Chapter 3: Structure of the Nervous System Flashcards
Functions to protect the brain by distributing its weight and absorbing shock.
Cerebrospinal fluid (CSF)
An imaginary line drawn through the length of the central nervous system, from the lower end of the spinal cord up to the front of the brain.
Neuraxis
Terms that means front.
Anterior/ Ventral
Term that means back.
Posterior/ Dorsal
Terms means toward the nose.
Rostral
Term means toward the tail.
Caudal
Terms means above.
Superior
Term means below.
Inferior
Term means to the side of, or away from, the middle of the body.
Lateral
Term means toward the middle or center.
Medial
Refers to structures on the same side of the body.
Ipsilateral
Refers to structures on opposite sides of the body.
Contralateral
A cut from the top to the bottom of the body, dividing it into left and right portions.
Saggital plane
A cross-sectional part that is achieved by cutting the body or any part of the body structure, in a horizontal plane.
Transverse plane
A section representing an object as cut horizontally through its center.
Horizontal plane
Divide the right and left sides of the brain into two equal parts.
Midsagittal plane
The protective sheaths around the brain and spinal cord.
Meninges
3 layers of meninges.
Dura mater
Arachnoid membrane
Pia mater
Outer layer that is durable,
thick, tough, and flexible but unstretchable.
Dura mater
Middle layer that is soft and spongy,
lies beneath the dura mater.
Arachnoid membrane
Inner layer of meninges.
Pia mater
A gap between the pia mater and arachnoid membrane; filled with CSF.
Subarachnoid space
A series of hollow, interconnected chambers which are filled with CSF.
Ventricles
Largest chambers which are connected to the third ventricle.
Lateral ventricles
Located at the midline of the brain; its walls divide the surrounding part of the brain into symmetrical halves.
Third ventricle
A bridge of neural tissue that crosses through the middle of the third ventricle and serves as a convenient reference point.
Massa intermedia
A long tube that connects the third ventricle to
the fourth ventricle.
Cerebral aqueduct
Special tissue with an especially rich blood supply.
Choroid plexus
Pouch-shaped structures protrude into the superior sagittal sinus.
Arachnoid granulations
A blood vessel that drains into the veins serving the brain.
Superior sagittal sinus
A condition that is produced when the walls
of the ventricles then expand.
Obstructive hydrocephalus
Outer layer of the embryo; begins to develop at approximately embryonic day 18.
Ectoderm
A tube that is formed when ridges touch each other and fuse together which gives rise to the brain and spinal cord.
Neural tube
Surrounds the cerebral hemispheres, approximately 3 mm thick.
Cerebral cortex
Stem cells that give rise to the cells of the brain.
Progenitor cells
Located just outside the wall of the neural tube.
Ventricular Zone (VZ)
Established when some progenitor cells migrate a short distance away from the ventricular zone, where they continue to divide into more progenitor cells.
Subventricular Zone (SVZ)
A period that begins seven weeks after conception; a phase where progenitor cells form two different kinds of cells as they divide: another progenitor cell and a brain cell.
Asymmetrical division
A phase where the division of each progenitor cell produces two new progenitor cells.
Symmetrical division
First brain cells produced through asymmetrical
division; end in cuplike feet that attach to the pia mater.
Radial glia
Occurs when the progenitor cells receive a
chemical signal that causes them to die.
Apoptosis
Develops from the rostral end of the neural tube.
Forebrain
2 major components of forebrain.
Telencephalon
Diencephalon
Includes most of the two symmetrical cerebral hemispheres that make up the cerebrum.
Telecephalon
Those located deep within the brain, beneath the cerebral cortex.
Subcortical regions
Convolutions in cerebral cortex.
Sulci (small grooves)
Fissures (large grooves)
Gyri (bulges between adjacent sulci or fissures)
4 areas of cerebral cortex.
Frontal lobe
Parietal lobe
Temporal lobe
Occipital lobe
Area that includes everything in front of
the central sulcus.
Frontal lobe
Area that is located on the side of the cerebral hemisphere, just behind the central sulcus, caudal to the frontal lobe.
Parietal lobe