Human Physiology Lab Manual

411 Pages·2002·31.348 MB·English

by  S.I.I.Fox

Fox: Human Physiology Lab Front Matter Preface © The McGraw−Hill
Manual, Ninth Edition Companies, 2002
Preface
The ninth edition, like the previous editions, is a stand- The review activities in the laboratory reports at the
alone human physiology manual that can be used in con- end of each exercise are thoroughly revised in this edi-
junction with any human physiology textbook. It includes tion. They now present questions at three levels: Test Your
a wide variety of exercises that support most areas covered Knowledge of Terms and Facts, Test Your Understanding of
in a human physiology course, allowing instructors the Concepts, and Test Your Ability to Analyze and Apply Your
flexibility to choose those exercises best suited to meet Knowledge. These three levels of questions are consistent
their particular instructional goals. Background informa- between laboratory exercises, and consistent with the Re-
tion that is needed to understand the principles and sig- view Activities approach in the textbook Human Physiol-
nificance of each exercise is presented in a concise ogy,seventh edition, by Stuart Ira Fox.
manner, so that little or no support is needed from the Clinically oriented laboratory exercises that
lecture text. heighten student interest and demonstrate the health ap-
However, lecture and laboratory segments of a plications of physiology have been a hallmark of previous
human physiology course are most effectively wedded editions and continue to be featured in this latest edition.
when they cover topics in a similar manner and sequence. We are indebted to our colleagues and students for
Thus, this laboratory guide is best used in conjunction their suggestions and encouragement in the development
with the textbook Human Physiology, seventh edition, by of these exercises. Drawing on these recommendations,
Stuart Ira Fox (McGraw-Hill, © 2002). many of the laboratory procedures have been altered to
The laboratory experiences provided by this guide accommodate both fluctuations in class size and labora-
allow students to become familiar—in an intimate way tory time constraints. Some alterations were necessary
that cannot be achieved by lecture and text alone—with since some of the sources of laboratory supplies and equip-
many fundamental concepts of physiology. In addition to ment have changed. New sources are indicated for some
providing hands-on experience in applying physiological of the reagents, test strips, or kits required for certain ex-
concepts, the laboratory sessions allow students to inter- ercises, reflecting changes made by the vendors.
act with the subject matter, with other students, and with
the instructor in a personal, less formal way. Active par- SAFETY
ticipation is required to carry out the exercise procedures, Special effort has been made to address concerns about
collect data, and to complete the laboratory report. Criti- the safe use and disposal of body fluids. For example, nor-
cal thinking is necessary to answer all questions at the mal and abnormal artificial serum can be used as a substi-
end of each exercise. tute for blood in Section 2 (plasma chemistry); artificial
saliva is suggested in exercise 10.2 (digestion); and in Sec-
N N E tion 9 (renal function) both normal and abnormal artifi-
EW TO THE INTH DITION
cial urine is now available. In the interest of safety, a
UPDATED INFORMATION substitute for the use of benzene (previously required in
The ninth edition is a thorough renovation of the eighth two exercises) is now provided.
edition. Each exercise has been carefully refined and up- The international symbol for caution is used
dated to keep pace with continual changes in laboratory throughout the laboratory guide to alert the
technology, vendor supply sources, and biohazard health reader when special attention is necessary while preparing
concerns. Laboratories that utilize the Biopac or Intelitool for or performing a laboratory exercise. For reference, lab-
systems for computer-assisted data acquisition will find oratory safety guidelines appear on the inside front cover.
references and correlations to the use of these systems
with the exercises presented in this edition. Similarly, TECHNOLOGY
those that use the A.D.A.M.interactive physiology pro- Computer-assisted and computer-guided instruction in
grams to supplement their classroom instruction will find human physiology laboratories has greatly increased in re-
correlations to those programs in the exercises of this cent years. Computer programs provide a number of bene-
edition. fits: some experiments that require animal sacrifice can be
ix
Fox: Human Physiology Lab Front Matter Preface © The McGraw−Hill
Manual, Ninth Edition Companies, 2002
simulated; data can be analyzed against a data bank and dis- 7. The procedureis stated in the form of easy-to-
played in an appealing and informative manner; class data follow steps. These directions are set off from the
records can be analyzed; and costs can be reduced by elimi- textual material through the use of a distinctive
nating the use of some of the most expensive equipment. typeface, making it easier for students to locate
This edition continues to reference programs of- them as they perform the exercise.
