PSYC 2240 Chapter 2

Afferent

Information that is incoming or sensory travelling toward the CNS or one of its parts

Autonomic Nervous System (ANS)

Division of peripheral nervous system that produces “rest & digest” response via parasympathetic nerves and “fight or flight” response via sympathetic nerves, balancing body’s internal functions

Axon

A nerve fiber that extends from a neuron & transmits electrical impulses away from cell body to other neurons, muscles, or glands 

Brainstem

Central core of brain, responsible for critical life functions (heart rate, breathing, sleeping, eating). Point of origin for cranial nerves 

CNS

Core of the nervous system, comprising brain & spinal cord, which mediates behavior

Central Sulcus

A prominent sulcus running across top of cerebrum, separating frontal lobe from parietal lobe

Cerebellum

The "little brain" located at the back of the brain, ventral to the cerebrum; involved in motor coordination, balance, and fine-tuning movement.

Cerebral Cortex

The heavily folded, outer layer of the cerebral hemispheres, often referred to as the brain's "bark." It is composed of gray matter and is crucial for higher-order functions.

Cerebrospinal Fluid (CSF)

A colorless solution that flows in the ventricles and around the brain and spinal cord, providing cushioning, buoyancy, and a stable chemical environment.

Contralateral

Located on or affecting the opposite side of the body. For example, the left hemisphere controls the contralateral (right) side of the body.

Coronal Section

A cut through the brain in a vertical plane, from the crown of the head down, yielding a frontal view.

Corpus Callosum

A large band of white matter containing millions of nerve fibers that connects the left and right cerebral hemispheres, allowing them to communicate.

Efferent

Information that is outgoing or motor, traveling away from the Central Nervous System (CNS) or one of its parts.

Encephalitis

An inflammation of the brain itself, often caused by a viral or microbial infection.

Enteric Nervous System (ENS)

A mesh of neurons embedded in the lining of the gut that controls digestion. It can communicate with the CNS but mostly operates autonomously.

Epigenetics

The study of factors that influence how genes express specific traits without changing the DNA sequence itself, often through chemical markers or "tags."

Frontal Lobe

The lobe of the brain located at the front of each cerebral hemisphere, responsible for executive functions, decision-making, and voluntary movement.

Gray Matter

Neural tissue that is darker in appearance, largely composed of neuron cell bodies, capillaries, and dendrites, where information is collected and processed.

Gyrus (pl. Gyri)

A ridge or "hill" on the folded surface of the cerebral cortex.

Hemisphere

One of the two nearly symmetrical halves of the cerebrum (left and right).

Ipsilateral

Located on or affecting the same side of the body.

Lateral Fissure

A deep sulcus that travels along the sides of the brain, separating the temporal lobe from the frontal and parietal lobes.

Longitudinal Fissure

The deep groove that runs between the left and right cerebral hemispheres.

Meninges

The triple-layered protective covering of the brain and spinal cord, consisting of the dura mater (outer layer), arachnoid layer (middle layer), and pia mater (inner layer).

Meningitis

An infection and inflammation of the meninges, particularly the pia mater and arachnoid layer, as well as the cerebrospinal fluid.

Neuroplasticity

The nervous system's fundamental potential to physically or chemically modify itself in response to a changing environment, learning, experience, or injury. It is the hallmark of nervous system functioning.

Neuron

A nerve cell; the fundamental unit of the brain and nervous system responsible for receiving, processing, and transmitting information through electrical and chemical signals.

Nucleus (in Neuroanatomy)

A cluster of neuron cell bodies within the central nervous system, often serving a specific function.

Occipital Lobe

The lobe at the back of each cerebral hemisphere, where visual processing begins.

Parietal Lobe

The lobe at the top of the skull, behind the frontal lobe, involved in directing movement toward a goal and processing sensory information related to touch, spatial awareness, and navigation.

Peripheral Nervous System (PNS)

The part of the nervous system outside the brain and spinal cord, including all cranial and spinal nerves and their branches.

Phenotype

The observable characteristics or traits of an individual, which result from the interaction of its genotype (genetic makeup) with the environment.

Phenotypic Plasticity

The capacity of an individual with a given genotype to develop a range of phenotypes in response to different environmental conditions.

Sagittal Section

A cut through the brain lengthways from front to back. A cut in the midsagittal plane divides the brain into symmetrical left and right halves.

Somatic Nervous System (SNS)

The division of the peripheral nervous system that transmits sensory information to the CNS from the muscles, joints, and skin, and carries motor commands from the CNS to produce movement.

Stroke

The sudden death of brain cells due to a blockage (ischemic stroke) or rupture (hemorrhagic stroke) of a blood vessel in the brain, leading to a severe reduction in blood flow.

Sulcus pl Sulci

A groove or "valley" on the folded surface of the cerebral cortex.

Temporal Lobe

The lobe on the side of each cerebral hemisphere, below the parietal lobe, responsible for higher-order hearing, language, musical abilities, and facial recognition.

Tract

A bundle of nerve fibers (axons) that travel together within the central nervous system.

Ventricles

A system of four interconnected cavities within the brain (lateral, third, and fourth ventricles) filled with cerebrospinal fluid.

White Matter

Neural tissue that is lighter in appearance, composed primarily of myelinated nerve fibers (axons) that form connections between different areas of gray matter.