How do we move blood in the body 22

1
How do we move blood in the body? 2/2

• A few final notes about blood, blood types, and
  glycemic response (material for unit 2 test)
• Todays Goals (CH19) What are the major features
  of our pump called the heart?
• How is the circulation divided into two loops
  with different pressure and degrees of hemoglobin
  oxygenation?
• What are the characteristics of a single cardiac
  myocyte?
• What are the three layers of the heart?
• How do the cardiac valves determine the direction
  of blood flow in the heart?
• How dependent is the heart upon oxygen supplies?
• How does blood reach the different regions of the
  heart?
• FIVE STEP cardiac cycle

2
Taking Tests and Grades

• Most persons find that studying for AP 212 is
  different from AP 211
• Most persons find AP 212 requires less
  memorization and more application
• Most persons find that each hour of lecture
  requires 2-3 hours of study time put in as you go
  (not just before the test) to be in ballpark for
  a B or better.
• If your study methods worked, use them again.
• If they did not, reassess and try something else.
• Essay Hint 1 remember to answer only the
  question being asked.
• Essay Hint 2 be able to use specifics when you
  answer a general question.

3
What are some common electrolyte imbalances and
the terminologies used to describe them?

• Ion----Plasma---ICF----Deficiency
  Term-------Excess Term
• ??
  ??
• Na--142-----------10------Hyponatremia---------Hy
  pernatremia
• K----5--------------141----Hypokalcemia----------
  Hyperkalcemia
• Ca-5-------------lt1------Hyopocalcemia--------Hy
  percalcemia
• Cl-----103-----------4--------Hypochloremia-------
  -Hypochloremia
• PO4---4-------------75-------Hyperphosphatemia-Hyp
  ophosphatemia
• The plasma levels are often evaluated in a panel
  test

4
Lipoproteins are large particles in the plasma
that are specialized for carrying non-water
soluble lipids.

• Chylomicron largest and synthesized by
  intestine Carry_____________from the
  _______to the ______________
• Very Low Density Lipoprotein VLDL Big and
  synthesized by liver Carry______________from
  the _______to the ______________
• Low Density Lipoprotein LDL VLDL-left over!
  Carry______________from the _______to the
  ______________
• High Density Lipoprotein HDL smallest and
  synthesized by liver Carry______________from
  the _______to the ______________
• HDL is called Good Cholesterol and
  LDL is called Bad Cholesterol
• Plasma cholesterol and coronary heart
  disease/stroke risk
• Dietary influence
• Genetic Influence
• Why do we often die of a heart attack a few hours
  after a fatty Christmas dinner? Look and see!

5
REVIEW BLOOD CELLS HAVE AN ANTIGENIC PROPERTY
CALLED BLOOD TYPE.

• Agglutinogens Polysaccharides on outside of RBC
  (antigens)
• Agglutinins Plasma antibodies that seek
  non-native agglutinogens in your blood
• Agglutination/hemolysis This occurs when your
  antibodies observe foreign antigens (foreign
  erythrocytes) in your blood and bind to these
  cells. Antibodies bound to foreign cells then
  bind other bound foreign cells and create clumps
  that clog capillaries and lead to cellular
  hemolysis, possible death from a bad transfusion.
• Blood Banking/ABO designation refers to
  antibodies found on your RBCs, so your blood
  destroys RBCs with other antigens.
• Type-O Type-A Type-B Type-AB
• Transfusions- Blood or Plasma?
• Plasma transfusionsLong shelf-life but fewer
  risks/benefits!
• IgG proteins and Rhesus designations- Rh or
  Rh- Hemolytic Disease of the Newborn
  (HDN)/Erythroblastosis fetalis First fetus gets
  off free! Following fetuses at risk of maternal
  Abs! HDN Fetal lysis, Bilirubin, Liver function,
  and UV-phototherapy

