Anatomy: Embryology - Gross Anatomy - Neuroanatomy - Microanatomy

239 Pages·1995·11.37 MB·English

by  Raymond E. Papka Ph.D. (auth.)

Basic Sciences Review for Medical Licensure
Developed at
The University of Oklahoma College of Medicine
Suitable Reviews for:
United States Medical Licensing Examination
(USMLE), Step 1
Anatomy
Embryology Neuroanatomy
Gross Anatomy Microanatomy
Edited by
Raymond E. Papka
With Contributions by
James J. Tomasek Daniel L. McNeill
Hubert W. Burden Raymond E. Papka
Springer-Verlag
New York Berlin Heidelberg London Paris
Tokyo Hong Kong Barcelona Budapest
Raymond E. Papka, Ph.D.
Department of Anatomical Sciences
University of Oklahoma
Health Science Center
P.O. Box 26901
Oklahoma City, OK 73190
USA
All contributors share the address above except:
Hubert W. Burden
Department of Anatomy and Cell Biology
East Carolina University
Greenville, NC 27858
USA
Library of Congress Cataloging-in-Publication Data
Anatomy: embryology, gross anatomy, neuroanatomy, microanatomy I
edited by Raymond E. Papka ; contributors, Raymond E. Papka ... let
al.].
p. cm. - (Oklahoma notes)
Includes bibliographical references.
lSBN-\3: 978-0-387-94395-4 e-lSBN-\3: 978-1-4612-4194-2
DOl: 10.1007/978-1-4612-4194-2
1. Human anatomy-Outlines, syllabi, etc. 2. Human anatomy
Examinations, questions, etc. 3. Embryology, Human-Outlines,
syllabi, etc. 4. Embryology, Human-Examinations, questions, etc.
I. Papka, Raymond E. II. Series.
[DNLM: 1. Anatomy-outlines. 2. Anatomy-examination questions.
QS 18 A536 1995]
QM31.A53 1995
611-dc20
DNLMIDLC
for Library of Congress 94-45449
Printed on acid-free paper.
© 1995 Springer-Verlag New York, Inc.
All rights reserved. This work may not be translated or copied in whole or in part without
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Production managed by Jim Harbison; manufacturing supervised by Jacqui Ashri.
Camera-ready copy prepared by the editor.
987654321
Preface to the
tJ~~
In 1973, the University of Oklahoma College of Medicine instituted a requirement
for passage of the Part 1 National Boards for promotion to the third year. To assist
students in preparation for this examination, a two-week review of the basic
sciences was added to the curriculum in 1975. Ten review texts were written by
the faculty: four in anatomical sciences and one each in the other six basic sci
ences. Self-instructional quizzes were also developed by each discipline and ad
ministered during the review period.
The first year the course was instituted the Total Score performance on National
Boards Part I increased 60 points, with the relative standing of the school chang
ing from 56th to 9th in the nation. The performance of the class since then has
remained near the national candidate mean. This improvement in our own stu
dents' performance has been documented (Hyde et al: Performance on NBME
Part I examination in relation to policies regarding use of test. J. Med. Educ. 60:
439-443, 1985).
A questionnaire was administered to one of the classes after they had completed
the Boards; 82% rated the review books as the most beneficial part of the course.
These texts were subsequently rewritten and made available for use by all stu
dents of medicine who were preparing for comprehensive examinations in the
Basic Medical Sciences. Since their introduction in 1987, over 300,000 copies
have been sold. Obviously these texts have proven to be of value. The main reason
is that they present a concise overview of each discipline, emphasizing the content
and concepts most appropriate to the task at hand, i.e., passage of a comprehen
sive examination over the Basic Medical Sciences.
The recent changes in the licensure examination that have been made to create a
Step l/Step 2/Step 3 process have necessitiated a complete revision of the Okla
homa Notes. This task was begun in the summer of 1991 and has been on-going
over the past 3 years. The book you are now holding is a product of that revision.
Besides bringing each book up to date, the authors have made every effort to make
the tests and review questions conform to the new format of the National Board
of Medical Examiners. Thus we have added numerous clinical vignettes and ex
tended match questions. A major revision in the review of the Anatomical Sci
ences has also been introduced. We have distilled the previous editions' content to
the details the authors believe to be of greatest importance and have combined the
four texts into a single volume. In addition a book over neurosciences has been
added to reflect the emphasis this interdisciplinary field is now receiving.
I hope you will find these review books valuable in your preparation for the
licensure exams. Good Luck!
Richard M. Hyde, Ph.D.
