Transcript Lecture 1

Biology 102
Laboratory 7
Microcirculation
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Objectives for Lab 7
• List the components of the microcirculatory system
and their functions.
• Identify arterioles, venules, and capillaries in a
goldfish tail under a dissecting microscope and
estimate the diameters of the vessels.
• Observe and explain the effect of the various
substances used in lab on the vessels in the goldfish
tail, i.e., vasodilation or vasoconstriction
• Explain WHY vasodilation or vasoconstriction
occurred.
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Review of Blood Vessels
Figure from: Saladin,
Anatomy & Physiology,
McGraw Hill, 2007
Microcirculation
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Arteriole
• smallest arterioles only have a few smooth muscle fibers
• can vasoconstrict (decrease diameter) or vasodilate (increase
diameter)
Figure from: Hole’s Human A&P, 12th edition, 2010
Most important in
controlling blood flow
to capillary beds
Arterioles are specialized for controlling blood flow into capillary beds
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Metarterioles
Figure from: Hole’s Human A&P, 12th edition, 2010
Each metarteriole
supplies about 10100 capillary beds
Metarterioles
form
arteriovenous
shunts that can
bypass capillary
beds
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Capillaries
• smallest diameter blood vessels (fit 1 RBC at a time)
• extensions of inner lining of arterioles
• walls consist of endothelium and basement membrane
only – NO smooth muscle
• semipermeable (plasma fluid can escape, but not proteins)
Figure from: Hole’s Human A&P, 12th edition, 2010
3 types:
- continuous (muscle)
- fenestrated (endocrine
glands, kidney, small
intestine)
- sinusoids (liver, spleen,
bone marrow)
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Capillary Network
Blood can follow
different pathways
through metabolically
active/inactive tissues
Figures from: Hole’s Human A&P, 12th edition, 2010
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Regulation of Capillary Blood Flow
Figure from: Hole’s Human A&P, 12th edition, 2010
Precapillary
sphincters
• may close a
capillary
• respond to needs
of the cells
• low oxygen and
nutrients cause
sphincter to relax
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Venules and Veins
Venule
• thinner wall than arteriole; larger lumen
• less smooth muscle and elastic tissue than arteriole
Vein
• thinner wall than artery; larger lumen
• three layers to wall but middle layer is poorly developed
• some have flaplike valves
• carries blood under relatively low pressure
• serves as blood reservoir
• are able to constrict (sympathetic innervation)
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Things you should do in lab today
• Obtain/Prepare a goldfish as described in the Lab Guide/Handout
Instructions (work in groups of four)
• Observe and identify the arterioles, capillaries, and venules in the
goldfish tail under the compound light microscope before doing
any experimental treatments. (Remember that the compound scope will
REVERSE things so be careful to correctly ID vessels)
– Take note of the normal vessel diameter in each type of vessel and record
their approximate diameter (what can you use as a handy guide?)
– Note the manner in which blood flows through the different vessels and
record your observations
– Record all observations on your lab report sheet
• Apply the treatments
– Record your observations in the table in your lab report handout
– Be sure to think about WHY you saw the reactions you observed
– You do NOT have to hand in your Lab Report sheet – but remember, you
will have to know this material for Lab Exam 1.
• After all groups have finished, we’ll review the results
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Next…
• After you do this lab today…
– We will review last week’s results
– Lab Exam 1; format/content
• Review Exercise 36 in Marieb’s Lab Manual in
preparation for looking at respiratory system
anatomy
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Review of Subjects for Lab Exam 1
•
Lab Exam 1 will consist of 24-25 stations and approximately 65 fill-in-theblank questions. You will be expected to be able to recognize all structures
listed in your Laboratory Guide and know the items listed on this study
guide.
• Remember that SPLLEING COUTNS!! You will lose 1 point for every
2 spelling errors you make.
• For help in studying the following items and getting practice, be sure to
look at the following items in the Laboratory Section of the
gserianne.com Web site
• 1. The online PowerPoint Quizzes
2. The 'Links to Explore' (if available) for each topic.
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Review of Subjects for Lab Exam 1
• Blood (Lab 1) - approximately 9 questions
– Know how to read a blood typing card (agglutination reaction) and
determine blood type from what you see
– Understand what determines blood type and under what circumstances a
transfusion reaction may occur, i.e., what serum antibodies must be
present for a reaction to take place
– Be able to distinguish the different types of leukocytes under the
microscope or given a photomicrograph, and know the approximate
percentage of neutrophils, lymphocytes, and monocytes
• Heart (Lab 2) – approximately 8 questions
– Using the heart models or photographs of hearts, be able to recognize
ALL the structures on the checklist in your Laboratory Guide
– Explain what is responsible for the first (S1) and second (S2) heart
sounds?
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Review of Subjects for Lab Exam1
• Blood vessels (Labs 3, 4, and 5) – approx. 20 questions (12 human, 8 cat)
– Given a histological slide or photomicrograph, identify the vessel as
either an artery or vein, and be able to identify the layers of the vessel.
– Be able to identify the human or cat arteries and/or veins shown in your
Guides for Laboratories 3 through 5. I may use human
models/photographs/diagrams, cats, or photographs of cats.
– Be able to trace the path of a drop of blood from any starting point in the
body to any ending location (using only the blood vessels/heart
structures for which you are responsible).
• Blood Pressure (BP) (Lab 6)- approximately 6 questions
– Identify, and correctly spell, the standard equipment used to determine blood pressure
(BP).
– Calculate: 1) Pulse Pressure and 2) Mean Arterial Pressure (MAP)
– Predict the physiological effects of body position and exercise on BP.
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Review of Subjects for Lab Exam 1
• Electrocardiogram (ECG) (Lab 6) – cont’d; approx. 4 questions
– Recognize/label:
•
•
–
–
–
–
a. The P, QRS, and T waves of an EKG
b. The P-R and Q-T intervals
Explain the meaning of each of the waves and intervals in the EKG
Recall the normal times/time ranges for the: PR, QT, and QRS intervals
Calculate the heart rate given an EKG tracing and a time interval between
two or more heartbeats (see Lab Guide 6 for an example).
• Microcirculation (Lab 7) – approx. 6 questions
– List the components (vessels) of the microcirculatory system and their functions.
– Predict the effect of the various substances on the vessels in the goldfish tail, i.e.,
vasodilation or vasoconstriction
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After our Lab Exam…
• We will do the Respiratory portion of the
Lecture Exam 2 Review. (Slides are posted
online)
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