Ch 3 vocab Flashcards
stroke
an interruption of blood flow to the brain that kills brain cells and causes neurological symptoms to appear suddenly.
ischemia
deficient blood flow to the brain due to functional constriction of a blood vessel by a clot.
hemorrhagic stroke
stroke resulting from a burst vessel bleeding into the brain
Tissue plasminogen activator
(t-PA) breaks up clots and allows blood flow to return to the affected region.
tracts
fiber pathways in the brain
ipsilateral
structures that lie on the same side of the brain
contralateral
structures on opposite sides of the brain
bilateral
structures on both sides of the brain
Proximal
structures that are close together
Distal
structures farther away from each other
afferent
toward the brain
efferent
away from the brain
precentral gyrus
aka: gyrus precentralis (Latin), motor strip, Jackson’s strip, primary motor cortex (M1), somatomotor strip, motor homunculus, area pyramidalis.
parasympathetic nerves
part of ANS, “rest and digest.”
sympathetic nerves
part of ANS, “fight or flight.”
meninges
triple-layered set of membranes including the dura mater, arachnoid membrane and pia mater.
hydrocephalus
“water brain” a build up of CSF from a blockage of outflow channels.
blood-brain barrier
limits the movement of chemicals from the rest of the body into the CNS and protects the brain from toxic substances and infections.
anterior cerebral artery
(ACA) irrigates the medial and dorsal parts of the cortex.
middle cerebral artery
(MCA) irrigates the lateral surface of the cortex
posterior cerebral artery
irrigates ventral and posterior surfaces
neural stem cell
a germinal cell, stem cells of the brain that create neurons and glia.
progenitor cells
migrate and act as precursor cells that give rise to blasts.
blasts
nondividing primitive nervous system cell types
sensory receptor
a cell that transduces sensory information into nervous system activity
bipolar neuron
simplest sensory receptor. consists of a cell body with a dendrite on one side and an axon on the other and is found in the retina of the eye.
somatosensory neuron
projects from a sensory receptor in the body to the spinal cord. Its dendrites and axons are connected, which speeds information conduction as it does not have to pass through the cell body.
Interneurons
link up sensory and motor neuron activity in the CNS. Multiple dendrites that branch extensively, with a lot of different types. includes stellate cells, pyramidal cells, and Purkinje cells of the cerebellum.
motor neurons
brainstem and spinal cord. Project to facial and body muscles. together are called the “final common path”
Ependymal cells
line the brain’s ventricles and make CSF.
Astroglia
provide structural support and nutrition to neurons.
Microglia
(tiny glia) fight infection and remove debris.
Oligodendroglia
(few branches) insulate neurons in the CNS
Schwann cells
insulate sensory and motor neurons in the PNS.
myelin
insulation for sensory and motor neurons; lipid.
gray matter
grey-brown color from capillaries and neuronal cell bodies. cortex is made up mostly of layers of neurons of grey matter.
white matter
consists largely of axons that extend from these cell bodies to form connections with neurons in other brain areas.
Reticular matter
gray and white “net” like appearance. mixture of cell bodies and axons
ganglia
clusters or layers of neurons in the PNS.
nerves
fibers and fiber pathways that enter and leave the CNS. called tracts when in the CNS.
prosencephalon
“front brain” responsible for olfaction in reptiles
mesencephalon
“middle brain” seat of vision and hearing in reptiles
rhombencephalon
“hind brain” controls movement and balance in reptiles
Telencephalon
“endbrain” advanced prosencephalon in mammals that make up the cerebral hemispheres.
diencephalon
“between brain” advanced posterior prosencephalon in mammals, includes the thalamus.
metencephalon
“across brain” advanced rhombencephalon in mammals that includes the cerebellum
myelencephalon
“spinal brain” advanced rhombencephalon that includes the lower region of the brainstem.
ventricles
hollow pockets in the brain that store CSF.
cerebral aqueduct
connects the third or fourth ventricles
dermatome
“skin cut” 30 total; sections of body that correspond to specific nerves of the spinal cord.
posterior root
band of strands of afferent fibers that enter the posterior spinal cord to bring information in from the body’s sensory receptors.
anterior root
collection of spinal nerve fibers that exit the spinal cord anteriorly that take efferent fibers to carry information to the muscles.