fered by Intelitool, and new to this edition, 8. A laboratory reportfollows each exercise. Students
A.D.A.M. Benjamin/Cummings InterActive enter data here when appropriate, and answer
PHYSIOLOGY Modules (800–755–2326; questions. The questions in the laboratory report
www.adam.com), and the Virtual Physiology begin with the most simple form (objective
Lab CD-ROM (ISBN 0–697–37994–9) by questions) in most exercises and progress to essay
McGraw-Hill and Cypris Publishing. questions. The essay questions are designed to
stimulate conceptual learning and to maximize the
ART PROGRAM educational opportunity provided by the laboratory
Almost every figure in this edition has been revised or im- experience.
proved, with a few deletions, and many new, exciting fig-
ures and tables added. These new figures enhance the S M
UPPLEMENTAL ATERIALS
pedagogical value and add to the aesthetic appeal of the
laboratory manual. Furthermore, the design was reworked, Instructor’s Manual for the Laboratory Guide to accompany
adding icons (such as the balance icon for nor- Human Physiology,ninth edition, by Laurence G. Thouin, Jr.
(ISBN 0–697–34221–2) provides a suggested correlation
mal values), boxes, and shading to important concepts to
between the textbook and laboratory manual for Human
enhance visual comprehension by students and to im-
Physiology, introductions, materials needed, approximate
prove overall continuity.
completion times, and solutions to the laboratory reports
for each exercise, a listing of laboratory supply houses, and
O
RGANIZATION OF THE
commonly used solutions.
L G
ABORATORY UIDE
Virtual Physiology Lab CD-ROMby McGraw-Hill and
The exercises in this guide are organized in the following Cypris Publishing (ISBN 0–697–37994–9) features ten
manner: simulations of the most common and important animal-
based experiments. The flexibility of this multimedia tool
1. Each exercise begins with a list of offers many pre-lab, actual lab, and post-lab options.
materialsneeded to perform the exercise, so that it Laboratory Atlas of Anatomy and Physiology, second
is easier to set up the laboratory. This section is edition, by Douglas Eder et al. (ISBN 0–697–39480–8), is
identified by a materials icon. a full-color atlas including histology, skeletal and muscu-
2. Following the materials section is an overview lar anatomy, dissections, and reference tables.
paragraph describing the conceptbehind the
laboratory exercise. EXPERIMENT IN THE VIRTUAL
3. Following the concept paragraph is a list of learning WORLD
objectives,to help students guide their learning
With ten simulations of the most common laboratory ex-
while performing the exercise.
periments, Virtual Physiology Lab lets you conduct lifelike
4. A box providing textbook correlationsis a new
research—without the animals or the lab.
feature of this edition. This section can be used to
You can work at your own pace and practice essential
help integrate the lecture textbook (if Human
techniques over and over. The flexibility of this multimedia
Physiology, seventh edition,by Stuart Ira Fox, is used)
tool offers many prelab, actual lab, and postlab options. You
with the laboratory material.
can work in a computer lab, at home, or in teams.