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Universal Donor is Type-O and has anti-A and B
antibodies and cannot accept A, B or AB blood.
Universal Recipient is Type AB antibodies on
their erythrocytes and has NO antibodies for A or
B, if they did they would destroy their own
blood. They are the universal recipient Rh
problems second Rh fetus in an Rh- mother
(first is usually ok because mother is not
exposed to enough fetal blood (Rh) to created
antibodies to fetal Rh until parturition occurs
(birth). Second birth is problematic because her
body needs far less Rh to create a response form
memory lymphocytes.
7
Clinical Data What happens when a healthy person
drinks two glasses of cranberry juice? Two
Players Glucose (mg/dl) and Insulin (uU/L)
8
Why did insulin secretion increase when these
diabetics drank cranberry jucie?This is a very
normal and very healthy response.What does a
Standard Deviation (error bars) of the mean
represent? (Also a test que for unit 2 what is
difference between Type 1 and Type 2 diabetes?)
9
What happens when a type 2 diabetic drinks just
ONE glass of cranberry juice? Why is the blood
glucose double that of a healthy student when
they drank HALF as much juice?What is the
purpose of a control group?
10
What does the insulinemic response in a type 2
diabetic who is insulin resistant? Why did they
secrete ten times as much insulin and still not
remove the glucose from the blood? What ar3 the
consequences?
.
Data expressed as mean SD (n12). Significant
differences (P lt 0.05) within treatments relative
to baseline (0 minutes) are signified by and
significant differences among treatments within
times are indicated by differing letters
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Lets Talk about your HEART!WHAT ARE THE PRIMARY
ANATOMICAL FEATURES OF THE HEART?

• Key Features
• 4 chambers
• Base (Top) vs. Apex (Bottom)
• Sides Anterior vs. Posterior vs. L/R Lateral
• Location in pericardial sac and thoracic cavity
• Cycles of Activity Systole vs. Diastole
• In Lab Remember to identify the anterior surface
  by looking for the more prominent anterior
  interventricular sulcus (posterior sulcus is less
  prominent), then you also know left vs. right,
  anterior/posterior.

12
Why is blood flow in the body divided into two
very different loops?

• 2 Pressure loops
• Low mmHg vs. High mmHg
• 2 Anatomical loops
• Pulmonary vs. Systemic
• 2 Oxygenation loops
• Oxygenated vs Deoxygenated
• Blood/body colors
• Bright red vs Cyanotic
• Blood Volumes in 2 circuits
• Resistance vs. Capacitance
• What is the expense of pressure? WORK!!!

13
WHAT ANATOMICAL CHARACTERISTICS OF CARDIAC
MYOCYTES MAKE THEM UNIQUE?

• Why do these cells function the way they do?
• Intercalated discs
• Striations
• Mitochondria
• Gap junctions
• Why is the cardiac cell very different from
  smooth muscle or skeletal muscle cells?

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WHAT IS THE SIGNIFICANCE OF HAVING THE WALL OF
THE HEART DIVIDED INTO THREE DISTINCT LAYERS?

• 1) Endocardium prevent clotting/infection
• 2) Myocardium force generation
• 3) Epicardium parietal vs. visceral
• Ischemia local hypoxia/injury Infarct
  cell death
• Post Infarct tissues consist mostly of
  non-contractile collagen deposited by fibroblasts
  (Scar Tissue)!
• What keeps the heart from smashing/bruising
  itself to pieces?
• Fat
• Fluid
• What protects the heart from the outside?

16
If excess fluids accumulate in the pericardial
cavity and put pressure on the heart, it cannot
be filled with venous return.
17
HOW DO THE HEART VALVES ENSURE ONE-WAY FLOW OF
BLOOD? WHY IS THIS CRITICAL?

• Blood flow through valves requires a pressure
  gradient.
• Two sets of Atrioventricular valves
• Right AV vs. Left AV
• Tricuspid vs. Bicuspid (mitral)
• Two sets of Semilunar valves
• Pulmonic vs. Aortic
• DISEASE Valvular stenosis vs. Mitral valve
  prolapse
• Streptococcal infection in childhood? Why at the
  valves?
• Thrombosis formation Why at the valves?
• Why does cardiac work increase dramatically when
  the valves of the heart fail?

