Gross Organization of the Mammalian Nervous System

Chapter 7

Anterior/Rostral

Latin for “beak”

Posterior/Caudal

Latin for "toward the tail"

Dorsal

Pointing up/ “Back”

Ventral

Pointing down/ “Belly”

Midline

Invisible line down the middle of the nervous system

Medial

Structures close to the midline

Lateral

Structures farther away from the midline

Ipsilateral

Structures on the same side of the midline

Contralateral

Structures on opposite sides of the midline

Midsagittal Plane

CUTTING into EQUAL right and left sections

Sagittal Plane

Parallel to the midsagittal plane

Horizontal Plane

Cutting horizontally, producing parts that are dorsal and ventral

Coronal Plane

Cutting perpendicular to the sagittal plane, thus producing parts that anterior/rostral and posterior/caudal

Central Nervous System (CNS)

They are bone-encased, and include the brain (which has parts) and the spinal cord

Brain

Consists of the cerebrum, cerebellum, and brain stem

Spinal Cord

Brings information to and from the brain to the skin, joints, and muscles

Cerebrum

The rostral-most and largest part of the brain

Cerebral Hemispheres

Contralateral for receiving sensations and controlling movement

Cerebellum

Ipsilateral for controlling movement

Brain Stem

Relays information from the cerebrum, cerebellum, and spinal cord. A regulator for breathing, consciousness, and body temperature

Spinal Nerve

Exit the spinal cord through notches in the vertebra

Dorsal Root

Attach the nerve to the spinal cord, and carries information to the cord

Ventral Root

Attach the nerve to the spinal cord, and carries information FROM the cord

Peripheral Nervous System (PNS)

Everything that is not in the CNS

Somatic PNS

Voluntary control of the skin, joints, and muscles

Dorsal Root Ganglion

Cell bodies that lay in clusters outside the spinal cord

Visceral PNS

Involuntary “control” of the internal organs, blood vessels, and glands

Autonomic Nervous System (ANS)

Synonym for the visceral PNS

Afferent

“Carry to”

Efferent

“Carry from”

Cranial Nerve

There are 12 that arise from the brain stem and innervate the head

Meninges

The 3 membranes between the skull and brain

Dura Mater

The outtermost layer, and has a leather-like texture

Arachnoid Membrane

Web-like membrane under the dura mater

Pia Mater

The 3rd layer “touching” the brain

Cerebrospinal Fluid (CSF)

Salty, clear liquid in the SUBARACHNOID space

Ventricular System

Fluid-filled caverns and canals in the hollow parts of the brain