5. A brief introductionto the exercise presents the
Each lab features: Objectives, Foundation, Experi-
essential information for understanding the
ment, Results, and Self-Testing.
physiological significance of the exercise. This
concisely written section eliminates the need to Contents
consult the lecture text. 1. Action Potential
6. Boxed information, set off as screened insets, 2. Synaptic Transmission
provide the clinical significanceof different aspects 3. Frog Muscle
of the laboratory exercise. This approach was 4. Effects of Drugs on the Frog Heart
pioneered by this laboratory manual and the current 5. Electrocardiogram
edition continues that tradition. 6. Pulmonary Function
x
Fox: Human Physiology Lab Front Matter Preface © The McGraw−Hill
Manual, Ninth Edition Companies, 2002
7. Respiration and Exercise and student friendly. I am also grateful to Dr. Jenine Tanabe
8. Digestion of Fat (Yuba College) for her help in incorporating the Biopac
9. Diffusion, Osmosis, and Tonicity procedures into this edition.
10. Enzyme Characteristics The shaping of the ninth edition was also aided by
suggestions from other colleagues and students. Ms. Karen
1998 CD-ROM for Macintosh and Windows ISBN
Gebhardt was particularly instrumental in checking labo-
0–697–37994–9
ratory sources for materials and reworking some of the
To order a copy of the Virtual Physiology Lab,check procedures that are new to this edition. I greatly appreci-
your bookstore or call McGraw-Hill Customer Service at ate the support of the editors at McGraw-Hill, Colin
1–800–338–3987. Wheatley and Lynne Meyers; their contributions help to
make this the best edition yet of the Laboratory Guide to
ACKNOWLEDGMENTS accompany Human Physiology.
The ninth edition was greatly benefited by input from my
colleague Dr. Laurence G. Thouin, Jr. His numerous sug-
gestions helped to make the ninth edition more accurate
xi
Fox: Human Physiology Lab Front Matter Front Cover: Laboratory © The McGraw−Hill
Manual, Ninth Edition Safety Guidelines Companies, 2002
L S G
ABORATORY AFETY UIDELINES
Most of the reagents (chemicals) and equipment in a off yourself and your clothing; and, if you
physiology laboratory are potentially dangerous. This cir- accidentally get any reagent in your mouth,
cumstance will not detract from the enjoyment and effi- immediately rinse your mouth thoroughly and
cacy of the laboratory learning experience providing all inform the instructor.
participants follow some commonsense rules of laboratory 4. Follow the procedures precisely as stated, or as
safety. Please read these laboratory safety guidelines care- modified by the instructor. Do notimprovise unless
fully and practice them in the laboratory. In time, safe be- the instructor specifically approves the change.
havior will become routine. 5. Clean glassware at the end of each exercise so that
residue from one exercise does not carry over to the
1. Read all exercises beforecoming to the laboratory.
next exercise.
Pay particular attention to the Materials section
6. Keep your work area clean, neat, and organized.
and note any chemicals, instruments, or equipment
This will reduce the possibilities of error and help
that might be hazardous if mishandled. Read all
make your work safer and more accurate.
notes and cautions associated with the exercise.
7. Do notoperate any equipment until you are
Disorganization and confusion in a laboratory can
instructed in its proper use. If you are unsure of the
be dangerous. Proper preparation will increase your
procedures, ask the instructor.
understanding, enjoyment, and safety during
8. Be careful about open flames in the laboratory. Do
exercises.
notleave a flame unattended; do notlight a Bunsen
2. With tremendous concern over the possibility of
burner near any gas tank or cylinder; and do not
transferring viruses (such as AIDS and herpes),
move a lit Bunsen burner around on the desk. Make
bacteria, or other pathogenic organisms from one
sure that long hair or loose clothing is well out of
person to another, it is strongly recommended that
the way of the flame.
each student handle only his or her own bodily
9. Always make sure that gas jets are off when you are
fluids.This warning is repeated in the appropriate
not operating the Bunsen burner.
exercises and is extended to include the cleanup of
10. Handle hot glassware with a test-tube clamp or
all spills and the proper disposal of all contaminated
tongs.
items in containers provided by the instructor.
11. Note the location of an emergency first-aid kit,
Some fluids, such as blood, can be purchased
eyewash bottle, and fire extinguisher in the room.
prescreened and “pathogen-free” from commercial
Report all accidents to the instructor immediately.
life science laboratories.