Bell-Magendie Law
principle that the dorsal or posterior roots are sensory and the ventral or anterior roots are motor.
paraplegic
persons whose spinal cord is cut below the cervical vertebrae and who have no use of their legs.
quadraplegic
persons with a spinal cord cut above the cervical vertebrae that have no use of legs or arms.
reflexes
produced by the spinal cord’s neural circuits, specific movements that elicit specific forms of sensory stimulation.
flexion reflexes
stimulation of pain and temperature receptors in a limb produce these. reflex that brings the limb inward, toward the body and away from injury.
extension reflexes
stimulation of fine touch and muscle receptors cause this, which extend the limb outward, away from the body.
cranial nerves
12 pairs, convey sensory and motor signals to and from the head.
referred pain
pain felt in one area of the body due to pain in internal organs.
cerebellum
most distinctive hindbrain structure; protrudes above the brainstem core, gathered into folia like the cortex but smaller, and its base contains several nuclei that send connections to other parts of the brain. evolved in size parallel to the neocortex. 4x more neurons than cortex, but dense.
Plays a role in motor coordination/learning and may participate in coordinating other mental processes.
Damage to the area results in equilibrium problems, postural defects, and impairments of skilled motor activity.
folia
folds of tissue in the cerebellum
reticular formation
see fig. 3.18 pg 71 for position; reticular activating system. responsible for maintaining arousal or consciousness.
Damage results in permanent unconsciousness.
tectum
“roof” the roof of the third ventricle; receives a massive amount of sensory information from the ears and eyes.
tegmentum
located anteriorly, a motor structure or the “floor” of the third ventricle
superior colliculi
one pair of nuclei in the tectum that receive projections from the retina
inferior colliculi
lower pair of nuclei in the tectum that receive projections from the ear
red nucleus
nuclei of the tegmentum that control limb movements
substantia nigra
“black substance” nuclei of the tegmentum that connect to the forebrain. this connection is important for rewarding behaviors such as approaching desired objects.
periacqueductal grey matter
PAG; made up of cell bodies that surround the cerebral aqueduct and contains circuits for controlling species-typical behaviors (sexual behavior) and for modulating pain responses.
hypothalamus
.3% of brain matter, 22 nuclei, take part in nearly all aspects of motivated behavior. connects to and interacts with the pituitary gland to control endocrine functions.
thalamus
largest structure in the diencephalon; 20 nuclei that project to speciric areas of the cerebral cortex (Fig 3.20, pg. 72)
epithalamus
posterior end of the diencephalon; includes pineal gland (melatonin) and the habenula (regulates hunger and thirst.)
basal ganglia
lies beneath the anterior regions of the cortex, collection of nuclei forming a circuit with the cortex. associated with movement and learning.
neocortex
six layered, “new bark”
limbic system
plays a role in self-regulatory behaviors including emotion, personal memories, spatial behavior, and social behavior.
amygdala
“almond” nuclei at the base of the temporal lobe that participates in emotion (part of limbic system)
hippocampus
“sea horse” structure lying in the anterior medial region of the temporal lobe that participates in personal memory.
the cingulate cortex
“girdle” a three layered strip of limbic cortex that lies just above the corpus callosum along the medial walls of the cerebral hemispheres. is involved in sexual behavior, among other social interactions.
central sulcus
binds frontal lobes posteriorly.
projection map
shows locations on the cortex that process various types of sensory information and those that produce movement.
primary areas
receive projections from the major sensory systems or send motor projections to the muscles.
secondary areas
interconnected w primary areas, they are involved in elaborating information received from primary areas or (primary motor) send commands to the primary area.
tertiary areas
aka association cortex; encompass all cortex not specialized for sensory or motor function. instead they mediate complex activities such as language, planning, memory, and attention.
cytoarchitectonic maps
(cell maps) parcel the cortex into many subregions.
Brodmann’s map
early cytoarchitectonic map (1909) by Korbinian Brodmann. divided the brain at the central sulcus and then examined the front and back halves separately, numbering new conformations of cells as he found them but without following a methodical path over the surface.
homotopic points
points that correspond to each other in the brain’s mirror-image structure.
decussations
crossings of sensory and motor fibers along the midline of the nervous system.
