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The Cardiovascular System

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The Cardiovascular System Powered By Docstoc
					CARDIOVASCULAR FUNCTION
IN Rana pipiens

Biology 305 Laboratory
ANNOUNCEMENTS
Lab Quiz Next Week:
   Based on:
       • Virtual Mouse Lab

       • Frog Cardiovascular Lab
ANNOUNCEMENTS
 Oral   & Poster Presentation:
  – Researched, written, prepared, presented as
    group
         – All individuals in group receive SAME grade
         – Combo is approx. 25% of final grade!

  – You must choose ONE lab from the semester:
         – Excluded labs include:
            » Lab #1 & 2
            » “Virtual” labs
ANNOUNCEMENTS
 Oral & Poster Presentation:
  – Majority of info for presentation comes directly
    from your lab notebook

             » Data, observations, tables, graphs and
               answers to questions

   – The oral presentation will be given first,
     followed by the poster

             » Absolutely NO LATE submissions!
NEXT WEEK’S EXERCISE:
FROG CARDIOVASCULAR
PHYSIOLOGY
The CV System:

   CV system is tied to respiratory system
FROG CARDIOVASCULAR
PHYSIOLOGY
Three Main Components:
   Heart

   Blood

   Vessels
FROG CARDIOVASCULAR
PHYSIOLOGY
Amphibian Heart:
   Heart has three chambers

   Two partially separate circuits

   One cardiac cycle
        • O2-deficient blood enters heart
        • May mix with O 2-rich blood from lung
        • Blood pumped out of heart to rest of
          body
ANATOMICAL FEATURES OF
THE AMPHIBIAN HEART
Sinus Venosus:

   Region of pacemaker
    cells between vena cava
    and right atrium
FROG CARDIOVASCULAR
PHYSIOLOGY
Leopard Frog (Rana pipiens):
   Use of force transducer

   Measure frequency and relative force of
    contraction

   May observe both atrial & ventricular contraction
    (systole) on trace
FROG CARDIOVASCULAR
PHYSIOLOGY
   Regulation of Heart Rate Represents
    Balance:
    – Intrinsic Factors:



    – Extrinsic Factors:
FROG CARDIOVASCULAR
PHYSIOLOGY
Intrinsic Factors:

   Innervations of the Heart:
    – Autonomic Nervous System (ANS) has two
      subdivisions that influence HR & force of
      contraction
FROG CARDIOVASCULAR
PHYSIOLOGY
Divisions of ANS:
   Sympathetic Division


   Parasympathetic Division


   The two divisions work antagonistically
FROG
CARDIOVASCULAR
PHYSIOLOGY
 Parasympathetic       Division
  – Releases Acetylcholine (Ach)




 Sympathetic Division
  – Releases Norepinephrine (NE)
  AUTONOMIC PATHWAYS

Sympathetic Pathway:        = ADRENERGIC


        < Ach                   < NE    Target
                                        Tissue




Parasympathetic Pathway:
                                        Target
                    <Ach        < Ach   Tissue



                           = CHOLINERGIC
FROG CARDIOVASCULAR
PHYSIOLOGY
Effect of Neurotransmitters (neurohormone):
   NE/Epi



   Ach
                     FROG
CARDIOVASCULAR PHYSIOLOGY
Extrinsic Factors:
   Agonists:




   Antagonists:
CARDIOVASCULAR
TERMINOLOGY
Cardiac Output (CO):
   Amount of blood pumped by ventricle per unit
    time
CARDIOVASCULAR
TERMINOLOGY

Heart Rate (HR):
 Number of contractions per minute
 Derived directly from period:
CARDIOVASCULAR
TERMINOLOGY
Stroke Volume (SV):

   Volume of blood ejected from heart during
    ventricular contraction
FROG CARDIOVASCULAR
PHYSIOLOGY
Relative Force of Contraction:
   Measured by amplitude of periodic cycle




   Influenced by:
CHANGES IN FORCE OF
CONTRACTION & STROKE VOLUME
                Starling’s Law of
                the Heart :

                •Amount of blood in
                ventricle when systole
                begins (EDV) influences
                force of contraction
             CONTRACTILITY
Contractility:
   Intrinsic ability of a cardiac muscle fiber to
    contract at a given length

        • Agents that increase contractility are called



        • Agents that decrease contractility are called
STARLING’S LAW OF THE HEART
             Stroke Volume As A Function of EDV


  Stroke
  Volume
                                                 ^
                                                  Normal
  (ml) or
  Force of
  Contraction

                                   *
                    End Diastolic Volume (ml)
Stretch of Myocardial Cells Causes Greater Force of Contraction (& SV)
CHANGES IN FORCE OF
CONTRACTION & STROKE VOLUME
Contractility:
•In mammals, NE/EPI typically
increase contractility

   •Results in increased force,
   even though they cause an
   increase HR
FROG CARDIOVASCULAR
PHYSIOLOGY
Some Hints For Lab:
   Avoid Contamination: label ALL beakers & pipettes!!!

   Apply NE, Ach& cold Ringers to heart and observe
    response (frequency/amplitude) on computer

   Apply Ringer’s solution often
            – Especially between each treatment

   Take baseline readings BEFORE addition of ea. treatment!

   After running agents of known origin, consult with group
    members on how to test identity of an unknown

				
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posted:12/30/2011
language:Latin
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