12. Wear safety glasses during those exercises in which
3. Assume that all reagents are poisonous and act
glassware and solutions are heated with a Bunsen
accordingly. Do notingest any reagents; eat, drink,
burner.
or smoke in the laboratory; carry reagent bottles
around the room; or pipette anything by mouth Remember, your safe behavior in the laboratory will serve
unless specifically told to do so by your instructor. as a model for others. It will also help you to experience
Dowash your hands thoroughly before leaving the the thrill of laboratory experimentation in a responsible
laboratory; stopper all reagent bottles when they are manner and to take pride in your successful results.
not in use; thoroughly clean up spills; wash reagents
Fox: Human Physiology Lab 1. Introduction: Structure Text © The McGraw−Hill
Manual, Ninth Edition and Physiological Control Companies, 2002
Systems
1
Introduction: Structure and
Section
Physiological Control Systems
The cell is the basic unit of structure and function
in the body. Each cell is surrounded by a cell(or
plasma) membrane and contains specialized
structures called organelles within the cell fluid,
or cytoplasm. The structure and functions of a
cell are largely determined by genetic information
contained within the membrane-bound nucleus.
This genetic information is coded by the specific
chemical structure of deoxyribonucleic acid
(DNA) molecules, the major component of chro-
mosomes.Through genetic control of ribonucleic
acid (RNA)and the synthesis of proteins (such as
enzymes described in section 2), DNA within the
cell nucleus directs the functions of the cell and,
ultimately, those of the entire body.
Cells with similar specializations are grouped
together to form tissues, and tissues are
grouped together to form larger units of struc-
ture and function known as organs.Organs that
are located in different parts of the body but
that cooperate in the service of a common func-
tion are called organ systems (e.g., the cardio-
vascular system).
The complex activities of cells, tissues, or-
gans, and systems are coordinated by a wide
variety of regulatory mechanisms that act to
maintain homeostasis—a state of dynamic con-
stancy in the internal environment. Physiologyis
largely the study of the control mechanisms that
participate in maintaining homeostasis.
Exercise 1.1 Microscopic Examination of
Cells
Exercise 1.2 Microscopic Examination of
Tissues and Organs
Exercise 1.3 Homeostasis and Negative
Feedback
1
Fox: Human Physiology Lab 1. Introduction: Structure Text © The McGraw−Hill
Manual, Ninth Edition and Physiological Control Companies, 2002
Systems
1.1
Microscopic Examination
E X E R C I S E
of Cells
Textbook Correlations
MATERIALS
1. Compound microscopes Before performing this exercise, you may want to con-
2. Prepared microscope slides, including whitefish sult the following references in Human Physiology,
blastula (early embryo), clean slides, and cover slips seventh edition, by Stuart I. Fox:
(Note: Slides with dots, lines, or the letter ecan be
• Cytoplasm and Its Organelles.Chapter 3, pp. 56–60.
prepared with dry transfer patterns used in artwork.)
• DNA Synthesis and Cell Division.Chapter 3,
3. Lens paper
pp.69–77.
4. Methylene blue stain
5. Cotton-tipped applicator sticks Those using different physiology textbooks may
want to consult the corresponding information in
those books.
The microscope and the metric system are important
tools in the study of cells. Cells contain numerous or-
ganelles with specific functions and are capable of 3. a substage condenser lens and iris diaphragm, each
reproducing themselves by mitosis. However, there with controls
is also a special type of cell division called meiosis 4. coarse focus and fine focus adjustment controls
that is used in the gonads to produce sperm or ova. 5. objective lenses on a revolving nosepiece (usually
include: a scanning lens, 4×; a low-power lens, 10×;
OBJECTIVES and a high-power lens, 45×)
1.Identify the major parts of a microscope and
CARE AND CLEANING
demonstrate proper technique in the care and
The microscope is an expensive, delicate instrument. To
handling of this instrument.
maintain it in good condition, always take the following
2.Define and interconvert units of measure in the
precautions:
metric system; and estimate the size of micro-
scopic objects. 1. Carry the microscope with two hands.
