Anatomy Exam 3 Content

Chapters 13, 9-11

Neurology

The study of the nervous system that includes the brain, spinal cord, and nerves.

Central Nervous System

Confined within the dorsal cavity, includes the brain and spinal cord.

Peripheral Nervous System

Includes cranial and spinal nerves.

Neurons

Functional cells of the nervous system that include fibrous extensions called dendrites and axons.

Dendrites

Neuron fibers that function as receptors and conduct impulses to the cell body, highly branched.

Axons

Neuron fiber that conducts impulses away from the cell body to another neuron, gland, or muscle.

Myelin Sheath

White, fatty substance that insulates and protects some axons.

Schwann Cells

Entire cells wrapped around the axon in the PNS.

Synapse

Tiny gap where impulses transfer at junction points between cells.

Synaptic Cleft/Node of Ranvier

Tiny gaps in the myelin sheath.

Neuroglia/Glial Cell

A support cell that surrounds the neuron.

Nerve

Many neurons bundled together in the PNS.

Tract

Many neurons bundled together in the CNS.

Fascicles

Organized nerves/tracts bound together by connective tissue.

Sensory/Afferent Neurons

Conduct impulses to the spinal cord and brain.

Motor/Efferent Neurons

Carry impulses from the CNS to muscles and glands.

Interneurons/Central/Association Neurons

Carry impulses from place to place within the CNS.

Bipolar Neurons

Contain a single dendrite at one end and a single axon on the other end.

Multipolar Neuron

Contain several dendrites at one end and a single axon on the other end.

Spinal Cord

Link between spinal nerves and the brain, coordinates actions that do not involve the brain, extends from the foramen magnum to the last lumbar rib, cauda equina, filum terminal.

Cauda Equina

Individual nerves that fan out from the end of the spinal cord like a horse’s tail within the vertebral canal.

Filum Terminal

Non-nervous tissue tip that stabilizes the distal spinal cord.

Myelinated Axons

Axons surrounded by white matter/myelin sheath.

Encephalon

Brain

Ventricles

4 cavities within the brain: right lateral, left lateral, 3rd ventricle, 4th ventricle.

Choroid Plexus

Capillaries that line each ventricle and produces cerebrospinal fluid.

Cerebrospinal Fluid

Circulates around the brain and spinal cord to support nervous tissue and cushion in the event of shock, deposited into the subarachnoid space of the meninges.

Meninges

3 layers of protective membrane that surround the brain and spinal cord: Pia Mater, Arachnoid Mater, Dura Mater, (Subarachnoid Space).

Pia Mater

Inner layer of the meninges.

Arachnoid Mater

Middle layer of the meninges loosely attached to the pia mater to form space for the cerebrospinal fluid.

Dura Mater

Outermost layer of the meninges that is fused to cranial bones.

Subarachnoid Space

Space between the layers of the meninges to allow cerebrospinal fluid to flow.

CNS: Parts of the Brain

Cerebrum, Diencephalon, Brain Stem, Cerebellum.

Cerebrum

Largest and most superior portion of the CNS. Divided into left and right hemispheres by a longitudinal fissure.

Corpus Callosum

Bride between the 2 hemispheres of the cerebrum.

Cerebral Cortex

Thin layer of grey matter that covers each hemisphere of the cerebrum, responsible for conscious thought, reasoning, and abstract mental functions.

4 Lobes of the Cerebrum

Frontal, parietal, temporal, occipital.

Cerebrum: Frontal Lobe

Involved in thinking, memory, behavior, and movement.

Cerebrum: Parietal Lobe

Involved with language and touch.

Cerebrum: Temporal Lobe

Involved with hearing, learning, and feelings.

Cerebrum: Occipital Lobe

Involved with sight and associating sight with meaning.

CNS: Diencephalon

Located between the cerebral hemispheres and the brain stem, includes thalamus and hypothalamus.

Thalamus

Sorts out all sensory impulses and directs them to certain areas of the cerebral cortex.

Hypothalamus

Control center for body temperature, food intake, and water balance.

CNS: Brain Stem

Most inferior portion of the brain that connects other regions to the spinal cord, responsible for breathing, heart rate, and temperature. Divided into 3 sections: Midbrain, Pons, and Medulla Oblongata.

Brain Stem: Midbrain

Center for certain eye and ear reflexes.

Brain Stem: Pons

Important connecting link between cerebellum and the rest of the nervous system.

Medulla Oblongata

Control Center for blood gas levels and blood pressure.

CNS: Cerebellum

Comprised of 2 lateral hemispheres and a middle portion, coordinates voluntary muscles and helps maintain balance and muscle tone.