meets ( Start of PNS)

brain and spinal cord

cranial and spinal nerves and their associated ganglia

Anterior/ventral horn cell

Peripheral Nervous System

2 divisions:

______ - muscles

______ - glands ( visceral motor → autonomic ns)

somatic

visceral

Lokin NTK

_______ tract - sensory

______ tract - motor

90% of nervous tissue are concentrated in the ______ & ______

The functional unit of the NS _____ & ___

ascending

descending

brain and spinal cord

dendrites and axons

Central Nervous System

In the CNS, the ______ & ______ are the main centers where correlation and integration of nervous information occur.Both the brain and spinal cord are covered with a system of membranes ______ and are suspended in________ .Meninges are further protected by the bones of the _____ and _______ .

brain and spinal cord

meninges

CSF

skull & vertebral column

Central Nervous System

It is composed of large numbers of ___ which are excitable cells and their processes known as ______. Neurons are supported by specialized tissue called _______

neurons

axon / nerve fibers

neuroglia

Central Nervous System

The CNS interior is organized into gray and white matter. ______ , which is gray in color, consists of nerve cells embedded in neuroglia.

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

Gray matter

neuroglia

White matter

Peripheral Nervous System

In the PNS, the ______ and ______, which consist of bundles of nerve fibers (or axons), conduct information to and from the CNS.

Nerves are relatively unprotected and are commonly damaged by trauma.

cranial and spinal nerves

Peripheral Nervous System

________ Is the part of the NS that innervates the body's involuntary structures, such as the heart, smooth muscle, and glands.

Distributed throughout the CNS and PNS and ls divided Into two parts, the _____ & ______, both containing afferent and efferent nerve fibers.

Autonomic Nervous system

sympathetic ( fight or flight) and the parasympathetic ( relax)

MAJOR DIVISIONS OF THE CNS

________ Is situated within the vertebral canal of the vertebral column and is surrounded by 3 meninges : _____ , ____. and ______. Further protection is provided by the _____, which surrounds the spinal cord in the ______ space.

Spinal Cord

dura mater, arachnoid mater & pia mater

CSF ; subarachnoid space

MAJOR DIVISIONS OF THE CNS: Spinal Cord

The spinal cord is roughly _____ and begins superiorly at the ______ in the skull, where it is continuous with the ______ of the brain.Below, the spinal cord tapers off Into the conus medullaris, from the apex of which the _______ (a prolongation of the pia mater) descends to attach to the back of the coccyx

cylindrical

foramen magnum

filum terminale

medulla oblongata

MAJOR DIVISIONS OF THE CNS: Spinal Cord

Along the entire length of the spinal cord, ____ pairs of spinal nerves are attached by the _____ and _____ roots

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

31 pairs of spinal nerves

anterior or motor roots and the posterior or sensory roots

posterior root ganglion

MAJOR DIVISIONS OF THE CNS: Spinal Cord

The spinal cord ls composed of an Inner core of ______, which ls surrounded by an outer covering of _____.

The gray matter is seen on cross section as an H-shaped pillar with _________ and ______. united by a thin _______ containing the ______.

The white matter is divided into _____, _____ and _____ white column/horn

gray matter → white matter

anterior and posterior gray horns

gray commissure

small central canal

anterior, lateral, and posterior horn

MAJOR DIVISIONS OF THE CNS: Brain

The 3 meninges which are _______ continuous with the corresponding meninges of the spinal cord. The _____ surrounds the brain in the subarachnoid space.

The brain is divided into 3 major divisions: ___ ,___ and _______

dura mater, arachnoid mater & pia mater

CSF

forebrain, midbrain & hindbrain

MAJOR DIVISIONS OF THE CNS: Brain

The _______ (collective term for the medulla oblongata, pons, and midbrain) is what remains after the cerebral hemispheres and cerebellum are removed.

brainstem

MAJOR DIVISIONS OF THE CNS: Brain - Hindbrain

It comprises the ______ , ______ and _____

_______ Is conical In shape and connects the pons superiorly to the spinal cord Inferiorly . It contains many collections of neurons, called _____ and serves as a conduit for ascending and descending nerve fibers.

_______ Is situated on the Ant. surface of the cerebellum, inferior to the midbrain and superior to the medulla oblongata. Derives it name from the large number of transverse fibers on its anterior aspect connecting the two cerebellar hemispheres. It also contains many nuclei and ascending and descending nerve fibers.

medulla oblongata , pons. and cerebellum

nuclei

Pons

MAJOR DIVISIONS OF THE CNS: Brain - Hindbrain

______ lies within the posterior cranial fossa of the skull , posterior to the pons and the medulla oblongata. It consists of 2 laterally placed hemispheres connected by a median portion, _____.

