Structure Of The Nervous System (Ch.3)

Front 1

Neuraxis

Back 1

An imaginary line drawn through the center of the length of the CNS, from the bottom of the spinal cord to the front of the forebrain.

Front 2

Anterior

Back 2

Located near or toward the head.

Front 3

Posterior

Back 3

Located near or toward the tail

Front 4

Rostral

Back 4

Along the neuraxis toward the front of the face

Front 5

Caudal

Back 5

Along the neuraxis away from the front of the face.

Front 6

Dorsal

Back 6

Perpendicular to the neuraxis toward the top of the head or the back

Front 7

Ventral

Back 7

Perpendicular to the neuraxis toward the bottom of the skull or the front surface of the body.

Front 8

Lateral

Back 8

Toward the side of the body, away from the middle.

Front 9

Medial

Back 9

Toward the middle of the body, away from the side.

Front 10

Ipsilateral

Back 10

Located on the same side of the body.

Front 11

Contralateral

Back 11

On the opposite side of the body

Front 12

Cross section

Back 12

A slice taken at right angles to the neuraxis.

Front 13

Frontal section

Back 13

A slice through the brain parallel to the forehead.

Front 14

Horizontal section

Back 14

Slice through the brain parallel to the ground.

Front 15

Sagittal section

Back 15

Slice through the brain parallel to the neuraxis and perpendicular to the ground.

Front 16

Midsagittal plane

Back 16

Plane through the neuraxis perpendicular to the ground; dibided the brain into two symmetrical halves.

Front 17

Meninges

Back 17

The three layered tissue that protects the CNS

Front 18

Dura Mater

Back 18

The outermost meninges; tough and flexible.

Front 19

Arachnoid membrane

Back 19

Middle layer of meninges; soft and spongy, between dura mater and inner pia mater.

Front 20

Pia mater

Back 20

Layer of meninges clings to the surface of the brain; thin and delicate.

Front 21

Subarachnoid space

Back 21

Fluid space that cushions the brain; between arachnoid membrane and the pia mater.

Front 22

Cerebrospinal fluid (CSF)

Back 22

Clear fluid that fills the ventricular system of the brain and the subarachnoid space surrounding the brain and spinal cord.

Front 23

Meninges in the PNS

Back 23

- Covered w/ two layers of meninges

- Middle layer: arachnoid membrane and CSF, which covers the brain and spinal cord

- Outside the PNS: Dura mater and pia mater cover the spinal and cranial nerves and the periphereal ganglia.

Front 24

Ventricle

Back 24

One of the hollow spaces w/in the brain, filled w/ cerebrospinal fluid.

Front 25

Lateral ventricles

Back 25

One of the two ventricles in the center of the telencephalon

Front 26

Third ventricle

Back 26

Ventricle in the center of the diencephalon and connected to the lateral ventricles.

Front 27

Cerebral Aqueduct

Back 27

A narrow tube connecting the third and fourth ventricles of the brain in the center of the mesencephalon

Front 28

Fourth ventricle

Back 28

Ventricle between the cerebellum and the dorsal pns, in the center of the metencephalon

Front 29

Chorid plexus

Back 29

Highly vascular tissue that extends beyond into the ventricles and procuces CSF

Front 30

How long does it take for the CSF to be replaced?

Back 30

Only half of the cerebrospinal fluid in three hours in the bentricular system is replaced by fresh fluid.

Front 31

What is the CSF made of?

Back 31

Made of choroid plexus of the lateral ventricles.

Front 32

Process of the CSF...

Back 32

1. Flows into the 3rd ventricle (more CSF made)

2. Flows through Cerebral aqueduct

3. To the 4th ventricle (CSF made)

4. CSF leaves 4th by small openings connected w. the subarachnoid space

5. In the subarachnoid space: CSF is reabsorbed into the blood supply through arachnoid granulations.

Front 33

Arachnoid granulations

Back 33

Small projections of the arachnoid membrane through the dural meter into the superior sagittal sinus; CSF flows through them to be reabsorbed into the blodd supply.

Front 34

Superior sagittal sinus

Back 34

Venous sinus in the midine dorsal to the sorpus callosum, between the two cerebral hemispheres.

Front 35

Obstructive hydrocephalus

Back 35

C ondition which all or some of the brain's ventricles enlarge; caused by an obstruction that impedes the normal flow of CSF

Front 36

Ectoderm

Back 36

Outer layer of the back of the embryo thickens and forms a plate.

Front 37

Neural tube

Back 37

A hollow tube closed @ the rostral end, that forms from ectodermal tissue early in embryonic development; serves as the origin of the CNS

Gives rise to brain and spinal cord

Front 38

18th day (of conception)

Back 38

The nervous system begins to develop

Front 39

21st

Back 39

Ridges of the ectoderm plate touch each other and fuse together making a tube (neural tube)

Front 40

28th

Back 40

Neural tube closed, rostral end had three connected chambers: forebrain, midbrain, and the hindbrain.

Front 41

Forebrain (rostral chamber)

Back 41

Divides into: two lateral ventricles and the 3rd ventricle. The region surrounding the two ventricles is the telencephalon ("end brain"), and the region around the 3rd ventricle is the diencephalon ("interbrain")

Front 42

Midbrain

Back 42

Inside, it has the mesencephalon that becomes narrow: making the cerebral aqueduct.

Front 43

Hindbrain

Back 43

Has..

1. The metencephalon "aferbrain"

2. Myelencephalon "marrowbrain"

Front 44

Cerebral Cortex

Back 44

Outermost layer of the gray matter of the cerebral hemispheres.

Front 45

Progenitor cells

Back 45

The stem cells that give rise to the cells of the brain. Cells of the ventricular zone that divide and give rise to cells of the CNS

Front 46

Ventricular zone (VZ)

Back 46

A layer of cells that line the inside of the neural tube; contains progenitor cells that divide and give rise to cells of the CNS

Front 47

Subventricular zone (SVZ):

Back 47

Layer os progenitor cells inside the ventricular zone; thickens in mammals w/ ;arge brains.

Front 48

Symmetrical division

Back 48

Process of dividing progenitor cells that gice rise to two identical protgenitor cells; increases the size of the ventricular zone and hence the brain that develops from it.

Front 49

Asymmetrical Division

Back 49

Process where progenitor cells divide and make two different kinds of cells: another progenitor cell and a brain cell. The brain cell migrates from the ventricular zone to the brain.

Front 50

Radial Glia

Back 50

Special glia w/ fibers growing radically outward from the ventricular zone to the cortex surface; aguidance for neurons migrating outward during brain development.