3.Describe the general structure of a cell and the 2. Use the coarsefocus knob onlywith low power and
specific functions of the principal organelles. always move the objective lens away from the slide,
4.Describe the processes of mitosis and meiosis never toward the slide.
and explain their significance. 3. Clean the ocular and objective lenses with lens
paper moistened with distilled water before and
after use. (Use alcohol only if oil has been used with
an oil-immersion, 100×lens.)
The microscope is the most basic and widely 4. Always leave the lowest power objective lens
(usually 4×or 10×) facing the stage before putting
used instrument in the life science laboratory.
the microscope away.
The average binocular microscope for student
use, as shown in figure 1.1, includes the following
parts: A. THE INVERTED IMAGE
1. eyepieces each with an ocular lens (usually 10× Obtain a slide with the letter e mounted on it. Place the
magnification, and may have a pointer) slide on the microscope stage, and rotate the nosepiece
2. a stage platform with manual or mechanical stage until the 10× objective clicks into the down position.
controls Using the coarse adjustment, carefully lower the objective
2
Fox: Human Physiology Lab 1. Introduction: Structure Text © The McGraw−Hill
Manual, Ninth Edition and Physiological Control Companies, 2002
Systems
Eyepiece with ocular lens
Body tube
Revolving nosepiece
Arm
Objective lenses
(10×, 40×, 43×)
Stage slide
Stage
retainer clips
Iris diaphragm lever
Condenser lens
Mechanical stage
movement knobs
Coarse focus
adjustment knob
Fine focus
adjustment knob
Substage lamp
Condenser lens
Base adjustment knob
Figure 1.1 The parts of a compound microscope.
lens until it almost touches the slide. Now, looking 3. While looking through the ocular lens, rotate the
through the ocular lens, slowly raise the objective lens mechanical stage controls so that the mechanical
until the letter ecomes into focus. stage moves towardyou. In which direction does the
emove?
___________
PROCEDURE
B. T M S :
HE ETRIC YSTEM
1. If the visual field is dark, increase the light by
E S
STIMATING THE IZE OF
adjusting the lever that opens (and closes) the iris
M O
ICROSCOPIC BJECTS
diaphragm. If there is still not enough light, move
the substage condenser lens closer to the slide by It is important in microscopy, as in other fields of science,
rotating its control knob. Bring the image into that units of measure are standardized and easy to use.
sharp focus using the fine focus control. Now, draw The metric system(from the Greek word metrikos,mean-
the letter eas it appears in the microscope. ing “measure”) first developed in late eighteenth-century
___________ France, is the most commonly used measurement system
2. While looking through the ocular lens, rotate the in scientific literature. The modern definitions of the
mechanical stage controls so that the mechanical units used in the metric system are those adopted by the
stage moves to the right.In which direction does the General Conference on Weights and Measures, which in
emove? 1960 established the International System of Units, also
___________ known (in French) as Système International d’Unités,
3
Fox: Human Physiology Lab 1. Introduction: Structure Text © The McGraw−Hill
Manual, Ninth Edition and Physiological Control Companies, 2002
Systems
Table 1.1 International System of Metric Units, Prefixes, and Symbols
Multiplication Factor Prefix Symbol Term
1,000,000 = 106Mega M One million
1,000 = 103 Kilo k One thousand
100 = 102 Hecto h One hundred
10 = 101 Deka da Ten
1 = 100
0.1 = 10–1 Deci d One-tenth
0.01 = 10–2 Centi c One-hundredth
0.001 = 10–3 Milli m One-thousandth
0.000001 = 10–6Micro µ One-millionth
0.000000001 = 10–9Nano n One-billionth
0.000000000001 = 10–12 Pico p One-trillionth
0.000000000000001 = 10–15 Femto f One-quadrillionth
Table 1.2 Sample Metric Conversions
To Convert From To Factor Move Decimal Point
Meter (Liter, gram) Milli- ×1,000 (103) 3 places to right
Meter (Liter, gram) Micro- ×1,000,000 (106) 6 places to right
Milli- Meter (Liter, gram) ÷1,000 (10–3) 3 places to left
Micro- Meter (Liter, gram) ÷1,000,000 (10–6) 6 places to left
Milli- Micro- ×1,000 (103) 3 places to right
Micro- Milli- ÷1,000 (10–3) 3 places to left
and abbreviated SI (in all languages). The definitions for 1. Multiplying a number by 1 does not change the
the metric units of length, mass, volume, and temperature value of that number.