Executive Editor
Preface
This book represents a major revision of the Oklahoma Notes that were previously
produced as individual volumes for the review of Embryology, Gross Anatomy,
Neuroanatomy, and Microanatomy. Within this single book, information regard
ing the four major topics of anatomical sciences has been reorganized and up
dated. The authors have endeavored to produce a concise and relevant study-book
that will provide students a reasonably thorough review of the components of the
anatomical sciences. The book is written in outline form in order to reduce the
volume of descriptive prose and to facilitate the student's opportunity to get to the
"meat" of the subjects.
This review narrative is written expressly for students preparing to take Step 1
of the USMLE. It is a distillation of headlines of essential content for medical
Embryology, Gross Anatomy, Neuroanatomy, and Microanatomy. It is written
with the assumption that you previously have completed medical school courses
that included dissections and microscopy. For most of us, anatomy is quickly
forgotten if not used. This outline volume attempts to organize the contents of the
anatomy courses into formats useful for review/recall purposes. This is not a
traditional review text-there are few illustrations or diagrams. The student is
encouraged to thoughtfully engage the narrative, highlight words/phrases as ap
propriate, and incorporate mental images of structures and their functions as you
read. If the mental images fail to focus clearly as you read the narrative, students
should consult atlases and more comprehensive texts used in your medical school
courses.
Questions for self-examination are placed separately at the end of the book. These
questions are intended to be integrative so students should not expect to review a
section of the anatomical sciences and then take a self-examination on that section
alone.
We wish you the best in your review!
R.E.P.
J.J.T.
D.L.M.
H.W.B.
Contents
Preface to the Oklahoma Notes ............. ........................................... .............. v
Preface ........................................................................................................... vii
Embryology James J. Tomasek
Gametogenesis, Reproductive Cycle and Fertilization ................. ................ 1
Early Development of the Conceptus: Weeks 1-2 ........................................ 6
Extraembryonic Membranes and Umbilical Cord ....................................... 8
Placenta ...... .................... ................................................................................ 10
Formation of the Trilaminar Embryo ........................................................... 12
Development of General Body Form, Body Cavities and Diaphragm .......... 15
Nervous System ............................................................................................. 18
Musculoskeletal System ................................................................................ 23
Integumentary System ................................................................................... 27
Development of the Head and Neck .............................................................. 29
Development of the Face, Palate, Tongue, and Thyroid Gland .................... 33
Respiratory System ........................................................................................ 36
Digestive System and Mesenteries System ...... .......................... .......... ......... 38
Urogenital System ......................................................................................... 43
Development of the Heart ............................................................................. 47
Development of the Vasculature ................................................................... 51
Gross Anatomy Hubert W. Burden
Basic Concepts of the Nervous System and Imaging ................................... 55
Back and Upper Limb .................................................................................... 57
Head and Neck ............................................................................................... 67
Thorax ............................................................................................................ 79
Abdomen ........................................................................................................ 84
Pelvis and Perineum 92
Lower Limb ....................................................... ............................................. 99
Neuroanatomy DanielL. McNeill
Histology of the Nervous System .................................................................. 106
Gross Features of the Brain and Brainstem .................................................. 109
Vasculature and Ventricular System of the CNS .......................................... 110
Spinal Cord and Peripheral Nerves ............................................................... 114
Cranial Nerves ............................................................................................... 124
Medulla Oblongata ........................................................................................ 136
Pons ................................................................................................................ 137
Mesencephalon .............................................................................................. 138
Diencephalon ................................................................................................. 139
Basal Ganglia ................................................................................................. 142
Cerebellum ..................................................................................................... 144
x Contents
Cerebrum ....................................................................................................... 148
Limbic System ................................................................................................ 152
Autonomic Nervous System .......................................................................... 153
Microanatomy Raymond E. Popko
Cytology ......................................................................................................... 158
Epithelium ...................................................................................................... 162
Connective Tissue Proper ............................................................................. 163
Cartilage ......................................................................................................... 165
Bone ............................................................................................................... 166
Peripheral Blood ............................................................................................ 170
Hematopoiesis ............................................................................................... 172
Immune System (Lymphatic System) ............................................................ 174
Muscle Tissue ................................................................................................ 178
Nerve Tissue (see Section on Neuroanatomy) .............................................. 181
Cardiovascular System ... ... ............ ..... ..... ........ ............. ....... .... .......... ... ......... 182
Integumentary System ... ............... ..... ............... ....... ................. ........ ..... .... .... 185
Respiratory System ........................................................................................ 187
Gastrointestinal System . ...... ...... ......... ....... ........... .... ... ... ...................... ......... 189
Urinary System .............................................................................................. 198
Endocrine System .. ......... ... ................. ....... ..... ...... ............................ ............. 202
Female Reproductive System ............ ....... .................................. ....... ... ......... 207
Male Reproductive System ............................................................................ 213
Review Questions .................................................................... 218
Answers to Review Questions ................................................ 231
EMBRYOLOGY
GAMETOGENESIS, REPRODUCTIVE CYCLE AND FERTILIZATION
I. CELLS AND CHROMOSOMES
A. Diploid Cells
In humans, the cells comprising all renewing cell populations (including the precursors of
germ cells) are diploid (2N) and possess a total of 46 chromosomes.
