Biology 102

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• 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 Holes Human AP, 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 Holes Human AP, 12th edition, 2010
Each metarteriole supplies about 10-100 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 Holes Human AP, 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 Holes Human AP, 12th edition, 2010
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Regulation of Capillary Blood Flow
Figure from Holes Human AP, 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, well review the
  results

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Next

• After you do this lab today
• We will review last weeks results
• Lab Exam 1 format/content
• Review Exercises 36 37 in Mariebs 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-the-blank 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) contd 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)