are as follows: 2. A number divided by itself is equal to 1.
meter (m)—unit of length equal to 1,650,763.73 These principles can be used to change the units of any
wavelengths in a vacuum of the orange-red measurement.
line of the spectrum of krypton-86
gram (g)—unit of mass based on the mass of 1 cubic Example
centimeter (cm3) of water at the temperature Since 1 meter (m) is equivalent to 1,000 millimeters
(4°C) of its maximum density (mm),
liter (L)—unit of volume equal to 1 cubic
1 m 1,000 mm
decimeter (dm3) or 0.001 cubic meter (m3) =1 and =1
1,000 mm 1 m
Celsius (C)—temperature scale in which 0°is the
freezing point of water and 100°is the boiling Suppose you want to convert 0.032 meter to millimeters:
point of water; this is equivalent to the
1,000 mm
centigrade scale 0.032 m× =32.0 mm
1 m
Conversions between different orders of magni-
tude in the metric system are based on powers of ten Notice that in dimensional analysis the problem is set up
(table 1.1). Therefore, you can convert from one order so that the unwanted units (meter, m in this example)
of magnitude to another simply by moving the decimal cancel each other. This technique is particularly useful
point the correct number of places to the right (for mul- when the conversion is more complex or when some of
tiplying by whole numbers) or to the left (for multiply- the conversion factors are unknown.
ing by decimal fractions). Sample conversions are
Example
illustrated in table 1.2.
Suppose you want to convert 0.1 milliliter (mL) to micro-
liter (µL) units. If you remember that 1 mL = 1,000 µL,
DIMENSIONAL ANALYSIS you can set up the problem as follows:
If you are unsure about the proper factor for making a
metric conversion, you can use a technique called dimen- 0.1 mL×1,000 µL=100 µL
sional analysis.This technique is based on two principles: 1 mL
4
Fox: Human Physiology Lab 1. Introduction: Structure Text © The McGraw−Hill
Manual, Ninth Edition and Physiological Control Companies, 2002
Systems
If you remember that a milliliter is one-thousandth of a through cell division in deeper layers. In contrast to cells
liter and that a microliter is one-millionth of a liter, you in the outer layer of the epidermis of the skin, which die
can set up the problem in this way: before they are lost, the cells in the outer layer of epithe-
lial tissue in the cheeks are still alive. You can therefore
1.0 L 1,000,000 µL
0.1 mL× × =100 µL easily collect and observe living human cells by simply
1,000 mL 1.0 L rubbing the inside of the cheeks.
Most living cells are difficult to observe under the
VISUAL FIELD AND THE ESTIMATION microscope unless they are stained. In this exercise, the
OF MICROSCOPIC SIZE stain methylene blue will be used. Methylene blue is posi-
If the magnification power of your ocular lens is 10×and tively charged and combines with negative charges in the
you use the 10×objective lens, the total magnification of chromosomes to stain the nucleus blue. The cytoplasm
the visual field will be 100×. At this magnification, the contains a lower concentration of negatively charged or-
diameter of the visual field is approximately 1,600 mi- ganic molecules, and so appears almost clear.
crometers (µm).
You can estimate the size of an object in the visual
field by comparing it with the total diameter (line AB) of PROCEDURE
the visual field. Using the diagram below: 1. Rub the inside of one cheek with the cotton tip of
How long is line ACin micrometers (µm)? _____ an applicator stick.
How long is line ADin micrometers (µm)? _____ 2. Press the cotton tip of the applicator stick against a
How long is line AEin micrometers (µm)? _____ clean glass slide. Maintaining pressure, rotate the
cotton tip against the slide and then push the cheek
smear across the slide about 1/2 inch.
