Chapter 2 Flashcards
neuroplasticity
The nervous system’s potential for physical or chemical change to adapt to environmental change and to compensate for injury.
phenotypic plasticity
An individual’s capacity to develop into more than one phenotype.
somatic nervous system (SNS)
Part of the PNS that includes the cranial and spinal nerves to and from the muscles, joints, and skin, which produce movement, transmit incoming sensory input, and inform the CNS about the position and movement of body parts.
autonomic nervous system (ANS)
Part of the PNS that regulates the functioning of internal organs and glands.
enteric nervous system (ENS)
Mesh of neurons embedded in the lining of the gut, running from the esophagus through the colon; controls the gut.
afferent
Conducting toward a CNS structure.
efferent
Conducting away from a CNS structure.
meninges
Three layers of protective tissue—dura mater, arachnoid, and pia mater—that encase the brain and spinal cord.
Anterior
Near or toward the front of the animal or the front of the head (see also frontal and rostral)
Caudal
Near or toward the tail of the animal (see also posterior)
Coronal
Cut vertically from the crown of the head down; used to reference the plane of a brain section that reveals a frontal view
Dorsal
On or toward the back of a four-legged animal (equivalent to posterior for human spinal cord); in reference to human brain nuclei, above, and to brain sections, viewed from above
Frontal
Of the front (see also anterior and rostral); in reference to brain sections, a viewing orientation from the front
Horizontal
Cut along the horizon; used to reference the plane of a brain section that reveals a dorsal view
Inferior
Below (see also ventral)
Lateral
Toward the side of the body or brain
Medial
Toward the middle, specifically the body’s midline; in reference to brain sections, a side view of the central structures
Posterior
Near or toward the animal’s tail (see also caudal); for human spinal cord, at the back
Rostral
Toward the beak (front) of the animal (see also anterior and frontal)
Sagittal
Cut lengthways from front to back of the skull to reveal a medial view into the brain from the side; a cut in the midsagittal plane divides the brain into symmetrical halves.
Superior
Above (see also dorsal)
Ventral
On or toward the belly of four-legged animals (see also inferior); in reference to human brain nuclei, below.
cerebrospinal fluid (CSF)
Clear solution of sodium chloride and other salts that fills the ventricles inside the brain and circulates around the brain and spinal cord beneath the arachnoid layer in the subarachnoid space.
cerebral cortex
Thin, heavily folded film of nerve tissue composed of neurons that is the outer layer of the forebrain. Also called neocortex.
temporal lobe
Part of the cerebral cortex that functions in connection with hearing, language, and musical abilities; lies below the lateral fissure, beneath the temporal bone at the side of the skull.
frontal lobe
Part of the cerebral cortex often generally characterized as performing the brain’s executive functions, such as decision making; lies anterior to the central sulcus and beneath the frontal bone of the skull.
parietal lobe
Part of the cerebral cortex that directs movements toward a goal or to perform a task, such as grasping an object; lies posterior to the central sulcus and beneath the parietal bone at the top of the skull.
occipital lobe
Part of the cerebral cortex where visual processing begins; lies at the back of the brain and beneath the occipital bone.
gyri (sing. gyrus)
A small protrusion or bump formed by the folding of the cerebral cortex.
sulci (sing. sulcus)
A groove in brain matter; most are in the neocortex or cerebellum.
stroke
Sudden appearance of neurological symptoms as a result of severely interrupted blood flow.
gray matter
Areas of the nervous system composed predominantly of cell bodies and capillary blood vessels that either collect and modify information or support this activity.
white matter
Areas of the nervous system rich in fat-sheathed neural axons that form the connections between brain cells.
ventricle
One of four cavities in the brain that contain CSF to cushion the brain; may play a role in maintaining brain metabolism.
corpus callosum
Band of white matter containing about 200 million nerve fibers that connects the two cerebral hemispheres to provide a route for direct communication between them.
nuclei (sing. nucleus)
A group of cells forming a cluster that can be identified with special stains to form a functional grouping.
