2. Describing features of the nervous system
2
The gross anatomy of the brain was
described long ago, and everything that
could be seen without the aid of a
microscope was given a name.
Early anatomists named most brain
structures according to their similarity to
commonplace objects: amygdala, or
“almond-shaped object”; hippocampus,
or “sea horse”; genu, or “knee”; cortex,
or “bark”; pons, or “bridge”; uncus, or
“hook,” to give a few examples.
https://limbicperformancesystem.com/the-powerful-almond/
https://en.m.wikipedia.org/wiki/File:Hippocampus_and_seahorse.JPG
3. Describing features of the nervous system
3
Neuroanatomical directions as they
pertain to the human nervous system.
When describing features of a
structure as complex as the brain, we
need to use terms denoting directions.
Directions in the nervous system are
normally described relative to the
neuraxis, an imaginary line drawn
through the length of the central
nervous system, from the lower end of
the spinal cord up to the front of the
brain.
Carlson. N.R. (2013). Physiology of behaviour. Pearson.
4. Describing features of the nervous system
4
Neuroanatomical directions as they pertain to the human nervous system.
• Anterior: With respect to the central nervous system, located near or toward the head.
• Posterior: With respect to the central nervous system, located near or toward the tail.
• Rostral: “Toward the beak”; with respect to the central nervous system, in a direction along the neuraxis
toward the front of the face.
• Caudal: “Toward the tail”; with respect to the central nervous system, in a direction along the neuraxis
away from the front of the face.
• Dorsal: “Toward the back”; with respect to the central nervous system, in a direction perpendicular to
the neuraxis toward the top of the head or the back.
• Ventral: “Toward the belly”; with respect to the central nervous system, in a direction perpendicular to
the neuraxis toward the bottom of the skull or the front surface of the body.
5. Describing features of the nervous system
5
https://www.anatomynote.com/human-anatomy/gross-view-of-
human-body/directional-references-of-human-body/
https://www.quora.com/What-does-each-of-these-relative-terms-mean-posterior-
ventral-and-dorsal-in-biology-What-are-some-examples-of-each
6. Describing features of the nervous system
6
Neuroanatomical directions as they pertain to the human nervous
system.
• Lateral: Toward the side of the body, away from the middle.
• Medial: Toward the middle of the body, away from the side.
• Ipsilateral: Located on the same side of the body.
• Contralateral: Located on the opposite side of the body.
https://www.sciencephoto.com/media/779239/view/human-male-figure-with-directional-terms
8. Describing features of the nervous system
8
Neuroanatomical terms indicating brain slices and planes of section as they pertain to the human nervous
system.
To see what is in the nervous system, we have to cut it open; to be able to convey information about what
we find, we slice it in a standard way. We can slice the nervous system in three ways:
• Transversely, like a salami, giving us cross sections (also known as frontal sections when referring to the
brain).
• Parallel to the ground, giving us horizontal sections.
• Perpendicular to the ground and parallel to the neuraxis, giving us sagittal sections. The midsagittal
plane divides the brain into two symmetrical halves.
12. Major divisions of the nervous system
12
The nervous system consists of
the brain and spinal cord,
which make up the central
nervous system (CNS), and the
cranial nerves, spinal nerves,
and peripheral ganglia, which
constitute the peripheral
nervous system (PNS). The CNS
is encased in bone: The brain is
covered by the skull, and the
spinal cord is encased by the
vertebral column.
http://www.pharmacy180.com/article/divisions-of-the-nervous-system-3541/
14. Summary
14
• Anatomists have adopted a set of terms to describe the locations of parts of the body.
• Anterior is toward the head, posterior is toward the tail, lateral is toward the side, medial is
toward the middle, dorsal is toward the back, and ventral is toward the front surface of the
body.
• In the special case of the nervous system, rostral means toward the beak (or nose), and caudal
means toward the tail. Ipsilateral means “same side,” and contralateral means “other side.”
• A cross section (or, in the case of the brain, a frontal section) slices the nervous system at right
angles to the neuraxis, a horizontal section slices the brain parallel to the ground, and a
sagittal section slices it perpendicular to the ground, parallel to the neuraxis.
• The central nervous system consists of the brain and spinal cord, and the peripheral nervous
system consists of the spinal and cranial nerves and peripheral ganglia.
15. REFERENCES
Books:
• Pinel. J.P.J., & Barnes. S.J. (2014). Introduction to biopsychology. Pearson.
• Carlson. N.R. (2013). Physiology of behaviour. Pearson.
• Rozenweig, M. H. (1989). Physiological Psychology.,Random, New York.
• Levinthal, C.R. (1991). Introduction to Physiological Psychology. New Jersey: Prentice Hall.
Further readings:
https://courses.lumenlearning.com/cuny-csi-ap-1/chapter/communication-between-neurons/
https://uk.sagepub.com/sites/default/files/upm-assets/61038_book_item_61038.pdf
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