ED C 3. Observe the unstainedcells under 100×and 450×
A B total magnification.
1,600 µ m 4. Remove the slide from the microscope. Holding it
100x over a sink or special receptacle, place a drop of
methylene blue stain on the smear.
The diameter of the field of vision using the 45× objec- 5. Place a cover slip over the stained smear and again
tive lens (total magnification 450×) is approximately 356 observe the stainedcheek cells at 100×and 450×
micrometers. Using the diagram above and applying the total magnification.
same technique, answer the following questions assuming 6. Using the procedure described in the previous
use of a 45×objective lens: section, estimate the size of the average cheek cell
How long is line ACin micrometers (µm)? _____ using both 100×and 450×total magnification.
How long is line ADin nanometers (nm)? _____ 100×__________ µm; 450×__________ µm
Are they the same?
PROCEDURE D. CELL STRUCTURE
C D
AND ELL IVISION
From your instructor, obtain a slide that contains a
pattern of small dots and a pattern of thin lines. Cells vary greatly in size and shape. The largest cell, an
ovum(egg cell), can barely be seen with the unaided eye;
1. Using the 10×objective lens:
other cells can be observed only through a microscope.
(a) estimate the diameter of one dot: ____ m
Each cell has an outer plasma membrane (or cell mem-
(b) estimate the distance between the nearestedges
brane) and generally one nucleus, surrounded by a fluid
of two adjacent dots: ____ m
matrix, or cytoplasm. Within the nucleus and the cyto-
2. Using the 45×objective lens:
plasm are a variety of subcellular structures, called or-
(a) estimate the width of one line: ____ m
ganelles (fig. 1.2). The structures and principal functions
(b) estimate the distance between the nearestedges
of important organelles and other cellular components are
of two adjacent lines: ____ m
listed in table 1.3.
C. M E The process of cell division, or replication, is called
ICROSCOPIC XAMINATION
C C mitosis (fig. 1.3). This process allows new cells to be
OF HEEK ELLS
formed to replace those that are dying and also permits
The surfaces of the body are covered and lined with ep- body growth. Mitosis consists of a continuous sequence of
ithelialmembranes (one of the primary tissues described in four stages (table 1.4 and fig. 1.3) in which both the nu-
exercise 1.2). In membranes that are several cell layers cleus and cytoplasm of a cell split to form two identical
thick, such as the membrane lining of the cheeks, cells daughter cells. During mitotic cell division, the chromo-
are continuously lost from the surface and replaced somes (which had been duplicated earlier) separate, and
5
Fox: Human Physiology Lab 1. Introduction: Structure Text © The McGraw−Hill
Manual, Ninth Edition and Physiological Control Companies, 2002
Systems
Pulse
rate 80
(beats
per 70
minute)
60
50
1 2 3 4 5 6 7 8 9 10
Measurements
Figure 1.2 Generalized cell. Most cells have the principal organelles shown here.
one of the duplicate sets of chromosomes goes to each daughter cells (the gametes) get only one set of twenty-
daughter cell. The two daughter cells therefore have the three chromosomes; they are said to be haploid, or 1n. In
same number of chromosomes as the parent cell. this way the original diploid number of forty-six chromo-
The forty-six chromosomes present in most human somes can be restored when the sperm and egg unite in
cells actually represent twenty-three pairs of chromo- the process of fertilization.
somes; one set of twenty-three was inherited from the
mother and the other set of twenty-three from the fa-
PROCEDURE
ther. A cell with forty-six chromosomes is said to be
diploid,or 2n. 1. Study figure 1.2. Cover the labels with a blank sheet
In the process of gamete(sperm and ova) production of paper and try to write them in (watch spelling!).
in the gonads (testes and ovaries), specialized germinal 2. Examine a slide of a whitefish blastula (or similar
cells undergo a type of division called meiosis (fig. 1.3). early embryo) and observe the different stages of
During meiosis, each germinal cell divides twice, and the mitosis as shown in figure 1.3.
6