The Central Nervous System Key Words

integumentary

integumentary

Aside from the nervous system, which other organ system develops out of the ectoderm?

mesencephalon

Which primary vesicle of the embryonic nervous system does not differentiate into more vesicles at the secondary stage?

thalamus, hypothalamus, retina

Which adult structure(s) arises from the diencephalon?

craniofacial bone

Which non-nervous tissue develops from the neuroectoderm?

neural crest

Which structure is associated with the embryologic development of the peripheral nervous system?

brain stem

region of the adult brain that includes the midbrain, pons, and medulla oblongata and develops from the mesencephalon, metencephalon, and myelencephalon of the embryonic brain

cephalic flexure

curve in midbrain of the embryo that positions the forebrain ventrally

diencephalon

region of the adult brain that retains its name from embryonic development and includes the thalamus and hypothalamus

forebrain

anterior region of the adult brain that develops from the prosencephalon and includes the cerebrum and diencephalon

hindbrain

posterior region of the adult brain that develops from the rhombencephalon and includes the pons, medulla oblongata, and cerebellum

mesencephalon

primary vesicle of the embryonic brain that does not significantly change through the rest of embryonic development and becomes the midbrain

metencephalon

secondary vesicle of the embryonic brain that develops into the pons and the cerebellum

midbrain

middle region of the adult brain that develops from the mesencephalon

myelencephalon

secondary vesicle of the embryonic brain that develops into the medulla

neural crest

tissue that detaches from the edges of the neural groove and migrates through the embryo to develop into peripheral structures of both nervous and non-nervous tissues

neural fold

elevated edge of the neural groove

neural groove

region of the neural plate that folds into the dorsal surface of the embryo and closes off to become the neural tube

neural plate

thickened layer of neuroepithelium that runs longitudinally along the dorsal surface of an embryo and gives rise to nervous system tissue

neural tube

precursor to structures of the central nervous system, formed by the invagination and separation of neuroepithelium

neuraxis

central axis to the nervous system, from the posterior to anterior ends of the neural tube; the inferior tip of the spinal cord to the anterior surface of the cerebrum

primary vesicle

initial enlargements of the anterior neural tube during embryonic development that develop into the forebrain, midbrain, and hindbrain

prosencephalon

primary vesicle of the embryonic brain that develops into the forebrain, which includes the cerebrum and diencephalon

rhombencephalon

primary vesicle of the embryonic brain that develops into the hindbrain, which includes the pons, cerebellum, and medulla

secondary vesicle

five vesicles that develop from primary vesicles, continuing the process of differentiation of the embryonic brain

telencephalon

secondary vesicle of the embryonic brain that develops into the cerebrum

internal carotid artery

What blood vessel enters the cranium to supply the brain with fresh, oxygenated blood?

dura mater

Which layer of the meninges surrounds and supports the sinuses that form the route through which blood drains from the CNS?

ependymal

What type of glial cell is responsible for filtering blood to produce CSF at the choroid plexus?

third ventricle

Which portion of the ventricular system is found within the diencephalon?

disruption of blood to the brain

What condition causes a stroke?

anastomosis

area where vessels unite to form interconnections that normally allow blood to circulate to a region even if there may be partial blockage in another branch.

anterior spinal artery

blood vessel from the merged branches of the vertebral arteries that runs along the anterior surface of the spinal cord

arachnoid granulation

outpocket of the arachnoid membrane into the dural sinuses that allows for reabsorption of CSF into the blood

arachnoid mater

middle layer of the meninges named for the spider-web–like trabeculae that extend between it and the pia mater

arachnoid trabeculae

filaments between the arachnoid and pia mater within the subarachnoid space

basilar artery

blood vessel from the merged vertebral arteries that runs along the dorsal surface of the brain stem

carotid canal

opening in the temporal bone through which the internal carotid artery enters the cranium

central canal

hollow space within the spinal cord that is the remnant of the center of the neural tube

cerebral aqueduct

connection of the ventricular system between the third and fourth ventricles located in the midbrain

choroid plexus

specialized structures containing ependymal cells lining blood capillaries that filter blood to produce CSF in the four ventricles of the brain

circle of Willis

unique anatomical arrangement of blood vessels around the base of the brain that maintains perfusion of blood into the brain even if one component of the structure is blocked or narrowed

common carotid artery

blood vessel that branches off the aorta (or the brachiocephalic artery on the right) and supplies blood to the head and neck

dura mater

tough, fibrous, outer layer of the meninges that is attached to the inner surface of the cranium and vertebral column and surrounds the entire CNS

dural sinus

any of the venous structures surrounding the brain, enclosed within the dura mater, which drain blood from the CNS to the common venous return of the jugular veins

foramen magnum

large opening in the occipital bone of the skull through which the spinal cord emerges and the vertebral arteries enter the cranium

fourth ventricle

the portion of the ventricular system that is in the region of the brain stem and opens into the subarachnoid space through the median and lateral apertures

internal carotid artery

branch from the common carotid artery that enters the cranium and supplies blood to the brain

interventricular foramina

openings between the lateral ventricles and third ventricle allowing for the passage of CSF

