Organs and Atomic Structures

Vocabulary flashcards for key terms related to the brain and nervous system.

Brain

Contained within the cranium, the center for coordinating body activities and comprises the cerebrum, cerebellum, and brainstem.

Cerebrum

Largest portion of the brain, divided into left and right hemispheres. Controls skeletal muscles, interprets general senses, and contains centers for sight and hearing. Intellect, memory, and emotional reactions also take place here.

Gray matter

Outer portion of the cerebrum, contains neuron cell bodies that collect and process information. Forms the inner portion of the spinal cord.

White matter

Inner portion of the cerebrum, contains axons that extend from neurons; conveys information. Forms the outer portion of the spinal cord.

Ventricles

Cavities within the brain that contain cerebrospinal fluid (CSF). CSF flows through the subarachnoid space.

Cerebellum

Located under the posterior portion of the cerebrum; assists in the coordination of skeletal muscles to maintain balance (also called hindbrain).

Brainstem

Stemlike portion of the brain that connects with the spinal cord; contains centers that control respiration and heart rate. Comprises pons, medulla oblongata, and midbrain.

Pons

Connects the cerebrum with the cerebellum and brainstem.

Medulla Oblongata

Located between the pons and spinal cord. Contains centers that control respiration, heart rate, and muscles in blood vessel walls.

Midbrain

Most superior portion of the brainstem.

Cerebrospinal fluid (CSF)

Clear, colorless fluid contained in the ventricles that flows through the subarachnoid space. Cushions the brain and spinal cord, transports nutrients, and clears metabolic waste.

Spinal cord

Passes through the vertebral canal, extending from the medulla oblongata to the level of the second lumbar vertebra. Conducts nerve impulses to and from the brain and initiates reflex action.

Meninges

Three layers of membrane that cover the brain and spinal cord.

Dura mater

Tough outer layer of the meninges.

Arachnoid

Delicate middle layer of the meninges, loosely attached to the pia mater by weblike fibers, which allow for the subarachnoid space.

Pia mater

Thin inner layer of the meninges.

Nerve

Cordlike structure made up of fibers that carries impulses from one part of the body to another. There are 12 pairs of cranial nerves and 31 pairs of spinal nerves.

Ganglion

Group of nerve cell bodies located outside the central nervous system.

Glia

Specialized cells located throughout the nervous system that support and nourish nervous tissue. Also called neuroglia, they do not conduct impulses.

Neuron

Nerve cell that conducts impulses to carry out the function of the nervous system. Destroyed neurons in the central nervous system cannot be replaced.