nerve
Large collection of axons coursing together outside the CNS.
tract
Large collection of axons coursing together in the CNS.
brainstem
Central structure of the brain, including the hindbrain, midbrain, thalamus, and hypothalamus, that is responsible for most unconscious behavior.
hindbrain
Evolutionarily the oldest part of the brain; contains the pons, medulla, reticular formation, and cerebellum, structures that coordinate and control most voluntary and involuntary movements.
reticular formation
Midbrain area in which nuclei and fiber pathways are mixed, producing a netlike appearance; associated with sleep–wake behavior and behavioral arousal.
midbrain
Central part of the brain; contains neural circuits for hearing and seeing as well as orienting movements.
tectum
Roof (area above the ventricle) of the midbrain; its functions are sensory processing, particularly visual and auditory, and the production of orienting movements.
tegmentum
Floor (area below the ventricle) of the midbrain; a collection of nuclei with movement-related, species-specific, and pain perception functions.
orienting movement
Movement related to sensory inputs, such as turning the head to see the source of a sound
diencephalon
The between brain, which integrates sensory and motor information on its way to the cerebral cortex.
hypothalamus
Diencephalon structure that contains many nuclei associated with temperature regulation, eating, drinking, and sexual behavior.
thalamus
Diencephalon structure through which information from all sensory systems is integrated and projected into the appropriate region of the neocortex.
forebrain
Evolutionarily the newest part of the brain; coordinates advanced cognitive functions such as thinking, planning, and language; contains the limbic system, basal ganglia, and neocortex.
neocortex (cerebral cortex)
Most recently evolved outer layer (new bark) of the forebrain, composed of about six layers of gray matter; constructs our reality.
cytoarchitectonic map
Map of the neocortex based on the organization, structure, and distribution of the cells.
basal ganglia
Subcortical forebrain nuclei that coordinate voluntary movements of the limbs and body; connected to the thalamus and to the midbrain.
Parkinson disease
Disorder of the motor system correlated with a loss of dopamine from the substantia nigra and characterized by tremors, muscular rigidity, and a reduction in voluntary movement.
Tourette syndrome
Disorder of the basal ganglia characterized by tics, involuntary vocalizations (including curse words and animal sounds), and odd, involuntary movements of the body, especially of the face and head.
limbic system
Disparate forebrain structures lying between the neocortex and the brainstem that form a functional system controlling affective and motivated behaviors and certain forms of memory; includes cingulate cortex, amygdala, and hippocampus, among other structures.
cranial nerve
One of a set of 12 nerve pairs that control sensory and motor functions of the head, neck, and internal organs.
vertebrae (sing. vertebra)
The bones that form the spinal column.
1 Olfactory
Smell
2 Optic
Vison
3 Oculomotor
Eye Movement
4 Trochlear
Eye Movement
5 Trigeminal
Masticatory movements and facial sensation
6 Abducens
Eye Movement
7 Facial
Facial movement and sensation
8 Auditory vestibular
Hearing and balance
9 Glossopharyngeal
Tongue and pharynx movement and sensation
10 Vagus
Heart, blood vessels, viscera, movement of larynx and pharynx
11 Spinal
accessory Neck movement
12 Hypoglossal
Tongue movement
dermatome
Body segment corresponding to a segment of the spinal cord.
law of Bell and Magendie
The principle that sensory fibers are dorsal and motor fibers are ventral.
sympathetic division
Part of the autonomic nervous system; arouses the body for action, such as mediating the involuntary fight-or-flight response to alarm by increasing heart rate and blood pressure.
parasympathetic division
Part of the autonomic nervous system; acts in opposition to the sympathetic division—for example, preparing the body to rest and digest by reversing the alarm response or stimulating digestion.
Alzheimer disease
Degenerative brain disorder related to aging that first appears as progressive memory loss and later develops into generalized dementia.
excitation
Increase in the activity of a neuron or brain area.
inhibition
Decrease in the activity of a neuron or brain area.
