chapter 2 vocab

Functional Neuroanatomy and the Evolution of the Nervous System

**afferent, nerve**

A nerve that carries sensory information to the CNS.

**amygdala**

An almond-shaped structure in the rostral temporal lobes that is part of the limbic system.

**anterior–posterior**

A directional term meaning toward the front. A directional term meaning toward the rear.

**arachnoid layer**

The middle layer of the meninges covering the central nervous system (CNS).

**association cortex**

An area of the cortex that does not process sensory or motor information directly but rather serves as a bridge between areas that do process these functions.

**autonomic nervous system**

The division of the peripheral nervous system (PNS) that directs the activity of the glands, organs, and smooth muscles of the body.

**basal ganglia**

A collection of nuclei within the cerebral hemispheres that participate in the control of voluntary movement.

**brainstem**

The hindbrain and midbrain.

**caudal**

A directional term meaning toward the tail of a four-legged animal.

**caudate nucleus**

One of the major input nuclei in the basal ganglia.

**central canal**

The small midline channel in the spinal cord that contains CSF.

**central nervous system (CNS)**

The brain and spinal cord.

**central sulcus**

The fissure separating the frontal and parietal lobes of the cerebral cortex.

**cerebellum**

A structure located in the metencephalon that participates in balance, muscle tone, muscle coordination, some types of learning, and possibly higher cognitive functions in humans.

**cerebral aqueduct**

The small channel running along the midline of the midbrain that connects the third and fourth ventricles.

**cerebral hemispheres**

One of the two large, globular structures that make up the telencephalon of the forebrain.

**cerebrospinal fluid (CSF)**

The special plasma-like fluid circulating within the ventricles of the brain, the central canal of the spinal cord, and the subarachnoid space.

**cingulate cortex**

A segment of older cortex just dorsal to the corpus callosum that is part of the limbic system.

**contralateral**

A directional term referring to structures on opposite sides of the midline.

**coronal sections**

An anatomical section dividing the brain front to back, parallel to the face.

**corpus callosum**

A wide band of axons connecting the right and left cerebral hemispheres.

cranial nerves

Twelve pairs of nerves that exit the brain as part of the peripheral nervous system (PNS).

**diencephalon**

A division of the forebrain made up of the hypothalamus, the thalamus, and the retina of the eye.

**distal**

A directional term meaning farther away from another structure, usually in reference to limbs; opposite of proximal.

**dorsal**

A directional term meaning toward the back of a four-legged animal.

**dorsolateral prefrontal cortex (DLPC)**

An area located at the top and sides of the frontal lobe that participates in executive functions such as attention and the planning of behavior.

**dura mater**

The outermost of the three layers of meninges.

**efferent, nerve**

A nerve that carries motor commands away from the CNS.

**endocrine system**

Glands that secrete hormones directly into the blood supply.

**enteric nervous system**

A division of the autonomic nervous system consisting of neurons embedded in the lining of the gastrointestinal system.

**fitness**

The ability of an organism with one genetic makeup to reproduce more successfully than organisms with other types of genetic makeup.

**forebrain**

The division of the brain containing the diencephalon and the telencephalon.

**frontal lobe**

The most rostral lobe of the cerebral cortex, separated from the parietal lobe by the central sulcus and from the temporal lobe by the lateral sulcus.

**globus pallidus**

One of the nuclei making up the basal ganglia that performs both intrinsic and output functions.

gray matter

An area of neural tissue primarily made up of cell bodies.

**gut–brain axis (GBA)**

A two-way communication system between the enteric nervous system and the brain.

**gyri**

One of the “hills” on the convoluted surface of the cerebral cortex.

**hindbrain**

The most caudal division of the brain, including the medulla, pons, and cerebellum.

**hippocampus**

A structure deep within the cerebral hemispheres that is involved with the formation of long-term declarative memories and responses to stress; part of the limbic system.

**hominin**

A primate in the family Hominidae, of which *Homo sapiens* is the only surviving member.

***Homo sapiens***

The species of modern humans.

**horizontal section**

An anatomical section that divides the brain from top to bottom.

inferior

below

**inferior colliculi**

A pair of bumps on the dorsal surface of the midbrain that processes auditory information.A pair of bumps on the dorsal surface of the midbrain that processes auditory information.

**insula**

The cortex located within the lateral sulcus between the frontal/parietal and temporal lobes. Referred to as “the fifth lobe.”

**ipsilateral**

A directional term referring to structures on the same side of the midline.

**lateral**

A directional term meaning away from the midline.

**lateral sulcus**

The fissure separating the temporal and frontal lobes of the cortex.

**lateral sulcus**

The fissure separating the temporal and frontal lobes of the cortex.

**limbic system**

A collection of forebrain structures that participate in emotional behavior, motivated behavior, and learning.

**locus coeruleus**

A structure in the pons that participates in arousal, sleep, and mood.

**longitudinal fissure**

The major fissure dividing the two cerebral hemispheres on the dorsal side of the brain.

medial

A directional term meaning toward the midline.