=
diploid (2N) 46 chromosomes
=
autosomal chromosomes 44 (22 homologous pairs)
=
sex chromosomes 2
=
females XX (homologous)
=
males XY (nonhomologous)
B. Haploid Cells (Gametes)
The gametes (sperm and ova) are highly specialized reproductive cells containing only one
half (N or 23) the number of chromosomes found in renewing cell populations. The
reduction in chromosome number is accomplished by two specialized cell cycles which are
referred to as Meiosis I and Meiosis II.
=
haploid (N) 23 chromosomes
=
autosomal chromosomes 22 (one member from each pair)
=
sex chromosomes 1
females = X (always)
males = XorY
C. Chromosome Morphology
1. centro meres
2. arms
3. chromatids
D. Mitosis
The two most important events occurring during mitosis are DNA replication (interphase)
and centromeric division (late metaphase). When DNA replication and centromeric division
occur during the same cell cycle, the number of chromosomes in both daughter cells will
remain constant (diploid) and the daughter cells will be identical genetically.
E. Meiosis
During the two specialized cell cycles of gametogenesis (meiosis I and meiosis II), DNA
replication and centromeric division occur in separate cell cycles. DNA replication occurs
during meiosis I; centromeric division occurs during meiosis II. When cells divide without
centromeric division, the number of chromosomes transmitted to daughter cells must be
reduced by one-half. The resulting haploid daughter cells will NOT be genetically identical,
each cell receives only one member (maternal or paternal) from each of the 23 chromosome
pairs.
1
II. ABNORMALITIES IN CHROMOSOME NUMBER (ANEUPLOID CELLS)
A. Nondisjunction
The most common event producing abnormal chromosome numbers (aneuploidy) is
nondisjunction. When nondisjunction occurs, the chromosomes are unequally distributed
between the daughter cells so that one cell receives an extra chromosome (trisomy) and the
other cell is missing that chromosome (monosomy). NONDISJUNCTION CAN OCCUR
ANYTIME A CELL DIVIDES (MITOTICALLY OR MEIOTICALLY) AND CAN AFFECT
EITHER AUTOSOMAL OR SEX CHROMOSOMES. It is generally accepted that one of the
most frequent causes for nondisjunction is delayed or asynchronous division of centromeres
during late metaphase.
B. Meiotic Nondisjunction
During gametogenesis, nondisjunction results in the production of two abnormal gametes
(haploid plus one or haploid minus one chromosome). If one of the abnormal gametes
participates in fertilization an aneuploid zygote is produced which either possesses an extra
chromosome (sex or autosomal trisomy) or lacks a chromosome (sex or autosomal
monosomy). Individuals developing from these abnormal zygotes will be either trisomic or
monosomic for the chromosome involved.
1. Zygotes with autosomal aneuploidy. Although 22 pairs of autosomal chromosomes are
present in human zygotes and any chromosome can be affected by nondisjunction (all
have been reported in aborted material), only a few (trisomic only) complete
development to present as postnatal medical problems.
a) Autosomal Monosomy. True monosomic conditions involving any of the 22
autosomal chromosomes have not been reported to complete intrauterine
development and are generally considered to be invariably lethal.
b) Autosomal Trisomy. Trisomic conditions for autosomal chromosomes are usually
but not invariably lethal. The only common autosomal trisomic condition with long
term survival is trisomy 21 (Down's syndrome). Trisomy 13 (Patau's syndrome)
and trisomy 18 (Edward's syndrome) are occasionally reported but these
individuals rarely survive beyond the first few months of postnatal life.
c) Maternal Age. The increased frequency of nondisjunction with advancing
maternal age is usually attributed to the fact that the first meiotic division of all ova
begins during fetal life. Ova produced during the later years of the reproductive
life span are very old and have been subjected to the cumulative environmental
(radiation, chemicals, therapeutic drugs, viral infections) and physiological
(endocrine changes) effects of aging.
2. Zygotes with Sex Chromosome Aneuploidy. In contrast to the small number of
aneuploid conditions resulting from unequal distribution of the 22 pairs of autosomes,
nondisjunction affecting the single pair of sex chromosomes may produce zygotes and
adult individuals of at least four basic genotypes. Monosomic and trisomic conditions
for sex chromosomes are well known clinically and are relatively common.
2