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Can you name all the structures of the heart that
blood would move across in moving from the vena
cava to the aorta? Can you also describe the
degree of oxygenation at these points?
BASE
LT AV Valve
RIGHT AV Valve
APEX
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WHY IS CIRCULATION THROUGH THE HEART SO VERY
COSTLY FOR THE BODY? THE STATISTICS

• 1) About 5 of CARDIAC OUTPUT goes right back
  into heart. The more blood you move, the more
  energy you USE!
• 2) Your heart USES about 10 of the oxygen
  consumed by the body! (This is called a HIGH
  extraction ratio)
• 3) The cardiac tissues mostly desaturate (remove
  oxygen from) the hemoglobin in the blood that
  passes thorough it! Does this leave much oxygen
  in reserve? How do you supply more oxygen?
• 4) Cardiac metabolism is mostly aerobic
  (mitochondria), why?
• 5) Anaerobic Metabolism in the heart is mostly a
  back-up and works largely via lactic acid and
  lactate dehydrogenase (LDH)
• Blood and O2 are only pumped to cardiac cells
  during diastole (cardiac period of rest or
  quiescence).
• Your heart never rests longer than about
  0.5-0.75 second!
• VIP What happens to the time available for blood
  flow into the heart when it spends more time
  contracted, as happens when the heart beats very
  rapidly (tachycardia)?

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WHAT ARE THE PRIMARY VESSELS SUPPLYING BLOOD TO
THE HEART?

• Two Major Coronary Arteries Supply the Heart!
• Left Coronary Artery (the Widow Maker?)?splits
• ?Left Anterior Descending or Circumflex
  Artery
• Right Coronary Artery?Posterior Interventricular
  Artery
• How do you predict the risk of a heart attack in
  any one part of the heart?
• 5) Does the region receive blood flow from a
  single artery?
• 4) Does the region receive blood from 2 or more
  arteries
• 4) Is the ventricular wall thick of thin?
• 2) Are coronary arteries occluded by a
  thrombosis/plaque?
• 1) Most important question HOW MUCH WORK IS THE
  HEART DOING?
• Heart Attack (Infarct) is relatively rare in the
  atria because of their low work load!

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(In the figure, dotted line means posterior
aspect of heart).
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An obstruction (thrombosis) of an artery can
prevent oxygen delivery to dependent tissues!

• Some regions of cardiac tissue can be perfused
  with blood from two or three coronary arteries!
  (collateral flow)
• i.e. Apex (bottom) infarct here is rare because
  these tissues are perfused with blood originating
  from the LAD and right posterior descending!
• i.e. Left lateral aspect of left ventricle only
  gets perfussion form one artery circumflex! HIGH
  RISK for thrombosis!
• Why do more anastomoses/collateral flow improve
  your chances for heart attack survival?
• Venous drainage during diastole occurs via the
  great cardiac veins, with some blood entering
  coronary sinus.
• Fetal Adaptations Ductus arteriosus and Foramen
  ovale
• What purpose do these fetal structures provide?

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Your heart pumps blood using a five step Cardiac
Cycle

• Remember the two equal cycles Pulmonary AND
  Systemic
• 1) Diastolic Filling of Atria and Ventricles (V.
  Diastole)
• Semilunars are closed and AV valves are open!
• 2) Atrial Systole (VIP occurs towards the end of
  V. Diastole)
• Ventricles are primed with atrial blood (topped
  off)
• Semilunar valves closed
• 3) Isovolumetric Ventricular Contraction (V.
  Systole)
• Semilunar valves remain closed, AV valve flaps
  are close by back flow of blood into atria when
  the ventricular pressure begins to increase.
• Pressure is generated until
• Ventricular mmHg gt Arterial mmHg

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• 4) Ventricular Ejection (V. Systole)
• When Vent P gt Arterial P, semilunars open and
  blood can exit the ventricle
• Volume of blood ejected from ventricle is
  dependent on magnitude of pressure gradient
• Semilunar valves must open before ejection can
  begin!
• 5) Isovolumetric Ventricular Relaxation (V.
  Diastole)
• End of contraction, semilunars close when VentPlt
  Arterial P
• AV valves open and diastolic filling begins next
  cycle
• Remember the two ventricles BOTH do these
  activities at about same time with the same
  volumes at two different pressures!
• While Atrial Systole does occur, it is not as
  clinically important because the atria only do
  about 5 of the work done by the ventricles, so
  they just dont use as much ATP or need as much
  oxygen.

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Remember that the AV and semilular valves close
to prevent flow of blood from high to low
pressure back into the atria or ventricles!