**medulla**

The most caudal part of the hindbrain; contains several cranial nerve nuclei and participates in the management of breathing, heart rate, and blood pressure.

**meninges**

The layers of membranes that cover the central nervous system (CNS).

**mesencephalon**

Another term for midbrain, the division of the brain lying between the hindbrain and forebrain.

**metencephalon**

The division of the hindbrain containing the pons and cerebellum

**midbrain**

The division of the brain lying between the hindbrain and forebrain, including the superior and inferior colliculi, periaqueductal gray, red nucleus, and substantia nigra.

**myelencephalon**

The most caudal part of the hindbrain.

**natural selection**

The process by which favorable traits would become more common and unfavorable traits would become less common in subsequent generations due to differences among organisms in their ability to reproduce successfully.

**nucleus accumbens**

An input nucleus in the basal ganglia known to be important in reward and addiction; also known as the ventral striatum.

**occipital lobe**

The most caudal lobe of the cortex; location of primary visual cortex.

**orbitofrontal cortex**

An area of the frontal lobe located just behind the eyes involved in impulse control; damage to this area is associated with antisocial behavior.

**parasympathetic nervous systems**

The division of the autonomic nervous system responsible for rest and energy storage.

**parietal lobe**

One of the four lobes of the cerebral cortex; located between the frontal and occipital lobes.

**periaqueductal gray**

Gray matter surrounding the cerebral aqueduct of the midbrain that is believed to play roles in sleep, complex movements, the sensation of pain, and parenting behavior.

**peripheral nervous system (PNS)**

The nerves exiting the brain and spinal cord that serve sensory and motor functions for the rest of the body.

**pia mater**

The innermost of the layers of meninges in the CNS.

**pituitary gland**

A gland located just above the roof of the mouth that is connected to the hypothalamus and serves as a major source of hormones.

**pons**

A structure located in the metencephalon between the medulla and midbrain that participates in the management of states of consciousness.

**postcentral gyrus**

The fold of parietal lobe tissue just caudal to the central sulcus; the location of the primary somatosensory cortex.

posterior

behind

**precentral gyrus**

The fold of frontal lobe tissue just rostral to the central sulcus; the location of the primary motor cortex.

**primary auditory cortex**

An area of the sensory cortex located within the temporal lobe that provides the initial cortical processing of sound information.

**primary motor cortex**

An area of the cortex located within the frontal lobe that provides the highest level of command to the motor systems.

**primary somatosensory cortex**

An area of the sensory cortex located within the parietal lobe that processes body senses such as touch, position, skin temperature, and pain.

**primary visual cortex**

An area of the sensory cortex located within the occipital lobe that provides the initial cortical processing of visual information.

**proximal**

A directional term that means closer to center; usually applied to limbs; opposite of distal.

**putamen**

One of the input nuclei contained in the basal ganglia.

**raphe nuclei**

Nuclei located in the pons that participate in the regulation of sleep, arousal, mood, appetite, and aggression.

**red nucleus**

A structure located within the reticular formation that communicates motor information between the spinal cord and the cerebellum; source of the rubrospinal tract.

**reticular formation**

A collection of brainstem nuclei located near the midline from the rostral medulla up into the midbrain that regulates consciousness, arousal, movement, and pain.

**rostral**

directional term meaning toward the head of a four-legged animal.

**sagittal sections**

An anatomical section that is parallel to the midline.

**somatic nervous system**

The peripheral nervous system (PNS) division that brings sensory input to the brain and spinal cord and returns commands to the muscles.

**spinal cord**

A long cylinder of nervous tissue extending from the medulla to the first lumbar vertebra.

**subarachnoid space**

A space filled with cerebrospinal fluid (CSF) that lies between the arachnoid and pia mater layers of the meninges in the central nervous system (CNS).

**substantia nigra**

Midbrain nuclei that communicate with the basal ganglia of the forebrain.

**subthalamic nucleus**

An intrinsic nucleus in the basal ganglia, located ventral to the thalamus.

**sulci**

A “valley” in the convoluted surface of the cerebral cortex.

**superior colliculi**

A pair of bumps on the dorsal surface of the midbrain that coordinates visually guided movements and visual reflexes

**superior–inferior**

A directional term meaning toward the top. A directional term meaning toward the bottom.

**sympathetic**

The division of the autonomic nervous system that coordinates arousal.

**tectum**

The “roof,” or dorsal portion, of the midbrain.

**tegmentum**

The “covering,” or ventral, portion of the midbrain.

**telencephalon**

The division of the brain comprising the bulk of the cerebral hemispheres.

**temporal lobe**

The lobe of the cerebral cortex lying ventral and lateral to the frontal and parietal lobes and rostral to the occipital lobe.

**thalamus**

A structure in the diencephalon that processes sensory information, contributes to states of arousal, and participates in learning and memory.

**ventral**

**ventral**

A directional term meaning toward the belly of a four-legged animal.

**ventricles**

One of four hollow spaces within the brain that contain CSF.