Chapter 3- Structure Of The Nervous System Flashcards
Anterior
Located near or toward the head
Neuraxis
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
Posterior
Located near or toward the tail
Rostral
“Toward the beak”
Caudal
“Toward the tail”
Dorsal
“Toward the back”
Ventral
“Toward the belly”
Lateral
Toward the side of the body, away from the middle
Medial
Toward the middle of the body, away from the side
Ipsilateral
Located on the same side of the body
Contralateral
Located on the opposite side of the body
Cross section
With respect to the central nervous system, a slice taken at right angles to the neuraxis
Frontal section
A slice through the brain parallel to the forehead
Horizontal section
A slice through the brain parallel to the ground
Sagittal section
A slice through the brain parallel to the neuraxis and perpendicular to the ground
Midsagittal plane
A plane through the neuraxis perpendicular to the ground; divides the brain into two symmetrical halves
Meninges
The three layers of tissue that encase the CNS: the dura mater, arachnoid membrane, and pia mater
Dura mater
Outermost of the meninges; tough and flexible
Arachnoid membrane
Middle layer of meninges; located between the outer dura mater and inner pia mater
Pia mater
The layer of meninges that clings to the surface of the brain; thin and delicate
Subarachnoid space
Fluid filled space that cushions the brain; located between the arachnoid membrane and the pia mater
Cerebrospinal fluid (CSF)
A clear fluid, similar to blood plasma, that fills the ventricular system of the brain and the subarachnoid space surrounding the brain and the spinal cord
Ventricle
One of the hollow spaces within the brain, filled with cerebrospinal spinal fluid
Lateral ventricle
One of the two ventricles located in the center of the telencephalon
Third ventricle
The ventricle located in the center of the diencephalon
Cerebral aqueduct
A narrow tube interconnecting the third and fourth ventricles of the brain, located in the center of the mesencephalon
Fourth ventricle
The ventricle located between the cerebellum and the dorsal pons, in the center of the metencephalon
Choroid plexus
The highly vascular tissue that protrudes into the ventricle and produces cerebrospinal fluid
Arachnoid granulation
Small projection of the arachnoid membrane through the dura mater into the superior sagittal sinus; CSF flows through them to be transformed into the blood supply
Superior sagittal sinus
A venous sinus located in the midline just dorsal to the corpus callosum, between the two cerebral hemispheres
Obstructive hydrocephalus
A condition in which all or some of the brains ventricles are enlarged; caused by an obstruction that impedes the normal flow of CSF
Neural tube
A hollow tube, closed at the rostral end, that forms from ectodermal tissue early in embryonic development; serves as the origin of the CNS
Cerebral cortex
The outermost layer of gray matter of the cerebral hemisphere
Progenitor cells
Cells of the ventricular zone that divide and give rise to cells of the CNS
Ventricular zone
A layer of cells that line the inside of the neural tube; contains progenitor cells that divide and give rise to cells of the central nervous system
Subventricular zone
A layer of progenitor cells located just inside the ventricular zone; thicker in annals with large brains
Symmetrical division
Division of a progenitor cell gives rise to two identical progenitor cells; increases the size of the ventricular zone and hence the brain develops from it
Asymmetrical division
Division of a progenitor cell that gives rise to another progenitor cell and a neuron, which migrates away from the ventricular soon towards its final resting place in the brain
Radial glia
Special glia with fibers that grow radially outward from the ventricular zone to the surface of the cortex; provide guidance for neurons migrating outward during brain development
Apoptosis
Death of a cell caused by chemical signal that activates a genetic mechanism inside the cell
Neurogenesis
Production of new neurons through the division of neural stem cells; occurs in the hippocampus and olfactory bulb and appears to play a role in learning
Forebrain
The most rostral of the three major divisions of the brain; includes the telencephalon and diencephalon
Cerebral hemisphere
One of the two major portions of the forebrain, covered by the cerebral cortex
Subcortical region
The region located with in the brain, beneath the cortical surface
Sulcus
A groove in the surface of the cerebral hemisphere, smaller than a fissure
Fissure
A major groove in the surface of the brain, larger than a sulcus
Gyrus
A convolution of the cortex of the cerebral hemispheres, separated by sulci or fissures
Primary visual cortex
A region of the posterior occipital lobe whose primary input is from the visual system
Calcarine fissure
The fissure located in the occipital lobe on the medial surface of the brain; most of the primary visual cortex is located along it’s upper and lower banks
Primary auditory cortex
The region of the superior temporal lobe whose primary input is from the auditory system
Lateral fissure
The fissure that separates the temporal lobe from the overlying frontal and parietal low
Primary somatosensory cortex
The region of the anterior parietal lobe whose primary endpoint is from the somatosensory system
Central sulcus
The sulcus that separates the frontal lobe from the parietal lobe
Insular cortex
A sunken region of the cerebral cortex that it’s normally covered by the rostral superior temporal lobe and caudal inferior frontal lobe
Primary motor cortex
The region of the posterior frontal lobe contains neurons the control movement of skeletal muscles
Frontal lobe
The anterior portion of the cerebral cortex, rostral to the parietal lobe and dorsal to the temporal lobe
Parietal lobe
The region of the cerebral cortex caudal to the frontal lobe and dorsal to the temporal lobe
Temporal lobe
The region of the cerebral cortex rostral to the occipital lobe and ventral to the parietal and frontal lobe
Occipital lobe
The region of the cerebral cortex caudal to the parietal and temporal lobe
Sensory association cortex
Those regions of the cerebral cortex that received information from the regions of primary sensory cortex
