PSYB64 Physiological Psychology
Chapter 2 Vocabulary Terms
Rostral/anterior: a directional term meaning toward the head of a four-legged animal.
Caudal/posterior: a directional term meaning toward the tail of a four-legged animal.
Inferior/ventral: a directional term meaning toward the belly of a four-legged animal.
Superior/dorsal: a directional term meaning toward the back of a four-legged animal.
Neuraxis: an imaginary line that runs the length of the spinal cord to the front of the brain.
Midline: an imaginary line dividing the body into two equal halves.
Ipsilateral: a directional term referring to structures on the same side of the midline.
Contralateral: a directional term referring to structures on opposite sides of the midline.
Medial: a directional term meaning toward the midline.
Lateral: a direction term meaning away from the midline.
Proximal: a directional term that means closer to center; usually applied to limbs; opposite of distal.
Distal: a directional term meaning farther away from another structure, usually in reference to limbs.
Coronal section: an anatomical section dividing the brain front to back, parallel to the face. Also known
as the frontal section.
Sagittal section: an anatomical section that is parallel to the midline.
Midsagittal section: a sagittal section that divides the brain into two approximately equal halves.
Horizontal/axial section: an anatomical section that divides the brain from top to bottom.
Meninges: the layers of membranes that cover the central nervous system and the peripheral nerves.
Dura mater: the outmost of the three layers of meninges, found in both the central and peripheral
Arachnoid layer: the middle layer of the meninges covering the central nervous system.
Pia mater: the innermost of the layers of the meninges, found in both the central and peripheral
Subarachnoid space: a space filled with cerebrospinal fluid that lies between the arachnoid and pia
mater layers of the meninges in the central nervous system.
Meningitis: an infection of the meninges.
Cerebrospinal fluid: the special plasma like fluid circulating within the ventricles of the brain, the
central canal of the spinal cord, and the subarachnoid space.
Ventricle: one of four hollow spaces within the brain that contain cerebrospinal fluid.
Choroid plexus: the lining of the ventricles, which secretes the cerebrospinal fluid.
Central canal: the small midline channel in the spinal cord that contains cerebrospinal fluid.
Carotid artery: one of the two major blood vessels that travel up the sides of the neck to supply the
Vertebral artery: one of the important blood vessels that enter the brain from the back of the skull.
Central nervous system: the brain and the spinal cord.
Peripheral nervous system: the nerves exiting the brain and spinal cord that serve sensory and motor
functions for the rest of the body.
Spinal cord: a long cylinder of nervous tissue extending from the medulla to the first lumbar vertebra
Vertebral column: the bones of the spinal column that protect and enclose the spinal cord.
Cervical nerve: one of the first eight spinal nerves that serve the area of the head, neck, and arms.
Thoracic nerve: one of twelve pairs of spinal nerves that serve the torso.
Lumbar nerve: one of the five spinal nerves serving the lower back and legs. Sacral nerve: one of the five spinal nerves that serve the back of the legs and the genitals.
Coccygeal nerve: the most caudal of the spinal nerves.
White matter: an area of neural tissue primarily made up of myelinated axons.
Gray matter: an area of neural tissue primarily made up of cell bodies.
Dorsal horns: gray matter in the spinal cord that contains sensory neurons.
Ventral horns: gray matter in the spinal cord that contains motor neurons.
Reflex: an involuntary action or response.
Patellar reflex: the knee-jerk reflex; a spinal reflex in which tapping below the knee produces a
reflexive contraction of the quadriceps muscle of the thigh, causing the foot to kick.
Withdrawal reflex: a spinal reflex that pulls a body apart away from a source of pain.
Hindbrain: the most caudal division of the brain, including the medulla, pons, and cerebellum.
Midbrain: the division of the brain lying between the hindbrain and forebrain.
Forebrain: the division of the brain containing the diencephalon and the telencephalon.
Brainstem: the lower two thirds of the brain, including the hindbrain and midbrain.
Mylencephalon/medulla: the most caudal part of the hindbrain.
Metencephalon: the division of the hindbrain containing the pons and cerebellum.
Nuclei: collections of cell bodies that share a function.
Reticular formation: a collection of brainstem nuclei, located near the midline from the rostral medulla
up into the midbrain, that regulate sleep and arousal.
Pons: a structure located in the metencephalon between the medulla and midbrain; part of the
brainstem located in the hindbrain.
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.
Cochlear nucleus: a nucleus found in the pons that receives information about sound from the inner ear.
Vestibular nucleus: a group of cell bodies in the pons that receive input about the location and
movement of the head from sensory structures in the inner ear.
Raphe nuclei: nuclei located in the pons that participate in the regulation of sleep and arousal.
Locus coeruleus: a structure in the pons that participates in arousal.
Mesencephalon: another term for midbrain, the division of the brain lying between the hindbrain and
Tectum: the ‘roof’, or dorsal half, of the midbrain.
Tegmentum: the ‘covering’, or ventral half of the midbrain.
Cerebral aqueduct: the small channel running along the midline of the midbrain that connects the third
and fourth ventricles.
Periaqueductal gray: gray matter surrounding the cerebral aqueduct of the midbrain that is believed to
play a role in the sensation of pain.
Red nucleus: a structure located within the reticular formation that communicates motor information
between the spinal cord and the cerebellum.
Substantia nigra: midbrain nuclei that communicate with the basal ganglia of the forebrain.
Superior colliculi: a pair of bumps on the dorsal surface of the midbrain that coordinate visually guided
movements and visual reflexes.
Inferior colliculi: a pair of bumps on the dorsal surface of the midbrain that process auditory
Diencephalon: a division of the forebrain made up of the hypothalamus and the thalamus.
Telencephalon: the division of the brain comprising the cerebral hemispheres. Cerebral hemisphere: one of the two large, globular structures that make up the telencephalon of the
Thalamus: a structure in the diencephalon that processes sensory information, contributes to states of
arousal, and participates in learning and memory.
Hypothalamus: a structure found in the diencephalon that participates in the regulation of hunger,
thirst, sexual behavior, and aggression; part of the limbic system.
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.
Basal ganglia: a collection of nuclei within the cerebral hemispheres that participate in the control of
Caudate nucleus: one of the major nuclei that make up th