jugular veins

blood vessels that return “used” blood from the head and neck

lateral apertures

pair of openings from the fourth ventricle to the subarachnoid space on either side and between the medulla and cerebellum

lateral ventricles

portions of the ventricular system that are in the region of the cerebrum

lumbar puncture

procedure used to withdraw CSF from the lower lumbar region of the vertebral column that avoids the risk of damaging CNS tissue because the spinal cord ends at the upper lumbar vertebrae

median aperture

singular opening from the fourth ventricle into the subarachnoid space at the midline between the medulla and cerebellum

meninges

protective outer coverings of the CNS composed of connective tissue

occipital sinuses

orthostatic reflex

sympathetic function that maintains blood pressure when standing to offset the increased effect of gravity

pia mater

thin, innermost membrane of the meninges that directly covers the surface of the CNS

sigmoid sinuses

dural sinuses that drain directly into the jugular veins

straight sinus

dural sinus that drains blood from the deep center of the brain to collect with the other sinuses

subarachnoid space

space between the arachnoid mater and pia mater that contains CSF and the fibrous connections of the arachnoid trabeculae

superior sagittal sinus

dural sinus that runs along the top of the longitudinal fissure and drains blood from the majority of the outer cerebrum

third ventricle

portion of the ventricular system that is in the region of the diencephalon; sends messages to and receives messages from the lateral ventricles

transverse sinuses

dural sinuses that drain along either side of the occipital–cerebellar space

ventricles

remnants of the hollow center of the neural tube that are spaces for cerebrospinal fluid to circulate through the brain

vertebral arteries

arteries that ascend along either side of the vertebral column through the transverse foramina of the cervical vertebrae and enter the cranium through the foramen magnum

myelinated axons

Which structure predominates in the white matter of the brain?

nerve

Which term describes a bundle of axons in the peripheral nervous system?

parietal

Which lobe of the cerebral cortex is responsible for generating motor commands?

hypothalamus

What region of the diencephalon coordinates homeostasis?

pons

What level of the brain stem is the major input to the cerebellum?

anterior horn

What region of the spinal cord contains motor neurons that direct the movement of skeletal muscles?

cerebral cortex

Brodmann’s areas map different regions of the ________ to particular functions.

ascending pathway

fiber structure that relays sensory information from the periphery through the spinal cord and brain stem to other structures of the brain

association area

region of cortex connected to a primary sensory cortical area that further processes the information to generate more complex sensory perceptions

chief sensory nucleus

component of the trigeminal nuclei that is found in the pons

decussate

to cross the midline, as in fibers that project from one side of the body to the other

dorsal column system

ascending tract of the spinal cord associated with fine touch and proprioceptive sensations

fasciculus cuneatus

lateral division of the dorsal column system composed of fibers from sensory neurons in the upper body

fasciculus gracilis

medial division of the dorsal column system composed of fibers from sensory neurons in the lower body

medial lemniscus

fiber tract of the dorsal column system that extends from the nuclei gracilis and cuneatus to the thalamus, and decussates

mesencephalic nucleus

component of the trigeminal nuclei that is found in the midbrain

multimodal integration area

region of the cerebral cortex in which information from more than one sensory modality is processed to arrive at higher level cortical functions such as memory, learning, or cognition

nucleus cuneatus

medullary nucleus at which first-order neurons of the dorsal column system synapse specifically from the upper body and arms

nucleus gracilis

medullary nucleus at which first-order neurons of the dorsal column system synapse specifically from the lower body and legs

primary sensory cortex

region of the cerebral cortex that initially receives sensory input from an ascending pathway from the thalamus and begins the processing that will result in conscious perception of that modality

sensory homunculus

topographic representation of the body within the somatosensory cortex demonstrating the correspondence between neurons processing stimuli and sensitivity

spinal trigeminal nucleus

component of the trigeminal nuclei that is found in the medulla

spinothalamic tract

ascending tract of the spinal cord associated with pain and temperature sensations

anterior corticospinal tract

division of the corticospinal pathway that travels through the ventral (anterior) column of the spinal cord and controls axial musculature through the medial motor neurons in the ventral (anterior) horn

Betz cells

output cells of the primary motor cortex that cause musculature to move through synapses on cranial and spinal motor neurons

Broca’s area

region of the frontal lobe associated with the motor commands necessary for speech production

cerebral peduncles

segments of the descending motor pathway that make up the white matter of the ventral midbrain

cervical enlargement

region of the ventral (anterior) horn of the spinal cord that has a larger population of motor neurons for the greater number of and finer control of muscles of the upper limb

corneal reflex

protective response to stimulation of the cornea causing contraction of the orbicularis oculi muscle resulting in blinking of the eye

corticobulbar tract

connection between the cortex and the brain stem responsible for generating movement

corticospinal tract

connection between the cortex and the spinal cord responsible for generating movement

executive functions

cognitive processes of the prefrontal cortex that lead to directing goal-directed behavior, which is a precursor to executing motor commands

extrapyramidal system

pathways between the brain and spinal cord that are separate from the corticospinal tract and are responsible for modulating the movements generated through that primary pathway

frontal eye fields

area of the prefrontal cortex responsible for moving the eyes to attend to visual stimuli