The cerebellum is connected to the midbrain by the ________ , to the pons by the _________, and to the medulla by the _________

The peduncles are composed of large bundles of nerve fibers connecting the cerebellum to NS

Cerebellum

vermis

superior cerebellar peduncles

middle cerebellar peduncles

Inferior cerebellar peduncles

MAJOR DIVISIONS OF THE CNS: Hindbrain - Cerebellum

The surface layer of each cerebellar hemisphere is called _____ and ls composed of ___ matter

The cerebellar cortex is thrown Into folds, or folia, separated by closely set transverse fissures. Certain masses of ___ matter are found inside the cerebellum, embedded in the _____ ; the largest of these is known as the ______

cortex

gray

gray matter ;white matter

dentate nucleus

MAJOR DIVISIONS OF THE CNS: Hindbrain - Cerebellum

The medulla oblongata, the pons, and the cerebellum surround a cavity filled with CSF, called the _______ . This is connected superiorly to the 3rd ventricle by the _______ ; Inferiorly, It Is continuous with the ______ of the spinal cord.

It communicates with the subarachnoid space through 3 openings In the Inferior part of the roof. Through these openings, the CSF within the CNS can enter the subarachnoid space.

4th ventricle

cerebral aqueduct

central canal

MAJOR DIVISIONS OF THE CNS: Brain

_____ Is the narrow part of the brain that connects forebrain → hindbrain. The narrow cavity of the midbrain Is the _______, which connects the 3rd and 4th ventricles. The midbrain contains many nuclei and bundles of ascending and descending nerve fibers.

Midbrain

cerebral aqueduct

MAJOR DIVISIONS OF THE CNS: Brain

The forebrain comprises the ______ (between brain), which ls the central part of the forebrain, and cerebrum.

Diencephalon consists of a _______ and ______. The _______ is a large, egg-shaped mass of gray matter that lies on either side of the 3rd ventricle.

The anterior end of the thalamus forms the posterior boundary of the__________, the opening between the third and lateral ventricles. The ______ forms the lower part of the lateral wall and floor of the third ventricle.

diencephalon

dorsal thalamus & ventral hypothalamus

thalamus

Interventricular forqmen

hypothalamus

MAJOR DIVISIONS OF THE CNS: Brain

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

The hemispheres are separated by a deep cleft , _______ , into which projects the _____

The surface layer of each hemisphere _______ is composed of gray matter. The cerebral cortex is thrown into folds _______ and separated by fissures ______

Within the hemisphere ls a central core of white matter containing several large masses of gray matter,_______

A number of the large sulci are conveniently used to subdivide the surface of each hemisphere Into lobes. Which are named from the bones of the cranium they lie under.

Corpus Callosum

Longitudinal fissure ; falx cerebri

cortex

gyri;sulci

basal nuclei / ganglia

MAJOR DIVISIONS OF THE CNS: Brain - Cerebrum

.A fan-shaped collection of nerve fibers,_______, passes in the white matter to and from the cerebral cortex to the brainstem. It converges on the basal nuclei and passes between them as ________

The tailed nucleus situated on the medial side of the internal capsule is the _______ and the lens-shaped nucleus on the lateral side of the internal capsule is ______

Within each cerebral hemisphere is a cavity called ________ . The lateral ventricles communicate with the 3rd ventricle through the ________

corona radiata

internal capsule

caudate nucleus; lentiform nucleus

lateral ventricle

lnterventricular foramina

MAJOR DIVISIONS OF THE CNS: Brain

Brain Is composed of an inner core of ___ matter. which Is surrounded by an outer covering of ___ matter. However , important masses of gray matter are situated deeply within the white matter: _______ in the cerebellum and ______, ____ &_____ in the cerebrum

white → gray

gray cerebellar nuclei in the cerebellum and the gray thalamic, caudate, and lentiform nuclei in the cerebrum.

MAJOR DIVISIONS OF THE PNS

The ______ of cranial nerves (see Fig. 1-8) leave the brain and pass through foramina in the skull. The ____ of spinal nerves (see Fig. 1-5) leave the spinal cord and pass through intervertebral foramina In the vertebral column.

The spinal nerves are associated with regions of the spinal cord: 8 _____, 12 ______ 5 _____, 5 ______, and 1 ______.

12 pairs ;31 pairs

8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coceygeal.

MAJOR DIVISIONS OF THE PNS

Each spinal nerve Is connected to the spinal cord by two roots: _____ & ____

The anterior root consists of bundles of nerve fibers carrying nerve Impulses AWAY from the CNS-efferent fibers Those that go to skeletal muscles and cause them to contract are ____ Their cells of origin lie in the ______ horn of the spinal cord.

The posterior root consists of bundles of afferent fibers that carry nervous impulses to the CNS. It conveys sensations of touch, pain, temperature, and vibration, called ______. The cell bodies of these nerve fibers are situated in a swelling on the posterior root called the _________

anterior & posterior root

motor fibers

anterior gray

sensory fibers

posterior root ganglion

MAJOR DIVISIONS OF THE PNS

The spinal nerve roots pass from the spinal cord to the level of their respective _______ , where they unite to form a spinal nerve. Thus, motor and sensory fibers mix

Because of the disproportionate growth in length of the vertebral column during development, compared with that of the spinal cord, the length of the roots Increases progressively from _______

intervertebral foramina

above downward

MAJOR DIVISIONS OF THE PNS

In the upper cervical region, the spinal nerve roots are short and run almost horizontally, but the roots of the lumbar and sacral nerves below the level of the termination of the cord (lower border of the 1st lumbar vertebra ln the adult) form a vertical leash of nerves around _________ (Fig. 1-15). Together, these lower nerve roots are called the ______

Filum terminale

cauda equina

MAJOR DIVISIONS OF THE PNS

After emerging from the intervertebral foramen, each spinal nerve Immediately divides Into a ______ ( supply muscles and skin anterolateral ) and ______, & smaller posterior ramus ( supply muscles and skin of back) each containing both motor and sensory fibers.

The anterior rami join one another at the root of the limbs to form complicated ___________. The _______ & ______ plexus are found at the root of the upper limbs, and the _____ and ______ plexuses are found at the root of the lower limbs.

large anterior ramus ( supply muscles and skin anterolateral ) & smaller posterior ramus ( supply muscles and skin of back)

nerve plexuses

cervical and brachial

lumbar and sacral

MAJOR DIVISIONS OF THE PNS

Ganglia can be divided into ____ ,______ and ______

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

Similar ganglia found along the course of cranial nerves ____ ,____,_____, __ & ___ are the sensory ganglia of these nerves.

sensory ganglia of spinal nerves, cranial nerves and autonomic ganglia

Posterior root ganglia

V, VII, VIII, IX, and X

MAJOR DIVISIONS OF THE PNS

________ often irregular in shape, are situated along the course of efferent nerve fibers of the ANS.They are found in the paravertebral sympathetic chains around the roots of the great visceral arteries in the abdomen and close to, or embedded within, the walls of various viscera.

Autonomic ganglia

Lokin NTK

Multiple strokes effects the

upper motor neuron, brain stem, cerebrum and cerebellum

affects both CNS & PNS

Lokin NTK

cover and protect the CNS and holds the CSF

Inflammation of meninges

______ is the final relay point of ascending sensory function

______ conducts somatic motor activities at subconscious level , hormones, regulates body temperature, circadian rhythm and behavioral changes

dura, pia and arachnoid matter

Meningitis

Thalamus

Hypothalamus

Lokin NTK

3 divisions of brainstem

• serves as pathways of ascending and descending tracts

• controls respiration and cardiovascular system

• Contains important nuclei of cranial nerves __ -__

______ is used for fine tuning movements.

Each cranial nerve will be attached to the ventrolateral surface of brainstem ( CN 3-12 goes to nuclei of brainstem for sensory of motor movement)

What CN goes to the posterior of brain stem?

midbrain ,Pons , medulla

3 -12

Cerebellum

CN 4 - trochlear nerve ( the longest intracranial nerve)

Lokin NTK

Spinal cord of adults end at ______ while infants ______

In the spinal cord, ______ covers the _____ matter inside

The biggest gray matter structure in the spinal cord is located in the ________ while ______ is smallest

The gray matter structure in the ventral portion would be largest in the ____ and _____

L1 & L2

L3 & L4

White→ gray matter

lumbar segment (butter fly shaped); thoracic (H shaped)

cervical (controls UE) and lumbar (controls LE)

Lokin NTK

The end of the spinal cord is ______ and located at _____

Spinal Cord → Peripheral Spinal cord → spinal nerve (mix sensory and motor)

Most common type of nerve in the body

conus medullaris

L1 & L2

motor neuron

Lokin NTK

Sensory of PNS is made up of ____ and _____

Autonomic NS (part of visceral motor) is divided into ____ and _____

somatic (skeletal muscles) and visceral ( smooth muscles)

sympathetic and parasympathetic

Lokin NTK : Nerve Sheats

_____ covers a single fiber

_____ covers the fasicle

_____ covers the peripheral nerve

Endoneurium

perineurium

epineurium

Lokin NTK

The ________ nervous system contains cell bodies that lie within the lateral gray column of the spinal cord running from T1 to L2.They synapse and activate nicotinic receptors on post-ganglionic neurons using acetylcholine.

Parasympathetic is between cranial nerve ___, ___ ,_ & __. Nearer to the organs

sympathetic

3,7, 9 & 10

Check Lesson 2 flashcards & neurolab

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